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Sample records for lanthanides separation preparacion

  1. Investigation of Gravity Lanthanide Separation Chemistry

    SciTech Connect

    Payne, Rosara F.; Schulte, Shannon M.; Douglas, Matthew; Friese, Judah I.; Farmer, Orville T.; Finn, Erin C.

    2011-03-01

    Lanthanides are common fission products and the ability to separate and quantify these elements is critical to rapid radiochemistry applications. Published lanthanide separations using Eichrom Ln Spec resin utilize an HCl gradient. Here it is shown that the efficacy and resolution of the separation is improved when a nitric acid gradient is used instead. The described method allows parallel processing of many samples in 1.5 hours followed by 60 minute counting for quantification of 9 isotopes of 7 lanthanide elements.

  2. Separation of actinides from lanthanides

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

    1989-01-01

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  3. Separation of actinides from lanthanides

    SciTech Connect

    Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

    1989-09-19

    This patent describes an organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which include a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  4. Separation of actinides from lanthanides

    DOEpatents

    Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

    1988-03-31

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form is described. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4- dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  5. Actinide Lanthanide Separation Process – ALSEP

    SciTech Connect

    Gelis, Artem V.; Lumetta, Gregg J.

    2014-01-29

    Separation of the minor actinides (Am, Cm) from the lanthanides at an industrial scale remains a significant technical challenge for closing the nuclear fuel cycle. To increase the safety of used nuclear fuel (UNF) reprocessing, as well as reduce associated costs, a novel solvent extraction process has been developed. The process allows for partitioning minor actinides, lanthanides and fission products following uranium/plutonium/neptunium removal; minimizing the number of separation steps, flowsheets, chemical consumption, and waste. This new process, Actinide Lanthanide SEParation (ALSEP), uses an organic solvent consisting of a neutral diglycolamide extractant, either N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) or N,N,N',N'-tetraoctyldiglycolamide (TODGA), and an acidic extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]), dissolved in an aliphatic diluent (e.g. n-dodecane). The An/Ln co-extraction is conducted from moderate-to-strong nitric acid, while the selective stripping of the minor actinides from the lanthanides is carried out using a polyaminocarboxylic acid/citrate buffered solution at pH anywhere between 3 and 4.5. The extraction and separation of the actinides from the fission products is very effective in a wide range of HNO3 concentrations and the minimum separation factors for lanthanide/Am exceed 30 for Nd/Am, reaching > 60 for Eu/Am under some conditions. The experimental results presented here demonstrate the great potential for a combined system, consisting of a neutral extractant such as T2EHDGA or TODGA, and an acidic extractant such as HEH[EHP], for separating the minor actinides from the lanthanides.

  6. Separations of actinides, lanthanides and other metals

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ensor, Dale D.

    1995-01-01

    An organic extracting solution comprised of a bis(acylpyrazolone or a substituted bis(acylpyrazolone) and an extraction method useful for separating certain elements of the actinide series of the periodic table having a valence of four from one other, and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also useful for separating hexavalent actinides from one or more of the substances in a group consisting of trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals.

  7. The Actinide-Lanthanide Separation Process

    SciTech Connect

    Lumetta, Gregg J.; Gelis, Artem V.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-02-21

    The Actinide-Lanthanide SEParation (ALSEP) process is described. The process uses an extractant phase consisting of either N,N,N',N'-tetraoctyldiglycolamide (TODGA) or N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). The neutral TODGA or T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid media. Switching the aqueous phase chemistry to a citrate buffered diethylenetriaminepentaacetic acid (DTPA) solution at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus resulting in separation of these two groups of elements.

  8. Actinide and lanthanide separation process (ALSEP)

    DOEpatents

    Guelis, Artem V.

    2013-01-15

    The process of the invention is the separation of minor actinides from lanthanides in a fluid mixture comprising, fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water by addition of an organic chelating aid to the fluid; extracting the fluid with a solvent comprising a first extractant, a second extractant and an organic diluent to form an organic extractant stream and an aqueous raffinate. Scrubbing the organic stream with a dicarboxylic acid and a chelating agent to form a scrubber discharge. The scrubber discharge is stripped with a simple buffering agent and a second chelating agent in the pH range of 2.5 to 6.1 to produce actinide and lanthanide streams and spent organic diluents. The first extractant is selected from bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA).

  9. Multicoordinate ligands for actinide/lanthanide separations.

    PubMed

    Dam, Henk H; Reinhoudt, David N; Verboom, Willem

    2007-02-01

    In nuclear waste treatment processes there is a need for improved ligands for the separation of actinides (An(III)) and lanthanides (Ln(III)). Several research groups are involved in the design and synthesis of new An(III) ligands and in the confinement of these and existing An(III) ligands onto molecular platforms giving multicoordinate ligands. The preorganization of ligands considerably improves the An(III) extraction properties, which are largely dependent on the solubility and rigidity of the platform. This tutorial review summarizes the most important An(III) ligands with emphasis on the preorganization strategy using (macrocyclic) platforms.

  10. Separation of Minor Actinides from Lanthanides by Dithiophosphinic Acid Extractants

    SciTech Connect

    D. R. Peterman; M. R. Greenhalgh; R. D. Tillotson; J. R. Klaehn; M. K. Harrup; T. A. Luther; J. D. Law; L. M. Daniels

    2008-09-01

    The selective extraction of the minor actinides (Am(III) and Cm(III)) from the lanthanides is an important part of advanced reprocessing of spent nuclear fuel. This separation would allow the Am/Cm to be fabricated into targets and recycled to a reactor and the lanthanides to be dispositioned. This separation is difficult to accomplish due to the similarities in the chemical properties of the trivalent actinides and lanthanides. Research efforts at the Idaho National Laboratory have identified an innovative synthetic pathway yielding new regiospecific dithiophosphinic acid (DPAH) extractants. The synthesis provides DPAH derivatives that can address the issues concerning minor actinide separation and extractant stability. For this work, two new symmetric DPAH extractants have been prepared. The use of these extractants for the separation of minor actinides from lanthanides will be discussed.

  11. Separation of actinides from lanthanides utilizing molten salt electrorefining

    SciTech Connect

    Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.; Gay, R.L.; Krueger, C.L.; Storvick, T.S.; Inoue, T.; Hijikata, T.; Takahashi, N.

    1996-10-01

    TRUMP-S (TRansUranic Management through Pyropartitioning Separation) is a pyrochemical process being developed to separate actinides form fission products in nuclear waste. A key process step involving molten salt electrorefining to separate actinides from lanthanides has been studied on a laboratory scale. Electrorefining of U, Np, Pu, Am, and lanthanide mixtures from molten cadmium at 450 C to a solid cathode utilizing a molten chloride electrolyte resulted in > 99% removal of actinides from the molten cadmium and salt phases. Removal of the last few percent of actinides is accompanied by lowered cathodic current efficiency and some lanthanide codeposition. Actinide/lanthanide separation ratios on the cathode are ordered U > Np > Pu > Am and are consistent with predictions based on equilibrium potentials.

  12. Plasma mass filtering for separation of actinides from lanthanides

    NASA Astrophysics Data System (ADS)

    Gueroult, R.; Fisch, N. J.

    2014-06-01

    Separating lanthanides from actinides is a key process in reprocessing nuclear spent fuel. Plasma mass filters, which operate on dissociated elements, offer conceptual advantages for such a task as compared with conventional chemical methods. The capabilities of a specific plasma mass filter concept, called the magnetic centrifugal mass filter, are analyzed within this particular context. Numerical simulations indicate separation of americium ions from a mixture of lanthanides ions for plasma densities of the order of 1012 cm-3, and ion temperatures of about 10 eV. In light of collision considerations, separating small fractions of heavy elements from a larger volume of lighter ones is shown to enhance the separation capabilities.

  13. Development of the Actinide-Lanthanide Separation (ALSEP) Process

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Niver, Cynthia M.; Gelis, Artem V.

    2014-09-30

    Separating the minor actinide elements (Am and Cm) from acidic high-level raffinates arising from the reprocessing of irradiated nuclear fuel is an important step in closing the nuclear fuel cycle. Most proposed approaches to this problem involve two solvent extraction steps: 1) co-extraction of the trivalent lanthanides and actinides, followed by 2) separation of the actinides from the lanthanides. The objective of our work is to develop a single solvent-extraction process for isolating the minor actinide elements. We report here a solvent containing N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) that can be used to separate the minor actinides in a single solvent-extraction process. T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid solution. Switching the aqueous phase chemistry to a citrate buffered solution of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus affecting separation of the actinides from the lanthanides. Separation factors between the lanthanides and actinides are approximately 20 in the pH range of 3 to 4, and the distribution ratios are not highly dependent on the pH in this system.

  14. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    DOEpatents

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  15. A TRUEX-based separation of americium from the lanthanides

    SciTech Connect

    Bruce J. Mincher; Nicholas C. Schmitt; Mary E. Case

    2011-03-01

    Abstract: The inextractability of the actinide AnO2+ ions in the TRUEX process suggests the possibility of a separation of americium from the lanthanides using oxidation to Am(V). The only current method for the direct oxidation of americium to Am(V) in strongly acidic media is with sodium bismuthate. We prepared Am(V) over a wide range of nitric acid concentrations and investigated its solvent extraction behavior for comparison to europium. While a separation is achievable in principal, the presence of macro amounts of cerium competes for the sparingly soluble oxidant and the oxidant itself competes for CMPO complexation. These factors conspire to reduce the Eu/Am separation factor from ~40 using tracer solutions to ~5 for extractions from first cycle raffinate simulant solution. To separate pentavalent americium directly from the lanthanides using the TRUEX process, an alternative oxidizing agent will be necessary.

  16. Advancing the scientific basis of trivalent actinide-lanthanide separations

    SciTech Connect

    Nash, K.L.

    2013-07-01

    For advanced fuel cycles designed to support transmutation of transplutonium actinides, several options have been demonstrated for process-scale aqueous separations for U, Np, Pu management and for partitioning of trivalent actinides and fission product lanthanides away from other fission products. The more difficult mutual separation of Am/Cm from La-Tb remains the subject of considerable fundamental and applied research. The chemical separations literature teaches that the most productive alternatives to pursue are those based on ligand donor atoms less electronegative than O, specifically N- and S-containing complexants and chloride ion (Cl{sup -}). These 'soft-donor' atoms have exhibited usable selectivity in their bonding interactions with trivalent actinides relative to lanthanides. In this report, selected features of soft donor reagent design, characterization and application development will be discussed. The roles of thiocyanate, aminopoly-carboxylic acids and lactate in separation processes are detailed. (authors)

  17. Rapid separation of individual lanthanide elements from mixed fission products

    SciTech Connect

    Baker, J.D.

    1980-11-01

    A microprocessor-controlled radiochemical separation system has been developed to separate lanthanide elements rapidly from fission products. The system is composed of two high performance liquid chromatography columns coupled in series by a stream-splitting injection valve. The first column separates the lanthanide group by extraction-chromatography using dihexyldiethylcarbamylmethyleneophoshate (DHDECMP) adsorbed on Vydac C/sub 8/ resin. The second column isolates the individual lanthanide elements by cation exchange using Aminex A-9 resin with ..cap alpha..-hydroxyisobutyric acid (..cap alpha..-HIBA) as the eluent. With this system, the fission-product lanthanide isotope /sup 158/Sm has been identified for the first time. It was produced from a spontaneously fissioning /sup 252/Cf source. Twenty-seven gamma-rays have been assigned to this activity which decays with a half-life of 5.51 +- 0.09 min. The /sup 158/Sm assignment is based upon the radiochemical separation of the Sm fraction from the lanthanide fission products and the observation of the growth and decay of the 45.9 min /sup 158/Eu daughter from an initially pure 5 min parent. The emission probability of the 324-keV gamma ray of /sup 158/Sm was also determined, from the growth and decay of the /sup 158/Eu daughter, to be 10.6 +- 1.2 gamma rays per 100 decays. Several new gamma rays have been identified by half-life as belonging to the decay of /sup 157/Sm. Gamma-ray energies and relative intensities for /sup 157/Sm and /sup 158/Sm are reported.

  18. Acylpyrazolones: Synthesis, self-assembly and lanthanide metal ion separation

    NASA Astrophysics Data System (ADS)

    Yang, Jun

    The central hypothesis that nanoscale self-assemblies can provide excellent metal ion recognition has been substantiated by employing acylpyrazolones and trivalent lanthanide metal ions as model systems. Several novel acylpyrazolones and their amphiphilic analogs have been designed, synthesized, and characterized. Their lanthanide metal ion recognition efficacies have been demonstrated through baseline separations of a mixture of light, middle, and heavy lanthanide metal ions by employing them in the aqueous mobile phase of high performance liquid chromatography (HPLC) with octadecylsilanized silica (ODS) as the stationary phase. The complex separation mechanism is influenced by the structures of acylpyrazolone and amphiphilic moieties, and spontaneous self-assembly of the ligand in the aqueous and on the stationary phases. Transmission electron microscopy (TEM) studies of the ligand self-assemblies in the aqueous phase in the absence and presence of lanthanide metal ions reveal spherical, dendritic, and linear (nanofibers, nanorods, and nanotubes) nanoscale structures. Such structures have also been observed when chloromethylated acylpyrazolones are stimulated to self-assemble by a base in nonaqueous solvents and when silica nanoparticles derivatized with them spontaneously self-assemble in aqueous and nonaqueous solvents.

  19. Citrate based ``TALSPEAK`` lanthanide-actinide separation process

    SciTech Connect

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ``geological`` periods of time. The costs of building, maintaining, and operating a ``geological TRU repository`` can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ``TALSPEAK`` process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced.

  20. Dynamic tests for actinide/lanthanide separation by CMPO solvent in fluorinated diluents

    SciTech Connect

    Tkachenko, L.; Babain, V.; Alyapyshev, M.; Vizniy, A.; Il'in, A.; Shadrin, A.

    2013-07-01

    Actinide and lanthanide extraction by new solvent: 0.2 M phenyl-octyl-N,N-diiso-butylcarbamoyl-phosphine oxide (CMPO) + 30% TBP + formal of octafluoro-pentanol was studied. A dynamic test with this solvent was performed. It was shown that americium and lanthanides are effectively extracted from PUREX process raffinate. The separation of americium from light lanthanides was confirmed in the modified SETFICS flowsheet with this new solvent. (authors)

  1. Feasibility of the electrochemical way in molten fluorides for separating thorium and lanthanides and extracting lanthanides from the solvent

    NASA Astrophysics Data System (ADS)

    Chamelot, P.; Massot, L.; Hamel, C.; Nourry, C.; Taxil, P.

    2007-01-01

    An alternative way of reprocessing nuclear fuel by hydrometallurgy could be using treatment with molten salts, particularly fluoride melts. Moreover, one of the six concepts chosen for GEN IV nuclear reactors (Technology Roadmap - http://gif.inel.gov/roadmap/) is the molten salt reactor (MSR). The originality of the concept is the use of molten salts as liquid fuel and coolant. During the running of the reactor, fission products, particularly lanthanides, accumulate in the melt and have to be eliminated to optimise reactor operation. This study concerns the feasibility of the separation actinides-lanthanides-solvent by selectively electrodepositing the elements to be separated on an inert (Mo, Ta) or a reactive (Ni) cathodic substrate in molten fluoride media. The main results of this work lead to the conclusions that: The solvents to be used for efficient separation must be fluoride media containing lithium as cation. Inert substrates are suitable for actinide/lanthanide separation; nickel substrate is more suitable for the extraction of lanthanides from the solvent, owing to the depolarisation occurring in the cathodic process through alloy formation.

  2. The separation of lanthanides and actinides in supercritical fluid carbon dioxide

    DOE PAGES

    Mincher, Bruce J.; Wai, Chien M.; Fox, Robert V.; ...

    2015-10-28

    Supercritical fluid carbon dioxide presents an attractive alternative to conventional solvents for recovery of the actinides and lanthanides. Carbon dioxide is a good solvent for fluorine and phosphate-containing ligands, including the traditional tributylphosphate ligand used in process-scale uranium separations. Actinide and lanthanide oxides may even be directly dissolved in carbon dioxide containing the complexes formed between these ligands and mineral acids, obviating the need for large volumes of acids for leaching and dissolution, and the corresponding organic liquid–liquid solvent extraction solutions. As a result, examples of the application of this novel technology for actinide and lanthanide separations are presented.

  3. Lanthanide/actinide separations with proton-ionizable lariat ethers

    SciTech Connect

    Bartsch, R.A.; Kim, J.S.; Yang, Y.

    1995-12-01

    Proton-ionizable lariat ethers are crown ethers with pendent ion-exchange sites. Such dual-function extractants provide both ion-exchange and polyether binding sites for metal ion complexation. A series of sym-(OR)-dibenzo-16-crown-5 compounds with R=CH{sub 2}CO{sub 2}H, CH{sub 2}P(O)(OC{sub 2}H{sub 5})OH, CH{sub 2}CH{sub 2}CH{sub 2}CH{sub 2}P(O)(OC{sub 2}H{sub 5})OH and CH{sub 2}CH{sub 2}CH{sub 2}SO{sub 3}Na have been prepared and their application as extractants in lanthanide/actinide separations explored. For solvent extraction of Eu and Am from moderately acidic aqueous solutions into chloroform, the lariat ether phosphonic acid monoethyl esters gave much larger distribution coefficients than did the lariat ether carboxylic and sulfonic acids. Subsequently a more lipophilic lariat ether phosphonic acid monoethyl ester was synthesized and utilized for the solvent extraction of Eu and Am into toluene.

  4. The TRUSPEAK Concept: Combining CMPO and HDEHP for Separating Trivalent Lanthanides from the Transuranic Elements

    SciTech Connect

    Lumetta, Gregg J.; Gelis, Artem V.; Braley, Jenifer C.; Carter, Jennifer C.; Pittman, Jonathan W.; Warner, Marvin G.; Vandegrift, George F.

    2013-04-08

    Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO) and bis-(2-ethylhexyl) phosphoric acid (HDEHP) into a single process solvent for separating transuranic elements from liquid high-level waste is explored. Co-extraction of americium and the lanthanide elements from nitric acid solution is possible with a solvent mixture consisting of 0.1-M CMPO plus 1-M HDEHP in n-dodecane. Switching the aqueous-phase chemistry to a citrate-buffered solution of diethylene triamine pentaacetic acid (DTPA) allows for selective stripping of americium, separating it from the lanthanide elements. Potential strategies for managing molybdenum and zirconium (both of which co-extract with americium and the lanthanides) have been developed. The work presented here demonstrates the feasibility of combining CMPO and HDEHP into a single extraction solvent for recovering americium from high-level waste and its separation from the lanthanides.

  5. A computational approach to predicting ligand selectivity for the size-based separation of trivalent lanthanides

    DOE PAGES

    Ivanov, Alexander S.; Bryantsev, Vyacheslav S.

    2016-06-20

    An accurate description of solvation effects for trivalent lanthanide ions is a main stumbling block to the qualitative prediction of selectivity trends along the lanthanide series. In this work, we propose a simple model to describe the differential effect of solvation in the competitive binding of a ligand by lanthanide ions by including weakly co-ordinated counterions in the complexes of more than a +1 charge. The success of the approach to quantitatively reproduce selectivities obtained from aqueous phase complexation studies demonstrates its potential for the design and screening of new ligands for efficient size-based separation.

  6. A computational approach to predicting ligand selectivity for the size-based separation of trivalent lanthanides

    SciTech Connect

    Ivanov, Alexander S.; Bryantsev, Vyacheslav S.

    2016-06-20

    An accurate description of solvation effects for trivalent lanthanide ions is a main stumbling block to the qualitative prediction of selectivity trends along the lanthanide series. In this work, we propose a simple model to describe the differential effect of solvation in the competitive binding of a ligand by lanthanide ions by including weakly co-ordinated counterions in the complexes of more than a +1 charge. The success of the approach to quantitatively reproduce selectivities obtained from aqueous phase complexation studies demonstrates its potential for the design and screening of new ligands for efficient size-based separation.

  7. Trivalent actinide and lanthanide separations using tetraalkyldiglycolamides (TCnDGA) in molecular and ionic liquid diluents

    SciTech Connect

    Bruce J. Mincher; Robert V. Fox; Mary E. Mincher; Chien M. Wai

    2014-09-01

    The use of the diglycolamide, tetrabutyldiglycolamide was investigated for intergroup separations of the lanthanides, focusing especially on those lanthanides (Y, Ce, Eu, Tb, Dy, Er, and Yb) found in lighting phosphors. Tetrabutyldiglycolamide extraction efficiency for the lanthanides varied depending on whether the diluent was the conventional molecular diluent 1-octanol, the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide, or a mixture of the two. This was attributed to extraction of either neutral, cationic or anionic lanthanide metal complexes with nitrate ion. Based on the batch contact solvent extraction results measured here, a series of extractions providing product streams containing separated Y, Ce, Eu, Tb/Dy, and Er/Yb are proposed.

  8. SEPARATION OF EUROPIUM FROM OTHER LANTHANIDE RAE EARTHS BY SOLVENT EXTRACTION

    DOEpatents

    Peppard, D.F.; Horwitz, E.P.; Mason, G.W.

    1963-02-12

    This patent deals with a process of separating europium from other lanthanides present in aqueous hydrochloric or sulfuric acid solutions. The europium is selectively reduced to the divalent state with a divalent chromium salt formed in situ from chromium(III) salt plus zinc amalgam. The other trivalent lanthanides are then extracted away from the divalent europium with a nitrogen-flushed phosphoric acid ester or a phosphonic acid ester. (AEC)

  9. Advanced Extraction Methods for Actinide/Lanthanide Separations

    SciTech Connect

    Scott, M.J.

    2005-12-01

    The separation of An(III) ions from chemically similar Ln(III) ions is perhaps one of the most difficult problems encountered during the processing of nuclear waste. In the 3+ oxidation states, the metal ions have an identical charge and roughly the same ionic radius. They differ strictly in the relative energies of their f- and d-orbitals, and to separate these metal ions, ligands will need to be developed that take advantage of this small but important distinction. The extraction of uranium and plutonium from nitric acid solution can be performed quantitatively by the extraction with the TBP (tributyl phosphate). Commercially, this process has found wide use in the PUREX (plutonium uranium extraction) reprocessing method. The TRUEX (transuranium extraction) process is further used to coextract the trivalent lanthanides and actinides ions from HLLW generated during PUREX extraction. This method uses CMPO [(N, N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide] intermixed with TBP as a synergistic agent. However, the final separation of trivalent actinides from trivalent lanthanides still remains a challenging task. In TRUEX nitric acid solution, the Am(III) ion is coordinated by three CMPO molecules and three nitrate anions. Taking inspiration from this data and previous work with calix[4]arene systems, researchers on this project have developed a C3-symmetric tris-CMPO ligand system using a triphenoxymethane platform as a base. The triphenoxymethane ligand systems have many advantages for the preparation of complex ligand systems. The compounds are very easy to prepare. The steric and solubility properties can be tuned through an extreme range by the inclusion of different alkoxy and alkyl groups such as methyoxy, ethoxy, t-butoxy, methyl, octyl, t-pentyl, or even t-pentyl at the ortho- and para-positions of the aryl rings. The triphenoxymethane ligand system shows promise as an improved extractant for both tetravalent and trivalent actinide recoveries form

  10. Citrate-based {open_quotes}Talspeak{close_quotes} actinide-lanthanide separation process

    SciTech Connect

    Del Cul, G.D.; Toth, L.M.; Bond, W.D.

    1997-01-01

    Lanthanide elements are produced in relatively high yield by fission of {sup 235}U. Almost all the lanthanide isotopes decay to stable nonradioactive lanthanide isotopes in a relatively short time. Consequently, it is highly advantageous to separate the relatively small actinide fraction from the relatively large quantities of lanthanide isotopes. The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. Previous work based on the use of lactic or glycolic acid has shown deleterious effects of some impurity ions such as zirconium(IV), even at concentrations on the order of 10{sup {minus}4} M. Other perceived problems were the need to maintain the pH and reagent concentrations within a narrow range and a significant solubility of the organic phase at high carboxylic acid concentrations. The authors` cold experiments showed that replacing the traditional extractants glycolic or lactic acid with citric acid eliminates or greatly reduces the deleterious effects produced by impurities such as zirconium. An extensive series of batch tests was done using a wide range of reagent concentrations at different pH values, temperatures, and contact times. The results demonstrated that the citrate-based TALSPEAK can tolerate appreciable changes in pH and reagent concentrations while maintaining an adequate lanthanide extraction. Experiments using a three-stage glass mixer-settler showed a good lanthanide extraction, appropriate phase disengagement, no appreciable deleterious effects due to the presence of impurities such as zirconium, excellent pH buffering, and no significant loss of organic phase.

  11. "Straining" to Separate the Rare Earths: How the Lanthanide Contraction Impacts Chelation by Diglycolamide Ligands.

    PubMed

    Ellis, Ross J; Brigham, Derek M; Delmau, Laetitia; Ivanov, Alexander S; Williams, Neil J; Vo, Minh Nguyen; Reinhart, Benjamin; Moyer, Bruce A; Bryantsev, Vyacheslav S

    2017-02-06

    The subtle energetic differences underpinning adjacent lanthanide discrimination are explored with diglycolamide ligands. Our approach converges liquid-liquid extraction experiments with solution-phase X-ray absorption spectroscopy (XAS) and density functional theory (DFT) simulations, spanning the lanthanide series. The homoleptic [(DGA)3Ln](3+) complex was confirmed in the organic extractive solution by XAS, and this was modeled using DFT. An interplay between steric strain and coordination energies apparently gives rise to a nonlinear trend in discriminatory lanthanide ion complexation across the series. Our results highlight the importance of optimizing chelate molecular geometry to account for both coordination interactions and strain energies when designing new ligands for efficient adjacent lanthanide separation for rare-earth refining.

  12. Lanthanide fission product separation from the transuranics in the integral fast reactor fuel cycle demonstration

    SciTech Connect

    Goff, K.M.; Mariani, R.D.; Benedict, R.W.; Ackerman, J.P.

    1993-12-31

    The Integral Fast Reactor (IFR) is an innovative reactor concept being developed by Argonne National Laboratory. This reactor uses liquid-metal cooling and metallic fuel. Its spent fuel will be reprocessed using a pyrochemical method employing molten salts and liquid metals in an electrofining operation. The lanthanide fission products are a concern during reprocessing because of heating and fuel performance issues, so they must be removed periodically from the system to lessen their impact. The actinides must first be removed form the system before the lanthanides are removed as a waste stream. This operation requires a relatively good lanthanide-actinide separation to minimize both the amount of transuranic material lost in the waste stream and the amount of lanthanides collected when the actinides are first removed. A computer code, PYRO, that models these operations using thermodynamic and empirical data was developed at Argonne and has been used to model the removal of the lanthanides from the electrorefiner after a normal operating campaign. Data from this model are presented. The results demonstrate that greater that 75% of the lanthanides can be separated from the actinides at the end of the first fuel reprocessing campaign using only the electrorefiner vessel.

  13. Separation of Lanthanide Ions with Kläui Ligand Resin

    SciTech Connect

    Granger, Trinity D.; Henry, Victoria A.; Latesky, Stanley

    2007-07-01

    Separation and pre-concentration of the desired analyte is often a critical step in many radioanalytical methods. Current procedures for separating and concentrating analytes for detection are complex, and can be both expensive and time consuming. Therefore, the purpose of this research is to develop an alternative method of separating lanthanide ions through the use of an extraction chromatography resin containing a Klaui ligand salt. This research is a continuation of a concerted effort to develop new methods of detecting small concentrations of radionuclides and lanthanides using Klaui ligands. The Klaui ligands, C5Me5Co(OP(OR)2)3- (R=Me, Et, n-Pr) (LOR-), have unique affinity for lanthanide and actinide ions in the presence of competing metal ions. The use of 1 wt% NaLOR (R=Et or n-Pr) adsorbed onto resin support has been shown to extract lanthanide ions from aqueous nitric acid solutions of different concentrations. In order to further evaluate the utility of these materials in radiochemical separation, the selectivity of the resins for the different lanthanide ions was examined by measuring the distribution coefficients (Kd) for a series of lanthanides over a range of solution conditions. Based on prior research with actinide ions, it was hypothesized that the lanthanide ions would bond strongly with the Klaui ligands. The success of this research is important, because it will assist in expanding and improving current automated radiochemical methods, which will decrease the cost of developing and implementing radiochemical methods. To date, Kd values have been determined for Eu+3, Nd+3 and Pr+3 under varying nitric acid (HNO3) concentration, using a resin consisting of 1.0 wt% NaLOPr on Amberlite XAD-7HP. The dependence of the Kd values for Eu+3 has also been examined as a function of the ligand-to-europium ratio and the nitrate concentration. Decreasing Kd values were obtained upon increasing the nitric acid concentration, indicating protonation of the

  14. Solid-liquid separation of oxidized americium from fission product lanthanides

    NASA Astrophysics Data System (ADS)

    Shehee, T. C.; Martin, L. R.; Nash, K. L.

    2010-03-01

    The separation of americium from the lanthanides and curium is a requirement if transmutation of americium is to be performed in advanced nuclear fuel cycles. Oxidation of Am3+ to AmO2+ or AmO22+ may allow separation of Am from Ln and Cm in one step, since the lanthanides and curium do not have higher oxidation states as accessible. Two possible solid-liquid separation methods have been developed to address this difficult separation. Under acidic conditions using oxone or persulfate, the oxidation and retention of tracer Am in the aqueous phase has been observed with a separation factor of 11 ± 1. Most of these studies have been conducted using 237NpO2(NO3), 233UO2(NO3)2, 238Pu(NO3)4 and 241Am(NO3)3 at radiotracer concentrations. Lanthanides precipitate as the sodium or potassium europium double sulfate salt. Under basic conditions, ozone oxidation of Am(CO3)OH(s) solubilizes Am from a lanthanide carbonate hydroxide solid phase to the aqueous phase as the AmO2(CO3)34-or AmO2(CO3)35- species. For the ozone oxidation of the americium tracer a separation factor of 1.6 ± 0.8 and 47 ± 2 for the oxidation/separation in Na2CO3 and NaHCO3 respectively.

  15. Coordination chemistry of several radius-sensitive complexones and applications to lanthanide-actinide separations

    SciTech Connect

    Potter, M.W.

    1981-10-01

    The relationships between the lanthanide complex formation equilibria and the lanthanide-actinide separation application of three radius sensitive ligands have been studied. The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of DHDMB and the tripositive lanthanides and yttrium were determined potentiometrically at 0.1 M ionic strength and 25/sup 0/C. Results indicate that three different coordination modes, one tridentate and two bidentate are in evidence. Tracer level /sup 241/Am - /sup 155/Eu cation-exchange experiments utilizing DHDMB eluents indicate that this dihydroxycarboxylate does not form a sufficiently strong americium complex to elute that actinide ahead of europium. The overall stability of the americium 3:1 complex appears intermediate between samarium and europium. Cation-exchange elutions of /sup 241/Am, /sup 155/Eu, and /sup 160/Tb mixtures with EEDTA solutions prove that the EEDTA ligand is capable of eluting americium ahead of all of the tripositive lanthanide cations. The minimum separation occurs with terbium, where the Am-Tb separation factor is 1.71. 1,5-diaminopentane-N,N,N',N'-tetraacetic acid (PMDTA) was synthesized using cation exchange. A mathematical method was developed for the formation constants of the protonated and unprotonated lanthanide-PMDTA complexes from potentiometry. Cation-exchange elutions of tracer quantities of Am, Eu, and Tb revealed that terbium is eluted ahead of both americium and europium.

  16. Method for forming an extraction agent for the separation of actinides from lanthanides

    DOEpatents

    Klaehn, John R.; Harrup, Mason K.; Law, Jack D.; Peterman, Dean R.

    2010-04-27

    An extraction agent for the separation of trivalent actinides from lanthanides in an acidic media and a method for forming same are described, and wherein the methodology produces a stable regiospecific and/or stereospecific dithiophosphinic acid that can operate in an acidic media having a pH of less than about 7.

  17. Design and synthesis of chelating diamide sorbents for the separation of lanthanides

    SciTech Connect

    Fryxell, Glen E.; Chouyyok, Wilaiwan; Rutledge, Ryan D.

    2011-06-01

    A nanoporous sorbent designed around chelating iminodiacetamide (“IDA-Amide”) moiety was made on mesoporous silica (MCM-41) and evaluated for lanthanide separations (Ce3+, Nd3+, Eu3+, Gd3+, and Lu3+). The effects of solution pH on lanthanide binding were studied, as well as sorption kinetics, and competition from other metal ions. The IDA-Amide SAMMS® demonstrated an interesting difference in the kinetics of sorption of the lanthanide ions in the order of Lu3+ > Eu3+ > Gd3+ > Nd3+ > Ce3+ . The close proximity of the ligands in the IDA-Amide SAMMS® may allow for multiple metal-ligand interactions (“macromolecular chelation”).

  18. Extraction systems using bis-1,2-dicarbollylcobaltate and polyoxonium compounds for lanthanide separations

    SciTech Connect

    Vanura, P.; Jedinakova-Krizova, V. )

    1992-12-01

    The extraction of rare earths (lanthanides, Y, Sc) by voluminous bis-1,2-dicarbollylcobaltate anions dissolved in nitrobenzene and in a nitrobenzene - carbon tetrachloride mixture has been investigated and the exchange extraction constants for both solvents, individual extraction constants and [Delta]G[sup 0] for ion transfer across the water - nitrobenzene phase boundary has been determined. Extraction decreases with increasing atomic number of the lanthanide. The influence of several polyoxonium compounds on the distribution ratios and the extraction selectivity has been investigated. In the extraction systems with bis-1,2-dicarbollylcobaltate - 18-crown-6 in nitrobenzene, synergism was found for the light lanthanides but antagonism was observed for the heavy ones. The overall separation factor is [alpha][sub La/Lu] [approx]10 compared to [alpha][sub La/Lu] [approx]2 in the absence of crown. 17 refs., 4 figs., 1 tab.

  19. Solvent Extraction Separation of Trivalent Americium from Curium and the Lanthanides

    SciTech Connect

    Jensen, Mark P.; Chiarizia, Renato; Ulicki, Joseph S.; Spindler, Brian D.; Murphy, Daniel J.; Hossain, M; Roca-Sabio, Adrian; de Blas, Andres; Rodriguez-Blas, Teresa

    2015-01-01

    The sterically constrained, macrocyclic, aqueous soluble ligand N,N′-bis[(6-carboxy-2-pyridyl)methyl]-1,10-diaza-18-crown-6 (H2BP18C6) was investigated for separating americium from curium and all the lanthanides by solvent extraction. Pairing H2BP18C6, which favors complexation of larger f-element cations, with acidic organophosphorus extractants that favor extraction of smaller f-element cations, such as bis-(2-ethylhexyl)phosphoric acid (HDEHP) or (2-ethylhexyl)phosphonic acid mono(2-ethylhexyl) ester (HEH[EHP]), created solvent extraction systems with good Cm/Am selectivity, excellent trans-lanthanide selectivity (Kex,Lu/Kex,La = 108), but poor selectivity for Am against the lightest lanthanides. However, using an organic phase containing both a neutral extractant, N,N,N’,N’-tetra(2-ethylhexyl)diglycolamide (TEHDGA), and HEH[EHP] enabled rejection of the lightest lanthanides during loading of the organic phase from aqueous nitric acid, eliminating their interference in the americium stripping stages. In addition, although it is a macrocyclic ligand, H2BP18C6 does not significantly impede the mass transfer kinetics of the HDEHP solvent extraction system

  20. Trivalent Lanthanide/Actinide Separation Using Aqueous-Modified TALSPEAK Chemistry

    SciTech Connect

    Travis S. Grimes; Richard D. Tillotson; Leigh R. Martin

    2014-05-01

    TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln3+) from minor actinides (MAs) Am3+ and Cm3+. Traditional TALSPEAK organic phase is comprised of a monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous phase contains a soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) in a concentrated (1.0-2.0 M) lactic acid (HL) buffer with the aqueous acidity typically adjusted to pH 3.0. TALSPEAK balances the selective complexation of the actinides by DTPA against the electrostatic attraction of the lanthanides by the HDEHP extractant to achieve the desired trivalent lanthanide/actinide group separation. Although TALSPEAK is considered a successful separations scheme, recent fundamental studies have highlighted complex chemical interactions occurring in the aqueous and organic phases during the extraction process. Previous attempts to model the system have shown thermodynamic models do not accurately predict the observed extraction trends in the p[H+] range 2.5-4.8. In this study, the aqueous phase is modified by replacing the lactic acid buffer with a variety of simple and longer-chain amino acid buffers. The results show successful trivalent lanthanide/actinide group separation with the aqueous-modified TALSPEAK process at pH 2. The amino acid buffer concentrations were reduced to 0.5 M (at pH 2) and separations were performed without any effect on phase transfer kinetics. Successful modeling of the aqueous-modified TALSPEAK process (p[H+] 1.6-3.1) using a simplified thermodynamic model and an internally consistent set of thermodynamic data is presented.

  1. Actinide-lanthanide separation with solvents on the base of amides of heterocyclic diacids

    SciTech Connect

    Babain, V.A.; Alyapyshev, M.Y.; Tkachenko, L.I.

    2013-07-01

    The separation of actinides from lanthanides with a particular emphasis on Am(III) from Eu(III) with amides of heterocyclic dicarboxylic diacids was reviewed. It was shown that the di-amides of the 2,2'-dipyridyl-6,6'-dicarboxylic acid are the most promising ligands for the simultaneous selective recovery of actinides from HLLW (high level radioactive liquid waste) within the GANEX concept. (author)

  2. Rapid separation of beryllium and lanthanide derivatives by capillary gas chromatography

    SciTech Connect

    Harvey, Scott D.; Lucke, Richard B.; Douglas, Matt

    2012-09-04

    Previous studies describe derivatization of metal ions followed by analysis using gas chromatography, usually on packed columns. In many of these studies, stable and volatile derivatives were formed using fluorinated β-diketonate reagents. This paper extends previous work by investigating separations of the derivatives on small-diameter capillary gas chromatography columns and exploring on-fiber, solid-phase microextraction derivatization techniques for beryllium. The β-diketonate used for these studies was 1,1,1,2,2,6,6,7,7,7-decafluoro-3,5-heptanedione. Derivatization of lanthanides also required addition of a neutral donor, dibutyl sulfoxide, in addition to 1,1,1,2,2,6,6,7,7,7-decafluoro-3,5-heptanedione. Unoptimized separations on a 100-μm i.d. capillary column proved capable of rapid separations (within 15 min) of lanthanide derivatives that are adjacent to one another in the periodic table. Full-scan mass spectra were obtained from derivatives containing 5 ng of each lanthanide. Studies also developed a simple on-fiber solid-phase microextraction derivatization of beryllium. Beryllium could be analyzed in the presence of other alkali earth elements (Ba(II) and Sr(II)) without interference. Finally, extension of the general approach was demonstrated for several additional elements (i.e. Cu(II), Cr(III), and Ga(III)).

  3. Separation and determination of lanthanides, thorium and uranium using a dual gradient in reversed-phase liquid chromatography.

    PubMed

    Raut, Narendra M; Jaison, P G; Aggarwal, Suresh K

    2004-10-15

    Separation and determination of lanthanides, Th and U is of great relevance in different fields of science and technology. Reversed-phase high-performance liquid chromatography (RP-HPLC) using alpha-hydroxy isobutyric acid (alpha-HIBA) as an eluent on reversed-phase column modified to cation exchanger has been reported to achieve the separation. However, under those conditions, Th and U are eluted amongst lanthanides, making their quantification difficult due to overlapping with some of the lanthanides peaks. In this work, different chromatographic parameters (concentrations of eluent and ion interaction reagent, pH, etc.) were studied systematically to arrive at optimum chromatographic conditions. Using the dual (concentration and pH) gradient conditions, lanthanides, Th and U could be separated in 11 min by RP-HPLC with sequential elution of Th and U after the elution of all the lanthanides. The separation methodology was tested using SY-3 rock sample for the separation and determination of lanthanides, Th and U. The method allows an accurate determination of these elements in a single run using a single column. Also, the method is fast and cost-effective compared to the reported methods.

  4. Radiometric evaluation of diglycolamide resins for the chromatographic separation of actinium from fission product lanthanides

    DOE PAGES

    Radchenko, Valery; Mastren, Tara; Meyer, Catherine A. L.; ...

    2017-07-20

    Actinium-225 is a potential Targeted Alpha Therapy (TAT) isotope. It can be generated with high energy (≥ 100 MeV) proton irradiation of thorium targets. The main challenge in the chemical recovery of 225Ac lies in the separation from thorium and many fission by-products most importantly radiolanthanides. We recently developed a separation strategy based on a combination of cation exchange and extraction chromatography to isolate and purify 225Ac. In this study, actinium and lanthanide equilibrium distribution coefficients and column elution behavior for both TODGA (N,N,N',N'-tetra-n-octyldiglycolamide) and TEHDGA (N,N,N',N'-tetrakis-2-ethylhexyldiglycolamide) were determined. Density functional theory (DFT) calculations were performed and were in agreementmore » with experimental observations providing the foundation for understanding of the selectivity for Ac and lanthanides on different DGA (diglycolamide) based resins. The results of Gibbs energy (ΔGaq) calculations confirm significantly higher selectivity of DGA based resins for LnIII over AcIII in the presence of nitrate. As a result, DFT calculations and experimental results reveal that Ac chemistry cannot be predicted from lanthanide behavior under comparable circumstances.« less

  5. Radiolytic Degradation in Lanthanide/Actinide Separation Ligands–NOPOPO: Radical Kinetics and Efficiencies Determinations

    SciTech Connect

    Katy L. Swancutt; Stephen P. Mezyk; Richard D. Tillotson; Sylvie Pailloux; Manab Chakravarty; Robert T. Paine; Leigh R. Martin

    2011-07-01

    Trivalent lanthanide/actinide separations from used nuclear fuel occurs in the presence radiation fields that degrades the extraction ligands and solvents. Here we have investigated the stability of a new ligand for lanthanide/actinide separation; 2,6-bis[(di(2-ethylhexyl)phosphino)methyl] pyridine N,P,P-trioxide, TEH(NOPOPO). The impact of {gamma}-radiolysis on the distribution ratios for actinide (Am) and Lanthanide (Eu) extraction both in the presence and absence of an acidic aqueous phase by TEH(NOPOPO) was determined. Corresponding reaction rate constants for the two major radicals, hydroxyl and nitrate, were determined for TEH(NOPOPO) in the aqueous phase, with room temperature values of (3.49 {+-} 0.10) x 10{sup 9} and (1.95 {+-} 0.15) x 10{sup 8} M{sup -1} s{sup -1}, respectively. The activation energy for this reaction was found to be 30.2 {+-} 4.1 kJ mol{sup -1}. Rate constants for two analogues (2-methylphosphonic acid pyridine N,P-dioxide and 2,6-bis(methylphosphonic acid) pyridine N,P,P-trioxide) were also determined to assist in determining the major reaction pathways.

  6. Radiometric evaluation of diglycolamide resins for the chromatographic separation of actinium from fission product lanthanides.

    PubMed

    Radchenko, Valery; Mastren, Tara; Meyer, Catherine A L; Ivanov, Alexander S; Bryantsev, Vyacheslav S; Copping, Roy; Denton, David; Engle, Jonathan W; Griswold, Justin R; Murphy, Karen; Wilson, Justin J; Owens, Allison; Wyant, Lance; Birnbaum, Eva R; Fitzsimmons, Jonathan; Medvedev, Dmitri; Cutler, Cathy S; Mausner, Leonard F; Nortier, Meiring F; John, Kevin D; Mirzadeh, Saed; Fassbender, Michael E

    2017-12-01

    Actinium-225 is a potential Targeted Alpha Therapy (TAT) isotope. It can be generated with high energy (≥ 100MeV) proton irradiation of thorium targets. The main challenge in the chemical recovery of (225)Ac lies in the separation from thorium and many fission by-products most importantly radiolanthanides. We recently developed a separation strategy based on a combination of cation exchange and extraction chromatography to isolate and purify (225)Ac. In this study, actinium and lanthanide equilibrium distribution coefficients and column elution behavior for both TODGA (N,N,N',N'-tetra-n-octyldiglycolamide) and TEHDGA (N,N,N',N'-tetrakis-2-ethylhexyldiglycolamide) were determined. Density functional theory (DFT) calculations were performed and were in agreement with experimental observations providing the foundation for understanding of the selectivity for Ac and lanthanides on different DGA (diglycolamide) based resins. The results of Gibbs energy (ΔGaq) calculations confirm significantly higher selectivity of DGA based resins for Ln(III) over Ac(III) in the presence of nitrate. DFT calculations and experimental results reveal that Ac chemistry cannot be predicted from lanthanide behavior under comparable circumstances. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Separation of Trivalent Actinides from Lanthanides Using a Capillary Electrophoresis

    SciTech Connect

    Mori, Tomotaka; Ishii, Yasuo; Hayashi, Kazunori; Suganuma, Hideo; Satoh, Isamu

    2007-07-01

    A separation of {sup 241}Am(III) from {sup 152,154}Eu(III) was carried out using a capillary electrophoresis technique in a mixed solvent (CH{sub 3}OH/H{sub 2}O) system containing thiocyanate ion. First, the formation constants ({beta}{sub n}) between thiocyanate ion and Eu(III) or Am(III) were investigated in the mixed solvent solutions by a back-extraction technique using bis (2-ethylhexyl) hydrogen phosphate-toluene. The mean charges calculated on the basis of the data of {beta}{sub n} for Eu(III) were comparatively higher than those for Am(III). Based on the differences between the mean charges of Eu(III) and Am(III), separations for Am(III)/Eu(III) by means of capillary electrophoresis technique were tried in the (H{sup +}, Na{sup +})(SCN{sup -}, ClO{sub 4}{sup -}) mixed solvent solutions. It was proved that Am(III) was completely separated from Eu(III). (authors)

  8. Thermodynamic Studies to Support Actinide/Lanthanide Separations

    SciTech Connect

    Rao, Linfeng

    2015-09-01

    This milestone report summarizes the data obtained in FY15 on the complexation of HEDTA with Np(V) and U(VI) in a temperature range from 25 to 70°C. The results show the effect of temperature on the chemical speciation of Np(V) and U(VI) in the modified TALSPEAK Process, and help to evaluate the effectiveness of the process when the operation envelope (e.g., temperature) varies. Eventually, the results from this study will help to achieve a better control of the separation process based on the HEDTA/HEH[EHP] combination.

  9. Evaluation of tertiary pyridine resin for the separation of lanthanides by simulated moving-bed chromatography.

    PubMed

    Sreedhar, Balamurali; Suzuki, Tatsuya; Hobbs, David T; Kawajiri, Yoshiaki

    2014-10-01

    Lanthanide separation by simulated moving-bed chromatography was studied as a model system for separating lanthanide fission products and minor actinides from used nuclear fuels. The simulated moving-bed system was modeled for a tertiary pyridine anion-exchange resin supported on silica particles as the stationary phase and a mixture of methanol and 1 M nitric acid as the mobile phase. Pulse injection tests using a single packed column were used to obtain chromatographic parameters for mathematical modeling of the simulated moving-bed system. Higher concentrations of methanol improved the separation, but the chromatograms showed evidence of nonlinearity of the isotherms. The mathematical model of the simulated moving-bed process predicted a production rate of purified samarium and neodymium at 118 g solute/L resin/day and a purity of 99.5%. The optimal methanol ratio for the production rate for various product purities was determined from the model. The excellent separation of Nd and Sm suggests that the simulated moving-bed system could be applied to the separation of minor actinides such as americium and curium.

  10. Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate

    SciTech Connect

    Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge

    2014-04-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.

  11. “Straining” to Separate the Rare Earths: How the Lanthanide Contraction Impacts Chelation by Diglycolamide Ligands

    SciTech Connect

    Ellis, Ross J.; Brigham, Derek M.; Delmau, Laetitia; Ivanov, Alexander S.; Williams, Neil J.; Vo, Minh Nguyen; Reinhart, Benjamin; Moyer, Bruce A.; Bryantsev, Vyacheslav S.

    2016-11-23

    The subtle energetic differences underpinning adjacent lanthanide discrimination are explored with diglycolamide ligands. Our approach converges liquid–liquid extraction experiments with solution-phase X-ray absorption spectroscopy (XAS) and density functional theory (DFT) simulations, spanning the lanthanide series. The homoleptic [(DGA)3Ln]3+ complex was confirmed in the organic extractive solution by XAS, and this was modeled using DFT. An interplay between steric strain and coordination energies apparently gives rise to a nonlinear trend in discriminatory lanthanide ion complexation across the series. Our results highlight the importance of optimizing chelate molecular geometry to account for both coordination interactions and strain energies when designing new ligands for efficient adjacent lanthanide separation for rare-earth refining.

  12. “Straining” to Separate the Rare Earths: How the Lanthanide Contraction Impacts Chelation by Diglycolamide Ligands

    DOE PAGES

    Ellis, Ross J.; Brigham, Derek M.; Delmau, Laetitia; ...

    2016-11-23

    The subtle energetic differences underpinning adjacent lanthanide discrimination are explored with diglycolamide ligands. Our approach converges liquid–liquid extraction experiments with solution-phase X-ray absorption spectroscopy (XAS) and density functional theory (DFT) simulations, spanning the lanthanide series. The homoleptic [(DGA)3Ln]3+ complex was confirmed in the organic extractive solution by XAS, and this was modeled using DFT. An interplay between steric strain and coordination energies apparently gives rise to a nonlinear trend in discriminatory lanthanide ion complexation across the series. Our results highlight the importance of optimizing chelate molecular geometry to account for both coordination interactions and strain energies when designing new ligandsmore » for efficient adjacent lanthanide separation for rare-earth refining.« less

  13. The separation of Am from lanthanides by purified Cyanex 301 extraction

    SciTech Connect

    Jing Chen; Yongjun Zhu; Rongzhou Jiao

    1996-11-01

    Separation factors of tracer amounts of Am from micro lanthanides (La, Ce, Pr, Nd, and Sm) by purified Cyanex 301 extraction in nitrate media have been determined: SF{sub Am/La} {approximately} 3500, SF{sub Am/Ce,Pr} {approximately} 1000, SF {sub Am/Nd} {approximately} 1900, and SF{sub Am/Sm}{approximately} 4500, with an average value > 2300. The distribution ratio decreases with increasing lanthanide concentration in the aqueous phase. In the presence of a macro amount of Pr + Nd(0.1 {approximately} 0.6 M) the separation factors SF{sub Am/Eu} and SF {sub Am/Pr+Nd} are about 4.7 x 10{sup 3} and 2.1 x 10{sup 3}, respectively. The results of the countercurrent fractional process show that by using three extraction stages and two scrubbing stages, >99.99% Am can be separated from a tracer amount of Eu with <0.1% extraction of Eu. Using six extraction stages, >99.99% Am and <0.6% macro amount of Pr + Nd are extracted into the organic phase.

  14. Solvent extraction separation of trivalent lanthanide and actinide ions using an aqueous aminomethanediphosphonic acid.

    SciTech Connect

    Jensen, M. P.

    1998-10-14

    The possibility of separating the trivalent lanthanides, represented by EU{sup 3+}, and actinides, represented by Cf{sup 3+}, using HDEHP in toluene and an aqueous phase containing N-piperidinomethane-1,1-diphosphotic acid, PMDPA, has been investigated. This modified aqueous phase offers potential advantages over the diethylenetriaminepentaacetic acid based TALSPEAK process because of the improved complexation properties of PMDPA in acidic solutions, and the ability to decompose PMDPA before disposal. Extraction experiments were conducted at 25 C in 2 M NaClO{sub 4} between -log [H{sup +}] 1 and 2. The studies enabled us to derive the aqueous phase speciation, the stability constants of the aqueous complexes, and the Cf/Eu separation factors. Despite the presence of an amino group in PMDPA that should favor the retention of the actinides in the aqueous phase, the Cf/Eu separation factors are near unity under the conditions studied.

  15. Combining CMPO and HEH[EHP] for Separating Trivalent Lanthanides from the Transuranic Elements

    SciTech Connect

    Braley, Jenifer C.; Lumetta, Gregg J.; Carter, Jennifer C.

    2013-09-05

    Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) into a single process solvent for separating transuranic elements from liquid high-level waste is explored. The lanthanides and americium can be co-extracted from HNO3 into 0.2 mol/L CMPO + 1.0 mol/L HEH[EHP] in n-dodecane. The extraction is relatively insensitive to the HNO3 concentration within 0.1 to 5 mol/L HNO3. Americium can be selectively stripped from the CMPO/HEH[EHP] solvent into a citrate-buffered N-(2-hydroxyethyl)ethylenediaminetriacetic acid solution . Separation factors >14 can be achieved in the range pH 2.5 to 3.7, and the separation factors are relatively insensitive to pH, a major advantage of this solvent formulation.

  16. Analytical-scale separations of lanthanides : a review of techniques and fundamentals.

    SciTech Connect

    Nash, K. L.; Jensen, M. P.

    1999-10-27

    Separations chemistry is at the heart of most analytical procedures to determine the rare earth content of both man-made and naturally occurring materials. Such procedures are widely used in mineral exploration, fundamental geology and geochemistry, material science, and in the nuclear industry. Chromatographic methods that rely on aqueous solutions containing complexing agents sensitive to the lanthanide cationic radius and cation-exchange phase transfer reactions (using a variety of different solid media) have enjoyed the greatest success for these procedures. In this report, they will briefly summarize the most important methods for completing such analyses. they consider in some detail the basic aqueous (and two-phase) solution chemistry that accounts for separations that work well and offer explanations for why others are less successful.

  17. Experimental Findings On Minor Actinide And Lanthanide Separations Using Ion Exchange

    SciTech Connect

    Hobbs, D. T.; Shehee, T. C.; Clearfield, A.

    2013-09-17

    This project seeks to determine if inorganic or hybrid inorganic ion-exchange materials can be exploited to provide effective americium and curium separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of the tested ion-exchange materials for actinide and lanthanide ions. During FY13, experimental work focused in the following areas: (1) investigating methods to oxidize americium in dilute nitric acid with subsequent ion-exchange performance measurements of ion exchangers with the oxidized americium and (2) synthesis, characterization and testing of ion-exchange materials. Ion-exchange materials tested included alkali titanates, alkali titanosilicates, carbon nanotubes and group(IV) metal phosphonates. Americium oxidation testing sought to determine the influence that other redox active components may have on the oxidation of Am(III). Experimental findings indicated that Pu(IV) is oxidized to Pu(VI) by peroxydisulfate, but there are no indications that the presence of plutonium affects the rate or extent of americium oxidation at the concentrations of peroxydisulfate being used. Tests also explored the influence of nitrite on the oxidation of Am(III). Given the formation of Am(V) and Am(VI) in the presence of nitrite, it appears that nitrite is not a strong deterrent to the oxidation of Am(III), but may be limiting Am(VI) by quickly reducing Am(VI) to Am(V). Interestingly, additional absorbance peaks were observed in the UV-Vis spectra at 524 and 544 nm in both nitric acid and perchloric acid solutions when the peroxydisulfate was added as a solution. These peaks have not been previously observed and do not correspond to the expected peak locations for oxidized americium in solution. Additional studies are in progress to identify these unknown peaks. Three titanosilicate ion exchangers were synthesized using a microwave-accelerated reaction system (MARS) and determined to have high affinities

  18. Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

    SciTech Connect

    Kenneth L. Nash

    2009-09-22

    Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am and Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their

  19. Sequential separation of ultra-trace U, Th, Pb, and lanthanides using a simple automatic system.

    PubMed

    Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

    2015-07-07

    Uranium, thorium, lead, and the lanthanides were automatically and sequentially separated with a single anion-exchange column. This separation was achieved using eluents consisting of a simple and highly pure acid mixture of HCl, HNO3, acetic acid, and HF. The elements of interest were separated from the major constituents, which included alkaline metal elements, alkaline earth metal elements, and iron. This simple and automatic system is driven with pressurized nitrogen gas and controlled using a computer program. An optimized separation was accomplished under the following conditions: a 50 mm long and 2 mm diameter column, 11 μm diameter anion-exchange resin, and a 35 μL min(-1) flow rate. Using this system, 50 ng of varied elements in a 100 μL feed solution were perfectly separated within 5 h with >400 decontamination factors and >95% yield. In order to evaluate the performance of this system, a reference powdered rock sample was separated using this system. Abundances of objective elements, including 0.23 ng of lutetium, were accurately determined without corrections of chemical recovery yield or subtraction of the process blank. This separation technique saves time and effort for chemical processing, and is useful for ultra-trace quantitative and isotopic analyses of elements in small environmental samples.

  20. Mixed monofunctional extractants for trivalent actinide/lanthanide separations: TALSPEAK-MME

    DOE PAGES

    Johnson, Aaron T.; Nash, Kenneth L.

    2015-08-20

    The basic features of an f-element extraction process based on a solvent composed of equimolar mixtures of Cyanex-923 (a mixed trialkyl phosphine oxide) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) extractants in n-dodecane are investigated in this report. This system, which combines features of the TRPO and TALSPEAK processes, is based on co-extraction of trivalent lanthanides and actinides from 0.1 to 1.0 M HNO3 followed by application of a buffered aminopolycarboxylate solution strip to accomplish a Reverse TALSPEAK selective removal of actinides. This mixed-extractant medium could enable a simplified approach to selective trivalent f-element extraction and actinide partitioning in a singlemore » process. As compared with other combined process applications in development for more compact actinide partitioning processes (DIAMEX-SANEX, GANEX, TRUSPEAK, ALSEP), this combination features only monofunctional extractants with high solubility limits and comparatively low molar mass. Selective actinide stripping from the loaded extractant phase is done using a glycine-buffered solution containing N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) or triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid (TTHA). Lastly, the results reported provide evidence for simplified interactions between the two extractants and demonstrate a pathway toward using mixed monofunctional extractants to separate trivalent actinides (An) from fission product lanthanides (Ln).« less

  1. Mixed monofunctional extractants for trivalent actinide/lanthanide separations: TALSPEAK-MME

    SciTech Connect

    Johnson, Aaron T.; Nash, Kenneth L.

    2015-08-20

    The basic features of an f-element extraction process based on a solvent composed of equimolar mixtures of Cyanex-923 (a mixed trialkyl phosphine oxide) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) extractants in n-dodecane are investigated in this report. This system, which combines features of the TRPO and TALSPEAK processes, is based on co-extraction of trivalent lanthanides and actinides from 0.1 to 1.0 M HNO3 followed by application of a buffered aminopolycarboxylate solution strip to accomplish a Reverse TALSPEAK selective removal of actinides. This mixed-extractant medium could enable a simplified approach to selective trivalent f-element extraction and actinide partitioning in a single process. As compared with other combined process applications in development for more compact actinide partitioning processes (DIAMEX-SANEX, GANEX, TRUSPEAK, ALSEP), this combination features only monofunctional extractants with high solubility limits and comparatively low molar mass. Selective actinide stripping from the loaded extractant phase is done using a glycine-buffered solution containing N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA) or triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid (TTHA). Lastly, the results reported provide evidence for simplified interactions between the two extractants and demonstrate a pathway toward using mixed monofunctional extractants to separate trivalent actinides (An) from fission product lanthanides (Ln).

  2. Challenging conventional f-element separation chemistry--reversing uranyl(VI)/lanthanide(III) solvent extraction selectivity.

    PubMed

    Hawkins, C A; Bustillos, C G; Copping, R; Scott, B L; May, I; Nilsson, M

    2014-08-14

    The water soluble tetradentate Schiff base, N,N'-bis(5-sulfonatosalicylidene)-diaminoethane (H2salen-SO3), will readily coordinate to the uranyl(VI) cation, but not to the same extent to trivalent lanthanide cations. This allows for the reversal of conventional solvent extraction properties and opens the possibility for novel separation processes.

  3. Separation of thorium (IV) from lanthanide concentrate (LC) and water leach purification (WLP) residue

    SciTech Connect

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-09-03

    Thorium (IV) content in industrial residue produced from rare earth elements production industry is one of the challenges to Malaysian environment. Separation of thorium from the lanthanide concentrate (LC) and Water Leach Purification (WLP) residue from rare earth elements production plant is described. Both materials have been tested by sulphuric acid and alkaline digestions. Th concentrations in LC and WLP were determined to be 1289.7 ± 129 and 1952.9±17.6 ppm respectively. The results of separation show that the recovery of Th separation from rare earth in LC after concentrated sulphuric acid dissolution and reduction of acidity to precipitate Th was found 1.76-1.20% whereas Th recovery from WLP was less than 4% after concentrated acids and alkali digestion processes. Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) was used to determine Th concentrations in aqueous phase during separation stages. This study indicated that thorium maybe exists in refractory and insoluble form which is difficult to separate by these processes and stays in WLP residue as naturally occurring radioactive material (NORM)

  4. Separation of thorium (IV) from lanthanide concentrate (LC) and water leach purification (WLP) residue

    NASA Astrophysics Data System (ADS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman

    2014-09-01

    Thorium (IV) content in industrial residue produced from rare earth elements production industry is one of the challenges to Malaysian environment. Separation of thorium from the lanthanide concentrate (LC) and Water Leach Purification (WLP) residue from rare earth elements production plant is described. Both materials have been tested by sulphuric acid and alkaline digestions. Th concentrations in LC and WLP were determined to be 1289.7 ± 129 and 1952.9±17.6 ppm respectively. The results of separation show that the recovery of Th separation from rare earth in LC after concentrated sulphuric acid dissolution and reduction of acidity to precipitate Th was found 1.76-1.20% whereas Th recovery from WLP was less than 4% after concentrated acids and alkali digestion processes. Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) was used to determine Th concentrations in aqueous phase during separation stages. This study indicated that thorium maybe exists in refractory and insoluble form which is difficult to separate by these processes and stays in WLP residue as naturally occurring radioactive material (NORM).

  5. Multigram group separation of actinide and lanthanide elements by LiCl-based anion exchange

    SciTech Connect

    Collins, E.D.; Benker, D.E.; Chattin, F.R.; Orr, P.B.; Ross, R.G.

    1980-01-01

    The laboratory-scale LiCl AIX process has been successfully adapted to the multigram scale and has been used effectively in transuranium element production campaigns to separate the lanthanide fission products from the transplutonium actinides and to partition americium and curium from the heavier elements. Corrosion of the tantalum and glass equipment has been negligible. Although radiolytic gas generation has not caused a problem, radiation exposure of the Dowex 1-X10 anion exchange resin does occur significantly. However, the 1.3-L resin bed can be used successfully to process up to 3 batches, each containing 19 g of /sup 244/Cm (54 W of decay heat). The chromatographic elution process is controlled by use of an alpha detector in the column effluent line and by periodic measurement of the neutron profile of the column. The development and use of feed pretreatment and operating methods has enabled effective and dependable operation.

  6. DISSOLUTION OF METAL OXIDES AND SEPARATION OF URANIUM FROM LANTHANIDES AND ACTINIDES IN SUPERCRITICAL CARBON DIOXIDE

    SciTech Connect

    Donna L. Quach; Bruce J. Mincher; Chien M. Wai

    2013-10-01

    This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO2 modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO2 and counter current stripping columns is presented.

  7. Dissolution of metal oxides and separation of uranium from lanthanides and actinides in supercritical carbon dioxide

    SciTech Connect

    Quach, D.L.; Wai, C.M.; Mincher, B.J.

    2013-07-01

    This paper investigates the feasibility of extracting and separating uranium from lanthanides and other actinides by using supercritical fluid carbon dioxide (sc-CO{sub 2}) as a solvent modified with tri-n-butylphosphate (TBP) for the development of a counter current stripping technique, which would be a more efficient and environmentally benign technology for spent nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U, Pu, and Np) and europium were extracted in sc-CO{sub 2} modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, uranium/europium and uranium/plutonium extraction and separation in sc-CO{sub 2} modified with TBP is successful at nitric acid concentrations of less than 6 M and at nitric acid concentrations of less than 3 M with acetohydroxamic acid or oxalic acid, respectively. A scheme for recycling uranium from spent nuclear fuel by using sc-CO{sub 2} and counter current stripping columns is presented. (authors)

  8. Hollow-fiber supported liquid membrane (HFSLM) for the separation of lanthanides and actinides

    SciTech Connect

    Mohapatra, P.K.; Ansari, S.A.; Bhattacharyya, A.; Manchanda, V.K.; Patil, C.B.

    2008-07-01

    The transport behavior of Nd(III) was investigated using hollow-fiber supported liquid membranes (HFSLM) from an acidic feed solution using N,N,N',N'-tetraoctyl-diglycolamide (TODGA) in normal paraffinic hydrocarbon (NPH) as the carrier. Near quantitative transport (>99%) of Nd(III) from 500 mL of feed containing 1 g/L Nd in 3.5 M HNO{sub 3} was possible in about 45 minutes. Quantitative transport time increased when the volume or Nd(III ) concentration in the feed was increased. The liquid membrane had excellent stability as indicated by eight consecutive runs that gave consistent transport rates. The HFSLM data using Cyanex- 301 in n-dodecane as carrier extractant for the lanthanide-actinide separation with the feed solution 1 M NaNO{sub 3} at pH 3.5 and stripping solution 0.01 M EDTA at a pH 3.5 were promising. (authors)

  9. Probing the difference in covalence by enthalpy measurements: a new heterocyclic N-donor ligand for actinide/lanthanide separation.

    PubMed

    Yang, Yanqiu; Liu, Jun; Yang, Liang; Li, Kun; Zhang, Huabei; Luo, Shunzhong; Rao, Linfeng

    2015-05-21

    Complexation of Am(III), Nd(III), and Eu(III) with a new heterocyclic nitrogen-donor ligand, 2,9-di(quinazolin-2-yl)-1,10-phenanthroline (denoted as BQPhen in this paper), was studied by thermodynamic measurements and theoretical computations. The stability constants of two successive complexes in dimethylformamide, ML(3+) and ML2(3+) where M stands for Nd, Eu, or Am while L stands for the BQPhen ligand, were determined by absorption spectrophotometry. The enthalpy of complexation was determined by microcalorimetry. Results show that BQPhen forms ten times stronger complexes with Am(III) than Eu(III) or Nd(III) under identical conditions, suggesting that BQPhen could be used as an efficient extractant for the separations of trivalent actinides from lanthanides. The higher binding strength of BQPhen towards Am(III) than Nd(III) or Eu(III) is mainly due to the more favourable enthalpy of complexation for Am(III)/BQPhen complexes, implying a higher degree of covalence in the Am(III)/BQPhen complexes than the lanthanide(III)/BQPhen complexes. The thermodynamic trend was corroborated with computational results and validated by solvent extraction experiments that demonstrated BQPhen preferably extracted Am(III) more than Eu(III), with a separation factor of about 10. Discussions have been made to compare BQPhen with other phenanthroline derivatives such as CyMe4-BTPhen, a bis-triazine-phenanthroline derivative that was reported in the literature. Data suggest that, under identical conditions, BQPhen would form stronger complexes with Am(III), Eu(III), and Nd(III) than CyMe4-BTPhen.

  10. Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

    SciTech Connect

    Kenneth L. Nash; Sue B. Clark; Gregg Lumetta

    2009-09-23

    With increased application of MOX fuels and longer burnup times for conventional fuels, higher concentrations of the transplutonium actinides Am and Cm (and even heavier species like Bk and Cf) will be produced. The half-lives of the Am isotopes are significantly longer than those of the most important long-lived, high specific activity lanthanides or the most common Cm, Bk and Cf isotopes, thus the greatest concern as regards long-term radiotoxicity. With the removal and transmutation of Am isotopes, radiation levels of high level wastes are reduced to near uranium mineral levels within less than 1000 years as opposed to the time-fram if they remain in the wastes.

  11. Synergism and separation factors in lanthanide extraction with mixtures of chelating extractant and amine salts in C{sub 6}H{sub 6}

    SciTech Connect

    Dukov, I.L.; Jordanov, V.M.

    1997-10-01

    The solvent extraction of Pr, Gd, and Yb with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HP) and an amine salt (AmHA) has been studied. The composition of the extracted species has been determined as (AmH)[LnP{sub 4}]. The values of the synergistic coefficients and separation factors have been calculated. The effect of the amine salt on the extraction and separation of lanthanides has been discussed.

  12. Evaluation of Cyanex 923-coated magnetic particles for the extraction and separation of lanthanides and actinides from nuclear waste streams

    NASA Astrophysics Data System (ADS)

    Shaibu, B. S.; Reddy, M. L. P.; Bhattacharyya, A.; Manchanda, V. K.

    2006-06-01

    In the magnetically assisted chemical separation (MACS) process, tiny ferromagnetic particles coated with solvent extractant are used to selectively separate radionuclides and hazardous metals from aqueous waste streams. The contaminant-loaded particles are then recovered from the waste solutions using a magnetic field. The contaminants attached to the magnetic particles are subsequently removed using a small volume of stripping agent. In the present study, Cyanex 923 (trialkylphosphine oxide) coated magnetic particles (cross-linked polyacrylamide and acrylic acid entrapping charcoal and iron oxide, 1:1:1, particle size=1-60 μm) are being evaluated for the possible application in the extraction and separation of lanthanides and actinides from nuclear waste streams. The uptake behaviour of Th(IV), U(VI), Am(III) and Eu(III) from nitric acid solutions was investigated by batch studies. The effects of sorption kinetics, extractant and nitric acid concentrations on the uptake behaviour of metal ions were systematically studied. The influence of fission products (Cs(I), Sr(II)) and interfering ions including Fe(III), Cr(VI), Mg(II), Mn(II), and Al(III) were investigated. The recycling capacity of the extractant-coated magnetic particles was also evaluated.

  13. Theoretical Prediction of Am(III)/Eu(III) Selectivity to Aid the Design of Actinide-Lanthanide Separation Agents

    DOE PAGES

    Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2015-03-20

    Selective extraction of minor actinides from lanthanides is a critical step in the reduction of radiotoxicity of spent nuclear fuels. However, the design of suitable ligands for separating chemically similar 4f- and 5f-block trivalent metal ions poses a significant challenge. Furthermore, first-principles calculations should play an important role in the design of new separation agents, but their ability to predict metal ion selectivity has not been systematically evaluated. We examine the ability of several density functional theory methods to predict selectivity of Am(III) and Eu(III) with oxygen, mixed oxygen–nitrogen, and sulfur donor ligands. The results establish a computational method capablemore » of predicting the correct order of selectivities obtained from liquid–liquid extraction and aqueous phase complexation studies. To allow reasonably accurate predictions, it was critical to employ sufficiently flexible basis sets and provide proper account of solvation effects. The approach is utilized to estimate the selectivity of novel amide-functionalized diazine and 1,2,3-triazole ligands.« less

  14. Theoretical Prediction of Am(III)/Eu(III) Selectivity to Aid the Design of Actinide-Lanthanide Separation Agents

    SciTech Connect

    Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2015-03-20

    Selective extraction of minor actinides from lanthanides is a critical step in the reduction of radiotoxicity of spent nuclear fuels. However, the design of suitable ligands for separating chemically similar 4f- and 5f-block trivalent metal ions poses a significant challenge. Furthermore, first-principles calculations should play an important role in the design of new separation agents, but their ability to predict metal ion selectivity has not been systematically evaluated. We examine the ability of several density functional theory methods to predict selectivity of Am(III) and Eu(III) with oxygen, mixed oxygen–nitrogen, and sulfur donor ligands. The results establish a computational method capable of predicting the correct order of selectivities obtained from liquid–liquid extraction and aqueous phase complexation studies. To allow reasonably accurate predictions, it was critical to employ sufficiently flexible basis sets and provide proper account of solvation effects. The approach is utilized to estimate the selectivity of novel amide-functionalized diazine and 1,2,3-triazole ligands.

  15. Thermally unstable complexants: Stability of lanthanide/actinide complexes, thermal instability of the ligands, and applications in actinide separations

    SciTech Connect

    Nash, K.L.; Rickert, P.G.

    1993-01-01

    Water soluble complexing agents are commonly used in separations to enhance the selectivity of both ion exchange and solvent extraction processes. Applications of this type in the treatment of nuclear wastes using conventional complexing agents have found mixed success due to the nature of the complexants. In addition, the residual solutions containing these species have led to potentially serious complications in waste storage. To overcome some of the limitations of carboxylic acid and aminopolycarboxylate ligands, the authors have initiated a program to investigate the complexing ability, thermal/oxidative instability, and separation potential of a group of water soluble organophosphorus compounds which they call Thermally Unstable Complexants, or simply TUCS. Complexants of this type appear to be superior to conventional analogues in a number of respects. In this report, they summarize their research to date on the actinide/lanthanide complexes with a series of substituted methanediphosphonic acids, the kinetics of their oxidative decomposition, and a few applications which have been developed for their use.

  16. Thermally unstable complexants: Stability of lanthanide/actinide complexes, thermal instability of the ligands, and applications in actinide separations

    SciTech Connect

    Nash, K.L.; Rickert, P.G.

    1991-01-01

    Water soluble complexing agents are commonly used in separations to enhance the selectivity of both ion exchange and solvent extraction processes. Applications of this type in the treatment of nuclear wastes using conventional complexing agents have found mixed success due to the nature of the complexants. In addition, the residual solutions containing these species have led to potentially serious complications in waste storage. To overcome some of the limitations of carboxylic acid and aminopolycarboxylate ligands, we have initiated a program to investigate the complexing ability, thermal/oxidative instability, and separation potential of a group of water soluble organophosphorus compounds which we call Thermally Unstable Complexants, or simply TUCS. Complexants of this type appear to be superior to conventional analogues in a number of respects. In this report, we will summarize our research to date on the actinide/lanthanide complexes with a series of substituted methanediphosphonic acids, the kinetics of their oxidative decomposition, and a few applications which have been developed for their use. 17 refs., 5 figs., 3 tab.

  17. Americium/Lanthanide Separations in Alkaline Solutions for Advanced Nuclear Fuel Cycles

    SciTech Connect

    Goff, George S.; Long, Kristy Marie; Reilly, Sean D.; Jarvinen, Gordon D.; Runde, Wolfgang H.

    2012-06-11

    Project goals: Can used nuclear fuel be partitioned by dissolution in alkaline aqueous solution to give a solution of uranium, neptunium, plutonium, americium and curium and a filterable solid containing nearly all of the lanthanide fission products and certain other fission products? What is the chemistry of Am/Cm/Ln in oxidative carbonate solutions? Can higher oxidation states of Am be stabilized and exploited? Conclusions: Am(VI) is kinetically stable in 0.5-2.0 M carbonate solutions for hours. Aliquat 336 in toluene has been successfully shown to extract U(VI) and Pu(VI) from carbonate solutions. (Stepanov et al 2011). Higher carbonate concentration gives lower D, SF{sub U/Eu} for = 4 in 1 M K{sub 2}CO{sub 3}. Experiments with Am(VI) were unsuccessful due to reduction by the organics. Multiple sources of reducing organics...more optimization. Reduction experiments of Am(VI) in dodecane/octanol/Aliquat 336 show that after 5 minutes of contact, only 30-40% of the Am(VI) has been reduced. Long enough to perform an extraction. Shorter contact times, lower T, and lower Aliquat 336 concentration still did not result in any significant extraction of Am. Anion exchange experiments using a strong base anion exchanger show uptake of U(VI) with minimal uptake of Nd(III). Experiments with Am(VI) indicate Am sorption with a Kd of 9 (10 minute contact) but sorption mechanism is not yet understood. SF{sub U/Nd} for = 7 and SF{sub U/Eu} for = 19 after 24 hours in 1 M K{sub 2}CO{sub 3}.

  18. Extraction and separation of thorium(IV) from lanthanides(III) with room-temperature ionic liquids containing primary amine N{sub 1923}

    SciTech Connect

    Zuo, Y.; Chen, J.; Bai, Y.; Li, D.Q.

    2008-07-01

    The extraction behavior of Th(IV) by primary amine N{sub 1923} in imidazolium-based ionic liquid namely 1-octyl-3-methylimidazolium hexafluorophosphate (N{sub 1923}/IL) was studied in this paper. Results showed that N{sub 1923}/IL had poorer extraction ability for Th(IV) than N{sub 1923} in n-heptane (N{sub 1923}/HEP). The separation coefficients between Th(IV) and lanthanides(III) ({beta}{sub Th/Ln}) were obtained and compared with those in the N{sub 1923}/HEP system. On this basis, we made a preliminary assessment for the possibility of using ionic liquids as solvents for the separation of Th(IV) from lanthanides(III) sulfate in a clean process. (authors)

  19. Gadolinium speciation with Tetradentate, N-donor extractants for minor actinide/lanthanide separation: an XRD, mass spectrometry and EPR study

    SciTech Connect

    Whittaker, D.M.; Sharrad, C.A.; Sproules, S.

    2013-07-01

    The hydrophobic organic molecules CyMe{sub 4}-BTPhen (1) and CyMe{sub 4}-BTBP (2) have been developed and tuned over many years to be able to separate the trivalent actinides from the trivalent lanthanides (Ln) selectively in bi-phasic solvent extraction processes for the separation of the long-lived radio-toxic minor actinides from spent nuclear fuel. The ability of these N-donor ligands to perform this separation is poorly understood, as is their speciation with the metal ions when extracted into the organic phase. Our previous work has shown Ln{sup 3+} speciation to be largely 1:2 Ln:L in nature with another small molecule, either water or nitrate, occupying a cavity between the tetradentate bound N-donor ligands. The identity of the small molecule changes across the lanthanide series, and here we continue investigations into this speciation. Complexes of these N-donor ligands with Gd{sup 3+} have been synthesised and characterised by X-ray crystallography, mass spectrometry and EPR spectroscopy. We show that the N-donor ligands have no effect on the electronic configuration of Gd{sup 3+} and that the lanthanide contraction with the steric rigidity of the N-donor ligand appears to determine the size of the cavity between the coordinated ligands. This in turn appears to control the identity of the small molecule on the ninth site in the 1:2 Gd:L species. (authors)

  20. Separation and purification of berkelium(III) from trivalent actinides and lanthanides using 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPBMP)

    SciTech Connect

    Mathur, J.N.; Khepkar, P.K.

    1983-01-01

    A solvent extraction method based on the preferential extraction of Bk(III) by 1-phenyl-3-methyl-4-benzeyl-pyrazolone-5 (HPMBP) has been devised for the separation and purification of Bk from other trivalent actinides and lanthanides. A single cycle purification of Bk(III) from most of the impurities is obtained by this method. An alternate method purification of Bk has been given using extraction chromatography with HPMBP impregnated celite columns wherein decontamination factors of approx. 10/sup 4/ are obtained from other trivalent actinides, lanthanides and inactive impurities like iron(Fe), chromium(Cr), aluminum(Al) and nickel(Ni). For Ce(III) (cerium III) a decontamination factor of approx. 60 is obtained.

  1. The Lanthanide Contraction beyond Coordination Chemistry.

    PubMed

    Ferru, Geoffroy; Reinhart, Benjamin; Bera, Mrinal K; Olvera de la Cruz, Monica; Qiao, Baofu; Ellis, Ross J

    2016-05-10

    The lanthanide contraction is conceptualized traditionally through coordination chemistry. Here we break this mold in a structural study of lanthanide ions dissolved in an amphiphilic liquid. The lanthanide contraction perturbs the weak interactions between molecular aggregates that drive mesoscale assembly and emergent behavior. The weak interactions correlate with lanthanide ion transport properties, suggesting new strategies for rare-earth separation that exploit forces outside of the coordination sphere. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Computer simulation of displacement cation exchange chromatography: separation of trivalent actinides and lanthanides

    SciTech Connect

    Forsberg, C.W.

    1980-05-01

    A first-generation mathematical model of displacement cation exchange chromatography (CES) was constructed. The model incorporated the following phenomena: diffusion of cations up and down the column, diffusion of cations from the bulk liquid to the resin surface, and equilibrium of cations between liquid and solid resin beads. A limited number of experiments with rare earths using DTPA as the separation agent were undertaken to increase the current understanding of the processes involved in cation exchange chromatography. The numerical computer program based on the mathematical model was written in FORTRAN IV for use on the IBM 360 series of computers.

  3. Secret lanthanides.

    PubMed

    Sturza, C M

    2014-09-15

    Lanthanides are a group of 15 chemical elements which, together with their salts, have come to be used in the last decade as homoeopathic remedies. The effective introduction of lanthanides and their salts into the clinical use, as homoeopathic remedies was based on the idea of Jan Scholten, MD to relate their physicochemical properties shown in the periodic table of elements to their homoeopathic potential. The lanthanides and their salts were prepared as homoeopathic remedies by Pharmacist Robert Münz.

  4. The lanthanide contraction beyond coordination chemistry

    DOE PAGES

    Ferru, Geoffroy; Reinhart, Benjamin; Bera, Mrinal K.; ...

    2016-04-06

    Lanthanide chemistry is dominated by the ‘lanthanide contraction’, which is conceptualized traditionally through coordination chemistry. Here we break this mold, presenting evidence that the lanthanide contraction manifests outside of the coordination sphere, influencing weak interactions between groups of molecules that drive mesoscale-assembly and emergent behavior in an amphiphile solution. Furthermore, changes in these weak interactions correlate with differences in lanthanide ion transport properties, suggesting new forces to leverage rare earth separation and refining. Our results show that the lanthanide contraction paradigm extends beyond the coordination sphere, influencing structure and properties usually associated with soft matter science.

  5. The lanthanide contraction beyond coordination chemistry

    SciTech Connect

    Ferru, Geoffroy; Reinhart, Benjamin; Bera, Mrinal K.; Olvera de la Cruz, Monica; Qiao, Baofu; Ellis, Ross J.

    2016-04-06

    Lanthanide chemistry is dominated by the ‘lanthanide contraction’, which is conceptualized traditionally through coordination chemistry. Here we break this mold, presenting evidence that the lanthanide contraction manifests outside of the coordination sphere, influencing weak interactions between groups of molecules that drive mesoscale-assembly and emergent behavior in an amphiphile solution. Furthermore, changes in these weak interactions correlate with differences in lanthanide ion transport properties, suggesting new forces to leverage rare earth separation and refining. Our results show that the lanthanide contraction paradigm extends beyond the coordination sphere, influencing structure and properties usually associated with soft matter science.

  6. Secret Lanthanides

    PubMed Central

    Sturza, CM

    2014-01-01

    Abstract Lanthanides are a group of 15 chemical elements which, together with their salts, have come to be used in the last decade as homoeopathic remedies. The effective introduction of lanthanides and their salts into the clinical use, as homoeopathic remedies was based on the idea of Jan Scholten, MD to relate their physicochemical properties shown in the periodic table of elements to their homoeopathic potential. The lanthanides and their salts were prepared as homoeopathic remedies by Pharmacist Robert Münz. PMID:25408760

  7. Synthesis of nano-pore samarium (III)-imprinted polymer for preconcentrative separation of samarium ions from other lanthanide ions via solid phase extraction.

    PubMed

    Shirvani-Arani, Simindokht; Ahmadi, Seyed Javad; Bahrami-Samani, Ali; Ghannadi-Maragheh, Mohammad

    2008-08-08

    A batch process was developed to separate samarium ions from some lanthanide ions by a novel solid phase which was prepared via the ion-imprinting technique. The samarium (III) ion-imprinted polymer (IIP) particles were synthesized by preparing the ternary complex of samarium ions with 5,7-dichloroquinoline-8-ol (DCQ) and 4-vinylpyridine (VP). Then, thermally copolymerization with styrene (functional monomer, STY) and divinylbenzene (cross-linking monomer, DVB) followed in the presence of 2-methoxy ethanol (porogen) and 2,2'-azobisisobutyronitrile (initiator, AIBN). The imprinted ion was removed by stirring the above particles with 50% (v/v) HCl to obtain the leached IIP particles. Moreover, control polymer (CP) particles were similarly prepared without the samarium ions. The unleached and leached IIP particles were characterized by X-ray diffraction (XRD), infra-red spectroscopy (IR), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). Finally, preconcentration and selectivity studies for samarium and the other lanthanide ions were carried out. The preconcentration of the samarium (III) traces was studied during rebinding with the leached IIP particles as a function of pH, the weight of the polymer material, the preconcentration and the elution times, the eluent volume and the aqueous phase volume. These studies indicated that the samarium (III) amount as low as 1 microg, present in 200 mL, could be preconcentrated into 25 mL of 1.0 M HCl.

  8. Transition Metal and Lanthanide Compounds.

    DTIC Science & Technology

    hexamethylbenzene niobium and tantalum derivatives; and lanthanide nitrate complexes of certain macrocyclic polyethers and the use of macrocyclic polyether columns for lanthanide separations....New research results in the following areas are briefly described: The synthesis of polyphosphines and their metal complexes including polyphosphines...with terminal methyl and neopentyl groups; reactions of polypyrazolylborates with the metal complexes C5H5Co(CO)(R(f)I(R(f)= perfluoroalkyl group

  9. Separation studies of yttrium(III) and lanthanide(III) ions with 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione and trioctylphosphine oxide using a robotic extraction system

    SciTech Connect

    Nekimken, H.L.; Smith, B.F.; Jarvinen, G.D.; Bartholdi, C.S.

    1992-07-01

    We studied the extraction of trivalent Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Er, and Lu from aqueous perchlorate solutions using a mixture of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (HBMPPT) and trioctylphosphine oxide (TOPO). The metal ion distribution coefficients (D-values) as a function of increasing lanthanide atomic number increased initially, reached a maximum value at Nd, then decreased to a nearly constant value for Gd and the later lanthanides. The D-values vary slightly across the lanthanide series, the maximum difference being a factor of 14 between La and Nd. Analysis of slopes of plots of log D versus pH, log [HBMPPT], and log [TOPO] indicated that the stoichiometries of the extraction complexes varied across the lanthanide series showing a decrease in the number of HBMPPT (and/or BMPPT) units and an increase in the number of TOPO molecules involved in the major extraction species. This extraction system can provide a good way to separate the trivalent actinides from the trivalent lanthanides. 21 refs., 2 figs., 3 tabs.

  10. ITP of lanthanides in microfluidic PMMA chip.

    PubMed

    Cong, Yongzheng; Bottenus, Danny; Liu, Bingwen; Clark, Sue B; Ivory, Cornelius F

    2014-03-01

    An ITP separation of eight lanthanides on a serpentine PMMA microchip with a tee junction and a 230-mm-long serpentine channel is described. The cover of the PMMA chip is 175 μm thick so that a C(4) D in microchip mode can be used to detect the lanthanides as they migrate through the microchannel. Acetate and α-hydroxyisobutyric acid are used as complexing agents to increase the electrophoretic mobility difference between the lanthanides. Eight lanthanides are concentrated within ∼ 6 min by ITP in the microchip using 10 mM ammonium acetate at pH 4.5 as the leading electrolyte and 10 mM acetic acid at ∼ pH 3.0 as the terminating electrolyte. In addition, a 2D numerical simulation of the lanthanides undergoing ITP in the microchip is compared with experimental results using COMSOL Multiphysics v4.3a.

  11. Separation of actinide(III) from lanthanide(III) by thermo-sensitive gel co-polymerized with TPPEN derivatives

    SciTech Connect

    Takeshita, Kenji; Fugate, Glenn; Matsumura, Tatsuro; Nakano, Yoshio; Mori, Atsunori; Fukuoka, Sachio

    2007-07-01

    Extraction separation of Am(III) and Eu(III) was examined by the thermal-swing extraction technique using a thermo-sensitive gel, poly-N-isopropyl-acrylamide (NIPA) co-polymerized with a TPEN derivative, N,N,N',N'- tetrakis(4-propenyl-oxy-2-pyridyl-methyl)ethylenediamine (TPPEN). The separation of Am(III) from Eu(III) was observed in the swollen state of gel (5 deg. C) and the separation factor of Am(III) was evaluated as about 18 at pH 5.2. More than 90% of Am(III) extracted into the gel was released by the volume phase transition of gel from the swollen state (5 deg. C) to the shrunken one (40 deg. C). The repetition test for the thermal swing extraction of a soft metal ion, Cd(II), which was used as a substitute of Am(III), was carried out and the extraction and release of Cd(II) were repeated three times stably under the thermal-swing operation between 5 deg. C and 40 deg. C. The radiation effect of gel on the extraction of Am and Eu was tested by the irradiation of {gamma}-ray (10 kGy) and the long-term adsorption of {alpha}-emitter ({sup 244}Cm). The TPPEN-NIPA gel sustained no damage by these radiation tests. These results suggest that the thermal-swing extraction technique is applicable to the MA partitioning process indispensable for the establishment of P and T technology. (authors)

  12. Understanding the complexation of Eu(3+) with potential ligands used for preferential separation of lanthanides and actinides in various stages of nuclear fuel cycle: A luminescence investigation.

    PubMed

    Sengupta, Arijit; Kadam, R M

    2017-02-15

    A systematic photoluminescence based investigation was carried out to understand the complexation of Eu(3+) with different ligands (TBP: tri-n-butyl phosphate, DHOA: di-n-hexyl octanamide, Cyanex 923: tri-n-alkyl phosphine oxide and Cyanex 272: Bis (2,4,4 trimethyl) pentyl phosphinic acid) used for preferential separation of lanthanides and actinides in various stages of nuclear fuel cycle. In case of TBP and DHOA complexes, 3 ligand molecules coordinated in monodentate fashion and 3 nitrate ion in bidentate fashion to Eu(3+) to satisfy the 9 coordination of Eu. In case of Cyanex 923 and Cyanex 272 complexes, 3 ligand molecules, 3 nitrate ion and 3 water molecules coordinated to Eu(3+) in monodentate fashion. The Eu complexes of TBP and DHOA were found to have D3h local symmetry while that for Cyanex 923 and Cyanex 272 were C3h. Judd-Ofelt analysis of these systems revealed that the covalency of EuO bond followed the trend DHOA>TBP>Cyanex 272>Cyanex 923. Different photophysical properties like radiative and non-radiative life time, branching ratio for different transitions, magnetic and electric dipole moment transition probabilities and quantum efficiency were also evaluated and compared for these systems. The magnetic dipole transition probability was found to be almost independent of ligand field perturbation while electric dipole transition probability for (5)D0-(7)F2 transition was found to be hypersensitive with ligand field with a trend DHOA>TBP>Cyanex 272>Cyanex 923. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Understanding the complexation of Eu3 + with potential ligands used for preferential separation of lanthanides and actinides in various stages of nuclear fuel cycle: A luminescence investigation

    NASA Astrophysics Data System (ADS)

    Sengupta, Arijit; Kadam, R. M.

    2017-02-01

    A systematic photoluminescence based investigation was carried out to understand the complexation of Eu3 + with different ligands (TBP: tri-n-butyl phosphate, DHOA: di-n-hexyl octanamide, Cyanex 923: tri-n-alkyl phosphine oxide and Cyanex 272: Bis (2,4,4 trimethyl) pentyl phosphinic acid) used for preferential separation of lanthanides and actinides in various stages of nuclear fuel cycle. In case of TBP and DHOA complexes, 3 ligand molecules coordinated in monodentate fashion and 3 nitrate ion in bidentate fashion to Eu3 + to satisfy the 9 coordination of Eu. In case of Cyanex 923 and Cyanex 272 complexes, 3 ligand molecules, 3 nitrate ion and 3 water molecules coordinated to Eu3 + in monodentate fashion. The Eu complexes of TBP and DHOA were found to have D3h local symmetry while that for Cyanex 923 and Cyanex 272 were C3h. Judd-Ofelt analysis of these systems revealed that the covalency of Eusbnd O bond followed the trend DHOA > TBP > Cyanex 272 > Cyanex 923. Different photophysical properties like radiative and non-radiative life time, branching ratio for different transitions, magnetic and electric dipole moment transition probabilities and quantum efficiency were also evaluated and compared for these systems. The magnetic dipole transition probability was found to be almost independent of ligand field perturbation while electric dipole transition probability for 5D0-7F2 transition was found to be hypersensitive with ligand field with a trend DHOA > TBP > Cyanex 272 > Cyanex 923. Supplementary Table 2: Determination of inner sphere water molecules from the different empirical formulae reported in the literature.

  14. Studies on the extraction and separation of lanthanide ions with a synergistic extraction system combined with 1,4,10,13-tetrathia-7,16-diazacyclooctadecane and lauric acid.

    PubMed

    Masuda, Y; Zhang, Y; Yan, C; Li, B

    1998-05-01

    1,4,10,13-Tetrathia-7,16-diazacyclooctadecane (ATCO) and its binary extraction system containing lauric acid were studied extensively as extractants of lanthanide (M(3+)=La(3+), Ce(3+), Pr(3+), Nd(3+), Sm(3+), Eu(3+) and Gd(3+)) in 1,2-dichloroethane solution. The percentage extraction of Ce(3+) and Eu(3+) by ATCO were only measured to be less than 5% during a pH range 5.5-7.0 in NCS(-), ClO(4)(-) and PF(6)(-) mediums respectively, which indicates that ATCO alone has very low extractability to lanthanide, due to the bad fit of metal ions in its cavity. However, when lauric acid was added to the ATCO organic phase, because of forming rare earth adduct, the percentage extraction for lanthanide until Gd(3+) was enhanced in the binary system in comparison with that did not adopt the lauric acid within the pH range 6-7. The extraction species and extraction equilibrium constants logK(ex) were found to be CeLA(3)3HA, -8.5, EuLA(3)HA, -6.7, and GdLA(2)NO(3)2HA, -1.8, respectively. The separation factor between Eu(3+) and Ce(3+) was found to be 2.5, however, poor selectivity for lanthanide was observed. From Gd(3+) to Er(3+) and Lu(3+), the synergistic effect of the binary extraction system decreases with increasing atomic number. For gadolinium, the synergistic effect becomes much weaker than that of Ce(3+) and Eu(3+), no synergistic effect existed for erbium and lutetium. Thermodynamic data for synergistic solvent extraction are also reported in this paper. The order of organic phase stability constants of the extraction species is Sm (5.8)>Pr (5.7)>Eu (5.6)>Ce (5.3)>La (5.2)>Gd (2.8).

  15. Lanthanide-containing polyimides

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St. Clair, Anne K.

    1987-01-01

    The preparation of a variety of lanthanide-containing polyimide films is described, and results of their characterization are presented. The properties investigated include the glass transition temperature, thermooxidative stability, magnetic susceptibility, and electrical conductivity of the polymer. Films containing lanthanide chlorides, fluorides, and sulfides are flexible, but those containing lanthanide nitrates are extremely brittle. The addition of lanthanide acetates and acetylacetonates caused immediate gelation of two of the synthesis-mixture ingredients. It was found that, in general, the addition of lanthanide to the polyimide increases the density and glass transition temperature of the polymer but slightly decreases the thermooxidative stability.

  16. Lanthanide-containing polyimides

    NASA Technical Reports Server (NTRS)

    Stoakley, D. M.; St. Clair, Anne K.

    1987-01-01

    The preparation of a variety of lanthanide-containing polyimide films is described, and results of their characterization are presented. The properties investigated include the glass transition temperature, thermooxidative stability, magnetic susceptibility, and electrical conductivity of the polymer. Films containing lanthanide chlorides, fluorides, and sulfides are flexible, but those containing lanthanide nitrates are extremely brittle. The addition of lanthanide acetates and acetylacetonates caused immediate gelation of two of the synthesis-mixture ingredients. It was found that, in general, the addition of lanthanide to the polyimide increases the density and glass transition temperature of the polymer but slightly decreases the thermooxidative stability.

  17. Improved method for extracting lanthanides and actinides from acid solutions

    DOEpatents

    Horwitz, E.P.; Kalina, D.G.; Kaplan, L.; Mason, G.W.

    1983-07-26

    A process for the recovery of actinide and lanthanide values from aqueous acidic solutions uses a new series of neutral bi-functional extractants, the alkyl(phenyl)-N,N-dialkylcarbamoylmethylphosphine oxides. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high-level nuclear reprocessing waste solutions.

  18. One-dimensional simulation of lanthanide isotachophoresis using COMSOL.

    PubMed

    Dixon, Derek R; Clark, Sue B; Ivory, Cornelius F

    2012-03-01

    Electrokinetic separations can be used to quickly separate rare earth metals to determine their forensic signature. In this work, we simulate the concentration and separation of trivalent lanthanide cations by isotachophoresis. A one-dimensional simulation is developed using COMSOL v4.0a, a commercial finite element simulator, to represent the isotachophoretic separation of three lanthanides: lanthanum, terbium, and lutetium. The binding ligand chosen for complexation with the lanthanides is α-hydroxyisobutyric acid (HIBA) and the buffer system includes acetate, which also complexes with the lanthanides. The complexes formed between the three lanthanides, HIBA, and acetate are all considered in the simulation. We observe that the presence of only lanthanide:HIBA complexes in a buffer system with 10 mM HIBA causes the slowest lanthanide peak (lutetium) to split from the other analytes. The addition of lanthanide:acetate complexes into the simulation of the same buffer system eliminates this splitting. Decreasing the concentration of HIBA in the buffer to 7 mM causes the analyte stack to migrate faster through the capillary.

  19. Ionization Energies of Lanthanides

    ERIC Educational Resources Information Center

    Lang, Peter F.; Smith, Barry C.

    2010-01-01

    This article describes how data are used to analyze the pattern of ionization energies of the lanthanide elements. Different observed pathways of ionization between different ground states are discussed, and the effects of pairing, exchange, and orbital interactions on ionization energies of the lanthanides are evaluated. When all the above…

  20. Ionization Energies of Lanthanides

    ERIC Educational Resources Information Center

    Lang, Peter F.; Smith, Barry C.

    2010-01-01

    This article describes how data are used to analyze the pattern of ionization energies of the lanthanide elements. Different observed pathways of ionization between different ground states are discussed, and the effects of pairing, exchange, and orbital interactions on ionization energies of the lanthanides are evaluated. When all the above…

  1. The Lanthanide Contraction Revisited

    SciTech Connect

    Seitz, Michael; Oliver, Allen G.; Raymond, Kenneth N.

    2007-04-19

    A complete, isostructural series of lanthanide complexes (except Pm) with the ligand TREN-1,2-HOIQO has been synthesized and structurally characterized by means of single-crystal X-ray analysis. All complexes are 1D-polymeric species in the solid state, with the lanthanide being in an eight-coordinate, distorted trigonal-dodecahedral environment with a donor set of eight unique oxygen atoms. This series constitutes the first complete set of isostructural lanthanide complexes with a ligand of denticity greater than two. The geometric arrangement of the chelating moieties slightly deviates across the lanthanide series, as analyzed by a shape parameter metric based on the comparison of the dihedral angles along all edges of the coordination polyhedron. The apparent lanthanide contraction in the individual Ln-O bond lengths deviates considerably from the expected quadratic decrease that was found previously in a number of complexes with ligands of low denticity. The sum of all bond lengths around the trivalent metal cation, however, is more regular, showing an almost ideal quadratic behavior across the entire series. The quadratic nature of the lanthanide contraction is derived theoretically from Slater's model for the calculation of ionic radii. In addition, the sum of all distances along the edges of the coordination polyhedron show exactly the same quadratic dependency as the Ln-X bond lengths. The universal validity of this coordination sphere contraction, concomitant with the quadratic decrease in Ln-X bond lengths, was confirmed by reexamination of four other, previously published, almost complete series of lanthanide complexes. Due to the importance of multidentate ligands for the chelation of rare-earth metals, this result provides a significant advance for the prediction and rationalization of the geometric features of the corresponding lanthanide complexes, with great potential impact for all aspects of lanthanide coordination.

  2. Ionic liquids as a novel solvent for lanthanide extraction.

    PubMed

    Nakashima, Kazunori; Kubota, Fukiko; Maruyama, Tatsuo; Goto, Masahiro

    2003-08-01

    Octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) dissolved in an ionic liquids, 1-butyl-3-methyl-imidazolium hexafluorophosphate, greatly enhances extractability and selectivity of lanthanide cations compared to that dissolved in conventional organic solvents; further, the recovery of lanthanides extracted into ionic liquids can be accomplished using several stripping solutions containing complexing agents. The possibility of utilizing ionic liquids as novel separation media in an industrial liquid-liquid extraction process was demonstrated.

  3. Luminescent macrocyclic lanthanide complexes

    DOEpatents

    Raymond, Kenneth N; Corneillie, Todd M; Xu, Jide

    2014-05-20

    The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

  4. Luminescent macrocyclic lanthanide complexes

    DOEpatents

    Raymond, Kenneth N [Berkeley, CA; Corneillie, Todd M [Campbell, CA; Xu, Jide [Berkeley, CA

    2012-05-08

    The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

  5. Preparation and study of binary compounds of actinides and lanthanides. X. Separation of the TPE and platinum (palladium) by extraction chromatography

    SciTech Connect

    Lebedeva, L.S.; Nezgovorov, N.Yu.; Radchenko, V.M.; Vasil'ev, V.Ya.

    1988-03-01

    The possibility of separation of TPE from compounds bearing platinum or palladium by extraction chromatography using D2EHPA has been explored. It has been found that TPE loss is practically nil. The coefficient of TPE isolation from platinum metals is above 10/sup 3/. It has been shown that macroamounts of platinum can be removed preliminarily by its precipitation as the sparingly soluble salt (NH/sub 4/)/sub 2/PtCl/sub 6/ without a significant loss of TPE. The technique can also be applied for regeneration of platinum group elements from compounds with TPE. The purity of regenerated platinum (palladium) is enough for repeated use as components of compounds with TPE.

  6. The Partitioning of Americium and the Lanthanides Using Tetrabutyldiglycolamide (TBDGA) in Octanol and in Ionic Liquid Solution

    SciTech Connect

    M.E. Mincher; D.L. Quach; Y.J. Liao; B.J. Mincher; C.M. Wai

    2012-11-01

    Separations among the lanthanides and the separation of Am from the lanthanides remain challenging, and research in this area continues to expand. The separation of adjacent lanthanides is of interest to high-tech industries because individual lanthanides have specialized uses and are in short supply. In nuclear fuel cycle applications Am would be incorporated into fast reactor fuels, yet the lanthanides are not desired. In this work the diamide N,N,N',N'-tetrabutyldiglycolamide (TBDGA) was investigated as a ligand for lanthanide and Am solvent extraction in both molecular and room temperature ionic liquid (RTIL) diluents. The RTIL [C4MIM][Tf2N-] showed very high extraction efficiency for these trivalent metals from low nitric acid concentrations, while the molecular diluent 1-octanol showed high extraction efficiency at high acid concentrations. This was attributed to the extraction of ionic nitrate complexes by the RTIL, whereas 1-octanol extracted neutral nitrate complexes. TBDGA in RTIL did not provide adequate separation factors for Am/lanthanide partitioning, but 1-octanol did show reasonable separation possibilities. Lanthanide intergroup separations appeared to be feasible in both diluents, but with higher separation factors from 1-octanol.

  7. Aromatic triamide-lanthanide complexes

    DOEpatents

    Raymond, Kenneth N; Petoud, Stephane; Xu, Jide

    2013-10-08

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  8. Photodetachment of Lanthanide Oxide Anions

    NASA Astrophysics Data System (ADS)

    Covington, A. M.; Emmons, E. D.; Kraus, R. G.; Thompson, J. S.; Calabrese, D.; Davis, V. T.

    2007-06-01

    Laser photodetached electron spectroscopy (LPES) has been used to study the structure and collision properties of lanthanide oxide anions including LaOn^- and CeOn^-. Preliminary photoelectron spectra from these anions will be presented along with ion beam production data from these and other lanthanide oxide anions.

  9. Method for extracting lanthanides and actinides from acid solutions

    DOEpatents

    Horwitz, E. Philip; Kalina, Dale G.; Kaplan, Louis; Mason, George W.

    1985-01-01

    A process for the recovery of actinide and lanthanide values from aqueous acidic solutions with an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high level nuclear reprocessing waste solutions.

  10. Characterization and thermogravimetric analysis of lanthanide hexafluoroacetylacetone chelates.

    PubMed

    Shahbazi, Shayan; Stratz, S Adam; Auxier, John D; Hanson, Daniel E; Marsh, Matthew L; Hall, Howard L

    2017-01-01

    This work reports the thermodynamic characterizations of organometallic species as a vehicle for the rapid separation of volatile nuclear fission products via gas chromatography due to differences in adsorption enthalpy. Because adsorption and sublimation thermodynamics are linearly correlated, there is considerable motivation to determine sublimation enthalpies. A method of isothermal thermogravimetric analysis, TGA-MS and melting point analysis are employed on thirteen lanthanide 1,1,1,5,5,5-hexafluoroacetylacetone complexes to determine sublimation enthalpies. An empirical correlation is used to estimate adsorption enthalpies of lanthanide complexes on a quartz column from the sublimation data. Additionally, four chelates are characterized by SC-XRD, elemental analysis, FTIR and NMR.

  11. Lanthanide contraction effect on crystal structures of lanthanide coordination polymers with cyclohexanocucurbit[6]uril ligand

    NASA Astrophysics Data System (ADS)

    Zheng, Li-Mei; Liu, Jing-Xin

    2017-01-01

    A series of compounds based on the macrocyclic ligand cyclohexanocucurbit[6]uril (Cy6Q[6]) with formulas {Ln(H2O)6Cy6Q[6]}·2(CdCl4)·H3O·xH2O [isomorphous with Ln=La (1), Ce (2), Pr (3) and Nd (4), x=11 (1), 11 (2), 10 (3) and 11 (4)], {Sm(H2O)5Cy6Q[6]}·2(CdCl4)·H3O·10H2O (5) and {Ln(H2O)5(NO3)@Cy6Q[6]}·2(CdCl4)·2H3O·xH2O [isomorphous with Ln=Gd (6), Tb (7) and Dy (8), x=8 (6), 6 (7) and 6 (8)], have been successfully synthesized by the self-assembly of Cy6Q[6] with the corresponding lanthanide nitrate under hydrochloric acid aqueous solution in the presence of CdCl2. Single-crystal X-ray diffraction analyses revealed that compounds 1-8 all crystallize in monoclinic space group P21/c, and display 1D coordination polymer structures. The lanthanide contraction effect on the structures of 1-8 has also been investigated and discussed in detail. In contrast, the reaction of Cy6Q[6] with the Ho(NO)3, Tm(NO)3, Yb(NO)3 under the same conditions resulted in the compounds 9-11 with formulas Cy6Q[6]·2(CdCl4)·2H3O·xH2O [isomorphous with x=10 (9), 10 (10), and 9 (11)], in which no lanthanide cations are observed. The structural difference of these compounds indicates that the Cy6Q[6] may be used in the separation of lanthanide cations.

  12. Calibration beads containing luminescent lanthanide ion complexes

    EPA Science Inventory

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  13. Calibration beads containing luminescent lanthanide ion complexes

    EPA Science Inventory

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  14. Key features of the Talspeak and similar trivalent actinide-lanthanide partitioning processes

    SciTech Connect

    Nash, Kenneth L.

    2008-07-01

    As closing of the nuclear-fuel cycle via the suite of UREX processes under development in the U.S. progresses, the Trivalent Actinide-Lanthanide Separation by Phosphorus Extractants and Aqueous Komplexants (TALSPEAK) process has been selected as the baseline process for partition of trivalent actinides away from fission-product lanthanides. In this report, selected features of the chemistry of the TALSPEAK process and the limited parallel information on other TALSPEAK-like processes are discussed. (author)

  15. New types of lanthanide complexes

    SciTech Connect

    Kahwa, I.A.K.

    1986-01-01

    Three new types of lanthanide (Ln) complexes, namely, the first examples of homodinuclear macrocyclic lanthanide complexes, novel binary and ternary gaseous polyatomic lanthanide oxides and new lanthanide oxalato complexes are described in chapters one, two and three respectively. The homodinuclear complexes are 2:2 condensation products of 2,6-diformyl-p-cresol and triethylenetetramine templated by Ln(NO/sub 3/)/sub 3/ and Ln(ClO/sub 4/)/sub 3/. The complexes are dimorphic, and are off-white (the more stable form) when they are obtained from dilute solutions and orange if they arise from more concentrated reactants. The complexes were characterized by elemental analysis, fast atom bombardment mass spectrometry (FAB MS), electronic absorption and IR spectroscopy, thermogravimetry along with preliminary spectroscopic studies using electron paramagnetic resonance, magnetic susceptibility and luminescence. The orange complexes exhibit more antiferromagnetic exchange interactions, low Ln/sup 3 +/magnetic moments and multi-exponential luminescence decay kinetics, whereas the off-white complexes show single exponential luminescence decay and free ion magnetic moments. At low temperatures and in presence of excess triethylenetetramine, solvated light lanthanide mononuclear complexes of a 1:1 acyclic Schiff base acetal were isolated and the structure of one of these was confirmed by single crystal x-ray diffraction crystallography.

  16. Lanthanides: New life metals?

    PubMed

    Chistoserdova, Ludmila

    2016-08-01

    Lanthanides (Ln(3+)) that are Rare Earth Elements, until recently thought to be biologically inert, have recently emerged as essential metals for activity and expression of a special type of methanol dehydrogenase, XoxF. As XoxF enzyme homologs are encoded in a wide variety of microbes, including microbes active in important environmental processes such as methane and methanol metabolism, Ln(3+) may represent some of the key biogeochemical drivers in cycling of carbon and other elements. However, significant gaps in understanding the role of Ln(3+) in biological systems remain as the functions of most of the proteins potentially dependent of Ln(3+) and their roles in specific metabolic networks/respective biogeochemical cycles remain unknown. Moreover, enzymes dependent on Ln(3+) but not related to XoxF enzymes may exist, and these so far have not been recognized. Through connecting the recently uncovered genetic divergence and phylogenetic distribution of XoxF-like enzymes and through elucidation of their activities, metal and substrate specificities, along with the biological contexts of respective biochemical pathways, most parsimonious scenarios for their evolution could be uncovered. Generation of such data will firmly establish the role of Ln(3+) in the biochemistry of Life inhabiting this planet.

  17. Biological toxicity of lanthanide elements on algae.

    PubMed

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Selective extraction of trivalent actinides from lanthanides with dithiophosphinic acids and tributylphosphate

    SciTech Connect

    Jarvinen, G.; Barrans, R.; Schroeder, N.; Wade, K.; Jones, M.; Smith, B.F.; Mills, J.; Howard, G.; Freiser, H.; Muralidharan, S.

    1995-01-01

    A variety of chemical systems have been developed to separate trivalent actinides from lanthanides based on the slightly stronger complexation of the trivalent actinides with ligands that contain soft donor atoms. The greater stability of the actinide complexes in these systems has often been attributed to a slightly greater covalent bonding component for the actinide ions relative to the lanthanide ions. The authors have investigated several synergistic extraction systems that use ligands with a combination of oxygen and sulfur donor atoms that achieve a good group separation of the trivalent actinides and lanthanides. For example, the combination of dicyclohexyldithiophosphinic acid and tributylphosphate has shown separation factors of up to 800 for americium over europium in a single extraction stage. Such systems could find application in advanced partitioning schemes for nuclear waste.

  19. Nonequivalent lanthanide defects: Energy level modeling

    NASA Astrophysics Data System (ADS)

    Joos, Jonas J.; Poelman, Dirk; Smet, Philippe F.

    2016-11-01

    Empirical charge-state transition level schemes are popular tools to model the properties of lanthanide-doped materials and their construction has become standard practice. Typically, it is implicitly assumed that all lanthanide ions form isostructural defects. However, in practice, multiple nonequivalent defects related to the same lanthanide can occur or different lanthanides can even incorporate in different ways. The consequences of these complications on the impurity energy levels are discussed in this article. It seems that small structural differences around the lanthanide dopant can give rise to important spectral differences in its emission. These are not always clearly reproduced by the charge-state transition level schemes. Improvements to the existing procedure are suggested and applied to the lanthanide ions in the well-studied host crystals SrAl2O4, Sr2Si5N8 and SrGa2S4.

  20. Strategy for photostable proximity bioassays using lanthanides

    PubMed Central

    Haushalter, Jeanne P.; Faris, Gregory W.

    2011-01-01

    We report initial findings for research aimed at creating photostable lanthanide chelate reporters for proximity assays. These reporters take advantage of the nanometer scale distance dependence of fluorescence enhancement for molecules in the vicinity of noble metal nanoparticles and also capitalize on some unique properties of lanthanide chelates. This approach promises to lead to proximity assays that do not suffer from photobleaching and offer very high on/off enhancement ratios. Results for lanthanide chelates on silver island films and in colloidal suspensions are reported. Enhancement factors range from 1 to 2 orders of magnitude, with larger enhancements for strongly quenched lanthanides. PMID:17356638

  1. Lanthanide-based luminescence biolabelling.

    PubMed

    Sy, Mohamadou; Nonat, Aline; Hildebrandt, Niko; Charbonnière, Loïc J

    2016-04-14

    Luminescent lanthanide complexes display unrivalled spectroscopic properties, which place them in a special category in the luminescent toolbox. Their long-lived line-like emission spectra are the cornerstones of numerous analytical applications ranging from ultrasensitive homogeneous fluoroimmunoassays to the study of molecular interactions in living cells with multiplexed microscopy. However, achieving such minor miracles is a result of years of synthetic efforts and spectroscopic studies to understand and gather all the necessary requirements for the labels to be efficient. This feature article intends to survey these criteria and to discuss some of the most important examples reported in the literature, before explaining in detail some of the applications of luminescent lanthanide labels to bioanalysis and luminescence microscopy. Finally, the emphasis will be put on some recent applications that hold great potential for future biosensing.

  2. Fracture-resistant lanthanide scintillators

    DOEpatents

    Doty, F Patrick [Livermore, CA

    2011-01-04

    Lanthanide halide alloys have recently enabled scintillating gamma ray spectrometers comparable to room temperature semiconductors (<3% FWHM energy resolutions at 662 keV). However brittle fracture of these materials upon cooling hinders the growth of large volume crystals. Efforts to improve the strength through non-lanthanide alloy substitution, while preserving scintillation, have been demonstrated. Isovalent alloys having nominal compositions of comprising Al, Ga, Sc, Y, and In dopants as well as aliovalent alloys comprising Ca, Sr, Zr, Hf, Zn, and Pb dopants were prepared. All of these alloys exhibit bright fluorescence under UV excitation, with varying shifts in the spectral peaks and intensities relative to pure CeBr.sub.3. Further, these alloys scintillate when coupled to a photomultiplier tube (PMT) and exposed to .sup.137Cs gamma rays.

  3. Magnetic ordering in lanthanide-molybdenum oxide nanostructure arrays

    NASA Astrophysics Data System (ADS)

    Hagmann, Joseph; Le, Son; Schneemeyer, Lynn; Olsen, Patti; Besara, Tiglet; Siegrist, Theo; Seiler, David; Richter, Curt

    Reduced ternary molybdenum oxides, or bronzes, offer an attractive materials platform to study a wide variety of remarkable physical phenomena in a system with highly varied structural chemistry. Interesting electronic behaviors, such as superconductivity, charge density waves, and magnetism, in these materials arise from the strong hybridization of the 4d states of high-valent Mo with O p orbitals. We investigate a series of molybdenum bronze materials with Lanthanide-Mo16O44 composition that can be described as a three-dimensional array of metallic Mo8O32 nanostructures computationally predicted to contain a single charge with spin 1/2 separated by insulating MoO4 tetrahedra. This study reveals novel magnetic ordering in Lanthanide-Mo16O44 systems arising, not from the inclusion of magnetic elements, but rather from an exchange interaction between cubic Mo8O32 units. Here, we report the magnetometry and transport behaviors of a series of Lanthanide-Mo16O44 materials, emphasizing an observed low-temperature phase transition signifying the onset of antiferromagnetic ordering between the arrayed nanostructures, and relate these behaviors to their experimentally-characterized structures to reveal the intriguing physics of these correlated electronic systems.

  4. Lanthanide corroles: a new class of macrocyclic lanthanide complexes.

    PubMed

    Buckley, Heather L; Anstey, Mitchell R; Gryko, Daniel T; Arnold, John

    2013-04-18

    The first examples of lanthanide corroles are prepared by two synthetic routes. (Mes2(p-OMePh)corrole)La·4.5DME (1·4.5DME) and (Mes2(p-OMePh)corrole)Tb·4DME (2·4DME) are prepared from the free base corrole and Ln((NSiMe3)2)3, while (Mes2(p-OMePh)corrole)Gd·TACNMe3 (3·TACNMe3) is prepared by metathesis of the recently reported Li3 corrole and GdCl3.

  5. Retention studies on uranium, thorium and lanthanides with amide modified reverse phase support and its applications.

    PubMed

    Raju, Ch Siva Kesava; Subramanian, M S; Sivaraman, N; Srinivasan, T G; Vasudeva Rao, P R

    2007-07-13

    The retention behaviour of uranium and thorium was investigated on modified reverse phase supports using 3-oxo-pentanedioicacid bis-[bis-(2-ethyl-hexyl)-amide (OPAEHA), 3-oxo-pentanedioicacid bis diisobutyl amide (OPAIBA) and bis-2-ethylhexyl succinamic acid (BEHSA). alpha-Hydroxy isobutyric acid (alpha-HIBA) was employed as the complexing reagent for elution. Elution profiles of uranium and thorium were studied as a function of the modifier concentration, mobile phase composition and its pH. Based on these investigations, a novel high performance liquid chromatography (HPLC) based separation technique was developed using BEHSA modified support for the isolation and quantitative determination of lanthanides as a group in uranium matrix. Hundreds of samples obtained from pyrochemical reprocessing of molten salts containing lanthanides in uranium matrix (e.g. 1:20,000) were separated and determined within 7 min using the coated support. The advantage of the present HPLC technique lies in the simultaneous separation and assay of total lanthanides and uranium whereas other analytical methods necessitate the separation of uranium matrix prior to lanthanide assay.

  6. Lateral diffusion contributes to FRET from lanthanide-tagged membrane proteins.

    PubMed

    Lan, Tien-Hung; Wu, Guangyu; Lambert, Nevin A

    2015-08-14

    Diffusion can enhance Förster resonance energy transfer (FRET) when donors or acceptors diffuse distances that are similar to the distances separating them during the donor's excited state lifetime. Lanthanide donors remain in the excited state for milliseconds, which makes them useful for time-resolved FRET applications but also allows time for diffusion to enhance energy transfer. Here we show that diffusion dramatically enhances FRET between membrane proteins labeled with lanthanide donors. This phenomenon complicates interpretation of experiments that use long-lived donors to infer association or proximity of mobile membrane proteins, but also offers a method of monitoring diffusion in membrane domains in real time in living cells.

  7. Method for extracting lanthanides and actinides from acid solutions by modification of Purex solvent

    DOEpatents

    Horwitz, E.P.; Kalina, D.G.

    1984-05-21

    A process has been developed for the extraction of multivalent lanthanide and actinide values from acidic waste solutions, and for the separation of these values from fission product and other values, which utilizes a new series of neutral bi-functional extractants, the alkyl(phenyl)-N, N-dialkylcarbamoylmethylphosphine oxides, in combination with a phase modifier to form an extraction solution. The addition of the extractant to the Purex process extractant, tri-n-butylphosphate in normal paraffin hydrocarbon diluent, will permit the extraction of multivalent lanthanide and actinide values from 0.1 to 12.0 molar acid solutions.

  8. Lateral diffusion contributes to FRET from lanthanide-tagged membrane proteins

    SciTech Connect

    Lan, Tien-Hung; Wu, Guangyu; Lambert, Nevin A.

    2015-08-14

    Diffusion can enhance Förster resonance energy transfer (FRET) when donors or acceptors diffuse distances that are similar to the distances separating them during the donor's excited state lifetime. Lanthanide donors remain in the excited state for milliseconds, which makes them useful for time-resolved FRET applications but also allows time for diffusion to enhance energy transfer. Here we show that diffusion dramatically enhances FRET between membrane proteins labeled with lanthanide donors. This phenomenon complicates interpretation of experiments that use long-lived donors to infer association or proximity of mobile membrane proteins, but also offers a method of monitoring diffusion in membrane domains in real time in living cells. - Highlights: • Diffusion enhances TR-FRET from membrane proteins labeled with lanthanide donors. • Diffusion-dependent FRET can overshadow FRET due to oligomerization or clustering. • FRET studies using lanthanide-tagged membrane proteins should consider diffusion. • FRET from lanthanide donors can be used to monitor membrane protein diffusion.

  9. Role of the antenna in tissue selective probes built of lanthanide-organic chelates.

    PubMed

    Hess, B Andes; Kedziorski, A; Smentek, L; Bornhop, D J

    2008-03-20

    The role of the antenna in the process of the host sensitized luminescence of the DOTA cage coordinated with the Eu ion is investigated. The analysis of the optimal geometries of DOTA modified by several antennas is based on the results of density functional theory (DFT) calculations. The physical environment of the luminescence center (the lanthanide ion) is illustrated by charge density maps and described by the values of the crystal field parameters directly evaluated. The conclusions derived from this theoretical analysis support earlier observations that antennas attached to the cage play the sole role of harvesting and transferring the energy to the lanthanide ion, whereas the cage perturbs the symmetry of the environment of the lanthanide ion, giving rise to the sensitized luminescence. The implications of the separation of the two parts of the organic chelate, cage and antenna, are discussed within the theoretical models of the energy transfer and of forced f <--> f electric dipole transitions.

  10. Lanthanides in the frame of Molecular Magnetism

    NASA Astrophysics Data System (ADS)

    Gatteschi, D.

    2014-07-01

    Molecular magnetism is producing new types of materials which cover up to date aspects of basic science together with possible applications. This article highlights recent results from the point of view of lanthanides which are now intensively used to produce single molecule magnets, single chain and single ion magnets. After a short introduction reminding the main steps of development of molecular magnetism, the basic properties of lanthanides will be covered highlighting important features which are enhanced by the electronic structure of lanthanides, like spin frustration and chirality, anisotropy and non collinear axes in zero and one dimensional materials. A paragraph of conclusions will discuss what has been done and theperspectives to be expected.

  11. The use of Diphonix{sup {trademark}} ion exchange resin as a preconcentration step for the lanthanides and actinides in analytical applications

    SciTech Connect

    Rollins, A.N.; Thakkar, A.H.; Fern, M.J.

    1995-12-01

    Diphonix ion exchange resin is a chelating ion exchange resin containing sulfonic and gemdiphosphonic acid groups. This resin has a high specificity for the lanthanides and actinides, especially at acidities below pH = 3. Currently, we are investigating new ways to use Diphonix resin as a preconcentration step to separate the lanthanides and actinides from interfering elements present in a variety of environmental matrices. Once the lanthanides and actinides have been separated from the interfering matrix constituents, the elements are removed from the resin and passed through subsequent separation schemes. This presentation will outline the use of Diphonix resin with a variety of problem matrices, and demonstrate its usefulness for analysis of the lanthanides and actinides.

  12. SEPARATION OF RARE EARTHS BY SOLVENT EXTRACTION

    DOEpatents

    Peppard, D.F.; Mason, G.W.

    1960-10-11

    A process is given for separating lanthanide rare earths from each other from an aqueous mineral acid solution, e.g., hydrochloric or nitric acid of a concentration of above 3 M, preferably 12 to 16 M, by extraction with a water- immiscible alkyl phosphate, such as tributyl phosphate or a mixture of mono-, di- and tributyl phosphate, and fractional back-extraction with mineral acid whereby the lanthanides are taken up by the acid in the order of increasing atomic number.

  13. The role of lanthanides in optical materials

    SciTech Connect

    Weber, M.J.

    1995-05-01

    A survey is presented of the use of the lanthanides as chemical components in transmitting optical materials and as activators in materials for luminescent, electro-optic, magneto-optic, and various photosensitive applications.

  14. Luminescent lanthanide chelates and methods of use

    DOEpatents

    Selvin, Paul R.; Hearst, John

    1997-01-01

    The invention provides lanthanide chelates capable of intense luminescence. The celates comprise a lanthanide chelator covalently joined to a coumarin-like or quinolone-like sensitizer. Exemplary sensitzers include 2- or 4-quinolones, 2- or 4-coumarins, or derivatives thereof e.g. carbostyril 124 (7-amino-4-methyl-2-quinolone), coumarin 120 (7-amino-4-methyl-2-coumarin), coumarin 124 (7-amino-4-(trifluoromethyl)-2-coumarin), aminomethyltrimethylpsoralen, etc. The chelates form high affinity complexes with lanthanides, such as terbium or europium, through chelator groups, such as DTPA. The chelates may be coupled to a wide variety of compounds to create specific labels, probes, diagnostic and/or therapeutic reagents, etc. The chelates find particular use in resonance energy transfer between chelate-lanthanide complexes and another luminescent agent, often a fluorescent non-metal based resonance energy acceptor. The methods provide useful information about the structure, conformation, relative location and/or interactions of macromolecules.

  15. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

    Nash, Kenneth L.; Clark, Sue; Meier, G Patrick; Alexandratos, Spiro; Paine, Robert; Hancock, Robert; Ensor, Dale

    2012-03-21

    One of the most challenging aspects of advanced processing of spent nuclear fuel is the need to isolate transuranium elements from fission product lanthanides. This project expanded the scope of earlier investigations of americium (Am) partitioning from the lanthanides with the synthesis of new separations materials and a centralized focus on radiochemical characterization of the separation systems that could be developed based on these new materials. The primary objective of this program was to explore alternative materials for actinide separations and to link the design of new reagents for actinide separations to characterizations based on actinide chemistry. In the predominant trivalent oxidation state, the chemistry of lanthanides overlaps substantially with that of the trivalent actinides and their mutual separation is quite challenging.

  16. Increasing the luminescence of lanthanide complexes.

    PubMed

    Leif, Robert C; Vallarino, Lidia M; Becker, Margie C; Yang, Sean

    2006-08-01

    This review compares the chemical and physical properties of lanthanide ion complexes and of other narrow-emitting species that can be used as labels for cytometry. A series of luminescent lanthanide ion macrocyclic complexes, Quantum Dyes, which do not release or exchange their central lanthanide ion, do accept energy transfer from ligands, and are capable of covalent binding to macromolecules, including proteins and nucleic acids, is described and their properties are discussed. Two methods are described for increasing the luminescence intensity of lanthanide ion complexes, which intrinsically is not as high as that of standard fluorophores or quantum dots. One method consists of adding a complex of a second lanthanide ion in a micellar solution (columinescence); the other method produces dry preparations by evaporation of a homogeneous solution containing an added complex of a second lanthanide ion or an excess of an unbound antenna ligand. Both methods involve the Resonance Energy Transfer Enhanced Luminescence, RETEL, effect as the mechanism for the luminescence enhancement.

  17. LANTHANIDE ENHANCE LUMINESCENCE (LEL) WITH ONE AND TWO PHOTON EXCITATION OF QUANTUM DYES LANTHANIDE (III) - MACROCYCLES

    EPA Science Inventory

    Title: Lanthanide Enhance Luminescence (LEL) with one and two photon excitation of Quantum Dyes? Lanthanide(III)-Macrocycles
    Principal Author:
    Robert C. Leif, Newport Instruments
    Secondary Authors:
    Margie C. Becker, Phoenix Flow Systems
    Al Bromm, Virginia Commonw...

  18. LANTHANIDE ENHANCE LUMINESCENCE (LEL) WITH ONE AND TWO PHOTON EXCITATION OF QUANTUM DYES LANTHANIDE (III) - MACROCYCLES

    EPA Science Inventory

    Title: Lanthanide Enhance Luminescence (LEL) with one and two photon excitation of Quantum Dyes? Lanthanide(III)-Macrocycles
    Principal Author:
    Robert C. Leif, Newport Instruments
    Secondary Authors:
    Margie C. Becker, Phoenix Flow Systems
    Al Bromm, Virginia Commonw...

  19. Nonaqueous method for dissolving lanthanide and actinide metals

    DOEpatents

    Crisler, L.R.

    1975-11-11

    Lanthanide and actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a lanthanide or actinide element in the elemental metallic state in a mixture of carbon tetrachloride and methanol.

  20. Effect of lanthanides on Porphyromonas gingivalis proteases.

    PubMed

    Sunkara, Sasi K; Ciancio, Sebastian G; Sojar, Hakimuddin T

    2010-01-01

    Host and bacterial proteases play a vital role in periodontitis. Inhibitors of these proteases are necessary for control of this disease. The purpose of this study was to evaluate the effect of lanthanides on proteins from Porphyromonas gingivalis, a major pathogen in periodontitis. Benzoyl-L-Arg-p-nitroanilide (BAPNA); H-Gly-Pro-pNA x HCl and gelatin were used to evaluate the activity of P. gingivalis proteins in the presence of lanthanides. Proteins extracted from cell surfaces and culture media of P. gingivalis were assessed for activity in the presence of different lanthanides by BAPNA assay. Only gadolinium chloride was used for H-Gly-Pro-pNA x HCl assay and gelatin-zymography. Concentration-dependent reduction of absorbance was observed in the presence of lanthanides with BAPNA and a similar observation was made with gadolinium chloride using H-Gly-Pro-pNa. Collagenolytic activity in cell surface extracts and culture media-precipitated proteins was absent in the presence of gadolinium chloride. These results suggest that the lanthanide gadolinium can be a potential inhibitor of P. gingivalis proteases.

  1. Switchable sensitizers stepwise lighting up lanthanide emissions.

    PubMed

    Zhang, Yan; Jiao, Peng-Chong; Xu, Hai-Bing; Tang, Ming-Jing; Yang, Xiao-Ping; Huang, Shaoming; Deng, Jian-Guo

    2015-03-20

    Analagous to a long-ranged rocket equipped with multi-stage engines, a luminescent compound with consistent emission signals across a large range of concentrations from two stages of sensitizers can be designed. In this approach, ACQ, aggregation-caused quenching effect of sensitizers, would stimulate lanthanide emission below 10(-4) M, and then at concentrations higher than 10(-3) M, the "aggregation-induced emission" (AIE) effect of luminophores would be activated with the next set of sensitizers for lanthanide emission. Simultaneously, the concentration of the molecules could be monitored digitally by the maximal excitation wavelengths, due to the good linear relationship between the maximal excitation wavelengths and the concentrations {lg(M)}. This model, wherein molecules are assembled with two stages (both AIE and ACQ effect) of sensitizers, may provide a practicable strategy for design and construction of smart lanthanide bioprobes, which are suitable in complicated bioassay systems in which concentration is variable.

  2. Switchable sensitizers stepwise lighting up lanthanide emissions

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Jiao, Peng-Chong; Xu, Hai-Bing; Tang, Ming-Jing; Yang, Xiao-Ping; Huang, Shaoming; Deng, Jian-Guo

    2015-03-01

    Analagous to a long-ranged rocket equipped with multi-stage engines, a luminescent compound with consistent emission signals across a large range of concentrations from two stages of sensitizers can be designed. In this approach, ACQ, aggregation-caused quenching effect of sensitizers, would stimulate lanthanide emission below 10-4 M, and then at concentrations higher than 10-3 M, the ``aggregation-induced emission'' (AIE) effect of luminophores would be activated with the next set of sensitizers for lanthanide emission. Simultaneously, the concentration of the molecules could be monitored digitally by the maximal excitation wavelengths, due to the good linear relationship between the maximal excitation wavelengths and the concentrations {lg(M)}. This model, wherein molecules are assembled with two stages (both AIE and ACQ effect) of sensitizers, may provide a practicable strategy for design and construction of smart lanthanide bioprobes, which are suitable in complicated bioassay systems in which concentration is variable.

  3. Curvature of the Lanthanide Contraction: An Explanation

    SciTech Connect

    Raymond, Kenneth; Wellman, Daniel; Sgarlata, Carmelo; Hill, Aru

    2009-12-21

    A number of studies have shown that for isostructural series of the lanthanides (elements La through Lu), a plot of equivalent metal-ligand bond lengths versus atomic number differs significantly from linearity and can be better fit as a quadratic equation. However, for hydrogen type wave functions, it is the inverse of the average distance of the electron from the nucleus (an estimate of size) that varies linearly with effective nuclear charge. This generates an apparent quadratic dependence of radius with atomic number. Plotting the inverse of lanthanide ion radii (the observed distance minus the ligand size) as a function of effective nuclear charge gives very good linear fits for a variety of lanthanide complexes and materials. Parameters obtained from this fit are in excellent agreement with the calculated Slater shielding constant, k.

  4. Electronic Structure of Small Lanthanide Containing Molecules

    NASA Astrophysics Data System (ADS)

    Kafader, Jared O.; Ray, Manisha; Topolski, Josey E.; Chick Jarrold, Caroline

    2016-06-01

    Lanthanide-based materials have unusual electronic properties because of the high number of electronic degrees of freedom arising from partial occupation of 4f orbitals, which make these materials optimal for their utilization in many applications including electronics and catalysis. Electronic spectroscopy of small lanthanide molecules helps us understand the role of these 4f electrons, which are generally considered core-like because of orbital contraction, but are energetically similar to valence electrons. The spectroscopy of small lanthanide-containing molecules is relatively unexplored and to broaden this understanding we have completed the characterization of small cerium, praseodymium, and europium molecules using photoelectron spectroscopy coupled with DFT calculations. The characterization of PrO, EuH, EuO/EuOH, and CexOy molecules have allowed for the determination of their electron affinity, the assignment of numerous anion to neutral state transitions, modeling of anion/neutral structures and electron orbital occupation.

  5. Energetic lanthanide complexes: coordination chemistry and explosives applications

    NASA Astrophysics Data System (ADS)

    Manner, V. W.; Barker, B. J.; Sanders, V. E.; Laintz, K. E.; Scott, B. L.; Preston, D. N.; Sandstrom, M.; Reardon, B. L.

    2014-05-01

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  6. Energetic Lanthanide Complexes: Coordination Chemistry and Explosives Applications

    NASA Astrophysics Data System (ADS)

    Manner, Virginia; Barker, Beau; Sanders, Eric; Laintz, Kenneth; Scott, Brian; Preston, Daniel; Sandstrom, Mary; Reardon, Bettina

    2013-06-01

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with ``tailor made'' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  7. Lanthanide sorbent based on magnetite nanoparticles functionalized with organophosphorus extractants

    PubMed Central

    Basualto, Carlos; Gaete, José; Molina, Lorena; Valenzuela, Fernando; Yañez, Claudia; Marco, Jose F

    2015-01-01

    In this work, an adsorbent was prepared based on the attachment of organophosphorus acid extractants, namely, D2EHPA, CYANEX 272, and CYANEX 301, to the surface of superparamagnetic magnetite (Fe3O4) nanoparticles. The synthesized nanoparticles were coated with oleic acid, first by a chemisorption mechanism and later by the respective extractant via physical adsorption. The obtained core–shell functionalized magnetite nanoparticle composites were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy, thermogravimetry, infrared absorption and vibrating sample magnetometry. All the prepared nanoparticles exhibited a high saturation magnetization capacity that varied between 72 and 46 emu g−1 and decreased as the magnetite nanoparticle was coated with oleic acid and functionalized. The scope of this study also included adsorption tests for lanthanum, cerium, praseodymium, and neodymium and the corresponding analysis of their results. Sorption tests indicated that the functionalized nanoparticles were able to extract the four studied lanthanide metal ions, although the best extraction performance was observed when the sorbent was functionalized with CYANEX 272, which resulted in a loading capacity of approximately 12–14 mgLa/gMNP. The magnetization of the synthesized nanoparticles was verified during the separation of the lanthanide-loaded sorbent from the raffinate by using a conventional magnet. PMID:27877811

  8. Lanthanide sorbent based on magnetite nanoparticles functionalized with organophosphorus extractants

    NASA Astrophysics Data System (ADS)

    Basualto, Carlos; Gaete, José; Molina, Lorena; Valenzuela, Fernando; Yañez, Claudia; Marco, Jose F.

    2015-06-01

    In this work, an adsorbent was prepared based on the attachment of organophosphorus acid extractants, namely, D2EHPA, CYANEX 272, and CYANEX 301, to the surface of superparamagnetic magnetite (Fe3O4) nanoparticles. The synthesized nanoparticles were coated with oleic acid, first by a chemisorption mechanism and later by the respective extractant via physical adsorption. The obtained core-shell functionalized magnetite nanoparticle composites were characterized by dynamic light scattering, scanning electron microscopy, transmission electron microscopy, thermogravimetry, infrared absorption and vibrating sample magnetometry. All the prepared nanoparticles exhibited a high saturation magnetization capacity that varied between 72 and 46 emu g-1 and decreased as the magnetite nanoparticle was coated with oleic acid and functionalized. The scope of this study also included adsorption tests for lanthanum, cerium, praseodymium, and neodymium and the corresponding analysis of their results. Sorption tests indicated that the functionalized nanoparticles were able to extract the four studied lanthanide metal ions, although the best extraction performance was observed when the sorbent was functionalized with CYANEX 272, which resulted in a loading capacity of approximately 12-14 mgLa/gMNP. The magnetization of the synthesized nanoparticles was verified during the separation of the lanthanide-loaded sorbent from the raffinate by using a conventional magnet.

  9. Shear viscosity coefficient of liquid lanthanides

    SciTech Connect

    Patel, H. P. Thakor, P. B. Prajapati, A. V.; Sonvane, Y. A.

    2015-05-15

    Present paper deals with the computation of shear viscosity coefficient (η) of liquid lanthanides. The effective pair potential v(r) is calculated through our newly constructed model potential. The Pair distribution function g(r) is calculated from PYHS reference system. To see the influence of local field correction function, Hartree (H), Tailor (T) and Sarkar et al (S) local field correction function are used. Present results are compared with available experimental as well as theoretical data. Lastly, we found that our newly constructed model potential successfully explains the shear viscosity coefficient (η) of liquid lanthanides.

  10. Preparation of Lanthanide-Polymer Composite Material via Click Chemistry.

    PubMed

    Chen, Bin; Wen, Guian; Wu, Jiajie; Feng, Jiachun

    2015-10-01

    Covalently attaching lanthanide complexes to the polymer backbone can effectively reduce the clustering of lanthanides and thus become an important strategy to fully unleash their potential. In this Communication, a metal-free click reaction is used for the first time to link a lanthanide complex to the polymer matrix. A diene-bearing copolymer with anthracenylmethyl methacrylate as a monomer and a dienophile-bearing lanthanide complex with 5-maleimido-1,10-phenanthroline as the second ligand are synthesized and coupled together through a Diels-Alder cycloaddition (DA). A comparative investigation demonstrates that the composite material prepared by DA click reaction shows the highest quantum yields in the same lanthanide concentration as compared to materials prepared by widely used "directly doping" and "in situ coordinating lanthanide ions with macromolecular ligand" approaches. This work suggests that the "metal-free" DA click reaction can be a promising tool in the synthesis of high efficient lanthanide functionalized polymeric materials.

  11. Method bacterial endospore quantification using lanthanide dipicolinate luminescence

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian (Inventor); Venkateswaran, Kasthuri J. (Inventor); Kirby, James Patrick (Inventor)

    2007-01-01

    A lanthanide is combined with a medium to be tested for endospores. The dipicolinic acid released from the endospores binds the lanthanides, which have distinctive emission (i.e., luminescence) spectra, and are detected using photoluminescence. The concentration of spores is determined by preparing a calibration curve generated from photoluminescence spectra of lanthanide complex mixed with spores of a known concentration. A lanthanide complex is used as the analysis reagent, and is comprised of lanthanide ions bound to multidentate ligands that increase the dipicolinic acid binding constant through a cooperative binding effect with respect to lanthanide chloride. The resulting combined effect of increasing the binding constant and eliminating coordinated water and multiple equilibria increase the sensitivity of the endospore assay by an estimated three to four orders of magnitude over prior art of endospore detection based on lanthanide luminescence.

  12. DISTRIBUTION OF LANTHANIDE AND ACTINIDE ELEMENTS BETWEEN BIS-(2-ETHYLHEXYL)PHOSPHORIC ACID AND BUFFERED LACTATE SOLUTIONS CONTAINING SELECTED COMPLEXANTS

    SciTech Connect

    Rudisill, Tracy S.; Diprete, David P.; Thompson, Major C.

    2013-04-15

    With the renewed interest in the closure of the nuclear fuel cycle, the TALSPEAK process is being considered for the separation of Am and Cm from the lanthanide fission products in a next generation reprocessing plant. However, an efficient separation requires tight control of the pH which likely will be difficult to achieve on a large scale. To address this issue, we measured the distribution of lanthanide and actinide elements between aqueous and organic phases in the presence of complexants which were potentially less sensitive to pH control than the diethylenetriaminepentaacetic (DTPA) used in the process. To perform the extractions, a rapid and accurate method was developed for measuring distribution coefficients based on the preparation of lanthanide tracers in the Savannah River National Laboratory neutron activation analysis facility. The complexants tested included aceto-, benzo-, and salicylhydroxamic acids, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), and ammonium thiocyanate (NH{sub 4}SCN). The hydroxamic acids were the least effective of the complexants tested. The separation factors for TPEN and NH{sub 4}SCN were higher, especially for the heaviest lanthanides in the series; however, no conditions were identified which resulted in separations factors which consistently approached those measured for the use of DTPA.

  13. La preparacion en ciencia de los candidatos a maestros del nivel elemental primario segun la reforma de la educacion cientifica en Puerto Rico: Una propuesta de secuencia curricular

    NASA Astrophysics Data System (ADS)

    Rodriguez Plaza, Evelyn

    El proposito de esta investigacion fue identificar los componentes de la preparacion en ciencia que deben recibir los estudiantes del Bachillerato en Artes en Educacion Elemental, Nivel Primario, de acuerdo a los documentos que dirigen la reforma de la educacion cientifica en Puerto Rico. Tambien, se identificaron los componentes de los cursos que forman parte de la preparacion en ciencia de estos estudiantes. Se compararon los componentes de la preparacion en ciencia y los componentes de los cursos para determinar congruencias y discrepancias. Con los datos recopilados se identificaron los componentes de los cursos de una secuencia curricular para la preparacion en ciencia de los candidatos a maestros del nivel elemental primario. La secuencia curricular que se propone en esta investigacion incluye cursos de contenido cientifico y de metodologia en la ensenanza de la ciencia disenados para satisfacer las necesidades de los candidatos. Se recomienda que en los procesos para el diseno, la implantacion y la evaluacion de estos cursos participen profesores de ciencia, profesores de educacion y maestros del nivel elemental primario. Todos los cursos de la secuencia curricular deben tener un enfoque constructivista. Las experiencias educativas que se incluyan en los cursos deben aspirar a desarrollar en los candidatos los atributos de la cultura cientifica y actitudes positivas hacia la ciencia y hacia la ensenanza de esta disciplina. El modelaje por parte de los profesores que ensenen los cursos de la secuencia curricular es fundamental en el desarrollo profesional de los candidatos. Se recomienda que en los cursos de contenido cientifico se estudien los conceptos y los conocimientos cientificos que forman parte del curriculo de Kindergarten a tercer grado de forma integrada y con una profundidad universitaria. Estos cursos deben tener un enfoque interdisciplinario e incluir el estudio de la naturaleza de la ciencia y un componente de laboratorio para desarrollar los

  14. Structural studies of lanthanide(III) 1,2-ethylene-diphosphonic acid complexes

    SciTech Connect

    McIlwraith, H.; Zhang, J.; Rogers, R.D.

    1995-12-31

    1,2-Ethylenediphosphonic acid can be classified in a class of extractants known as thermally unstable complexants (TUCS). Extraction accomplished using TUCS ligands can be followed by thermal degradation of the extractant. Despite their proposed utility in separation, few structures of lanthanide(III)/TUCS complexes are known. Structural studies can help us to understand the extraction mechanism and the interaction between metal ions and the ligand.

  15. Extraction of actinide and lanthanide complexonates in potassium carbonate-poly(ethylene glycol)-water two-phase aqueous system

    SciTech Connect

    Molochnikova, N.P.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.; Myasoedov, B.F.

    1988-09-01

    An extraction system based on poly(ethylene glycol) for preconcentrating, isolating and separating actinides, is proposed. The extraction of actinides and lanthanides in a potassium carbonate-poly(ethylene glycol)-water two-phase aqueous system in the presence of various complexones was studied. Trivalent actinides are quantitatively extracted by poly(ethylene glycol) from potassium carbonate solutions in a system with Xylenol Orange and alizarin complexone. Under these conditions, uranium (VI) and plutonium (IV) are extracted inappreciably into a phase enriched with poly(ethylene glycol), so that they can be separated from trivalent actinides with a separation factor of 10/sup 2/-10/sup 3/. To separate actinides and lanthanides, two complexones were introduced into the system, one of which served as an extractant, and the other as a masking reagent. The best results were obtained for a mixture of Xylenol Orange and hydroxyethylidenediphosphonic acid. The separation coefficients of americium and europium are 4.5-5.6.

  16. Luminogenic "clickable" lanthanide complexes for protein labeling.

    PubMed

    Candelon, Nicolas; Hădade, Niculina D; Matache, Mihaela; Canet, Jean-Louis; Cisnetti, Federico; Funeriu, Daniel P; Nauton, Lionel; Gautier, Arnaud

    2013-10-14

    Development of lanthanide-based luminescent "switch-on" systems via azide-alkyne [3+2] cycloaddition is described. We used these for non-specific protein labeling and as tags for specific and selective activity-based protein labeling.

  17. Thermodynamic Studies to Support Actinide/Lanthanide Separations

    SciTech Connect

    Rao, Linfeng

    2016-09-04

    Thermodynamic data on the complexation of Np(V) with HEDTA in a wide pH region were re-modeled by including a dimeric complex species, (NpO2)2(OH)2L26- where L3- stands for the fully deprotonated HEDTA ligand and better fits were achieved for the spectrophotometric data. The presence of the dimeric complex species in high pH region was verified for the first time by the EXAFS experiments at Stanford Synchrotron Radiation Laboratory (SSRL).

  18. Zirconium(IV)-Benzene Phosphonate Coordination Polymers: Lanthanide and Actinide Extraction and Thermal Properties.

    PubMed

    Luca, Vittorio; Tejada, Juan J; Vega, Daniel; Arrachart, Guilhem; Rey, Cyrielle

    2016-08-15

    Coordination polymers with different P/(Zr + P) molar ratios were prepared by combining aqueous solutions of Zr(IV) and benzenephosphonate derivatives. 1,3,5-Benzenetrisphosphonic acid (BTP) as well as phosphonocarboxylate derivatives in which carboxylate substitutes one or two of the phosphonate groups were chosen as the building blocks. The precipitates obtained on combining the two solutions were not X-ray amorphous but rather were indicative of poorly ordered materials. Hydrothermal treatment did not alter the structure of the materials produced but did result in improved crystalline order. The use of HF as a mineralizing agent during hydrothermal synthesis resulted in the crystallization of at least three relatively crystalline phases whose structure could not be determined owing to the complexity of the diffraction patterns. Gauging from the similarity of the diffraction patterns of all the phases, the poorly ordered precipitates and crystalline materials appeared to have similar underlying structures. The BTP-based zirconium phosphonates all showed a higher selectivity for lanthanides and thorium compared with cations such as Cs(+), Sr(2+), and Co(2+). Substitution of phosphonate groups by carboxylate groups did little to alter the pattern of selectivity implying that selectivity in the system was entirely determined by the -POH group with little influence from the -COOH groups. Samples with the highest phosphorus content showed the highest extraction efficiencies for lanthanide elements, especially the heavy lanthanides such as Dy(3+) and Ho(3+) with separation factors of around four with respect to La(3+). In highly acid solutions (4 M HNO3) there was a pronounced variation in extraction efficiency across the lanthanide series. In situ, nonambient diffraction was performed on ZrBTP-0.8 loaded with Th, Ce, and a complex mixture of lanthanides. In all cases the crystalline Zr2P2O7 pyrophosphate phase was formed at ∼800 °C demonstrating the versatility of

  19. Biological and Clinical Aspects of Lanthanide Coordination Compounds

    PubMed Central

    Misra, Sudhindra N.; M., Indira Devi; Shukla, Ram S.

    2004-01-01

    The coordinating chemistry of lanthanides, relevant to the biological, biochemical and medical aspects, makes a significant contribution to understanding the basis of application of lanthanides, particularly in biological and medical systems. The importance of the applications of lanthanides, as an excellent diagnostic and prognostic probe in clinical diagnostics, and an anticancer material, is remarkably increasing. Lanthanide complexes based X-ray contrast imaging and lanthanide chelates based contrast enhancing agents for magnetic resonance imaging (MRI) are being excessively used in radiological analysis in our body systems. The most important property of the chelating agents, in lanthanide chelate complex, is its ability to alter the behaviour of lanthanide ion with which it binds in biological systems, and the chelation markedly modifies the biodistribution and excretion profile of the lanthanide ions. The chelating agents, especially aminopoly carboxylic acids, being hydrophilic, increase the proportion of their complex excreted from complexed lanthanide ion form biological systems. Lanthanide polyamino carboxylate-chelate complexes are used as contrast enhancing agents for Magnetic Resonance Imaging. Conjugation of antibodies and other tissue specific molecules to lanthanide chelates has led to a new type of specific MRI contrast agents and their conjugated MRI contrast agents with improved relaxivity, functioning in the body similar to drugs. Many specific features of contrast agent assisted MRI make it particularly effective for musculoskeletal and cerebrospinal imaging. Lanthanide-chelate contrast agents are effectively used in clinical diagnostic investigations involving cerebrospinal diseases and in evaluation of central nervous system. Chelated lanthanide complexes shift reagent aided 23Na NMR spectroscopic analysis is used in cellular, tissue and whole organ systems. PMID:18365075

  20. Gold Coated Lanthanide Phosphate Nanoparticles for Targeted Alpha Generator Radiotherapy

    SciTech Connect

    McLaughlin, Mark F; Woodward, Jonathan; Boll, Rose Ann; Wall, Jonathan; Rondinone, Adam Justin; Kennel, Steve J; Mirzadeh, Saed; Robertson, David J.

    2013-01-01

    Targeted radiotherapies maximize cytotoxicty to cancer cells. In vivo generators such as 225Ac, which emits four particles in its decay chain, can significantly amplify the radiation dose delivered to the target site. However, renal dose from unbound 213Bi escaping during the decay process limits the dose of 225Ac that can be administered. Traditional chelating moieties are unable to sequester the radioactive daughters because of the high recoil energy from alpha particle emission. To counter this, we demonstrate that an engineered multilayered nanoparticle-antibody conjugate can both deliver radiation and contain the decay daughters of the in vivo -generator 225Ac while targeting biologically relevant receptors. These multi-shell nanoparticles combine the radiation resistance of crystalline lanthanide phosphate to encapsulate and contain 225Ac and its radioactive decay daughters, the magnetic properties of gadolinium phosphate for easy separation, and established surface chemistry of gold for attachment of nanoparticles to targeting antibodies.

  1. Rare earth separations by selective borate crystallization

    PubMed Central

    Yin, Xuemiao; Wang, Yaxing; Bai, Xiaojing; Wang, Yumin; Chen, Lanhua; Xiao, Chengliang; Diwu, Juan; Du, Shiyu; Chai, Zhifang; Albrecht-Schmitt, Thomas E.; Wang, Shuao

    2017-01-01

    Lanthanides possess similar chemical properties rendering their separation from one another a challenge of fundamental chemical and global importance given their incorporation into many advanced technologies. New separation strategies combining green chemistry with low cost and high efficiency remain highly desirable. We demonstrate that the subtle bonding differences among trivalent lanthanides can be amplified during the crystallization of borates, providing chemical recognition of specific lanthanides that originates from Ln3+ coordination alterations, borate polymerization diversity and soft ligand coordination selectivity. Six distinct phases are obtained under identical reaction conditions across lanthanide series, further leading to an efficient and cost-effective separation strategy via selective crystallization. As proof of concept, Nd/Sm and Nd/Dy are used as binary models to demonstrate solid/aqueous and solid/solid separation processes. Controlling the reaction kinetics gives rise to enhanced separation efficiency of Nd/Sm system and a one-step quantitative separation of Nd/Dy with the aid of selective density-based flotation. PMID:28290448

  2. Rare earth separations by selective borate crystallization

    NASA Astrophysics Data System (ADS)

    Yin, Xuemiao; Wang, Yaxing; Bai, Xiaojing; Wang, Yumin; Chen, Lanhua; Xiao, Chengliang; Diwu, Juan; Du, Shiyu; Chai, Zhifang; Albrecht-Schmitt, Thomas E.; Wang, Shuao

    2017-03-01

    Lanthanides possess similar chemical properties rendering their separation from one another a challenge of fundamental chemical and global importance given their incorporation into many advanced technologies. New separation strategies combining green chemistry with low cost and high efficiency remain highly desirable. We demonstrate that the subtle bonding differences among trivalent lanthanides can be amplified during the crystallization of borates, providing chemical recognition of specific lanthanides that originates from Ln3+ coordination alterations, borate polymerization diversity and soft ligand coordination selectivity. Six distinct phases are obtained under identical reaction conditions across lanthanide series, further leading to an efficient and cost-effective separation strategy via selective crystallization. As proof of concept, Nd/Sm and Nd/Dy are used as binary models to demonstrate solid/aqueous and solid/solid separation processes. Controlling the reaction kinetics gives rise to enhanced separation efficiency of Nd/Sm system and a one-step quantitative separation of Nd/Dy with the aid of selective density-based flotation.

  3. Rare earth separations by selective borate crystallization.

    PubMed

    Yin, Xuemiao; Wang, Yaxing; Bai, Xiaojing; Wang, Yumin; Chen, Lanhua; Xiao, Chengliang; Diwu, Juan; Du, Shiyu; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2017-03-14

    Lanthanides possess similar chemical properties rendering their separation from one another a challenge of fundamental chemical and global importance given their incorporation into many advanced technologies. New separation strategies combining green chemistry with low cost and high efficiency remain highly desirable. We demonstrate that the subtle bonding differences among trivalent lanthanides can be amplified during the crystallization of borates, providing chemical recognition of specific lanthanides that originates from Ln(3+) coordination alterations, borate polymerization diversity and soft ligand coordination selectivity. Six distinct phases are obtained under identical reaction conditions across lanthanide series, further leading to an efficient and cost-effective separation strategy via selective crystallization. As proof of concept, Nd/Sm and Nd/Dy are used as binary models to demonstrate solid/aqueous and solid/solid separation processes. Controlling the reaction kinetics gives rise to enhanced separation efficiency of Nd/Sm system and a one-step quantitative separation of Nd/Dy with the aid of selective density-based flotation.

  4. Use of dipicolinate-based complexes for producing ion-imprinted polystyrene resins for the extraction of yttrium-90 and heavy lanthanide cations.

    PubMed

    Chauvin, Anne-Sophie; Bünzli, Jean-Claude G; Bochud, François; Scopelliti, Rosario; Froidevaux, Pascal

    2006-09-06

    Highly selective separation of yttrium (and lanthanides) is of interest for the design of radiopharmaceuticals, and an efficient method based on the ion-imprinting concept is proposed here. The synthesis and structural, thermodynamic and photophysical characterization of complexes of trivalent yttrium and lanthanides with two new vinyl derivatives of dipicolinic acid, HL1 and L2, are described. The feasibility of using ion-imprinted resins for yttrium and lanthanide separation is demonstrated. The resins were obtained by copolymerization with styrene and divinylbenzene and subsequent acid treatment to remove the metal ion. High-resolution Eu luminescence experiments revealed that the geometry of the complexation sites is well preserved in the imprinted polymers. The ion-imprinted polymer based on HL1 proved to be particularly well adapted for yttrium extraction, having a sizeable capacity (8.9+/-0.2 mg g(-1) resin) and a fast rate of extraction (t(1/2)=1.7 min). In addition, lighter and heavier lanthanide ions are separated. Finally, the resin displays high selectivity for yttrium and lanthanide cations against alkali and alkaline earth metals. For instance, in a typical experiment, 10 mg of yttrium was extracted from 5 g of milk ash sample by 2 g of the resin. The good separation properties displayed by the resin based on HL1 open interesting perspectives for the production of highly pure (90)Y and radiolanthanides for medical applications, and for trace analysis of these radiochemicals in food and in the environment.

  5. Monodentate vs bidentate binding of lanthanide cations to PO{sub 2}{sup -} in bacteriorhodopsin

    SciTech Connect

    Griffiths, J.A.; Masciangioli, T.M.; El-Sayed, M.A.; Roselli, C.

    1996-04-18

    The frequency difference between the symmetric and antisymmetric stretching vibration of PO{sub 2}{sup +} in phosphatidylglycerol phosphate (PGP) is used to differentiate between monodentate and bidentate binding of these groups to metal cations in the membrane of bacteriorhodopsin (bR) and phosphatidylglycerol phosphate. The binding of Ca{sup 2}{sup +} to PGP is found to have a frequency difference corresponding to monodentate binding. The symmetric and antisymmetric PO{sub 2}{sup +} bands in bR show similar frequency shifts upon Ca{sup 2}{sup +} binding, which is independent of pH. This suggests that Ca{sup 2}{sup +} has a monodentate type binding with the PO{sub 2}{sup -} in bR. In contrast, the PO{sub 2}{sup -} symmetric and antisymmetric frequencies of PGP complexes with trivalent lanthanide cations with higher charge density (Ho{sup 3}{sup +} and Dy{sup 3}{sup +}) are observed to have smaller separations and to increase their separation with increasing pH toward the value observed for Ca{sup 2}{sup +} binding. Lanthanide cations (Ho{sup 3}{sup +}, Dy{sup 3}{sup +}, Eu{sup 3}{sup +}, Nd{sup 3}{sup +}, and La{sup 3}{sup +}) binding in bR and pH 4 show small frequency separations that are observed to have similar frequency shifts with pH, the magnitude to which is dependent on the cation. It is proposed that at low pH the lanthanide cations with higher charge density have bidentate binding to bR, while at high pH, complexation with the OH{sup -} competes with one of the oxygens of the PO{sub 2}{sup -} for the binding of the lanthanide ion thus changing the bidentate to monodentate type binding. 25 refs., 5 figs.

  6. Lanthanide doped strontium-barium cesium halide scintillators

    DOEpatents

    Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

    2015-06-09

    The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

  7. Collection of lanthanides and actinides from natural waters with conventional and nanoporous sorbents.

    PubMed

    Johnson, Bryce E; Santschi, Peter H; Chuang, Chia-Ying; Otosaka, Shigeyoshi; Addleman, Raymond Shane; Douglas, Matt; Rutledge, Ryan D; Chouyyok, Wilaiwan; Davidson, Joseph D; Fryxell, Glen E; Schwantes, Jon M

    2012-10-16

    Effective collection of trace-level lanthanides and actinides is advantageous for recovery and recycling of valuable resources, environmental remediation, chemical separations, and in situ monitoring. Using isotopic tracers, we have evaluated a number of conventional and nanoporous sorbent materials for their ability to capture and remove selected lanthanides (Ce and Eu) and actinides (Th, Pa, U, and Np) from fresh and salt water systems. In general, the nanostructured materials demonstrated a higher level of performance and consistency. Nanoporous silica surface modified with 3,4-hydroxypyridinone provided excellent collection and consistency in both river water and seawater. The MnO(2) materials, in particular the high surface area small particle material, also demonstrated good performance. Other conventional sorbents typically performed at levels below the nanostructured sorbents and demonstrate a larger variability and matrix dependency.

  8. Strong Exchange Coupling Between the Lanthanide Ions and Phthalocyaniato Ligand Radical in Bis(phthalocyaninato)Lanthanide Sandwich Compounds

    DTIC Science & Technology

    1992-07-06

    trstonQeai n Report ~1 ,fero 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Strong Exchange Coupling Between the Lanthanide Ions and Phthalocyaniato Ligand...Radical in N00014-92-J-1637 Bis(phthalocyaninato) lanthanide Sandwich Compoun s 6. AUTHOR(S) Kathleen L. Trojan, Jonathan L. Kendall, Keith Kepler and...200 words) A series of lanthanide phthalocyanine sandwich compounds with the formula [ (Pc 2")Ln 1 (Pc ’ ) ] have been synthesized and characterized

  9. Lanthanide Enhanced Luminescence (LEL) with One and Two Photon Excitation of Quantum Dyes(copyright) Lanthanide(III)-Macrocycles

    DTIC Science & Technology

    2004-01-01

    Quagliano, and L. M. Vallarino, The Addition of a Second Lanthanide Ion to Increase the Luminescence of Europium(IIl) Macrocyclic Complexes ...Increasing the Luminescence of Lanthanide (III) Macrocyclic Complexes , 2002, and United States Patent Application 20020132992, September 19, 2002. 3. J...R. Quagliano, R. C. Leif, L. M. Vallarino, and S. A. Williams, Methods to Increase the Luminescence of Lanthanide (III) Macrocyclic Complexes , Optical

  10. Lanthanide-halide based humidity indicators

    DOEpatents

    Beitz, James V.; Williams, Clayton W.

    2008-01-01

    The present invention discloses a lanthanide-halide based humidity indicator and method of producing such indicator. The color of the present invention indicates the humidity of an atmosphere to which it is exposed. For example, impregnating an adsorbent support such as silica gel with an aqueous solution of the europium-containing reagent solution described herein, and dehydrating the support to dryness forms a substance with a yellow color. When this substance is exposed to a humid atmosphere the water vapor from the air is adsorbed into the coating on the pore surface of the silica gel. As the water content of the coating increases, the visual color of the coated silica gel changes from yellow to white. The color change is due to the water combining with the lanthanide-halide complex on the pores of the gel.

  11. Giant exchange interaction in mixed lanthanides

    PubMed Central

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F.

    2016-01-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction. PMID:27087470

  12. Solid-state and solution-state coordination chemistry of lanthanide(III) complexes with α-hydroxyisobutyric acid.

    PubMed

    Chen, Xiao-Yan; Goff, George S; Ewing, William C; Scott, Brian L; Runde, Wolfgang

    2012-12-17

    Despite the wide range of applications of α-hydroxyisobutyric acid (HIBA) in biochemical processes, pharmaceutical formulations, and group and elemental separations of lanthanides and actinides, the structures and geometries of lanthanide-HIBA complexes are still not well understood. We reacted HIBA with lanthanides in aqueous solution at pH = 5 and synthesized 14 lanthanide-HIBA complexes of the formula [Ln(HIBA)(2)(H(2)O)(2)](NO(3))·H(2)O (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Ho (10), Er (11), Tm (12), Yb (13), Lu (14)), isolating single crystals (1-7, 10, and 11) and powders (8, 9, and 12-14). Both single-crystal and powder X-ray diffraction studies reveal a two-dimensional extended structure across the entire lanthanide series. The environment around the eight-coordinated Ln(III) atom is best described as a distorted dodecahedron, where HIBA acts as a monoanionic tridentate ligand with one carboxylato oxygen atom and one hydroxyl oxygen atom chelating to one Ln(III) center. The carboxylato oxygen atom from a second HIBA ligand bridges to a neighboring Ln(III) atom to form a two-dimensional extended structure. While the coordination mode for HIBA is identical across the lanthanide series, three different structure types are found for La, Ce-Ho, and Er-Lu. Solution characterization using (13)C NMR further confirmed a single solution complex under the crystallization conditions. Raman and UV-vis-NIR absorbance and diffuse reflectance spectra of HIBA-Ln(III) complexes were also measured.

  13. Rapid fluorophosphate nerve agent detection with lanthanides.

    PubMed

    Menzel, E Roland; Menzel, Laird W; Schwierking, Jake R

    2005-08-15

    We explore the detection of vapors of diisopropylfluorophosphate, a model compound for nerve agents such as Sarin, by means of photoluminescence quenching of filter paper impregnated with sensitized complexes of lanthanides, involving thenoyltrifluoroacetone and 1,10-phenanthroline as sensitizing ligands. We find that the presence of the fluorophosphate vapor is detectable in as little as 2s, by simple visual observation under illumination with a hand-held low intensity ultraviolet lamp.

  14. Hexaaza macrocyclic complexes of the lanthanides

    SciTech Connect

    De Cola, L.; Smailes, D.L.; Vallarino, L.M.

    1986-05-07

    The authors systematically investigate the conditions leading to the metal-templated macrocyclic synthesis and obtain by an appropriate combination of counterions and experimental conditions, two series of complexes of the macrocyclic ligand L = C/sub 22/H/sub 26/N/sub 6/, with every lanthanide(III) ion except radioactive Pm. Their synthesis, characterization, and properties are described here. 13 references, 2 figures.

  15. Nanometrization of Lanthanide-Based Coordination Polymers.

    PubMed

    Neaime, Chrystelle; Daiguebonne, Carole; Calvez, Guillaume; Freslon, Stéphane; Bernot, Kevin; Grasset, Fabien; Cordier, Stéphane; Guillou, Olivier

    2015-11-23

    Heteronuclear lanthanide-based coordination polymers are microcrystalline powders, the luminescence properties of which can be precisely tuned by judicious choice of the rare-earth ions. In this study, we demonstrate that such materials can also be obtained as stable solutions of nanoparticles in non-toxic polyols. Bulk powders of the formula [Ln2-2x Ln'2x (bdc)3 ⋅4 H2 O]∞ (where H2 bdc denotes 1,4-benzene-dicarboxylic acid, 0≤x≤1, and Ln and Ln' denote lanthanide ions of the series La to Tm plus Y) afford nanoparticles that have been characterized by dynamic light-scattering (DLS) and transmission electron microscopy (TEM) measurements. Their luminescence properties are similar to those of the bulk materials. Stabilities versus time and versus dilution with another solvent have been studied. This study has revealed that it is possible to tune the size of the nanoparticles. This process offers a reliable means of synthesizing suspensions of nanoparticles with tunable luminescence properties and tunable size distributions in a green solvent (glycerol). The process is also extendable to other coordination polymers and other solvents (ethylene glycol, for example). It constitutes a new route for the facile solubilization of lanthanide-based coordination polymers.

  16. Switchable sensitizers stepwise lighting up lanthanide emissions

    PubMed Central

    Zhang, Yan; Jiao, Peng-Chong; Xu, Hai-Bing; Tang, Ming-Jing; Yang, Xiao-Ping; Huang, Shaoming; Deng, Jian-Guo

    2015-01-01

    Analagous to a long-ranged rocket equipped with multi-stage engines, a luminescent compound with consistent emission signals across a large range of concentrations from two stages of sensitizers can be designed. In this approach, ACQ, aggregation-caused quenching effect of sensitizers, would stimulate lanthanide emission below 10−4 M, and then at concentrations higher than 10−3 M, the “aggregation-induced emission” (AIE) effect of luminophores would be activated with the next set of sensitizers for lanthanide emission. Simultaneously, the concentration of the molecules could be monitored digitally by the maximal excitation wavelengths, due to the good linear relationship between the maximal excitation wavelengths and the concentrations {lg(M)}. This model, wherein molecules are assembled with two stages (both AIE and ACQ effect) of sensitizers, may provide a practicable strategy for design and construction of smart lanthanide bioprobes, which are suitable in complicated bioassay systems in which concentration is variable. PMID:25791467

  17. Acidic 1,3-propanediaminetetraacetato lanthanides with luminescent and catalytic ester hydrolysis properties

    SciTech Connect

    Chen, Mao-Long; Shi, Yan-Ru; Yang, Yu-Chen; Zhou, Zhao-Hui

    2014-11-15

    In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H{sub 3}pdta)(H{sub 2}O){sub 5}]{sub n}·2Cl{sub n}·3nH{sub 2}O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H{sub 4}pdta=1,3-propanediaminetetraacetic acid, C{sub 11}H{sub 18}N{sub 2}O{sub 8}) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CPs, respectively, two 1D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 3}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 2}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd, 14] were isolated at 70 °C. When the crystals of 1–4 were hydrothermally heated at 180 °C with 1–2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)]{sub n}·nH{sub 2}O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 18] were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H{sub 2}O)]{sub n}·4nH{sub 2}O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1–5 are soluble in water and 1 was traced by solution {sup 13}C({sup 1}H) NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature. - Graphical abstract: A series

  18. Lanthanides in soils of the Cherepovets steel mill impact zone

    NASA Astrophysics Data System (ADS)

    Ladonin, D. V.

    2017-06-01

    Contents of different lanthanide forms in soddy-calcareous soils at different distances from the Cherepovets steel mill (Vologda oblast) have been studied. Increased contents of Pr and Tb are found in soils near the pollution source. Less manifested increases in the contents of other lanthanides (from La to Gd) are also observed. Along with the increase in total content, technogenic pollution increases the content of acid-soluble lanthanides and affects their degree of extraction. The residual fraction strongly bound to aluminosilicates contains 80 to 95% of lanthanides. Soil processes result in the partial binding of lanthanides with organic matter (5-18% of their total content) and Fe and Mn (hydr)oxides (0.1-5% of the total content). The individual properties of lanthanides are clearly manifested in their interaction with these soil components. The highest share of the fraction bound to organic matter contains medium lanthanides, and the highest share of the fraction bound to Fe and Mn (hydr)oxides contains heavy lanthanides.

  19. Phthalamide-lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N.; Petoud, Stephane; Cohen, Seth M.; Xu, Jide

    2005-03-08

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  20. Salicylamide-lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N.; Petoud, Stephane; Cohen, Seth; Xu, Jide

    2002-01-01

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one salicylamidyl moiety. Also provided are probes incorporating the salicylamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  1. Salicylamide-lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N [Berkeley, CA; Petoud, Stephane [Berkeley, CA; Cohen, Seth [Boston, MA; Xu, Jide [Berkeley, CA

    2008-07-29

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one salicylamidyl moiety. Also provided are probes incorporating the salicylamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  2. Salicylamide-lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N.; Petoud, Stephane; Cohen, Seth; Xu, Jide

    2006-03-28

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one salicylamidyl moiety. Also provided are probes incorporating the salicylamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  3. Phthalamide-lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N [Berkeley, CA; Petoud, Stephane [Pittsburgh, PA; Cohen, Seth [Boston, MA; Xu, Jide [Berkeley, CA

    2008-10-28

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  4. Phthalamide lanthanide complexes for use as luminescent markers

    DOEpatents

    Raymond, Kenneth N.; Petoud, Stephane; Cohen, Seth M.; Xu, Jide

    2003-01-01

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  5. End-to-end azido-pinned interlocking lanthanide squares.

    PubMed

    Li, Xiao-Lei; Wu, Jianfeng; Zhao, Lang; Shi, Wei; Cheng, Peng; Tang, Jinkui

    2017-03-09

    A rare end-to-end azido-pinned interlocking lanthanide square was self-assembled using a ditopic Schiff-base (H2L) and NaN3 as ligands. Obvious ferromagnetic interaction and a record anisotropy barrier of 152(4) K among lanthanide azido-bridged SMMs in a zero dc field were observed.

  6. Structure and Magnetic Properties of Lanthanide Nanocrystals

    SciTech Connect

    Dickerson, James Henry

    2014-06-01

    We have had considerable success on this project, particularly in the understanding of the relationship between nanostructure and magnetic properties in lanthanide nanocrystals. We also have successfully facilitated the doctoral degrees of Dr. Suseela Somarajan, in the Department of Physics and Astronomy, and Dr. Melissa Harrison, in the Materials Science Program. The following passages summarize the various accomplishments that were featured in 9 publications that were generated based on support from this grant. We thank the Department of Energy for their generous support of our research efforts in this area of materials science, magnetism, and electron microscopy.

  7. Understanding stability trends along the lanthanide series.

    PubMed

    Regueiro-Figueroa, Martín; Esteban-Gómez, David; de Blas, Andrés; Rodríguez-Blas, Teresa; Platas-Iglesias, Carlos

    2014-04-01

    The stability trends across the lanthanide series of complexes with the polyaminocarboxylate ligands TETA(4-) (H4TETA=2,2',2'',2'''-(1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetrayl)tetraacetic acid), BCAED(4-) (H4BCAED=2,2',2'',2'''-{[(1,4-diazepane-1,4-diyl)bis(ethane-2,1-diyl)]bis(azanetriyl)}tetraacetic acid), and BP18C6(2-) (H2BP18C6=6,6'-[(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis(methylene)]dipicolinic acid) were investigated using DFT calculations. Geometry optimizations performed at the TPSSh/6-31G(d,p) level, and using a 46+4f(n) ECP for lanthanides, provide bond lengths of the metal coordination environments in good agreement with the experimental values observed in the X-ray structures. The contractions of the Ln(3+) coordination spheres follow quadratic trends, as observed previously for different isostructural series of complexes. We show here that the parameters obtained from the quantitative analysis of these data can be used to rationalize the observed stability trends across the 4f period. The stability trends along the lanthanide series were also evaluated by calculating the free energy for the reaction [La(L)](n+/-)(sol)+Ln(3+)(sol)→[Ln(L)](n+/-)(sol)+La(3+)(sol). A parameterization of the Ln(3+) radii was performed by minimizing the differences between experimental and calculated standard hydration free energies. The calculated stability trends are in good agreement with the experimental stability constants, which increase markedly across the series for BCAED(4-) complexes, increase smoothly for the TETA(4-) analogues, and decrease in the case of BP18C6(2-) complexes. The resulting stability trend is the result of a subtle balance between the increased binding energies of the ligand across the lanthanide series, which contribute to an increasing complex stability, and the increase in the absolute values of hydration energies along the 4f period.

  8. Lanthanides in humic acids of soils, paleosols and cultural horizons (Southern Urals, Russia)

    NASA Astrophysics Data System (ADS)

    Dergacheva, Maria; Nekrasova, Olga

    2013-04-01

    .13 to 0.49 mg/kg, terbium and lutetium - two orders of magnitude. The quantities determined by us for lanthanum is also high at 1,9-3,3 mg/kg. In this case all lanthanides in modern soils have the degree of accumulation in humic acids distinguished from other objects: Ce>La>Sm>Yb>Eu>Tb>Lu. In the paleosols and cultural layer these series are identical: Ce>La>Yb>Sm>Eu>Lu>Tb. There is suggested the approach to direct estimation of share of the lanthanides connected by humic acids in the their total soil pool which includes recalculation of the content of separate elements in humic acid preparations on carbon of soil humic acids (in mg/kg) and the subsequent correlation of their quantities. The content of the total organic carbon in soil, a share of humic acids as a humus part, the lanthanide content and weight carbon percentage in humic acid preparations were considered during recalculations. The results have shown that the highest shares of all elements are found in modern background soils, the lowest - in the soils buried under barrows. The total percentage of all lanthanides in humic acids is 4.63% in relation to their content in modern soil, 1.56% - in CL and 1.36% - in buried paleosols.

  9. Relationship between lanthanide contents in aquatic turtles and environmental exposures.

    PubMed

    Censi, P; Randazzo, L A; D'Angelo, S; Saiano, F; Zuddas, P; Mazzola, S; Cuttitta, A

    2013-05-01

    Trace elements released in the environment during agricultural practices can be incorporated and accumulated in biological fluids and tissues of living organisms. The assessment of these exposures were carried out investigating lanthanide distributions in blood and exoskeleton samples collected from Emys trinacris turtle specimens coming from sites with anthropogenic discharge in western and south Sicily, along migration paths of many bird species from Africa to Europe. The data show a significant (Rxy=0.72; Rxy>0.67; α=0.025) linear relationship between the size of turtle specimens and the lanthanide contents in blood lower than 0.4 μg L(-1) whereas this relationship disappears in blood with higher lanthanide contents. Comparative evaluations of normalised concentrations show that lanthanides fractionate between blood and exoskeleton inducing antithetical lanthanide patterns therein. These features are more evident in specimens with high lanthanide contents in blood, suggesting that lanthanide accumulations in the exoskeleton can represent the physiological response of E. trinacris to environmental and the further confirmation of relationship occurring between the environmental and the biological fluids.

  10. Lanthanide Complexes as a Test for Evidence of Life

    NASA Technical Reports Server (NTRS)

    Benavides, Jeannette

    1998-01-01

    The objective of this research is to advance the understanding of the interaction of lanthanide metals with biological organic molecules and to develop a technique to detect these compounds in the solid state and in situ in Mars and other planetary bodies. The detection of these complexes should provide evidence of life past or present. In addition, detection of the metals alone will provide important information about the geological history of a planetary body. Lanthanides were chosen as our focus of interest because they form very stable complexes with organic molecules in solution and they produce intense luminescence in the ultraviolet and visible spectra. The rare earth complexes available are mostly synthetic for diverse applications in medicine. There is not much work done on the complexes that form in nature. Lanthanides have many applications and they are mined aR over the world, however, since the interest has been only in the elements, the analytical techniques employed destroy any organic ligands that may be present. In order to determine if and which lanthanide complexes form in nature and their concentration, soil samples have been collected from areas rich in soluble lanthanide compounds like phosphates and also rich in vegetation. The soil samples will be analyzed and the lanthanide complexes if present will be isolated and characterized. A spectrometer to detect the lanthanide complexes in situ and in the solid state will be designed. In this workshop, the research approach and its implications will be discussed.

  11. Spectral studies of Lanthanide interactions with membrane surfaces

    SciTech Connect

    Karukstis, K.K.; Kao, M.Y.; Savin, D.A.; Bittker, R.A.; Kaphengst, K.J.; Emetarom, C.M.; Naito, N.R.; Takamoto, D.Y.

    1995-03-23

    We have monitored the interactions of the series of trivalent lanthanide cations with the thylakoid membrane surface of spinach chloroplasts using two complementary spectral techniques. Measurements of the fluorescence emission of the extrinsic probe 2-p-toluidinonaphthalene-6-sulfonate (TNS) and the absorbance of the intrinsic chromophore chlorophyll provide two sensitive means of characterizing the dependence of the cation-membrane interaction on the nature of the cation. In these systems, added lanthanide cations adsorb onto the membrane surface to neutralize exposed segments of membrane-embedded protein complexes. The lanthanide-induced charge neutralization increases the proximity of added TNS anion to the membrane surface as evidenced by variations in the TNS fluorescence level and wavelength of maximum emission. Our results reveal a strong dependence of TNS fluorescence parameters on both lanthanide size and total orbital angular momentum L value. Lanthanides with greater charge density (small size and/or low L value) enhance the TNS fluorescence level to a greater extent. A possible origin for the lanthanide-dependent TNS fluorescence levels is suggested in terms of a heterogeneity in the number and type of TNS binding sites. The data are consistent with the proposal that larger lanthanides with smaller enthalpies of hydration induce more significant membrane appression. 59 refs., 9 figs., 2 tabs.

  12. Lanthanide coordination polymers: Synthesis, diverse structure and luminescence properties

    SciTech Connect

    Song, Xue-Qin Lei, Yao-Kun; Wang, Xiao-Run; Zhao, Meng-Meng; Peng, Yun-Qiao; Cheng, Guo-Quan

    2014-10-15

    The new semirigid exo-bidentate ligand incorporating furfurysalicylamide terminal groups, namely, 1,4-bis([(2′-furfurylaminoformyl)phenoxyl]methyl)-2,5-bismethylbenzene (L) was synthesized and used as building blocks for constructing lanthanide coordination polymers with luminescent properties. The series of lanthanide nitrate complexes have been characterized by elemental analysis, IR spectroscopy, and X-ray diffraction analysis. The semirigid ligand L, as a bridging ligand, reacts with lanthanide nitrates forming three distinct structure types: chiral noninterpenetrated two-dimensional (2D) honeycomblike (6,3) (hcb, Schläfli symbol 6{sup 3}, vertex symbol 6 6 6) topological network as type I, 1D zigzag chain as type II and 1D trapezoid ladder-like chain as type III. The structural diversities indicate that lanthanide contraction effect played significant roles in the structural self-assembled process. The luminescent properties of Eu{sup III}, Tb{sup III} and Dy{sup III} complexes are discussed in detail. Due to the good match between the lowest triplet state of the ligand and the resonant energy level of the lanthanide ion, the lanthanide ions in Eu{sup III}, Tb{sup III} and Dy{sup III} complexes can be efficiently sensitized by the ligand. - Graphical abstract: We present herein six lanthanide coordination polymers of a new semirigid exo-bidentate ligand which not only display diverse structures but also possess strong luminescence properties. - Highlights: • We present lanthanide coordination polymers of a new semirigid exo-bidentate ligand. • The lanthanide coordination polymers exhibit diverse structures. • The luminescent properties of Tb{sup III}, Eu{sup III} and Dy{sup III} complexes are discussed in detail.

  13. Derivatives of imidopyrophosphoric acids as extractants. Part 2. The extraction behaviour of some tetraalkyl derivatives with selected lanthanide ions

    SciTech Connect

    Preez, J.G.H. du; Krueger, L.; Sumter, N.M. )

    1992-12-01

    The extraction behaviour of some tetraalkyl derivatives towards selected lanthanide ions is discussed. The effect of structure and size of the alkyl group, pH of aqueous solution and nature of counter anions (nitrate and chloride) on the extraction were investigated. High extraction efficiencies were achieved, but their separation factors were only moderately good, except for those between the smaller ions (Ho to Yb) which were good. 7 refs., 14 figs., 3 tabs.

  14. N,N'-Dialkyl-N,N'-diaryl-1,10-phenanthroline-2,9-dicarboxamides as donor ligands for separation of rare earth elements with a high and unusual selectivity. DFT computational and experimental studies.

    PubMed

    Ustynyuk, Yu A; Borisova, N E; Babain, V A; Gloriozov, I P; Manuilov, A Y; Kalmykov, S N; Alyapyshev, M Yu; Tkachenko, L I; Kenf, E V; Ustynyuk, N A

    2015-05-01

    N,N'-Dialkyl-N,N'-diaryl-1,10-phenanthroline-2,9-dicarboxamides (IV) were predicted (DFT simulation) and then were proved experimentally to be efficient donor ligands with high and unusual selectivity for the extraction separation of lanthanides. Distribution coefficients D of lanthanide cations in two-phase aqueous solution-polar organic solvent decrease with increasing Ln(3+) atomic number. The selectivity factors SFLn1/Ln2 for adjacent lanthanide ions were found to be about 3.

  15. The solution structure of Ln (DOTP) 5- complexxes. A comparison of lanthanide-induced paramagnetic shifts with the MMX energy-minimized structure

    NASA Astrophysics Data System (ADS)

    Geraldes, Carlos F. G. C.; Sherry, A. Dean; Kiefer, Garry E.

    Complexes between the trivalent lanthanide ions and the macrocyclic chelate 1,4,7,10-tetraazacyclododecane- N,N',N″,N‴-tetra(methylene phosphonate) (DOTP) have been examined by high-resolution NMR spectroscopy. The proton spectra of the diamagnetic La(DOTP) 5- and Lu(DOTP) 5- complexes provide evidence for very rigid chelate structures with the ethylenediamine-containing chelate rings essentially locked into a single conformation at room temperature. The activation energy for ethylenediamine chelate ring interconversions in these complexes is approximately 100 kJ mol -1, considerably higher than that reported previously for the corresponding Ln(DOTA) - complexes (DOTA is the tetraacetate analog of DOTP). Lanthanide-induced shifts are reported for all 1H, 13C, and 31P nuclei in 11 Ln(DOTP) 5- complexes. The proton spectra of these complexes display unusually large lanthanide-induced shifts, one showing a spectrum in which the 1H resonances span 900 ppm. The contact and pseudocontact contributions to these shifts were separated using Reilley's temperature-independent method and the resulting pseudocontact lanthanide-induced NMR shifts were in excellent agreement with those calculated for a structure derived using MMX molecular modeling methods. The pseudocontact shifts provide evidence for Ln (DOTP) 5- chelates which have virtually identical structures along the lanthanide series, with the possible exception of Tm(DOTP) 5-.

  16. Ion exchange in hydroxyapatite with lanthanides.

    PubMed

    Cawthray, Jacqueline F; Creagh, A Louise; Haynes, Charles A; Orvig, Chris

    2015-02-16

    Naturally occurring hydroxyapatite, Ca5(PO4)3(OH) (HAP), is the main inorganic component of bone matrix, with synthetic analogues finding applications in bioceramics and catalysis. An interesting and valuable property of both natural and synthetic HAP is the ability to undergo cationic and anionic substitution. The lanthanides are well-suited for substitution for the Ca(2+) sites within HAP, because of their similarities in ionic radii, donor atom requirements, and coordination geometries. We have used isothermal titration calorimetry (ITC) to investigate the thermodynamics of ion exchange in HAP with a representative series of lanthanide ions, La(3+), Sm(3+), Gd(3+), Ho(3+), Yb(3+) and Lu(3+), reporting the association constant (Ka), ion-exchange thermodynamic parameters (ΔH, ΔS, ΔG), and binding stoichiometry (n). We also probe the nature of the La(3+):HAP interaction by solid-state nuclear magnetic resonance ((31)P NMR), X-ray diffraction (XRD), and inductively coupled plasma-optical emission spectroscopy (ICP-OES), in support of the ITC results.

  17. Picosecond dynamics from lanthanide chloride melts

    NASA Astrophysics Data System (ADS)

    Kalampounias, Angelos G.

    2012-12-01

    The picosecond dynamics of molten lanthanide chlorides is studied by means of vibrational spectroscopy. Polarized Raman spectra of molten LaCl3, NdCl3, GdCl3, DyCl3, HoCl3 and YCl3 are fitted to a model enabling to obtain the times of vibrational dephasing, tν and vibrational frequency modulation tω. Our aim is to find possible sensitive indicators of short-time dynamics. It has been found that all lanthanide chlorides exhibit qualitative similarities in the vibrational relaxation and frequency modulation times in the molten state. It appears that the vibrational correlation functions of all melts comply with the Rothschild approach assuming that the environmental modulation is described by a stretched exponential decay. The evolution of the dispersion parameter α indicates the deviation of the melts from the model simple liquid and the similar local environment in which the oscillator is placed and with which it is coupled. The "packing" of the anions around central La3+ cation seems to be the key factor for the structure and the dynamics of the melts. The results are discussed in the framework of the current phenomenological status of the field.

  18. Ultrasonic relaxations in lanthanide phosphate glasses

    NASA Astrophysics Data System (ADS)

    Carini, G.; D'angelo, G.; Federico, M.; Tripodo, G.; Saunders, G. A.; Senin, H. B.

    1994-08-01

    The attenuation and velocity of ultrasonic waves of frequencies in the range of 10 to 90 MHz have been measured in La2O3-P2O5 and Sm2O3-P2O5 glasses with high lanthanide concentrations as a function of temperature between 1.5 and 400 K. Two distinct features characterize the attenuation behavior: (i) a plateau at temperatures below 15 K and (ii) a broad high-temperature peak. The former feature is interpreted in terms of the phonon-assisted relaxation of two-level systems and the latter by assuming the existence of a distribution of thermally activated relaxing centers. For both these mechanisms the product of the deformation potential squared and the density of relaxing particles decreases with increasing lanthanide-ion concentration. This result, taken together with previous observations of the properties of oxide glasses, provides physical insight into the microscopic origin of the relaxation effects and suggests that the source of the low- and high-temperature attenuation mechanisms is the same. At temperatures below 100 K, the sound velocity, after the subtraction of the relaxation and anharmonic contributions, follows a linear law as predicted by the soft-potential model for the relaxation of soft harmonic oscillators. An encouraging agreement is obtained between the parameters regulating this mechanism and those determined from the acoustic attenuation plateau.

  19. Ab Initio Crystal Field for Lanthanides.

    PubMed

    Ungur, Liviu; Chibotaru, Liviu F

    2017-03-13

    An ab initio methodology for the first-principle derivation of crystal-field (CF) parameters for lanthanides is described. The methodology is applied to the analysis of CF parameters in [Tb(Pc)2 ](-) (Pc=phthalocyanine) and Dy4 K2 ([Dy(4) K(2) O(OtBu)(12) ]) complexes, and compared with often used approximate and model descriptions. It is found that the application of geometry symmetrization, and the use of electrostatic point-charge and phenomenological CF models, lead to unacceptably large deviations from predictions based on ab initio calculations for experimental geometry. It is shown how the predictions of standard CASSCF (Complete Active Space Self-Consistent Field) calculations (with 4f orbitals in the active space) can be systematically improved by including effects of dynamical electronic correlation (CASPT2 step) and by admixing electronic configurations of the 5d shell. This is exemplified for the well-studied Er-trensal complex (H3 trensal=2,2',2"-tris(salicylideneimido)trimethylamine). The electrostatic contributions to CF parameters in this complex, calculated with true charge distributions in the ligands, yield less than half of the total CF splitting, thus pointing to the dominant role of covalent effects. This analysis allows the conclusion that ab initio crystal field is an essential tool for the decent description of lanthanides.

  20. The Crystal Structure of Lanthanide Zirconates

    NASA Astrophysics Data System (ADS)

    Clements, Richard; Kennedy, Brendan; Ling, Christopher; Stampfl, Anton P. J.

    2010-03-01

    The lanthanide zirconates of composition Ln2Zr2O7 (Ln = La-Gd) are of interest for use in inert matrix fuels and nuclear wasteforms. The series undergoes a pyrochlore to fluorite phase transition as a function of the Ln atomic radii. The phase transition has been attributed to disordering of both the cation and the anion [1]. We have undertaken a synthesis of the lanthanide zirconate series Ln2Zr2O7 (Ln = La-Gd), Ln0.2Zr0.8O1.9 (Ln = Tb-Yb) and NdxHo2-xZr2O7 (0

  1. Luminescent lanthanide complexes for advanced photonic applications

    NASA Astrophysics Data System (ADS)

    Puntus, Lada N.; Sergeeva, Elena V.; Antonov, Dmitrii Y.; Lyssenko, Konstantin A.; Kajzar, Francois

    2010-10-01

    The lanthanide compounds containing unsymmetrical β-diketone with [2.2]paracyclophane moiety in particular the europium complex with three [1-(4-[2.2]paracyclophanyl)]-3-phenylpropane-1,3-dione and 1,10-phenanthroline has been synthesized for the first time. The optical properties of [2.2]paracyclophane-derived ligands (symmetrical β-diketones and their respective N-phenylimines) as well as those of the europium complex were studied by UV-visible and luminescence spectroscopy. The diastereomers (racemic chiral, (R*,R*)- and achiral meso, (R,S)-) of the β-diketones and their respective N-phenylimines exhibit quite identical absorption spectra with intense broad band centered at 360 and 380 nm, respectively. The designed blue-emitting unsymmetrical β-diketone acts as a very efficient sensitizer of the EuIII emission and does so in the near-UV region. The introduction of [2.2]paracyclophane moiety in the β-diketones allows to expand the excitation wavelength of the lanthanide complex up to 500 nm and to obtain the relatively high overall quantum yield for the europium ion.

  2. Some aspects of the geochemistry of yttrium and the lanthanides

    USGS Publications Warehouse

    Fleischer, Michael

    1965-01-01

    Recent data on the relative abundances of the lanthanides and yttrium in meteorites, basaltic rocks, granitic rocks and sedimentary rocks are reviewed. It is shown that the data are inadequate to substantiate or to disprove Taylor's derivation from these data of a 1:1 abundance ratio of basaltic to granitic rocks in the continental crust. Graphs are given to illustrate the variation of lanthanides in minerals with paragenesis. Both the paragenesis and the crystal chemistry of minerals affect the composition of the lanthanides.

  3. Nuclear magnetic resonance structural studies of an axially symmetric lanthanide ion chelate in aqueous solution

    NASA Astrophysics Data System (ADS)

    Sherry, A. D.; Singh, M.; Geraldes, C. F. G. C.

    The complexes of the macrocyclic ligand 1,4, 7-triazacyclononane- N,N',N″-triacetic acid (NOTA) with the paramagnetic trivalent lanthanide canons have been examined by proton and 13C magnetic resonance spectroscopy. Lanthanide-induced shifts (LIS) have been measured for all proton and carbon resonances in nine paramagnetic Ln(NOTA) complexes at 25 and 70°C. At both temperatures the ethylene protons appear as a pair of resonances forming an AA'XX' splitting pattern (visible only in the Eu(NOTA) spectrum) while the acetate protons remain a singlet. The directions and magnitudes of the 1H and 13C shifts indicate they are dominated by contact interactions in most of the Ln(NOTA) complexes. The 13C spectrum of Pr(NOTA) provides evidence that more than one chelate structure is present in solution. The addition of LiCl to Pr(NOTA) and Eu(NOTA) samples results in significant shifts in the bound 1H and 13C resonances whereas the spectra of Dy(NOTA) and Yb(NOTA) do not change significantly when LiCl is added. These results, along with observed breaks in plots of experimental LIS data versus theoretical pseudocontact and contact shift values, suggest that the early members of the lanthanide ion series form mixed complexes with NOTA in aqueous solution, some with NOTA bound as a hexadentate chelate and some a pentadentate species with one unbound acetate group. The smaller trivalent lanthanide cations (Dy → Yb) appear to form complexes containing only hexadentate chelated NOTA. The contact and pseudocontact contributions to each of the observed LIS have been separated and the resulting pseudocontact shifts for the Dy → Yb complexes agree reasonably well with those calculated using the axial symmetry model. The 1H and 13C relaxation rates determined for three Ln(NOTA) complexes indicate that the smaller lanthanide cations fit into the triazamacrocyclic cavity better than do the larger ions resulting in structurally more rigid Ln(NOTA) complexes.

  4. Monolithic column incorporated with lanthanide metal-organic framework for capillary electrochromatography.

    PubMed

    Zhang, Li-Shun; Du, Pei-Yao; Gu, Wen; Zhao, Qing-Li; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-08-26

    A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA-co-EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu2(ABTC)1.5(H2O)3(DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3',5,5'-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA-co-EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N,N-dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA-co-EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA-co-EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000plates/m), the NKU-1-poly (BMA-co-EDMA) monoliths have displayed greater column efficiency (maximum 210,000plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA-co-EDMA) monoliths are promising stationary phases for CEC separations.

  5. A review on solid phase extraction of actinides and lanthanides with amide based extractants.

    PubMed

    Ansari, Seraj A; Mohapatra, Prasanta K

    2017-05-26

    Solid phase extraction is gaining attention from separation scientists due to its high chromatographic utility. Though both grafted and impregnated forms of solid phase extraction resins are popular, the later is easy to make by impregnating a given organic extractant on to an inert solid support. Solid phase extraction on an impregnated support, also known as extraction chromatography, combines the advantages of liquid-liquid extraction and the ion exchange chromatography methods. On the flip side, the impregnated extraction chromatographic resins are less stable against leaching out of the organic extractant from the pores of the support material. Grafted resins, on the other hand, have a higher stability, which allows their prolong use. The goal of this article is a brief literature review on reported actinide and lanthanide separation methods based on solid phase extractants of both the types, i.e., (i) ligand impregnation on the solid support or (ii) ligand functionalized polymers (chemically bonded resins). Though the literature survey reveals an enormous volume of studies on the extraction chromatographic separation of actinides and lanthanides using several extractants, the focus of the present article is limited to the work carried out with amide based ligands, viz. monoamides, diamides and diglycolamides. The emphasis will be on reported applied experimental results rather than on data pertaining fundamental metal complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The design, synthesis, and characterization of polydentate polyphosphine ligands for actinide and lanthanide extraction

    SciTech Connect

    Harwell, D.E.

    1993-01-01

    As the proliferation of nuclear facilities continues, the need for a cheap, efficient way to selectively extract and separate the elements of the lanthanide and actinide families becomes paramount. [open quotes]Wastes[close quotes] from these facilities often contain long-lived radioactive particles (which must be safely removed and isolated from the environment) along with elements of great commercial or scientific value. Separation schemes exist, but better methods must be developed which offer the selectivity necessary to obtain useful, pure materials. These methods must be safe, easy to use, and cost effective. A series of triphosphine oxide compounds with a tripodal structure have been synthesized for this purpose. These ligands should be ideal for the chelation of lanthanide and actinide ions. They allow for tridentate coordination and should separate radionuclides into small groups of like characteristics on the basis of size. Further selectivity should be provided by the substitution of either electron-withdrawing or electron-donating groups on the phosphorus atom. Electron-withdrawing groups cause the phosphine oxide to become a softer ligand. The synthesis, characterization and properties of this family of tripodal triphosphine oxides will be examined.

  7. Photo-reactive charge trapping memory based on lanthanide complex.

    PubMed

    Zhuang, Jiaqing; Lo, Wai-Sum; Zhou, Li; Sun, Qi-Jun; Chan, Chi-Fai; Zhou, Ye; Han, Su-Ting; Yan, Yan; Wong, Wing-Tak; Wong, Ka-Leung; Roy, V A L

    2015-10-09

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 10(4) s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices.

  8. Gold Coated Lanthanide Phosphate Nanoparticles for Targeted Alpha Generator Radiotherapy

    PubMed Central

    McLaughlin, Mark F.; Woodward, Jonathan; Boll, Rose A.; Wall, Jonathan S.; Rondinone, Adam J.; Kennel, Stephen J.; Mirzadeh, Saed; Robertson, J. David

    2013-01-01

    Targeted radiotherapies maximize cytotoxicty to cancer cells. In vivo α-generator targeted radiotherapies can deliver multiple α particles to a receptor site dramatically amplifying the radiation dose delivered to the target. The major challenge with α-generator radiotherapies is that traditional chelating moieties are unable to sequester the radioactive daughters in the bioconjugate which is critical to minimize toxicity to healthy, non-target tissue. The recoil energy of the 225Ac daughters following α decay will sever any metal-ligand bond used to form the bioconjugate. This work demonstrates that an engineered multilayered nanoparticle-antibody conjugate can deliver multiple α radiations and contain the decay daughters of 225Ac while targeting biologically relevant receptors in a female BALB/c mouse model. These multi-shell nanoparticles combine the radiation resistance of lanthanide phosphate to contain 225Ac and its radioactive decay daughters, the magnetic properties of gadolinium phosphate for easy separation, and established gold chemistry for attachment of targeting moieties. PMID:23349921

  9. Photo-reactive charge trapping memory based on lanthanide complex

    NASA Astrophysics Data System (ADS)

    Zhuang, Jiaqing; Lo, Wai-Sum; Zhou, Li; Sun, Qi-Jun; Chan, Chi-Fai; Zhou, Ye; Han, Su-Ting; Yan, Yan; Wong, Wing-Tak; Wong, Ka-Leung; Roy, V. A. L.

    2015-10-01

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 104 s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices.

  10. Photo-reactive charge trapping memory based on lanthanide complex

    PubMed Central

    Zhuang, Jiaqing; Lo, Wai-Sum; Zhou, Li; Sun, Qi-Jun; Chan, Chi-Fai; Zhou, Ye; Han, Su-Ting; Yan, Yan; Wong, Wing-Tak; Wong, Ka-Leung; Roy, V. A. L.

    2015-01-01

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 104 s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices. PMID:26449199

  11. Luminescent lanthanide nanomaterials: an emerging tool for theranostic applications.

    PubMed

    Ranjan, Shashi; Jayakumar, Muthu Kumara Gnanasammandhan; Zhang, Yong

    2015-05-01

    Lanthanide materials have been gaining popularity for use in various theranostic applications, primarily due to their unique optical properties such as narrow emission bands, multiple emission wavelengths, emission tunability, long fluorescence lifetime and large Stokes shift. Apart from these, some lanthanide materials also exhibit magnetic and light-up conversion properties. Such nanomaterials have been used for a wide range of applications ranging from detection of biomarkers, in vitro and in vivo imaging to therapeutic applications. Recently, combined modalities of lanthanide nanomaterials for simultaneous detection/imaging and delivery of therapeutic agents (termed 'theranostics') have been explored. The various advantages and disadvantages of using lanthanide nanomaterials as theranostic agents and potential areas for future development have been discussed in this review.

  12. Lighting up cells with lanthanide self-assembled helicates

    PubMed Central

    Bünzli, Jean-Claude G.

    2013-01-01

    Lanthanide bioprobes and bioconjugates are ideal luminescent stains in view of their low propensity to photobleaching, sharp emission lines and long excited state lifetimes permitting time-resolved detection for enhanced sensitivity. We show here how the interplay between physical, chemical and biochemical properties allied to microfluidics engineering leads to self-assembled dinuclear lanthanide luminescent probes illuminating live cells and selectively detecting biomarkers expressed by cancerous human breast cells. PMID:24511387

  13. Luminescence properties of lanthanide and ytterbium lanthanide titanate thin films grown by atomic layer deposition

    SciTech Connect

    Hansen, Per-Anders Fjellvåg, Helmer; Nilsen, Ola; Finstad, Terje G.

    2016-01-15

    Lanthanide based luminescent materials are highly suitable as down conversion materials in combination with a UV-absorbing host material. The authors have used TiO{sub 2} as the UV-absorbing host material and investigated the energy transfer between TiO{sub 2} and 11 different lanthanide ions, Ln{sup 3+} (Ln = La, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb) in thin films grown by atomic layer deposition. They have also investigated the possibility to improve the overall energy transfer from TiO{sub 2} to Yb{sup 3+} with a second Ln{sup 3+}, in order to enhance down conversion. The films were grown at a substrate temperature of 300 °C, using the Ln(thd){sub 3}/O{sub 3} (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) and TiCl{sub 4}/H{sub 2}O precursor pairs. The focus of the work is to explore the energy transfer from TiO{sub 2} to Ln{sup 3+} ions, and the energy transfer between Ln{sup 3+} and Yb{sup 3+} ions, which could lead to efficient down conversion. The samples have been characterized by x-ray diffraction, x-ray fluorescence, spectroscopic ellipsometry, and photoluminescence. All films were amorphous as deposited, and the samples have been annealed at 600, 800, and 1000 °C in order to investigate the correlation between the crystallinity and luminescence. The lanthanum titanium oxide samples showed a weak and broad emission centered at 540 nm, which was absent in all the other samples, indicating energy transfer from TiO{sub 2} to Ln{sup 3+} in all other lanthanide samples. In the amorphous phase, all samples, apart from La, Tb, and Tm, showed a typical f-f emission when excited by a 325 nm HeCd laser. None of the samples showed any luminescence after annealing at 1000 °C due to the formation of Ln{sub 2}Ti{sub 2}O{sub 7}. Samples containing Nd, Sm, and Eu show a change in emission spectrum when annealed at 800 °C compared to the as-deposited samples, indicating that the smaller lanthanides crystallize in a different manner than the larger

  14. Extraction separation of rare-earth ions via competitive ligand complexations between aqueous and ionic-liquid phases.

    PubMed

    Sun, Xiaoqi; Bell, Jason R; Luo, Huimin; Dai, Sheng

    2011-08-21

    The extraction separation of rare earth elements is one of the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (trivalent actinide lanthanide separations by phosphorus-reagent extraction from aqueous komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([C(n)mim][NTf(2)] and [C(n)mim][BETI], n = 4,6,8,10) and one pyrrolidinium IL ([C(4)mPy][NTf(2)]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for the separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as a diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and of different anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper. This journal is © The Royal Society of Chemistry 2011

  15. Extraction Separation of Rare-Earth Ions via Competitive Ligand Complexations between Aqueous and Ionic-Liquid Phases

    SciTech Connect

    Luo, Huimin; Sun, Xiaoqi; Bell, Jason R; Dai, Sheng

    2011-01-01

    The extraction separation of rare earth elements is the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([Cnmim][NTf2] and [Cnmim][BETI], n=4,6,8,10) and one pyrrolidinium IL ([C4mPy][NTf2]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper.

  16. Tough photoluminescent hydrogels doped with lanthanide.

    PubMed

    Wang, Mei Xiang; Yang, Can Hui; Liu, Zhen Qi; Zhou, Jinxiong; Xu, Feng; Suo, Zhigang; Yang, Jian Hai; Chen, Yong Mei

    2015-03-01

    Photoluminescent hydrogels have emerged as novel soft materials with potential applications in many fields. Although many photoluminescent hydrogels have been fabricated, their scope of usage has been severely limited by their poor mechanical performance. Here, a facile strategy is reported for preparing lanthanide (Ln)-alginate/polyacrylamide (PAAm) hydrogels with both high toughness and photoluminescence, which has been achieved by doping Ln(3+) ions (Ln = Eu, Tb, Eu/Tb) into alginate/PAAm hydrogel networks, where Ln(3+) ions serve as both photoluminescent emitters and physical cross-linkers. The resulting hydrogels exhibit versatile advantages including excellent mechanical properties (∼ MPa strength, ≈ 20 tensile strains, ≈ 10(4) kJ m(-3) energy dissipation), good photoluminescent performance, tunable emission color, excellent processability, and cytocompatibility. The developed tough photoluminescent hydrogels hold great promises for expanding the usage scope of hydrogels.

  17. Review Article: The Effects of Radiation Chemistry on Solvent Extraction 3: A Review of Actinide and Lanthanide Extraction

    SciTech Connect

    Bruce J. Mincher; Giuseppe Modolo; Stephen P. Mezyk

    2009-12-01

    The partitioning of the long-lived ?-emitters and the high-yield fission products from dissolved nuclear fuel is a key component of processes envisioned for the safe recycling of nuclear fuel and the disposition of high-level waste. These future processes will likely be based on aqueous solvent extraction technologies for light water reactor fuel and consist of four main components for the sequential separation of uranium, fission products, group trivalent actinides and lanthanides, and then trivalent actinides from lanthanides. Since the solvent systems will be in contact with highly radioactive solutions, they must be robust toward radiolytic degradation in an irradiated mixed organic, aqueous acidic environment. Therefore, an understanding of their radiation chemistry is important to the design of a practical system. In the first paper in this series we reviewed the radiation chemistry of irradiated aqueous nitric acid and the tributyl phosphate ligand for uranium extraction in the first step of these extractions. In the second, we reviewed the radiation chemistry of the ligands proposed for use in the extraction of cesium and strontium fission products. Here, we review the radiation chemistry of the ligands that might be used in the third step in the series of separations, for the group extraction of the lanthanides and actinides. This includes traditional organophosphorous reagents such as CMPO and HDEHP, as well as novel reagents such as the amides and diamides currently being investigated.

  18. Lanthanide contraction and magnetism in the heavy rare earth elements.

    PubMed

    Hughes, I D; Däne, M; Ernst, A; Hergert, W; Lüders, M; Poulter, J; Staunton, J B; Svane, A; Szotek, Z; Temmerman, W M

    2007-04-05

    The heavy rare earth elements crystallize into hexagonally close packed (h.c.p.) structures and share a common outer electronic configuration, differing only in the number of 4f electrons they have. These chemically inert 4f electrons set up localized magnetic moments, which are coupled via an indirect exchange interaction involving the conduction electrons. This leads to the formation of a wide variety of magnetic structures, the periodicities of which are often incommensurate with the underlying crystal lattice. Such incommensurate ordering is associated with a 'webbed' topology of the momentum space surface separating the occupied and unoccupied electron states (the Fermi surface). The shape of this surface-and hence the magnetic structure-for the heavy rare earth elements is known to depend on the ratio of the interplanar spacing c and the interatomic, intraplanar spacing a of the h.c.p. lattice. A theoretical understanding of this problem is, however, far from complete. Here, using gadolinium as a prototype for all the heavy rare earth elements, we generate a unified magnetic phase diagram, which unequivocally links the magnetic structures of the heavy rare earths to their lattice parameters. In addition to verifying the importance of the c/a ratio, we find that the atomic unit cell volume plays a separate, distinct role in determining the magnetic properties: we show that the trend from ferromagnetism to incommensurate ordering as atomic number increases is connected to the concomitant decrease in unit cell volume. This volume decrease occurs because of the so-called lanthanide contraction, where the addition of electrons to the poorly shielding 4f orbitals leads to an increase in effective nuclear charge and, correspondingly, a decrease in ionic radii.

  19. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

    Nash, Ken; Martin, Leigh; Lumetta, Gregg

    2015-04-02

    One of the most challenging aspects of advanced processing of used nuclear fuel is the separation of transplutonium actinides from fission product lanthanides. This separation is essential if actinide transmutation options are to be pursued in advanced fuel cycles, as lanthanides compete with actinides for neutrons in both thermal and fast reactors, thus limiting efficiency. The separation is difficult because the chemistry of Am3+ and Cm3+ is nearly identical to that of the trivalent lanthanides (Ln3+). The prior literature teaches that two approaches offer the greatest probability of devising a successful group separation process based on aqueous processes: 1) the application of complexing agents containing ligand donor atoms that are softer than oxygen (N, S, Cl-) or 2) changing the oxidation state of Am to the IV, V, or VI state to increase the essential differences between Am and lanthanide chemistry (an approach utilized in the PUREX process to selectively remove Pu4+ and UO22+ from fission products). The latter approach offers the additional benefit of enabling a separation of Am from Cm, as Cm(III) is resistant to oxidation and so can easily be made to follow the lanthanides. The fundamental limitations of these approaches are that 1) the soft(er) donor atoms that interact more strongly with actinide cations than lanthanides form substantially weaker bonds than oxygen atoms, thus necessitating modification of extraction conditions for adequate phase transfer efficiency, 2) soft donor reagents have been seen to suffer slow phase transfer kinetics and hydro-/radiolytic stability limitations and 3) the upper oxidation states of Am are all moderately strong oxidants, hence of only transient stability in media representative of conventional aqueous separations systems. There are examples in the literature of both approaches having been described. However, it is not clear at present that any extant process is sufficiently robust for application at the scale

  20. Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides

    DOE PAGES

    Hackett, Timothy A.; Baldwin, D. J.; Paudyal, Durga

    2017-05-17

    Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spinmore » orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericity and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low

  1. Lanthanide accumulation in the periplasmic space of Escherichia coli B.

    PubMed Central

    Bayer, M E; Bayer, M H

    1991-01-01

    Treatment of growing Escherichia coli B with lanthanide ions [lanthanum(III), terbium(III), and europium(III)] and subsequent aldehyde-OsO4 fixation caused areas of high contrast to appear within the periplasm (the space between inner and outer membrane of the cell envelope). X-ray microanalysis of ultrathin sections of Epon-embedded or acrylic resin-embedded cells revealed the presence of the lanthanide and of phosphorus in the areas, whose contrast greatly exceeded that of other stained structures. Comparatively small amounts of the lanthanide were also present in the outer membrane and in the cytoplasm. The distribution of the periplasmic areas of high contrast was found to be random and not clustered at areas of current or future septum formation. Irregular cell shapes were observed after lanthanide treatment before onset of fixation. In contrast to glutaraldehyde-OsO4 fixation, glutaraldehyde used as the sole fixer caused a scattered distribution of the lanthanide. Cryofixation (slam-freezing) and freeze substitution revealed a lanthanum stain at both the periplasm and the outer part of the outer membrane. Deenergization of the cell membrane by either phage T4 or carbonyl cyanide m-chlorophenylhydrazone abolished the metal accumulation. Furthermore, addition of excess calcium, administered together with the lanthanide solution, diminished the quantity and size of areas of high contrast. Cells grown in media of high NaCl concentration revealed strongly stained areas of periplasmic precipitates, whereas cells grown under low-salt conditions showed very few high-contrast patches in the periplasm. Terbium treatment (during fixation) enhanced the visibility of the sites of inner-outer membrane contact (the membrane adhesion sites) in plasmolized cells, possibly as the result of an accumulation of the metal at the adhesion domains. The data suggest a rapid interaction of the lanthanides with components of the cell envelope, the periplasm, and the energized inner

  2. Sintering behavior of lanthanide-containing glass-ceramic sealants for solid oxide fuel cells

    SciTech Connect

    Goel, Ashutosh; Reddy, Allu Amarnath; Pascual, Maria J.; Gremillard, Laurent; Malchere, Annie; Ferreira, Jose M.

    2012-05-01

    This article reports on the influence of different lanthanides (La, Nd, Gd and Yb) on sintering behavior of alkaline-earth aluminosilicate glass-ceramics sealants for their application in solid oxide fuel cells (SOFC). All the glasses have been prepared by melt-quench technique. The in situ follow up of sintering behavior of glass powders has been done by high temperature - environmental scanning electron microscope (HT-ESEM) and hot-stage microscope (HSM) while the crystalline phase evolution and assemblage has been analyzed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). All the glass compositions exhibit a glass-in-glass phase separation followed by two stage sintering resulting in well sintered glass powder compacts after heat treatment at 850 C for 1 h. Diopside (CaMgSi{sub 2}O{sub 6}) based phases constituted the major crystalline part in glass-ceramics followed by some minor phases. The increase in lanthanide content in glasses suppressed their tendency towards devitrification, thus, resulting in glass-ceramics with high amount of residual glassy phase (50-96 wt.%) which is expected to facilitate their self-healing behavior during SOFC operation. The electrical conductivity of the investigated glass-ceramics varied between (1.19 and 7.33) x 10{sup -7} S cm{sup -1} (750-800 C), and depended on the ionic field strength of lanthanide cations. Further experimentation with respect to the long term thermal and chemical stability of residual glassy phase under SOFC operation conditions along with high temperature viscosity measurements will be required in order to elucidate the potential of these glass-ceramics as self-healing sealants.

  3. Density functional theory investigations of the trivalent lanthanide and actinide extraction complexes with diglycolamides.

    PubMed

    Wang, Cong-Zhi; Lan, Jian-Hui; Wu, Qun-Yan; Zhao, Yu-Liang; Wang, Xiang-Ke; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-06-21

    At present, designing novel ligands for efficient actinide extraction in spent nuclear fuel reprocessing is extremely challenging due to the complicated chemical behaviors of actinides, the similar chemical properties of minor actinides (MA) and lanthanides, and the vulnerability of organic ligands in acidic radioactive solutions. In this work, a quantum chemical study on Am(III), Cm(III) and Eu(III) complexes with N,N,N',N'-tetraoctyl diglycolamide (TODGA) and N,N'-dimethyl-N,N'-diheptyl-3-oxapentanediamide (DMDHOPDA) has been carried out to explore the extraction behaviors of trivalent actinides (An) and lanthanides (Ln) with diglycolamides from acidic media. It has been found that in the 1 : 1 (ligand : metal) and 2 : 1 stoichiometric complexes, the carbonyl oxygen atoms have stronger coordination ability than the ether oxygen atoms, and the interactions between metal cations and organic ligands are substantially ionic. The neutral ML(NO3)3 (M = Am, Cm, Eu) complexes seem to be the most favorable species in the extraction process, and the predicted relative selectivities are in agreement with experimental results, i.e., the diglycolamide ligands have slightly higher selectivity for Am(III) over Eu(III). Such a thermodynamical priority is probably caused by the higher stabilities of Eu(III) hydration species and Eu(III)-L complexes in aqueous solution compared to their analogues. In addition, our thermodynamic analysis from water to organic medium confirms that DMDHOPDA has higher extraction ability for the trivalent actinides and lanthanides than TODGA, which may be due to the steric hindrance of the bulky alkyl groups of TODGA ligands. This work might provide an insight into understanding the origin of the actinide selectivity and a theoretical basis for designing highly efficient extractants for actinide separation.

  4. Theoretical Insights into Covalency Driven f Element Separations

    SciTech Connect

    Lindsay E. Roy; Nicholas J. Bridges; Leigh R. Martin

    2013-02-01

    The lanthanide series, Am, and Cm are predominantly found in the trivalent oxidation state in aqueous solutions making their separation very difficult to achieve. To date, one of the mostly promising separation processes for transplutonium elements from the lanthanides is the TALSPEAK process. Though the mechanism of the TALSPEAK process is not fully understood, it has been demonstrated to provide excellent separation factors between the lanthanides and the trivalent lanthanides. Through Density Function Theory (DFT) calculations of di 2-ethylenetriamine-N,N,N',N”,N”-pentaacetic acid (DTPA), we set out to understand the structures and stabilities of the aqueous phase complexes [MIII(DTPA)-H2O]2- (M = Nd, Am) as well as the changes in Gibbs free energy for complexation in the gas phase and aqueous solution. Mulliken population analysis, Bader’s Atoms-in-Molecules (AIM) approach, and Natural Bond Orbital (NBO) analysis were then used to analyze the bonding in both molecules. The results discussed below suggest that the preference of the DTPA5- ligand for Am over Nd is mainly due to electrostatic and covalent interactions from the oxygen atoms with the nitrogen chelates provide an additional, yet small, covalent interaction. These results question the exclusive use of hard and soft acids and bases (HSAB) concepts for the design of extracting reagents and suggest that hard-soft interactions play more of a role in the separations process than previously thought.

  5. A Simple Empirical Analysis of the Enthalpies of Formation of Lanthanide Halides and Oxides.

    ERIC Educational Resources Information Center

    Smith, Derek W.

    1986-01-01

    Proposes a simple and general method whereby the lattice energies of lanthanide(II) and (IV) compounds are derived directly from those found experimentally for the corresponding lanthanide(III) compounds. The method is applicable to all lanthanide halides and oxides and involves calculations which can be easily and quickly performed by students.…

  6. First observation of enhanced luminescence from single lanthanide chelates on silver nanorods.

    PubMed

    Zhang, Jian; Ray, Krishanu; Fu, Yi; Lakowicz, Joseph R

    2014-08-25

    We used near-field interactions with a silver nanorod (AgNR) to greatly enhance luminescence of a lanthanide (Ln) chelate. The enhancement factor was 280-fold, making single lanthanide luminescence detectable. This is also the first observation on single molecule detection (SMD) of a lanthanide dye.

  7. A Simple Empirical Analysis of the Enthalpies of Formation of Lanthanide Halides and Oxides.

    ERIC Educational Resources Information Center

    Smith, Derek W.

    1986-01-01

    Proposes a simple and general method whereby the lattice energies of lanthanide(II) and (IV) compounds are derived directly from those found experimentally for the corresponding lanthanide(III) compounds. The method is applicable to all lanthanide halides and oxides and involves calculations which can be easily and quickly performed by students.…

  8. Luminescent chiral lanthanide(III) complexes as potential molecular probes

    PubMed Central

    Muller, Gilles

    2009-01-01

    This perspective gives an introduction into the design of luminescent lanthanide(III)-containing complexes possessing chiral properties and used to probe biological materials. The first part briefly describes general principles, focusing on the optical aspect (i.e. lanthanide luminescence, sensitization processes) of the most emissive trivalent lanthanide ions, europium and terbium, incorporated into molecular luminescent edifices. This is followed by a short discussion on the importance of chirality in the biological and pharmaceutical fields. The second part is devoted to the assessment of the chiroptical spectroscopic tools available (typically circular dichroism and circularly polarized luminescence) and the strategies used to introduce a chiral feature into luminescent lanthanide(III) complexes (chiral structure resulting from a chiral arrangement of the ligand molecules surrounding the luminescent center or presence of chiral centers in the ligand molecules). Finally, the last part illustrates these fundamental principles with recent selected examples of such chiral luminescent lanthanide-based compounds used as potential probes of biomolecular substrates. PMID:19885510

  9. Lanthanide-doped hollow nanomaterials as theranostic agents.

    PubMed

    Kang, Xiaojiao; Li, Chunxia; Cheng, Ziyong; Ma, Ping'an; Hou, Zhiyao; Lin, Jun

    2014-01-01

    The field of theranostics has sprung up to achieve personalized medicine. The theranostics fuses diagnostic and therapeutic functions, empowering early diagnosis, targeted drug delivery, and real-time monitoring of treatment effect into one step. One particularly attractive class of nanomaterials for theranostic application is lanthanide-doped hollow nanomaterials (LDHNs). Because of the existence of lanthanide ions, LDHNs show outstanding fluorescent and paramagnetic properties, enabling them to be used as multimodal bioimaging agents. Synchronously, the huge interior cavities of LDHNs are able to be applied as efficacious tools for storage and delivery of therapeutic agents. The LDHNs can be divided into two types based on difference of component: single-phase lanthanide-doped hollow nanomaterials and lanthanide-doped hollow nanocomposites. We describe the synthesis of first kind of nanomaterials by use of hard template, soft template, template-free, and self-sacrificing template method. For lanthanide-doped hollow nanocomposites, we divide the preparation strategies into three kinds (one-step, two-step, and multistep method) according to the synthetic procedures. Furthermore, we also illustrate the potential bioapplications of these LDHNs, including biodetection, imaging (fluorescent imaging and magnetic resonance imaging), drug/gene delivery, and other therapeutic applications. © 2013 Wiley Periodicals, Inc.

  10. Enantiomeric purity determination of acetyl-L-carnitine by NMR with chiral lanthanide shift reagents.

    PubMed

    Kagawa, Miyuki; Machida, Yoshio; Nishi, Hiroyuki; Haginaka, Jun

    2005-08-10

    Enantiomer signal separation of acetyl-carnitine chloride was obtained on a 500 MHz Nuclear Magnetic Resonance (1H NMR) analysis by fast diastereomeric interaction with chiral shift reagents such as chiral lanthanide-camphorato or chiral samarium-pdta shift reagents. Effects of the kinds of chiral shift reagents and the molar ratio of chiral shift reagent to acetyl-carnitine chloride on enantiomer signal separation were investigated and evaluated. Optimization of the experimental conditions provided two significant split signals for the enantiomers, leading to the successful quantitative analysis. Distinguishment of 0.5% of the minor enantiomer (D-form) in acetyl-L-carnitine chloride was found to be possible by 1H NMR with tris[3-(heptafluoropropylhydroxymethylene)-D-camphorato] and praseodymium derivative, (Pr[hfc]3), as chiral shift reagents.

  11. Lanthanide Metal-Organic Framework Materials

    NASA Astrophysics Data System (ADS)

    Hsieh, Ping-Yen; Green, Mark A.; Briber, Robert M.

    2009-03-01

    A series of lanthanide metal-organic framework materials (MOF) with variable organic linkages including benzene-dicarboxylic acid (BDC); 1,3,5-benzene-tricarboxylic acid (BTC); and 1,3,5-tris(4-carboxyphenyl)benzene (BTB) have been synthesized. The low density and high porosity of MOFs make them candidates molecular sieve or hydrogen storage materials. The crystal structures have been determined using a combination of single crystal X-ray diffractometer and synchrotron powder X-ray diffraction work. Holmium with the BDC ligand material (Ho-BDC) crystallizes in a monoclinic C2/c space group, with lattice parameters of a = 17.06 å, b = 10.67 å, c = 10.57 å, b = 96.12^o. The crystal structure of Ho-BTC is in tetragonal P 41 2 2 space group and Ho-BTB is in a triclinic P-1 space group. A comprehensive examination of Ho-MOF with different ligands by x-ray and thermogravimetric analysis shows that there is a stable nanoporous structure for dehydrated Ho-BTC up to 250^oC. The same phenomenon is not observed in the Ho-BDC and Ho-BTB materials. The collapsed structure with BDC and BTB indicates the stability of dehydrated samples is strongly related to the interactions between the metal and the organic linkers.

  12. Structural Effects of Lanthanide Dopants on Alumina

    PubMed Central

    Patel, Ketan; Blair, Victoria; Douglas, Justin; Dai, Qilin; Liu, Yaohua; Ren, Shenqiang; Brennan, Raymond

    2017-01-01

    Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. The delay in phase transition (θ → α), and alteration of powder morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. This study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications. PMID:28059121

  13. Structural Effects of Lanthanide Dopants on Alumina

    DOE PAGES

    Patel, Ketan; Blair, Victoria; Douglas, Justin; ...

    2017-01-06

    Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. In addition, the delay in phase transition (θ → α), and alteration of powdermore » morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. Lastly, this study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications.« less

  14. Thermodynamics of the lanthanide with organic acids

    SciTech Connect

    Al-Ansi, T.Y.

    1985-01-01

    The thermodynamic parameters (..delta..G, ..delta..H, and ..delta..S) of the formation of the europium monooxalate complex has been determined at 25/sup 0/C and 0.1 M ionic strength (NaClO/sub 4/) by means of solvent extraction. ..delta..G values show that the 5-membered oxalate ring is more stable than those of longer chain aliphatic dicarboxylates (malonate, succinate, glutarate or adipate). This effect is reflected in the complexation entropy values, ..delta..S/sub 101/. The stability constants for trivalent Eu complexes with benzene polycarboxylates (trimetallitate, hemimellitate, and pyromellitate) were measured using a solvent extraction system at 25/sup 0/C and 0.1 M ionic strength (NaClO/sub 4/). The values measured at varying hydrogen ion concentrations show that either protonated species do not form or their formation constants are not significant enough to influence the overall observed conditional constants. The enthalpies for lanthanide hemimellitate and pyromellitate were determined by calorimetric titration. Solvent extraction studies were conducted for Eu and Am complexes with mellitate at 0.1 M and 2.0 M (NaClO/sub 4/). In this case the stability constants for protonated species, MHL and MH/sub 2/L, were determined. The effective charges calculated from the experimental free energy values of these polycarboxylates indicate a significant charge polarization in the ligand which could be induced through inductive and/or resonance effects.

  15. Structural Effects of Lanthanide Dopants on Alumina

    NASA Astrophysics Data System (ADS)

    Patel, Ketan; Blair, Victoria; Douglas, Justin; Dai, Qilin; Liu, Yaohua; Ren, Shenqiang; Brennan, Raymond

    2017-01-01

    Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. The delay in phase transition (θ → α), and alteration of powder morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. This study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications.

  16. Remarkable luminescence properties of lanthanide complexes with asymmetric dodecahedron structures.

    PubMed

    Miyata, Kohei; Nakagawa, Tetsuya; Kawakami, Ryuhei; Kita, Yuki; Sugimoto, Katsufumi; Nakashima, Takuya; Harada, Takashi; Kawai, Tsuyoshi; Hasegawa, Yasuchika

    2011-01-10

    The distorted coordination structures and luminescence properties of novel lanthanide complexes with oxo-linked bidentate phosphane oxide ligands--4,5-bis(diphenylphosphoryl)-9,9-dimethylxanthene (xantpo), 4,5-bis(di-tert-butylphosphoryl)-9,9-dimethylxanthene (tBu-xantpo), and bis[(2-diphenylphosphoryl)phenyl] ether (dpepo)--and low-vibrational frequency hexafluoroacetylacetonato (hfa) ligands are reported. The lanthanide complexes exhibit characteristic square antiprism and trigonal dodecahedron structures with eight-coordinated oxygen atoms. The luminescence properties of these complexes are characterized by their emission quantum yields, emission lifetimes, and their radiative and nonradiative rate constants. Lanthanide complexes with dodecahedron structures offer markedly high emission quantum yields (Eu: 55-72 %, Sm: 2.4-5.0 % in [D(6)]acetone) due to enhancement of the electric dipole transition and suppression of vibrational relaxation. These remarkable luminescence properties are elucidated in terms of their distorted coordination structures.

  17. Strong exchange coupling in lanthanide bis(phthalocyaninato) sandwich compounds

    NASA Astrophysics Data System (ADS)

    Trojan, Kathleen L.; Hatfield, William E.; Kepler, Keith D.; Kirk, Martin L.

    1991-03-01

    Bis (phthalocyaninato) lanthanide sandwich compounds, which have the formula Pc2-LnPc1-, have been synthesized for Ln = terbium, homium and lutecium. Low temperature magnetic susceptibility data for Ho (Pc)2 and Tb (Pc)2 show a reduction in moment from that which is expected for the lanthanide free ion value, which correlates with an antiferromagnetic exchange between the lanthanide f-electrons and the phthalocyaninato ligand radical electron. The g-factors determined from least squares fitting of the Curie-Weiss Law to the magnetic data show excellent agreement to the g-factors calculated for the strongly coupled state. Magnetic moments calculated from the experimentally determined Curie constants are also in good agreement with those expected for the strongly coupled state.

  18. Mixed lanthanide oxide nanoparticles as dual imaging agent in biomedicine

    PubMed Central

    Xu, Wenlong; Bony, Badrul Alam; Kim, Cho Rong; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2013-01-01

    There is no doubt that the molecular imaging is an extremely important technique in diagnosing diseases. Dual imaging is emerging as a step forward in molecular imaging technique because it can provide us with more information useful for diagnosing diseases than single imaging. Therefore, diverse dual imaging modalities should be developed. Molecular imaging generally relies on imaging agents. Mixed lanthanide oxide nanoparticles could be valuable materials for dual magnetic resonance imaging (MRI)-fluorescent imaging (FI) because they have both excellent and diverse magnetic and fluorescent properties useful for dual MRI-FI, depending on lanthanide ions used. Since they are mixed nanoparticles, they are compact, robust, and stable, which is extremely useful for biomedical applications. They can be also easily synthesized with facile composition control. In this study, we explored three systems of ultrasmall mixed lanthanide (Dy/Eu, Ho/Eu, and Ho/Tb) oxide nanoparticles to demonstrate their usefulness as dual T2 MRI–FI agents. PMID:24220641

  19. Synthesis and chemistry of yttrium and lanthanide metal complexes

    SciTech Connect

    Evans, W.J.

    1991-09-01

    The objective of this research project is to determine the special features of complexes of yttrium and the lanthanide metals which will allow the design and synthesis of materials with unique chemical, physical, and catalytic properties. Past studies of yttrium and lanthanide metal alkyl and hydride complexes stabilized by cyclopentadienyl co-ligands have shown that a substantial, often singular, organometallic chemistry is available via these metals. More extensive utilization of the chemical opportunities available through yttrium and the lanthanides would be possible, however, if stabilizing ancillary ligand systems less sensitive to oxidation and protonolysis than cyclopentadienides could be developed. Alkoxide ligands are attractive in this regard and our recent research had focused on alkoxides and the special opportunities they can provide to these metals. 6 refs., 10 figs.

  20. Mixed lanthanide oxide nanoparticles as dual imaging agent in biomedicine

    NASA Astrophysics Data System (ADS)

    Xu, Wenlong; Bony, Badrul Alam; Kim, Cho Rong; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2013-11-01

    There is no doubt that the molecular imaging is an extremely important technique in diagnosing diseases. Dual imaging is emerging as a step forward in molecular imaging technique because it can provide us with more information useful for diagnosing diseases than single imaging. Therefore, diverse dual imaging modalities should be developed. Molecular imaging generally relies on imaging agents. Mixed lanthanide oxide nanoparticles could be valuable materials for dual magnetic resonance imaging (MRI)-fluorescent imaging (FI) because they have both excellent and diverse magnetic and fluorescent properties useful for dual MRI-FI, depending on lanthanide ions used. Since they are mixed nanoparticles, they are compact, robust, and stable, which is extremely useful for biomedical applications. They can be also easily synthesized with facile composition control. In this study, we explored three systems of ultrasmall mixed lanthanide (Dy/Eu, Ho/Eu, and Ho/Tb) oxide nanoparticles to demonstrate their usefulness as dual T2 MRI-FI agents.

  1. Lanthanides in molecular magnetism: so fascinating, so challenging.

    PubMed

    Luzon, Javier; Sessoli, Roberta

    2012-11-28

    Due to their usual large magnetic moments and large magnetic anisotropy lanthanide ions are investigated for the search of Single Molecule Magnets with high blocking temperature. However, the low symmetry crystal environment, the complexity of the electronic states or the non-collinearity of the magnetic anisotropy easy-axes in polynuclear systems make the rationalization of the magnetic behaviour of lanthanide based molecular systems difficult. In this perspective article we expose a methodology in which the use of additional characterization techniques, like single crystal magnetic measurements or luminescence experiments, complemented by relativistic ab initio calculations and a suitable choice of spin Hamiltonian models, can be of great help in order to overcome such difficulties, representing an essential step for the rational design of lanthanide based Single Molecule Magnets with enhanced physical properties.

  2. Topological aspects of lanthanide-adipate-aqua compounds: Close packed and open framework structures

    NASA Astrophysics Data System (ADS)

    Chowdhuri, Durga Sankar; Kumar Jana, Swapan; Hazari, Debdoot; Zangrando, Ennio; Dalai, Sudipta

    2013-07-01

    A search in the Cambridge Structural Database (CSD) for lanthanide complexes with adipate [OOC(CH2)4COO]2- and aqua ligands retrieved a fair number of compounds. To this dataset a new lanthanum metal-organic framework, {[La2(adip)3(H2O)2] (1) (adipH2=adipic acid), synthesised and structurally characterized in these labs, was included. The crystal structures of these coordination polymers, of general formulation [Ln2(adip)3(H2O)x], exhibit a variety of topologies and dimensionality, which were clustered in different classes and described in detail. It was explored that the majority of these evidences the presence of metal chains or dinuclear Ln2 entities (separated in both cases by 4.0-4.8 Å), where lanthanide ions are differently connected by carboxylate groups with chelating or oxygen-bridging mode. The different amount of coordinated water molecules appear to affect the solid state networks. Moreover the crystal packing of these compounds shows peculiar aspects and examples were reported in the literature where the long alkyl chain of adipate connectors give rise to interpenetrated structures, or to porous material where lattice water or neutral larger molecules are clathrated.

  3. Extraction behavior of actinides and lanthanides in a molten fluoride/liquid aluminum system

    NASA Astrophysics Data System (ADS)

    Conocar, Olivier; Douyere, Nicolas; Lacquement, Jérôme

    2005-09-01

    As one of the basic investigations on the group partitioning of actinides and lanthanides by a pyrochemical reductive extraction process, the distribution ratios of Pu, Am, Ce and Sm have been experimentally determined in the binary liquid LiF-AlF 3/Al-Cu system at the temperature of 830 °C. The distribution ratios of Pu and Am are much larger than those of Ce and Sm. They would allow a high recovery yield of the actinides and good separation factors with lanthanides. The influence of the salt composition (LiF/AlF 3 ratio) on the distribution coefficients has been investigated. Coupling the obtained experimental results and literature data, a thermodynamic model that describes the extraction in terms of Gibbs enthalpies of formation and the fluorobasicity of the melt (p F) has been developed. The activity coefficients of Sm(+II) et Ce(+III) versus the p F have been infered: they clearly reveal the difference in solvation behavior between divalent and trivalent species.

  4. Lutetium speciation and toxicity in a microbial bioassay: testing the free-ion model for lanthanides.

    PubMed

    Weltje, Lennart; Verhoof, Lars R C W; Verweij, Wilko; Hamers, Timo

    2004-12-15

    The validity of the free-ion model (FIM) for the element lutetium (Lu), a member of the lanthanides, was assessed in experiments with the bacterium Vibrio fischeri. The FIM is mainly based on divalent metals and synthetic ligands and has not yet been validated for the trivalent lanthanides. The bioluminescence response of V. fischeri was studied at different Lu concentrations in the presence and absence of natural and synthetic organic ligands [citrate, malate, oxalate, acetate, ethylenediaminetetraacetate (EDTA), and nitrilotriacetate (NTA)]. All ligands were tested separately to ensure that their concentrations would not cause adverse effects themselves. Free Lu3+ concentrations were calculated with a speciation program, after extension of its database with the relevant Lu equilibria. The results confirmed the FIM for Lu: that is, in contrast to total dissolved Lu concentrations, free Lu3+ concentrations had an apparent relationship with the response of V. fischeri. However, a contribution of minor inorganic Lu complexes cannot be ruled out. In the presence of malate and oxalate, the EC50 for Lu3+ decreased faster in time than for the other ligands, indicating lower elimination rates. With an EC50 of 1.57 microM, Lu3+ is more toxic than La3+, Cd2+, or Zn2+ and approximately equally as toxic as Cu2+. Although the pH increased slightly during the experiments, it was shown that the influence of pH on Lu speciation was limited.

  5. Analysis of Performance of Selected AFC, ATF Fuels, and Lanthanide Transport

    SciTech Connect

    Unal, Cetin; Galloway, Jack D.

    2015-09-29

    We started to look at the performance of ATF concept in LWRs late in FY14 and finish our studies in FY15. The work has been presented in AFC review meetings, ICAPP and TOPFUEL conferences. The final version of the work is accepted for publication in Nuclear Engineering and Science Journal (NES). The copy of ICAPP and NES papers are attached separately to this document as our milestone deliverables. We made an important progress in the modeling of lanthanide transport in FY15. This work produced an ANS Winter Meeting paper and GLOBAL 2015 paper. GLOBAL 2015 paper is also attached as deliverable of FY15. The work on the lanthanide transport is preliminary. We are exploring other potential mechanisms, in addition to “liquid-like” diffusion mechanisms, proposed by Robert Mariani [1] before we analyze data that will be taken by Ohio State University. This year, we concentrate on developing diffusion kernels and principles of modeling. Next year, this work will continue and analyze the Ohio State data and develop approaches to solve multicomponent diffusion. In addition to three papers we attached to this report, we have done some research on coupling and the development of gas release model for metallic fuels in FY15. They are also preliminary in nature; therefore, we give the summary of what we found rather than an extended report that will be done in FY16.

  6. Extraction study of lanthanide nitrato complexes - the adogen-464NO/sub 3/ - NH/sub 4/NO/sub 3/ system

    SciTech Connect

    Sokolowska, A.; Siekierski, S.

    1983-01-01

    Extraction of lanthanides and yttrium was studied in the interval of ammonium nitrate concentrations from 1 to 10M, and of Adogen-464 nitrate concentrations from 0.00039 to 0.39M. From the aqueous phase separation factor and from the published stability constant for europium (Eu), stability constants for 1:1 complexes of lanthanum (La), neodymium (Nd), gadolinium (Gd), holmium (Ho), thulium (Tm), lutetium (Lu) and yttrium (Y) have been determined, at 1M ammonium nitrate concentration. Results show that stability constant decreases from 2.7 for La to 2.3 for Lu. In the range of Adogen-464 nitrate concentrations employed, lanthanides from La to Nd appear in the organic phase as 1:5 complexes, whereas lanthanides heavier than Nd appear also as 1:4 complexes. Relative values (with regard to lanthanum) of Gibbs energy, enthalpy (from the temperture effect) and entropy for formation of 1:5 complexes, and the position of yttrium within lanthanides have been determined. Conclusions are that the extracted 1:4 and 1:5 complexes are of the inner sphere type, with nitrate ions acting as bidentate ligands, and that the contribution from covalency to bonding is the same in the aquo ion and in the 1:5 nitrato complex. 5 figures, 1 table.

  7. Lanthanide complexes of azidophenacyl-DO3A as new synthons for click chemistry and the synthesis of heterometallic lanthanide arrays.

    PubMed

    Tropiano, Manuel; Kenwright, Alan M; Faulkner, Stephen

    2015-04-07

    Lanthanide complexes of azidophenacyl DO3A are effective substrates for click reactions with ethyne derivatives, giving rise to aryl triazole appended lanthanide complexes, in which the aryl triazole acts as an effective sensitising chromophore for lanthanide luminescence. They also undergo click chemistry with propargylDO3A derivatives, giving rise to heterometallic complexes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Method for providing oxygen ion vacancies in lanthanide oxides

    DOEpatents

    Kay, D. Alan R.; Wilson, William G.

    1989-12-05

    A method for desulfurization of fuel gases resulting from the incomplete combustion of sulfur containing hydrocarbons whereby the gases are treated with lanthanide oxides containing large numbers of oxygen-ion vacancies providing ionic porosity which enhances the ability of the lanthanide oxides to react more rapidly and completely with the sulfur in the fuel gases whereby the sulfur in such gases is reduced to low levels suitable for fuels for firing into boilers of power plants generating electricity with steam turbine driven generators, gas turbines, fuel cells and precursors for liquid fuels such as methanol and the like.

  9. Thermodynamical properties of liquid lanthanides-A variational approach

    SciTech Connect

    Patel, H. P.; Thakor, P. B.; Sonvane, Y. A.

    2015-06-24

    Thermodynamical properties like Entropy (S), Internal energy (E) and Helmholtz free energy (F) of liquid lanthanides using a variation principle based on the Gibbs-Bogoliubuv (GB) inequality with Percus Yevick hard sphere reference system have been reported in the present investigation. To describe electron-ion interaction we have used our newly constructed parameter free model potential along with Sarkar et al. local field correction function. Lastly, we conclude that our newly constructed model potential is capable to explain the thermodynamical properties of liquid lanthanides.

  10. Extraction of lanthanide ions by 2-methyl-8-quinolinol

    SciTech Connect

    Taguchi, S.; Freiser, H.

    1985-01-01

    The equilibrium extraction behavior of a series of tervalent lanthanides (La, Pr, Eu, Ho, and Yb) with 2-methyl-8-quinolinol (HL) in chloroform has been studied. Although the sterically hindered extractant does not form neutral LnL/sub 3/ complexes, ion pair complexes of intermediate chelates with either perchlorate or thiocyanate ions are extractable. The extraction constants of such species are smaller than those of other 8-quinolinols and closer together because the adverse steric influence of the 2-methyl group is greater on the heavier lanthanide ions. 12 refs., 3 figs., 1 tab.

  11. Microwave synthesis of nanostructured oxide sorbents doped with lanthanides

    SciTech Connect

    Mitrofanov, Andrey A. Silyavka, Elena S.; Shilovskikh, Vladimir V.; Kolonitckii, Petr D.; Sukhodolov, Nikolai G.; Selyutin, Artem A.

    2016-06-17

    A number of nanostructured mesoporous oxide systems based on aluminum oxide, doped with lanthanide ions have been obtained in this study. Structure and morphology of oxides obtained have been examined by X-ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy. The surface area of the samples was determined by the BET method. The dependence of the adsorption of insulin on synthesized oxides from the concentration was investigated. The containing of insulin in solutions after adsorption was determined by the Bradford method. The isotherms of adsorption of insulin on resulting oxide sorbents were plotted, the dependence capacity of the sorption of insulin from the lanthanide dopant was determined.

  12. Recent developments in lanthanide single-molecule magnets.

    PubMed

    Lu, Jingjing; Guo, Mei; Tang, Jinkui

    2017-09-01

    Single-molecule magnets (SMMs) exhibiting slow relaxation of magnetization of purely molecular origin are highly attractive owing to their potential applications in spintronic devices, high-density information storage and quantum computing. Particularly, lanthanide SMMs have been playing a major role in the advancement of this field because of the large intrinsic magnetic anisotropy of lanthanide metal ions. In this Focus Review, some recent breakthroughs that are changing the perspective of the field will be highlighted with special emphasis on the synthetic strategies towards the design of high-performance SMMs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Mixed ligand chelate extraction of lanthanide ions in systems involving 7-(1-vinyl-3,3,6,6-tetramethylhexyl)-8-quinolinol, 8-quinolinol, and 1,10-phenanthroline

    SciTech Connect

    Yamada, E.; Freiser, H.

    1981-11-01

    A study of the equilibrium extraction behavior of a series of representative tervalent lanthanide ions, Pr, Eu, and Yb, was carried out with chloroform solutions containing either 7-dodecenyl-8-quinolinol (DDQ or HK) alone or combined with 1,10-phenanthroline (phen). The results demonstrated that the lanthanides are extracted as a simple chelate, LnK/sub 3/, or in the presence of phen, as LnK/sub 3/.phen. Solvent extraction of lanthanides has been studied further with mixtures of HK and 8-quinolinol (HQ) in chloroform. The mixed complexes in chloroform were considered to be LnK/sub 2/Q, and at higher 8-quinolinol concentration LnKQ/sub 2/, but the addition of 0.1 M phen changes the species to LnK/sub a/Q/sub 3-a/.phen complexes. The formations of mixed complexes and addition of phen improve both the extraction and separation.

  14. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays.

    SciTech Connect

    Anstey, Mitchell R.; Fruetel, Julia A.; Foster, Michael E.; Hayden, Carl C.; Buckley, Heather L.; Arnold, John

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  15. Experimental and Theoretical Studies on Biologically Active Lanthanide (III) Complexes

    NASA Astrophysics Data System (ADS)

    Kostova, I.; Trendafilova, N.; Georgieva, I.; Rastogi, V. K.; Kiefer, W.

    2008-11-01

    The complexation ability and the binding mode of the ligand coumarin-3-carboxylic acid (HCCA) to La(III), Ce(III), Nd(III), Sm(III), Gd(III) and Dy(III) lanthanide ions (Ln(III)) are elucidated at experimental and theoretical level. The complexes were characterized using elemental analysis, DTA and TGA data as well as 1H NMR and 13C NMR spectra. FTIR and Raman spectroscopic techniques as well as DFT quantum chemical calculations were used for characterization of the binding mode and the structures of lanthanide(III) complexes of HCCA. The metal—ligand binding mode is predicted through molecular modeling and energy estimation of different Ln—CCA structures using B3LYP/6-31G(d) method combined with a large quasi-relativistic effective core potential for lanthanide ion. The energies obtained predict bidentate coordination of CCA- to Ln(III) ions through the carbonylic oxygen and the carboxylic oxygen. Detailed vibrational analysis of HCCA, CCA- and Ln(III) complexes based on both calculated and experimental frequencies confirms the suggested metal—ligand binding mode. The natural bonding analysis predicts strongly ionic character of the Ln(III)-CCA bonding in the- complexes studied. With the relatively resistant tumor cell line K-562 we obtained very interesting in-vitro results which are in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.

  16. Luminescent 1-hydroxy-2-pyridinone chelates of lanthanides

    DOEpatents

    Raymond, Kenneth N.; Xu, Jide; Moore, Evan G.; Werner, Eric J.

    2013-10-15

    The present invention provides luminescent complexes between a lanthanide ion and an organic ligand which contains 1,2-hydroxypyridinone units. The complexes of the invention are stable in aqueous solutions and are useful as molecular probes, for example in medical diagnostics and bioanalytical assay systems. The invention also provides methods of using the complexes of the invention.

  17. Luminescent 1-hydroxy-2-pyridinone chelates of lanthanides

    DOEpatents

    Raymond, Kenneth N.; Xu, Jide; Moore, Evan G.; Werner, Eric J.

    2017-01-31

    The present invention provides luminescent complexes between a lanthanide ion and an organic ligand which contains 1,2-hydroxypyridinone units. The complexes of the invention are stable in aqueous solutions and are useful as molecular probes, for example in medical diagnostics and bioanalytical assay systems. The invention also provides methods of using the complexes of the invention.

  18. Ion-assisted deposition of lanthanide trifluorides for VUV applications

    NASA Technical Reports Server (NTRS)

    Lingg, L. J.; Targove, J. D.; Lehan, J. P.; Macleod, H. A.

    1987-01-01

    The lanthanide trifluorides show promise as vacuum ultraviolet (VUV) coating materials. The optical properties of single-layer coatings vary with deposition temperature, and with ion-beam energy and current density. The optical constants, stoichiometry, durability, moisture adsorption, and crystallinity are studied for trifluoride films made under a variety of deposition conditions.

  19. Intracellular Adenosine Triphosphate Deprivation through Lanthanide-Doped Nanoparticles.

    PubMed

    Tian, Jing; Zeng, Xiao; Xie, Xiaoji; Han, Sanyang; Liew, Oi-Wah; Chen, Yei-Tsung; Wang, Lianhui; Liu, Xiaogang

    2015-05-27

    Growing interest in lanthanide-doped nanoparticles for biological and medical uses has brought particular attention to their safety concerns. However, the intrinsic toxicity of this new class of optical nanomaterials in biological systems has not been fully evaluated. In this work, we systematically evaluate the long-term cytotoxicity of lanthanide-doped nanoparticles (NaGdF4 and NaYF4) to HeLa cells by monitoring cell viability (mitochondrial activity), adenosine triphosphate (ATP) level, and cell membrane integrity (lactate dehydrogenase release), respectively. Importantly, we find that ligand-free lanthanide-doped nanoparticles induce intracellular ATP deprivation of HeLa cells, resulting in a significant decrease in cell viability after exposure for 7 days. We attribute the particle-induced cell death to two distinct cell death pathways, autophagy and apoptosis, which are primarily mediated via the interaction between the nanoparticle and the phosphate group of cellular ATP. The understanding gained from the investigation of cytotoxicity associated with lanthanide-doped nanoparticles provides keen insights into the safe use of these nanoparticles in biological systems.

  20. Lanthanide template synthesis of a molecular trefoil knot.

    PubMed

    Ayme, Jean-François; Gil-Ramírez, Guzmán; Leigh, David A; Lemonnier, Jean-François; Markevicius, Augustinas; Muryn, Christopher A; Zhang, Gen

    2014-09-24

    We report on a complex featuring three 2,6-pyridinedicarboxamide ligands entwined around a lanthanide (Ln(3+)) ion. The ligand strands can be cyclized by ring-closing olefin metathesis to form a molecular trefoil knot in 58% yield. Demetalation with tetraethylammonium fluoride quantitatively generates the wholly organic 81-atom-loop trefoil knot.

  1. Influencing fatty acid composition of yeasts by lanthanides.

    PubMed

    Kolouchova, Irena; Sigler, Karel; Zimola, Michal; Rezanka, Tomas; Matatkova, Olga; Masak, Jan

    2016-08-01

    The growth of microorganisms is affected by cultivation conditions, concentration of carbon and nitrogen sources and the presence of trace elements. One of the new possibilities of influencing the production of cell mass or lipids is the use of lanthanides. Lanthanides are biologically non-essential elements with wide applications in technology and industry and their concentration as environmental contaminants is therefore increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants but their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements or operate as potent blockers of Ca(2+) channels. We tested the effect of low concentrations of lanthanides on traditional biotechnologically useful yeast species (Kluyveromyces polysporus, Saccharomyces cerevisiae, Torulospora delbrueckii), and species capable of high accumulation of lipids (Rhodotorula glutinis, Trichosporon cutaneum, Candida sp., Yarrowia lipolytica). Low concentrations of lanthanum and monazite were conducive to an increase in cell mass and lipids and also higher production of palmitoleic acid, commonly used in cosmetics and medicine, and ω6-linoleic acid which is a precursor of thromboxanes, prostaglandins and leucotrienes.

  2. Electrochemical study of the mechanism of lanthanide extraction with thenoyltrifluoroacetone.

    PubMed

    Yu, W H; Freiser, H

    1989-01-01

    Current-scan polarography at the ascending-water electrode (AWE) was used to examine the electrochemical behavior of HTTA and La(3+), both in the absence and presence of neutral ligands, TOPO or MBDPO, and the light this sheds on the mechanism of extraction of lanthanides with HTTA, as well as the role played by mixed-ligand chelate formation.

  3. Detection of bacterial spores with lanthanide-macrocycle binary complexes.

    PubMed

    Cable, Morgan L; Kirby, James P; Levine, Dana J; Manary, Micah J; Gray, Harry B; Ponce, Adrian

    2009-07-15

    The detection of bacterial spores via dipicolinate-triggered lanthanide luminescence has been improved in terms of detection limit, stability, and susceptibility to interferents by use of lanthanide-macrocycle binary complexes. Specifically, we compared the effectiveness of Sm, Eu, Tb, and Dy complexes with the macrocycle 1,4,7,10-tetraazacyclododecane-1,7-diacetate (DO2A) to the corresponding lanthanide aquo ions. The Ln(DO2A)(+) binary complexes bind dipicolinic acid (DPA), a major constituent of bacterial spores, with greater affinity and demonstrate significant improvement in bacterial spore detection. Of the four luminescent lanthanides studied, the terbium complex exhibits the greatest dipicolinate binding affinity (100-fold greater than Tb(3+) alone, and 10-fold greater than other Ln(DO2A)(+) complexes) and highest quantum yield. Moreover, the inclusion of DO2A extends the pH range over which Tb-DPA coordination is stable, reduces the interference of calcium ions nearly 5-fold, and mitigates phosphate interference 1000-fold compared to free terbium alone. In addition, detection of Bacillus atrophaeus bacterial spores was improved by the use of Tb(DO2A)(+), yielding a 3-fold increase in the signal-to-noise ratio over Tb(3+). Out of the eight cases investigated, the Tb(DO2A)(+) binary complex is best for the detection of bacterial spores.

  4. Detection of Bacterial Spores with Lanthanide-Macrocycle Binary Complexes

    PubMed Central

    Cable, Morgan L.; Kirby, James P.; Levine, Dana J.; Manary, Micah J.; Gray, Harry B.; Ponce, Adrian

    2009-01-01

    The detection of bacterial spores via dipicolinate-triggered lanthanide luminescence has been improved in terms of detection limit, stability, and susceptibility to interferents by use of lanthanide-macrocycle binary complexes. Specifically, we compared the effectiveness of Sm, Eu, Tb and Dy complexes with the macrocycle 1,4,7,10-tetraazacyclododecane-1,7-diacetate (DO2A) to the corresponding lanthanide aquo ions. The Ln(DO2A)+ binary complexes bind dipicolinic acid (DPA), a major constituent of bacterial spores, with greater affinity and demonstrate significant improvement in bacterial spore detection. Of the four luminescent lanthanides studied, the terbium complex exhibits the greatest dipicolinate binding affinity (100-fold greater than Tb3+ alone, and 10-fold greater than other Ln(DO2A)+ complexes) and highest quantum yield. Moreover, the inclusion of DO2A extends the pH range over which Tb-DPA coordination is stable, reduces the interference of calcium ions nearly 5-fold, and mitigates phosphate interference 1000-fold compared to free terbium alone. In addition, detection of Bacillus atrophaeus bacterial spores was improved by the use of Tb(DO2A)+, yielding a 3-fold increase in the signal-to-noise ratio over Tb3+. Out of the eight cases investigated, the Tb(DO2A)+ binary complex is best for the detection of bacterial spores. PMID:19537757

  5. Heat capacities of lanthanide and actinide monazite-type ceramics

    NASA Astrophysics Data System (ADS)

    Kowalski, Piotr M.; Beridze, George; Vinograd, Victor L.; Bosbach, Dirk

    2015-09-01

    (Ln, An)xPO4 monazite-type ceramics are considered as potential matrices for the disposal of nuclear waste. In this study we computed the heat capacities and the standard entropies of these compounds using density functional perturbation theory. The calculations of lanthanide monazites agree well with the existing experimental data and provide information on the variation of the standard heat capacities and entropies along the lanthanide series. The results for AnPO4 monazites are similar to those obtained for the isoelectronic lanthanide compounds. This suggests that the missing thermodynamic data on actinide monazites could be similarly computed or assessed based on the properties of their lanthanide analogs. However, the computed heat capacity of PuPO4 appear to be significantly lower than the measured data. We argue that this discrepancy might indicate potential problems with the existing experimental data or with their interpretation. This shows a need for further experimental studies of the heat capacities of actinide-bearing, monazite-type ceramics.

  6. Enhancement of anion binding in lanthanide optical sensors.

    PubMed

    Cable, Morgan L; Kirby, James P; Gray, Harry B; Ponce, Adrian

    2013-11-19

    In the design of molecular sensors, researchers exploit binding interactions that are usually defined in terms of topology and charge complementarity. The formation of complementary arrays of highly cooperative, noncovalent bonding networks facilitates protein-ligand binding, leading to motifs such as the "lock-and-key". Synthetic molecular sensors often employ metal complexes as key design elements as a way to construct a binding site with the desired shape and charge to achieve target selectivity. In transition metal complexes, coordination number, structure and ligand dynamics are governed primarily by a combination of inner-sphere covalent and outer-sphere noncovalent interactions. These interactions provide a rich variable space that researchers can use to tune structure, stability, and dynamics. In contrast, lanthanide(III)-ligand complex formation and ligand-exchange dynamics are dominated by reversible electrostatic and steric interactions, because the unfilled f shell is shielded by the larger, filled d shell. Luminescent lanthanides such as terbium, europium, dysprosium, and samarium display many photophysical properties that make them excellent candidates for molecular sensor applications. Complexes of lanthanide ions act as receptors that exhibit a detectable change in metal-based luminescence upon binding of an anion. In our work on sensors for detection of dipicolinate, the unique biomarker of bacterial spores, we discovered that the incorporation of an ancillary ligand (AL) can enhance binding constants of target anions to lanthanide ions by as much as two orders of magnitude. In this Account, we show that selected ALs in lanthanide/anion systems greatly improve sensor performance for medical, planetary science, and biodefense applications. We suggest that the observed anion binding enhancement could result from an AL-induced increase in positive charge at the lanthanide ion binding site. This effect depends on lanthanide polarizability, which can be

  7. Enhancement of Anion Binding in Lanthanide Optical Sensors

    PubMed Central

    Cable, Morgan L.; Kirby, James P.; Gray, Harry B.; Ponce, Adrian

    2013-01-01

    In the design of molecular sensors, researchers exploit binding interactions that are usually defined in terms of topology and charge complementarity. The formation of complementary arrays of highly cooperative, noncovalent bonding networks facilitates protein-ligand binding, leading to motifs such as the ‘lock-and-key.’ Synthetic molecular sensors often employ metal complexes as key design elements as a way to construct a binding site with the desired shape and charge to achieve target selectivity. In transition metal complexes, coordination number, structure and ligand dynamics are governed primarily by a combination of inner-sphere covalent and outer-sphere noncovalent interactions. These interactions provide a rich variable space that researchers can use to tune structure, stability and dynamics. In contrast, lanthanide(III)-ligand complex formation and ligand-exchange dynamics are dominated by reversible electrostatic and steric interactions, because the unfilled f shell is shielded by the larger, filled d shell. Luminescent lanthanides such as terbium, europium, dysprosium and samarium display many photophysical properties that make them excellent candidates for molecular sensor applications. Complexes of lanthanide ions act as receptors that exhibit a detectable change in metal-based luminescence upon binding of an anion. In our work on sensors for detection of dipicolinate, the unique biomarker of bacterial spores, we discovered that the incorporation of an ancillary ligand (AL) can enhance binding constants of target anions to lanthanide ions by as much as two orders of magnitude. In this Account, we show that selected ALs in lanthanide/anion systems greatly improve sensor performance for medical, planetary science and biodefense applications. We suggest that the observed anion binding enhancement could result from an AL-induced increase in positive charge at the lanthanide ion binding site. This effect depends on lanthanide polarizability, which can

  8. The role of carboxylic acids in TALSQueak separations

    SciTech Connect

    Braley, Jenifer C.; Carter, Jennifer C.; Sinkov, Sergey I.; Nash, Ken L.; Lumetta, Gregg J.

    2012-04-13

    Recent reports have indicated TALSPEAK-type separations chemistry can be improved through the replacement of bis-2-ethyl(hexyl) phosphoric acid (HDEHP) and diethylenetriamine-N,N,N,N,N-pentaacetic acid (DTPA) with the weaker reagents 2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), respectively. This modified TALSPEAK has been provided with an adjusted acronym of TALSQueak (Trivalent Actinide Lanthanide Separation using Quicker Extractants and Aqueous Komplexes). Among several benefits, TALSQueak chemistry provides more rapid phase transfer kinetics, is less reliant on carboxylic acids to mediate lanthanide extraction and allows a simplified thermodynamic description of the separations process that generally requires only parameters available in the literature to describe metal transfer. This manuscript focuses on the role of carboxylic acids in aqueous ternary (M-HEDTA-carboxylate) complexes, americium/lanthanide separations, and extraction kinetics. Spectrophotometry (UV-vis) of the Nd hypersensitive band indicates the presence of aqueous ternary species (K111 = 1.83 {+-} 0.01 at 1.0 M ionic strength, Nd(HEDTA) + Lac <-> Nd(HEDTA)Lac). Varying the carboxylic acid does not have a significant impact on Ln/Am separations or extraction kinetics. TALSqueak separations come to equilibrium in five minutes at the conventional operational pH of 3.6 using only 0.1 M total lactate or citrate.

  9. Thermal NF3 fluorination/oxidation of cobalt, yttrium, zirconium, and selected lanthanide oxides

    SciTech Connect

    Scheele, Randall D.; McNamara, Bruce K.; Casella, Andrew M.; Kozelisky, Anne E.; Neiner, Doinita

    2013-02-01

    This paper presents results of our continuing investigation on the use of nitrogen trifluoride as a fluorination or fluorination/oxidation agent for separating valuable constituents from used nuclear fuels by exploiting the different volatilities of the constituent fission product and actinide fluorides. This article focuses on fission products that do not have volatile fluorides or oxyfluorides at expected operations temperatures. Our thermodynamic calculations show that nitrogen trifluoride has the potential to completely fluorinate fission product oxides to their fluorides. Simultaneous thermogravimetric and differential thermal analyses show that the oxides of cobalt, zirconium, and the lanthanides are fluorinated but do not form volatile fluorides when treated with nitrogen trifluoride at temperatures up to 550°C. Our studies of gadolinium-doped commercial nuclear fuel indicate that nitrogen trifluoride can extract uranium from the non-volatile gadolinium.

  10. The use of decylamine for the extraction of actinides and lanthanides from carbonate solutions

    SciTech Connect

    Karalov, Z.K.; Bukina, T.V.; Myasoedov, B.F.; Rodionova, L.M.

    1985-09-01

    This paper studies the extraction of actinides (Th, U, Pu, Am, Cm, Bk, Cf) and the lanthanides (Ce, Eu, Yb, Lu) from solutions of ammonium bicarbonate by decylamine (DA) chloride in chloroform. The following order of extraction of the actinides in various oxidation states was established: Me(III) >Me(IV) > (Me(VI). The extraction of trivalent transplutonium elements increases in the series Cf < Bk < Cm < Am, and that of the rare earth elements Lu < Yb < Eu. The distribution coefficients decrease with increasing HCO/sup -//sub 3/ ion concentration and, conversely, increase with increasing concentration of the metal and extraction reagent. In the system NH/sub 4/HCO/sub 3/-DA in chloroform, a high separation factor of the Am-U pair, equal to 10/sup 3/, is observed.

  11. r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE

    SciTech Connect

    Lippuner, Jonas; Roberts, Luke F.

    2015-12-20

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka and Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Y{sub e}, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Y{sub e} ≳ 0.22−0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Y{sub e} lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Y{sub e}, but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Y{sub e}, s, and τ to estimate whether or not the ejecta is lanthanide-rich.

  12. r-process Lanthanide Production and Heating Rates in Kilonovae

    NASA Astrophysics Data System (ADS)

    Lippuner, Jonas; Roberts, Luke F.

    2015-12-01

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka & Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Ye, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Ye ≳ 0.22-0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Ye lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Ye, but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Ye, s, and τ to estimate whether or not the ejecta is lanthanide-rich.

  13. Methyltrihydroborate complexes of the lanthanides and actinides

    SciTech Connect

    Shinomoto, R.S.

    1984-11-01

    Reaction of MC1/sub 4/ (M = Zr, Hf, U, Th, Np) with LiBH/sub 3/CH/sub 3/ in chlorobenzene produces volatile, hexane-soluble M(BH/sub 3/CH/sub 3/)/sub 4/. Crystal structures are monomeric, tetrahedral species. Lewis base adducts prepared include U(BH/sub 3/CH/sub 3/)/sub 4/.THT, Th(BH/sub 3/CH/sub 3/)/sub 4/.L (L = THF (tetrahydrofuran), THT (tetrahydrothiophene), SMe/sub 2/, OMe/sub 2/), U(BH/sub 3/CH/sub 3/)/sub 4/.2L (L = THF, pyridine, NH/sub 3/), Th(BH/sub 3/CH/sub 3/)/sub 4/.2L (L = THF, THT, py, NH/sub 3/), M(BH/sub 3/CH/sub 3/)/sub 4/.L-L (M = U, Th; L-L = dme (1,2-dimethoxyethane), bmte (bis(1,2-methylthio)ethane), tmed (N,N,N',N'-tetramethylethylenediamine), dmpe (1,2-dimethylphosphinoethane)) and Th(BH/sub 3/CH/sub 3/)/sub 4/.1/2 OEt/sub 2/. Reaction of MC1/sub 3/ (M = Ho, Yb, Lu) with LiBH/sub 3/CH/sub 3/ in diethyl ether produces volatile, toluene-soluble M(BH/sub 3/CH/sub 3/)/sub 3/.OEt/sub 2/. Other Lewis base adducts prepared from M(BH/sub 3/CH/sub 3/)/sub 3/.OEt/sub 2/ include Ho(BH/sub 3/CH/sub 3/)/sub 3/.L (L = THT, THF, py), Ho(BH/sub 3/CH/sub 3/)/sub 3/.2L (L = THT, THF, py), Ho(BH/sub 3/CH/sub 3/)/sub 3/.tmed, Ho(BH/sub 3/CH/sub 3/)/sub 3/.3/2 L-L (L-L = dmpe, bmte), Yb(BH/sub 3/CH/sub 3/)/sub 3/.3/2 dmpe, Yb(BH/sub 3/Ch/sub 3/).L (L = THF, dme), Yb(BH/sub 3/CH/sub 3/)/sub 3/.2THF, and Lu(BH/sub 3/CH/sub 3/)/sub 3/.THF. By structural criteria, the bonding in actinide and lanthanide methyltrihydroborate complexes is primarily ionic in character even though they display covalent-like physical properties. Spectroscopic measurements indicate that there is some degree of covalent bonding in U(BH/sub 3/CH/sub 3/)/sub 4/.

  14. Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

    SciTech Connect

    Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

    2015-01-15

    A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln{sub 2}(phen){sub 2}(SO{sub 4}){sub 3}(H{sub 2}O){sub 2}]{sub n} (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)]{sub n} (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO{sub 4}{sup 2−} anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic–inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature. - Graphical abstract: Lanthanide sulfates and lanthanide sulfonate-carboxylates have been hydrothermally synthesized. Interestingly, sulfate anions, 2-sulfobenzoate and benzoate ligands came from the in situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. - Highlights: • In situ oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. • The organic–inorganic hybrid lanthanide sulfates with one-dimensional column-like structure. • The dinuclear lanthanide sulfonate-carboxylates. • The emission spectra exhibit the characteristic transition of {sup 5}D{sub 0}→{sup 7}F{sub J} (J=0–4) of the Eu(III)

  15. The effect of lanthanides on photosynthesis, growth, and chlorophyll profile of the green alga Desmodesmus quadricauda.

    PubMed

    Řezanka, Tomáš; Kaineder, Katrin; Mezricky, Dana; Řezanka, Michal; Bišová, Kateřina; Zachleder, Vilém; Vítová, Milada

    2016-12-01

    Lanthanides (La, Gd, Nd, Ce) accumulated in the green alga Desmodesmus quadricauda but their intracellular localizations were distinctly different: lanthanum and gadolinium were localized in cytoplasm, while neodymium and cerium were in the chloroplast. The effect of lanthanum and neodymium, as representatives of these two groups, on growth, chlorophyll content and photosynthetic rate at different light intensities was studied. At the lowest light intensity used (50 µmol photons m(-2) s(-1)), in the presence of lanthanides (Nd), growth was enhanced by as much as 36 % over lanthanide free control, and the photosynthetic rate increased by up to 300 %. At high light intensities (238, 460, and 750 µmol photons m(-2) s(-1)), photosynthetic rate increased markedly, but there was no significant difference between rates in the presence or absence of lanthanides. However, growth, measured as a percentage of dry weight, if compared with lanthanide free control, increased at all light intensities (31, 39, and 20 %, respectively). The total amount of chlorophyll after lanthanide treatment increased by up to 21 % relative to the control culture, mainly due to an increase in the level of chlorophyll b. Addition of lanthanides caused a change in the chlorophyll a/b ratio from 4.583 in control cultivation, to 1.05. Possible mechanisms of lanthanide-induced photosynthetic change, alterations in photosynthetic structures, and increases in growth are discussed and compared with findings in higher plants. The hypothesis that the lanthanide effect could be due to formation of lanthanide-pheophytins was not confirmed as lanthanide pheophytins were not found in D. quadricauda. Furthermore, we have shown that the preferential incorporation of heavy isotopes of magnesium, namely (25)Mg and (26)Mg, into chlorophyll during photosynthesis that occurred in controls was diminished in the presence of lanthanides.

  16. Structural characterization and thermal behavior of lanthanide(III)-vanadium(V)-oxide xerogels

    SciTech Connect

    Oliveira, H.P.; Anaissi, F.J.; Toma, H.E.

    1998-12-01

    Lanthanide ions react with vanadium(V)-oxide xerogels forming intercalation compounds. In contrast to the pure vanadium(V)-oxide matrix, the removal of the water molecules from the interlamellar space and from the lanthanide coordination shell is practically complete at 150 C, disrupting the bidimensional layered structure. The heating above 450 C leads to the formation of orthorhombic V{sub 2}O{sub 5} and tetragonal lanthanide orthovanadates.

  17. Extraction of trivalent lanthanides and actinides by ``CMPO-like`` calixarenes

    SciTech Connect

    Delmau, L.H.; Simon, N.; Schwing-Weill, M.J.

    1999-04-01

    Extractive properties of calix[4]arenes bearing carbamoylmethylphosphine oxide moieties on their upper rim toward trivalent lanthanide and actinide cations were investigated. The study revealed that these molecules selectively extract light lanthanides and actinides from heavy lanthanides. All parameters present in the extraction system were varied to determine the origin of the selectivity. It was found that this selectivity requires a calix[4]arene platform and acetamidophosphine oxide groups containing phenyl substituents on the four phosphorus atoms.

  18. Lanthanide-to-lanthanide energy-transfer processes operating in discrete polynuclear complexes: can trivalent europium be used as a local structural probe?

    PubMed

    Zaïm, Amir; Eliseeva, Svetlana V; Guénée, Laure; Nozary, Homayoun; Petoud, Stéphane; Piguet, Claude

    2014-09-15

    This work, based on the synthesis and analysis of chemical compounds, describes a kinetic approach for identifying intramolecular intermetallic energy-transfer processes operating in discrete polynuclear lanthanide complexes, with a special emphasis on europium-containing entities. When all coordination sites are identical in a (supra)molecular complex, only heterometallic communications are experimentally accessible and a Tb → Eu energy transfer could be evidenced in [TbEu(L5)(hfac)6] (hfac = hexafluoroacetylacetonate), in which the intermetallic separation amounts to 12.6 Å. In the presence of different coordination sites, as found in the trinuclear complex [Eu3(L2)(hfac)9], homometallic communication can be induced by selective laser excitation and monitored with the help of high-resolution emission spectroscopy. The narrow and non-degenerated character of the Eu((5)D0 ↔ (7)F0) transition excludes significant spectral overlap between donor and acceptor europium cations. Intramolecular energy-transfer processes in discrete polynuclear europium complexes are therefore limited to short distances, in agreement with the Fermi golden rule and with the kinetic data collected for [Eu3(L2)(hfac)9] in the solid state and in solution. Consequently, trivalent europium can be considered as a valuable local structural probe in discrete polynuclear complexes displaying intermetallic separation in the sub-nanometric domain, a useful property for probing lanthanido-polymers.

  19. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    SciTech Connect

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, Kenneth M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a “hard” anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized.

  20. Lanthanide Selective Sorbents: Self-Assembled Monolayers on Mesoporous Supports (SAMMS)

    SciTech Connect

    Fryxell, Glen E.; Wu, Hong; Lin, Yuehe; Shaw, Wendy J.; Birnbaum, Jerome C.; Linehan, John C.; Nie, Zimin; Kemner, K. M.; Kelly, Shelley

    2004-11-01

    Through the marriage of mesoporous ceramics with self-assembled monolayer chemistry, the genesis of a powerful new class of environmental sorbent materials has been realized. By coating the mesoporous ceramic backbone with a monolayer terminated with a lanthanide-specific ligand, it is possible to couple high lanthanide binding affinity with the high loading capacity (resulting from the extremely high surface area of the support). This lanthanide-specific ligand field is created by pairing a ''hard'' anionic Lewis base with a suitable synergistic ligand, in a favorable chelating geometry. Details of the synthesis, characterization, lanthanide binding studies, binding kinetics, competition experiments and sorbent regeneration studies are summarized

  1. Comparison in accumulation of lanthanide elements among three Brassicaceae plant sprouts.

    PubMed

    Anan, Yasumi; Awaya, Yumi; Ogihara, Yurie; Yoshida, Miyuki; Yawata, Ayako; Ogra, Yasumitsu

    2012-07-01

    Three kinds of sprouts in the Brassicaceae family of plants, namely, pink kale, radish and mustard were evaluated for the possibility of phytoremediation of lanthanides. The mustard sprout more efficiently accumulated lanthanides (e.g. 0.26 nmol La/g) than other Brassicaceae family plant sprouts (0.16 nmol La/g in the radish), however the radish sprout showed the fastest growth among three sprouts. Faster growth compensated for less efficiency in lanthanide accumulation (28 pmol La in the radish vs. 12 pmol La in the mustard) indicating that the radish is the most preferable sprout for the phytoremediation of lanthanides.

  2. Spectrally resolved confocal microscopy using lanthanide centred near-IR emission.

    PubMed

    Liao, Zhiyu; Tropiano, Manuel; Mantulnikovs, Konstantins; Faulkner, Stephen; Vosch, Tom; Sørensen, Thomas Just

    2015-02-11

    The narrow, near infrared (NIR) emission from lanthanide ions has attracted great interest, particularly with regard to developing tools for bioimaging, where the long lifetimes of lanthanide excited states can be exploited to address problems arising from autofluorescence and sample transparency. Despite the promise of lanthanide-based probes for near-IR imaging, few reports on their use are present in the literature. Here, we demonstrate that images can be recorded by monitoring NIR emission from lanthanide complexes using detectors, optical elements and a microscope that were primarily designed for the visible part of the spectrum.

  3. The lanthanides and yttrium in minerals of the apatite group; a review

    USGS Publications Warehouse

    Fleischer, Michael; Altschuler, Z.S.

    1982-01-01

    More than 1000 analyses have been tabulated of the distribution of the lanthanides and yttrium in minerals of the apatite group, recalculated to atomic percentages. Average compositions have been calculated for apatites from 14 types of rocks. These show a progressive change of composition from apatites of granitic pegmatites, highest in the heavy lanthanides and yttrium, to those from alkalic pegmatites, highest in the light lanthanides and lowest in yttrium. This progression is clearly shown in plots of S (= at % La+Ce+Pr) vs the ratio La/Nd and of S vs the ratio 100Y/(Y+Ln), where Ln is the sum of the lanthanides. Apatites of sedimentary phosphorites occupy a special position, being relatively depleted in Ce and relatively enriched in yttrium and the heavy lanthanides, consequences of deposition from sea water. Apatites associated with iron ores are close in composition to apatites of carbonatites, alkalic ultramafic, and ultramafic rocks, being enriched in the light lanthanides and depleted in the heavy lanthanides. Their compositions do not support the hypothesis of Parak that the Kiruna-type ores are of sedimentary origin. Table 9 and Figures 1-3 show the dependence of lanthanide distribution on the nature of the host rock. Although a given analysis of the lanthanides does not unequivocally permit certain identification of the host rock, it can indicate a choice of highly probable host rocks.

  4. Photoacoustic spectroscopy study on lanthanide complexes with aromatic carboxylic acid in silica gels

    NASA Astrophysics Data System (ADS)

    Yang, Y.-T.; Zhang, S.-Y.

    2005-06-01

    Using a sol-gel process, lanthanide complexes Ln (Sal)3.HO (Ln^3+: Nd^3+, Tb^3+; Sal: salicylic acid) are incorporated into silica gels by the hydrolysis and condensation of tetraethoxysilane (TEOS). After heat treatment at 150 °C for the lanthanide complexes in gels, the photoacoustic (PA) intensity of the ligand changes remarkably, while this difference can not be observed for the samples without heat treatment. Different PA intensities of lanthanide complexes in silica gels can be interpreted by comparison them with their luminescence spectra. The formation of lanthanide complex in silica gel is discussed by two aspects: radiative and nonradiative processes.

  5. Lanthanide Template Synthesis of Trefoil Knots of Single Handedness.

    PubMed

    Zhang, Gen; Gil-Ramírez, Guzmán; Markevicius, Augustinas; Browne, Colm; Vitorica-Yrezabal, Iñigo J; Leigh, David A

    2015-08-19

    We report on the assembly of 2,6-pyridinedicarboxamide ligands (1) with point chirality about lanthanide metal ion (Ln(3+)) templates, in which the helical chirality of the resulting entwined 3:1 ligand:metal complexes is covalently captured by ring-closing olefin metathesis to form topologically chiral molecular trefoil knots of single handedness. The ligands do not self-sort (racemic ligands form a near-statistical mixture of homoleptic and heteroleptic lanthanide complexes), but the use of only (R,R)-1 leads solely to a trefoil knot of Λ-handedness, whereas (S,S)-1 forms the Δ-trefoil knot with complete stereoselectivity. The knots and their isomeric unknot macrocycles were characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography and the expression of the chirality that results from the topology of the knots studied by circular dichroism.

  6. Deep-UV biological imaging by lanthanide ion molecular protection

    PubMed Central

    Kumamoto, Yasuaki; Fujita, Katsumasa; Smith, Nicholas Isaac; Kawata, Satoshi

    2015-01-01

    Deep-UV (DUV) light is a sensitive probe for biological molecules such as nucleobases and aromatic amino acids due to specific absorption. However, the use of DUV light for imaging is limited because DUV can destroy or denature target molecules in a sample. Here we show that trivalent ions in the lanthanide group can suppress molecular photodegradation under DUV exposure, enabling a high signal-to-noise ratio and repetitive DUV imaging of nucleobases in cells. Underlying mechanisms of the photodegradation suppression can be excitation relaxation of the DUV-absorptive molecules due to energy transfer to the lanthanide ions, and/or avoiding ionization and reactions with surrounding molecules, including generation of reactive oxygen species, which can modify molecules that are otherwise transparent to DUV light. This approach, directly removing excited energy at the fundamental origin of cellular photodegradation, indicates an important first step towards the practical use of DUV imaging in a variety of biological applications. PMID:26819825

  7. A self-assembling lanthanide molecular nanoparticle for optical imaging†

    PubMed Central

    Brown, Katherine A.; Yang, Xiaoping; Schipper, Desmond; Hall, Justin W.; DePue, Lauren J.; Gnanam, Annie J.; Arambula, Jonathan F.; Jones, Jessica N.; Swaminathan, Jagannath; Dieye, Yakhya; Vadivelu, Jamuna; Chandler, Don J.; Marcotte, Edward M.; Sessler, Jonathan L.; Ehrlich, Lauren I. R.; Jones, Richard A.

    2015-01-01

    Chromophores that incorporate f-block elements have considerable potential for use in bioimaging applications because of their advantageous photophysical properties compared to organic dye, which are currently widely used. We are developing new classes of lanthanide-based self-assembling molecular nanoparticles as reporters for imaging and as multi-functional nanoprobes or nanosensors for use with biological samples. One class of these materials, which we call lanthanide “nano-drums”, are homogeneous 4d–4f clusters approximately 25 to 30 Å in diameter. These are capable of emitting from the visible to near-infrared wavelengths. Here, we present the synthesis, crystal structure, photophysical properties and comparative cytotoxicity data for a 32 metal Eu-Cd nano-drum [Eu8Cd24L12(OAc)48] (1). We also explored the imaging capabilities of this nano-drum using epifluorescence, TIRF, and two-photon microscopy platforms. PMID:25512085

  8. Complexation of lanthanides and actinides by acetohydroxamic acid

    SciTech Connect

    Taylor, R.J.; Sinkov, S.I.; Choppin, G.R.

    2008-07-01

    Acetohydroxamic acid (AHA) has been proposed as a suitable reagent for the complexant-based, as opposed to reductive, stripping of plutonium and neptunium ions from the tributylphosphate solvent phase in advanced PUREX or UREX processes designed for future nuclear-fuel reprocessing. Stripping is achieved by the formation of strong hydrophilic complexes with the tetravalent actinides in nitric acid solutions. To underpin such applications, knowledge of the complexation constants of AHA with all relevant actinide (5f) and lanthanide (4f) ions is therefore important. This paper reports the determination of stability constants of AHA with the heavier lanthanide ions (Dy-Yb) and also U(IV) and Th(IV) ions. Comparisons with our previously published AHA stability-constant data for 4f and 5f ions are made. (authors)

  9. The synthesis, design and applications of lanthanide cored complexes

    NASA Astrophysics Data System (ADS)

    Phelan, Gregory David

    Novel luminescent materials based on lanthanide cored complexes have been designed and synthesized. The complexes consist of a beta-diketone ligand chelated to a lanthanide metal such as europium or gadolinium. A series of beta-diketone ligands were designed and synthesized. The ligands consist of a polycyclic aromatic sensitizer, phenanthrene, and a second functional group. The second groups consisted of another unit of phenanthrene, a dendritic structure, or a fluorinated alkyl chain. The europium complexes have been incorporated into organic light emitting devices that have a major emission at 615 nm and a maximum brightness of 300 cd/m2. The gadolinium complexes were used to dope into the resulting organic light emitting devices to help improve the efficiency of the device. The use of the gadolinium complexes results in a 25 fold increase in efficiency.

  10. Superabsorbing gel for actinide, lanthanide, and fission product decontamination

    SciTech Connect

    Kaminski, Michael D.; Mertz, Carol J.

    2016-06-07

    The present invention provides an aqueous gel composition for removing actinide ions, lanthanide ions, fission product ions, or a combination thereof from a porous surface contaminated therewith. The composition comprises a polymer mixture comprising a gel forming cross-linked polymer and a linear polymer. The linear polymer is present at a concentration that is less than the concentration of the cross-linked polymer. The polymer mixture is at least about 95% hydrated with an aqueous solution comprising about 0.1 to about 3 percent by weight (wt %) of a multi-dentate organic acid chelating agent, and about 0.02 to about 0.6 molar (M) carbonate salt, to form a gel. When applied to a porous surface contaminated with actinide ions, lanthanide ions, and/or other fission product ions, the aqueous gel absorbs contaminating ions from the surface.

  11. Lanthanide ions as spectral converters for solar cells.

    PubMed

    van der Ende, Bryan M; Aarts, Linda; Meijerink, Andries

    2009-12-21

    The use of lanthanide ions to convert photons to different, more useful, wavelengths is well-known from a wide range of applications (e.g. fluorescent tubes, lasers, white light LEDs). Recently, a new potential application has emerged: the use of lanthanide ions for spectral conversion in solar cells. The main energy loss in the conversion of solar energy to electricity is related to the so-called spectral mismatch: low energy photons are not absorbed by a solar cell while high energy photons are not used efficiently. To reduce the spectral mismatch losses both upconversion and downconversion are viable options. In the case of upconversion two low energy infrared photons that cannot be absorbed by the solar cell, are added up to give one high energy photon that can be absorbed. In the case of downconversion one high energy photon is split into two lower energy photons that can both be absorbed by the solar cell. The rich and unique energy level structure arising from the 4f(n) inner shell configuration of the trivalent lanthanide ions gives a variety of options for efficient up- and downconversion. In this perspective an overview will be given of recent work on photon management for solar cells. Three topics can be distinguished: (1) modelling of the potential impact of spectral conversion on the efficiency of solar cells; (2) research on up- and downconversion materials based on lanthanides; and (3) proof-of-principle experiments. Finally, an outlook will be given, including issues that need to be resolved before wide scale application of up- and downconversion materials can be anticipated.

  12. Thermal Decomposition of Lanthanide, Yttrium, and Scandium Oxalates and Carbonates

    NASA Astrophysics Data System (ADS)

    Sharov, Vyacheslav A.; Bezdenezhnykh, G. V.

    1981-07-01

    Data concerning the thermal decomposition of lanthanide, yttrium, and scandium oxalates and carbonates are surveyed. The complexity of the process, the large number of stages involved, and the dependence of the composition of the intermediates in the thermal transformations on the experimental conditions is noted. Certain process characteristics have been discovered and it is concluded that the decomposition process depends on the ionic radius of the metal. The bibliography includes 83 references.

  13. Lanthanide macrocyclic complexes, 'quantum dyes': optical properties and significance

    NASA Astrophysics Data System (ADS)

    Vallarino, Lidia M.; Harlow, Patrick M.; Leif, Robert C.

    1993-05-01

    Macrocylic complexes of the lanthanide (III) ions were functionalized to permit their attachment to antibodies, nucleic acid probes, and any other species capable of specific binding. The Eu(III) complex was found to possess a combination of properties (water solubility, inertness to metal release, ligand-sensitized luminescence, reactive peripheral functionalities) that make it suitable as a luminescent marker for bio-substrates. Its coupling to avidin was achieved, and the properties of the resulting conjugate were investigated.

  14. Magnetic circular dichroism of porphyrin lanthanide M3+ complexes.

    PubMed

    Andrushchenko, Valery; Padula, Daniele; Zhivotova, Elena; Yamamoto, Shigeki; Bouř, Petr

    2014-10-01

    Lanthanide complexes exhibit interesting spectroscopic properties yielding many applications as imaging probes, natural chirality amplifiers, and therapeutic agents. However, many properties are not fully understood yet. Therefore, we applied magnetic circular dichroism (MCD) spectroscopy, which provides enhanced information about the underlying electronic structure to a series of lanthanide compounds. The metals in the M(3+) state included Y, La, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu; the spectra were collected for selected tetraphenylporphin (TPP) and octaethylporphin (OEP) complexes in chloroform. While the MCD and UV-VIS absorption spectra were dominated by the porphyrin signal, metal binding significantly modulated them. MCD spectroscopy was found to be better suited to discriminate between various species than absorption spectroscopy alone. The main features and trends in the lanthanide series observed in MCD and absorption spectra of the complexes could be interpreted at the Density Functional Theory (DFT) level, with effective core potentials on metal nuclei. The sum over state (SOS) method was used for simulation of the MCD intensities. The combination of the spectroscopy and quantum-chemical computations is important for understanding the interactions of the metals with the organic compounds.

  15. Dye-sensitized lanthanide-doped upconversion nanoparticles.

    PubMed

    Wang, Xindong; Valiev, Rashid R; Ohulchanskyy, Tymish Y; Ågren, Hans; Yang, Chunhui; Chen, Guanying

    2017-07-17

    Lanthanide-doped upconversion nanoparticles (UCNPs) are promising for applications as wide as biological imaging, multimodal imaging, photodynamic therapy, volumetric displays, and solar cells. Yet, the weak and narrow absorption of lanthanide ions poses a fundamental limit of UCNPs to withhold their brightness, creating a long-standing hurdle for the field. Dye-sensitized UCNPs are emerging to address this performance-limiting problem, yielding up to thousands-fold brighter luminescence than conventional UCNPs without dye sensitization. In their configuration, organic dyes with spectrally broad and intense absorption are anchored to the surface of UCNPs to harvest the excitation light energy, which is then transferred via Förster and/or Dexter mechanisms across the organic/inorganic interface to the lanthanides incorporated in UCNPs (with or devoid of a shell) to empower efficient upconversion. This tutorial review highlights recent progress in the development of dye sensitized UCNPs, with an emphasis on the theory of energy transfer, the geometric classification of the dye sensitized core and core/shell nanocrystals, and their emerging photonic and biophotonic applications. Opportunities and challenges offered by dye sensitized UCNPs are also discussed.

  16. Semiempirical quantum chemistry model for the lanthanides: RM1 (Recife Model 1) parameters for dysprosium, holmium and erbium.

    PubMed

    Filho, Manoel A M; Dutra, José Diogo L; Rocha, Gerd B; Simas, Alfredo M; Freire, Ricardo O

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes' coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 Å, for the sparkle models, to 0.04 Å for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models.

  17. Semiempirical Quantum Chemistry Model for the Lanthanides: RM1 (Recife Model 1) Parameters for Dysprosium, Holmium and Erbium

    PubMed Central

    Filho, Manoel A. M.; Dutra, José Diogo L.; Rocha, Gerd B.; Simas, Alfredo M.; Freire, Ricardo O.

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes’ coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 Å, for the sparkle models, to 0.04 Å for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models. PMID:24497945

  18. Lanthanide Chemistry: From Coordination in Chemical Complexes Shaping Our Technology to Coordination in Enzymes Shaping Bacterial Metabolism.

    PubMed

    Martinez-Gomez, Norma Cecilia; Vu, Huong N; Skovran, Elizabeth

    2016-10-17

    Lanthanide chemistry has only been extensively studied for the last 2 decades, when it was recognized that these elements have unusual chemical characteristics including fluorescent and potent magnetic properties because of their unique 4f electrons.1,2 Chemists are rapidly and efficiently integrating lanthanides into numerous compounds and materials for sophisticated applications. In fact, lanthanides are often referred to as "the seeds of technology" because they are essential for many technological devices including smartphones, computers, solar cells, batteries, wind turbines, lasers, and optical glasses.3-6 However, the effect of lanthanides on biological systems has been understudied. Although displacement of Ca(2+) by lanthanides in tissues and enzymes has long been observed,7 only a few recent studies suggest a biological role for lanthanides based on their stimulatory properties toward some plants and bacteria.8,9 Also, it was not until 2011 that the first biochemical evidence for lanthanides as inherent metals in bacterial enzymes was published.10 This forum provides an overview of the classical and current aspects of lanthanide coordination chemistry employed in the development of technology along with the biological role of lanthanides in alcohol oxidation. The construction of lanthanide-organic frameworks will be described. Examples of how the luminescence field is rapidly evolving as more information about lanthanide-metal emissions is obtained will be highlighted, including biological imaging and telecommunications.11 Recent breakthroughs and observations from different exciting areas linked to the coordination chemistry of lanthanides that will be mentioned in this forum include the synthesis of (i) macrocyclic ligands, (ii) antenna molecules, (iii) coordination polymers, particularly nanoparticles, (iv) hybrid materials, and (v) lanthanide fuel cells. Further, the role of lanthanides in bacterial metabolism will be discussed, highlighting the

  19. Lanthanide tris(β-diketonates) as useful probes for chirality determination of biological amino alcohols in vibrational circular dichroism: ligand to ligand chirality transfer in lanthanide coordination sphere.

    PubMed

    Miyake, Hiroyuki; Terada, Keiko; Tsukube, Hiroshi

    2014-06-01

    A series of lanthanide tris(β-diketonates) functioned as useful chirality probes in the vibrational circular dichroism (VCD) characterization of biological amino alcohols. Various chiral amino alcohols induced intense VCD signals upon ternary complexation with racemic lanthanide tris(β-diketonates). The VCD signals observed around 1500 cm(-1) (β-diketonate IR absorption region) correlated well with the stereochemistry and enantiomeric purity of the targeted amino alcohol, while the corresponding monoalcohol, monoamine, and diol substrates induced very weak VCD signals. The high-coordination number and dynamic property of the lanthanide complex offer an effective chirality VCD probing of biological substrates.

  20. Americium separation from nuclear fuel dissolution using higher oxidation states.

    SciTech Connect

    Bruce J. Mincher

    2009-09-01

    Much of the complexity in current AFCI proposals is driven by the need to separate the minor actinides from the lanthanides. Partitioning and recycling Am, but not Cm, would allow for significant simplification because Am has redox chemistry that may be exploited while Cm does not. Here, we have explored methods based on higher oxidation states of Am (AmV and AmVI) to partition Am from the lanthanides. In a separate but related approach we have also initiated an investigation of the utility of TRUEX Am extraction from thiocyanate solution. The stripping of loaded TRUEX by Am oxidation or SCN- has not yet proved successful; however, the partitioning of inextractable AmV by TRUEX shows promise.

  1. Helical lanthanide(III) complexes with chiral nonaaza macrocycle.

    PubMed

    Gregoliński, Janusz; Starynowicz, Przemysław; Hua, KimNgan T; Lunkley, Jamie L; Muller, Gilles; Lisowski, Jerzy

    2008-12-31

    The chiral nonaazamacrocyclic amine L, which is a reduction product of the 3 + 3 Schiff base macrocycle, wraps around the lanthanide(III) ions to form enantiopure helical complexes. These Ce(III), Pr(III), Nd(III), Eu(III), Gd(III), Tb(III), Er(III), Yb(III) and Lu(III) complexes have been isolated in enantiopure form and have been characterized by spectroscopic methods. X-ray crystal structures of the Ln(III) complexes with L show that the thermodynamic product of the complexation of the RRRRRR-isomer of the macrocycle is the (M)-helical complex in the case of Ce(III), Pr(III), Nd(III) and Eu(III). In contrast, the (P)-helical complex is the thermodynamic product in the case of Yb(III) and Lu(III). The NMR and CD spectra show that the (M)-helicity for the kinetic complexation product of the RRRRRR-isomer of the macrocycle is preferred for all investigated lanthanide(III) ions, while the preferred helicity of the thermodynamic product is (M) for the early lanthanide(III) ions and (P) for the late lanthanide(III) ions. In the case of the late lanthanide(III) ions, a slow inversion of helicity between the kinetic (M)-helical product and the thermodynamic (P)-helical product is observed in solution. For Er(III), Yb(III) and Lu(III) both forms have been isolated in pure form and characterized by NMR and CD. The analysis of 2D NMR spectra of the Lu(III) complex reveals the NOE correlations that prove that the helical structure is retained in solution. The NMR spectra also reveal large isotopic effect on the 1H NMR shifts of paramagnetic Ln(III) complexes, related to NH/ND exchange. Photophysical measurements show that L(RRRRRR) appears to favor an efficient 3pipi*-to-Ln energy transfer process taking place for Eu(III) and Tb(III), but these Eu(III)- and Tb(III)-containing complexes with L(RRRRRR) lead to small luminescent quantum yields due to an incomplete intersystem crossing (isc) transfer, a weak efficiency of the luminescence sensitization by the ligand, and

  2. Interactions of Plutonium and Lanthanides with Ordered Mesoporous Materials

    NASA Astrophysics Data System (ADS)

    Parsons-Moss, Tashi

    Ordered mesoporous materials are porous solids with a regular, patterned structure composed of pores between 2 and 50 nm wide. Such materials have attracted much attention in the past twenty years because the chemistry of their synthesis allows control of their unique physicochemical properties, which can be tuned for a variety of applications. Generally, ordered mesoporous materials have very high specific surface areas and pore volumes, and offer unique structures that are neither crystalline nor amorphous. The large tunable interface provided by ordered mesoporous solids may be advantageous in applications involving sequestration, separation, or detection of actinides and lanthanides in solution. However, the fundamental chemical interactions of actinides and lanthanides must be understood before applications can be implemented. This dissertation focuses primarily on the fundamental interactions of plutonium with organically modified mesoporous silica, as well as several different porous carbon materials, both untreated and chemically oxidized. A method for functionalizing mesoporous silica by self assembly and molecular grafting of functional organosilane ligands was optimized for the 2D-hexagonal ordered mesoporous silica known as SBA-15 (Santa Barbara amorphous silica). Four different organically-modified silica materials were synthesized and characterized with several techniques. To confirm that covalent bonds were formed between the silane anchor of the ligand and the silica substrate, functionalized silica samples were analyzed with 29Si nuclear magnetic resonance spectroscopy. Infrared spectroscopy was used in combination with 13C and 31P nuclear magnetic resonance spectroscopy to verify the molecular structures of the ligands after they were synthesized and grafted to the silica. The densities of the functional silane ligands on the silica surface were estimated using thermogravimetric analysis. Batch sorption experiments were conducted with solutions of

  3. Raman and absorption spectrophotometric studies of selected lanthanide, californium-doped lanthanide, and actinide trihalides in the solid state

    SciTech Connect

    Wilmarth, W.R.

    1988-03-01

    The solid-state absorption spectra of Cf(III) ions as a dopant in lanthanide trihalide hosts (LnCl/sub 3/: Ln = Ce, Sm, and Y; LnBr/sub 3/: Ln = Ce, Sm, Tb, and Y; LnI/sub 3/: Ln = Ce and Y) have been recorded. The spectra of Cf(III) have been correlated with the various crystal structures. The phonon Raman spectra and solid-state absorption spectra of PmF/sub 3/, PmCl/sub 3/, PmBr/sub 3/, and two crystal modifications of PmI/sub 3/ have been recorded. Symmetry assignments have been made for the Raman-active bands for these trihalides and also the sesquioxide. The room-temperature absorption spectra have been correlated to crystal field effects. The symmetry assignments of the Raman-active phonon modes have been made based on polarized Raman spectra from single crystals of YF/sub 3/-type orthorhombic TbF/sub 3/ and PuBr/sub 3/-type orthorhombic NdBr/sub 3/. Raman spectra of other isostructural lanthanide compounds have been recorded and compared. Symmetry assignments for these compounds have been made by analogy to the single-crystal assignments. Raman spectra have been obtained and catalogued for a number of actinide compounds. Symmetry assignments have been made for the observed Raman-active phonon bands in this work based on the assignments made for isostructural lanthanide compounds. 29 figs., 22 tabs.

  4. Selective liquid chromatographic separation of yttrium from heavier rare earth elements using acetic acid as a novel eluent.

    PubMed

    Kifle, Dejene; Wibetoe, Grethe

    2013-09-13

    One of the major difficulties in the rare earth elements separation is purification of yttrium from heavy rare earth elements. Thus, an HPLC method using acetic acid as novel eluent was explored for selective separation of yttrium form the heavy rare earth elements. When acetic acid is used as a mobile phase yttrium eluted with the lighter lanthanides. This is contrary to its relative position amongst heavier lanthanides when eluents commonly used for separation of rare earth elements were employed. The shift in elution position of yttrium with acetic acid as eluent may reflect a relatively lower stability constant of the yttrium-AcOH complex (in the same order as for the lighter lanthanides) compared to the corresponding AcOH complexes with heavy lanthanides, enabling selective separation of yttrium from the latter. The method was successfully used for selective separation of yttrium in mixed rare earth sample containing about 80% of yttrium and about 20% of heavy rare earth oxides. Thus, the use of AcOH as eluent is an effective approach for separating and determining the trace amounts of heavy rare earth elements in large amounts of yttrium matrix. Separation was performed on C18 column by running appropriate elution programs. The effluent from the column was monitored with diode array detector at absorbance wavelength of 658nm after post column derivatization with Arsenazo III.

  5. Separation of the rare earths by anion-exchange in the presence of lactic acid

    NASA Technical Reports Server (NTRS)

    Faris, J. P.

    1969-01-01

    Investigation of adsorption of rare earths and a few other elements to an anion-exchange resin from mixed solvents containing lactic acid shows that the lanthanides are absorbed more strongly than from the alpha-hydroxyisobutryric acid system, but with less separation between adjacent members of the series.

  6. Extraction of lanthanide(III) and yttrium nitrates by trialkylmethylammonium nitrate from multicomponent solutions

    SciTech Connect

    Pyartman, A.K.; Kopyrin, A.A.; Puzikov, E.A.

    1995-07-01

    The extraction of lanthanide(III) and yttrium nitrates from multicomponent solutions by trialkylmethylammonium nitrate at 298.15 K and pH 2 is examined. Physicochemical and mathematical models describing the distributions of lanthanide(III) (Pr-Lu) and Y in multicomponent solutions as a function of the total metal concentration in the aqueous phase and concentrate composition are presented.

  7. Two-Color Three-State Luminescent Lanthanide Core-Shell Crystals.

    PubMed

    Balogh, Cristina M; Veyre, Laurent; Pilet, Guillaume; Charles, Cyril; Viriot, Laurent; Andraud, Chantal; Thieuleux, Chloé; Riobé, François; Maury, Olivier

    2017-02-03

    Luminescent core-shell crystals based on lanthanide tris-dipicolinate complexes were obtained from the successive growing of two different lanthanide complex layers. Selective or simultaneous emission of each part of the crystal can be achieved by a careful choice of the excitation wavelength.

  8. Fungus-promoted transformation of lanthanides during the biooxidation of divalent manganese

    NASA Astrophysics Data System (ADS)

    Yu, Qianqian; Ohnuki, Toshihiko; Tanaka, Kazuya; Kozai, Naofumi; Yamasaki, Shinya; Sakamoto, Fuminori; Tani, Yukinori

    2016-02-01

    Although microorganisms possess high sorption capability for lanthanides, the effect of their biological response on lanthanides migration is unclear. Using active fungus Acremonium strictum KR21-2, supplied with nutrients, this study compared the transformation of lanthanides during the biooxidation of Mn(II) in the absence and presence of trisodium citrate. In the absence of trisodium citrate, lanthanides were rapidly sorbed on fungal cells within 24 h, followed by the preferential desorption of Ce over other lanthanides as Mn oxide formed. Most of the desorbed Ce was in the colloidal phase and associated with a biomolecule produced by the active fungus. In contrast, neither desorption of Ce nor release of this biomolecule occurred in the presence of trisodium citrate. Most importantly, the Ce-binding biomolecule was not found to associate with any other trivalent lanthanides tested or with Fe. The biomolecule was characterized as c.a. 4700 Da in size, and it contains saccharides that differed from those non-nuclide-specific organic substances released from resting cells, as reported previously. This study highlights the importance of biotic reactions between lanthanides and microbial cells, which may affect the migration of lanthanides at the water-Mn oxide interface.

  9. Allosteric effects in coiled-coil proteins folding and lanthanide-ion binding.

    PubMed

    Samiappan, Manickasundaram; Alasibi, Samaa; Cohen-Luria, Rivka; Shanzer, Abraham; Ashkenasy, Gonen

    2012-10-07

    Peptide sequences modified with lanthanide-chelating groups at their N-termini, or at their lysine side chains, were synthesized, and new Ln(III) complexes were characterized. We show that partial folding of the conjugates to form trimer coiled coil structures induces coordination of lanthanides to the ligand, which in turn further stabilizes the 3D structure.

  10. Separation of Americium from Europium using Camphor-BisTriazinyl Pyridine: A Fundamental Study

    SciTech Connect

    Tevepaugh, Kayron N.; Carrick, Jesse D.; Tai, Serene; Coonce, Janet G.; Delmau, Lætitia H.; Ensor, Dale D.

    2015-10-27

    Among the different components present in spent nuclear fuel, long-lived trivalent actinides are particularly difficult to separate from the shorter-lived lanthanide fission products due to their similar chemical properties. We achieved selective extraction of americium from acidic solution (up to 2M HNO3) containing tenth molar quantities of lanthanides using neutral pyridine-based ligands dissolved in polar diluents. Nitrogen-based Bis Triazinyl Pyridine (BTP) ligands are desirable for both their excellent An/Ln selectivity and incinerability. Our results pertaining to ligand solubility, kinetics, hydrolytic stability, and extraction performance in various nitric acid environments are presented.

  11. Separation of Americium from Europium using Camphor-BisTriazinyl Pyridine: A Fundamental Study

    DOE PAGES

    Tevepaugh, Kayron N.; Carrick, Jesse D.; Tai, Serene; ...

    2015-10-27

    Among the different components present in spent nuclear fuel, long-lived trivalent actinides are particularly difficult to separate from the shorter-lived lanthanide fission products due to their similar chemical properties. We achieved selective extraction of americium from acidic solution (up to 2M HNO3) containing tenth molar quantities of lanthanides using neutral pyridine-based ligands dissolved in polar diluents. Nitrogen-based Bis Triazinyl Pyridine (BTP) ligands are desirable for both their excellent An/Ln selectivity and incinerability. Our results pertaining to ligand solubility, kinetics, hydrolytic stability, and extraction performance in various nitric acid environments are presented.

  12. Diverse lanthanide coordination polymers tuned by the flexibility of ligands and the lanthanide contraction effect: syntheses, structures and luminescence.

    PubMed

    Zhou, Xiaoyan; Guo, Yanling; Shi, Zhaohua; Song, Xueqin; Tang, Xiaoliang; Hu, Xiong; Zhu, Zhentong; Li, Pengxuan; Liu, Weisheng

    2012-02-14

    Two new flexible exo-bidentate ligands were designed and synthesized, incorporating different backbone chain lengths bearing two salicylamide arms, namely 2,2'-(2,2'-oxybis(ethane-2,1-diyl)bis(oxy))bis(N-benzylbenzamide) (L(I)) and 2,2'-(2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))bis(oxy)bis(N-benzylbenzamide) (L(II)). These two structurally related ligands are used as building blocks for constructing diverse lanthanide polymers with luminescent properties. Among two series of lanthanide nitrate complexes which have been characterized by elemental analysis, TGA analysis, X-ray powder diffraction, and IR spectroscopy, ten new coordination polymers have been determined using X-ray diffraction analysis. All the coordination polymers exhibit the same metal-to-ligand molar ratio of 2 : 3. L(I), as a bridging ligand, reacts with lanthanide nitrates forming two different types of 2D coordination complexes: herringbone framework {[Ln(2)(NO(3))(6)(L(I))(3)·mC(4)H(8)O(2)](∞) (Ln = La (1), and Pr (2), m = 1, 2)} as type I,; and honeycomb framework {[Ln(2)(NO(3))(6)(L(I))(3)·nCH(3)OH](∞) (Ln = Nd (3), Eu (4), Tb (5), and Er (6), n = 0 or 3)} as type II, which change according to the decrease in radius of the lanthanide. For L(II), two distinct structure types of 1D ladder-like coordination complexes were formed with decreasing lanthanide radii: [Ln(2)(NO(3))(6)(L(II))(3)·2C(4)H(8)O(2)](∞) (Ln = La (7), Pr (8), Nd (9)) as type III, [Ln(2)(NO(3))(6)(L(I))(3)·mC(4)H(8)O(2)·nCH(3)OH](∞) (Ln = Eu (10), Tb (11), and Er (12), m, n = 2 or 0) as type IV. The progressive structural variation from the 2D supramolecular framework to 1D ladder-like frameworks is attributed to the varying chain length of the backbone group in the flexible ligands. The photophysical properties of trivalent Sm, Eu, Tb, and Dy complexes at room temperature were also investigated in detail.

  13. Effect of indium addition in U-Zr metallic fuel on lanthanide migration

    NASA Astrophysics Data System (ADS)

    Kim, Yeon Soo; Wiencek, T.; O'Hare, E.; Fortner, J.; Wright, A.; Cheon, J. S.; Lee, B. O.

    2017-02-01

    Advanced fast reactor concepts to achieve ultra-high burnup (∼50%) require prevention of fuel-cladding chemical interaction (FCCI). Fission product lanthanide accumulation at high burnup is substantial and significantly contributes to FCCI upon migration to the cladding interface. Diffusion barriers are typically used to prevent interaction of the lanthanides with the cladding. A more active method has been proposed which immobilizes the lanthanides through formation of stable compounds with an additive. Theoretical analysis showed that indium, thallium, and antimony are good candidates. Indium was the strongest candidate because of its low reactivity with iron-based cladding alloys. Characterization of the as-fabricated alloys was performed to determine the effectiveness of the indium addition in forming compounds with lanthanides, represented by cerium. Tests to examine how effectively the dopant prevents lanthanide migration under a thermal gradient were also performed. The results showed that indium effectively prevented cerium migration.

  14. Anion effects in the extraction of lanthanide 2-thenoyltrifluoroacetone complexes into an ionic liquid

    SciTech Connect

    Jensen, Mark P.; Beitz, James V.; Rickert, Paul G.; Borkowski, Marian; Laszak, Ivan; Dietz, Mark L.

    2012-07-01

    The extraction of trivalent lanthanides from an aqueous phase containing 1 M NaClO{sub 4} into the room temperature ionic liquid 1-butyl-3-methylimidazolium nonafluoro-1-butane sulfonate by the beta-diketone extractant 2-thenoyltrifluoroacetone (Htta) was studied. Radiotracer distribution, absorption spectroscopy, time-resolved laser-induced fluorescence spectroscopy, and X-ray absorption fine structure measurements point to the extraction of multiple lanthanide species. At low extractant concentrations, fully hydrated aqua cations of the lanthanides are present in the ionic liquid phase. As the extractant concentration is increased 1:2 and 1:3 lanthanide:tta species are observed. In contrast, 1:4 Ln:tta complexes were observed in the extraction of lanthanides by Htta into 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide. (authors)

  15. Selective lanthanide sorption and mechanism using novel hybrid Lewis base (N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide) ligand modified adsorbent.

    PubMed

    Awual, Md Rabiul; Kobayashi, Tohru; Miyazaki, Yuji; Motokawa, Ryuhei; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro; Yaita, Tsuyoshi

    2013-05-15

    This study aims to develop a highly selective Lewis base adsorbent to investigate the selective sorption and recovery of Eu(III) and Sm(III) from wastewater. The oxygen and nitrogen donor atoms containing Lewis base N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide (MePhPTA) ligand was synthesized and subsequently an adsorbent was prepared by direct immobilization onto mesoporous silica. Determined maximum adsorption capacities were 125.63 and 124.38 mg/g for Eu(III) and Sm(III), respectively. Experiments with mixed-cations solutions showed that the sequence of preferential adsorption was Eu(III)>Sm(III). The lanthanide sorption by hybrid Lewis base adsorbent (HyLBA) was not adversely affected by the presence of sodium, potassium, calcium, magnesium, chloride, sulfate and nitrate ions due to strong affinity between hard Lewis acid lanthanide and hard Lewis base adsorbent. The crystallography for the Sm-MePhPTA complex suggested that MePhPTA was strongly coordinated to Sm(III) with oxygen and nitrogen by forming a stable complex with two 5-membered rings. The data clarified that bond lengths between Sm(III) and amide oxygen (2.475Å) were shorter than SmN (2.662Å) in phenanthroline moiety indicating strong oxygen driven HyLBA. The results suggested that HyLBA has a good prospect of promising applications for separation/sorption of lanthanide ions from effluents.

  16. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    SciTech Connect

    Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Carter, Jennifer C.

    2012-08-22

    This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.

  17. Tracking petroleum refinery emission events using lanthanum and lanthanides as elemental markers for PM2.5.

    PubMed

    Kulkarni, Pranav; Chellam, Shankararaman; Fraser, Matthew P

    2007-10-01

    Fine particulate matter levels at four air sampling stations in the Houston, TX area are apportioned to quantify the impact of emissions from a local refinery during a reported emission event. Through quantification of lanthanum and lanthanides using a recently developed analytical technique, the impacts of emissions from fluidized-bed catalytic cracking (FCC) units are quantitatively tracked across the Houston region. The results show a significant (33-106-fold) increase in contributions of FCC emissions to PM2.5 compared with background levels associated with routine operation. This impact from industrial emissions to ambient air quality occurs simultaneously with a larger, regional haze episode that lead to elevated PM2.5 concentrations throughout the entire region. By focusing on detailed chemical analysis of unique maker metals (lanthanum and lanthanides), the impact of emissions from the FCC unit was tracked from the local refinery that reported the emission event to a site approximately 50 km downwind, illustrating the strength of the analytical method to isolate an important source during a regional haze episode not related to the emission event. While this source apportionment technique could separate contributions from FCC emissions, improved time-resolved sampling is proposed to more precisely quantify the impacts of transient emission events on ambient PM2.5.

  18. Isotopic signature of selected lanthanides for nuclear activities profiling using cloud point extraction and ICP-MS/MS.

    PubMed

    Labrecque, Charles; Lebed, Pablo J; Larivière, Dominic

    2016-05-01

    The presence of fission products, which include numerous isotopes of lanthanides, can impact the isotopic ratios of these elements in the environment. A cloud point extraction (CPE) method was used as a preconcentration/separation strategy prior to measurement of isotopic ratios of three lanthanides (Nd, Sm, and Eu) by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). To minimise polyatomic interference, the combination of interferents removal by CPE, reaction/collision cell conditions in He and NH3 mode and tandem quadrupole configuration was investigated and provided optimal results for the determination of isotopic ratio in environmental samples. Isotopic ratios were initially measured in San Joaquin soil (NIST-2709a), an area with little contamination of nuclear origin. Finally, samples collected from three sites with known nuclear activities (Fangataufa Lagoon in French Polynesia, Chernobyl and the Ottawa River near Chalk River Laboratory) were analysed and all exhibited altered isotopic ratios for (143/145)Nd, (147/149)Sm, and (151/153)Eu. These results demonstrate the potential of CPE and ICP-MS/MS for the detection of altered isotopic ratio in environmental samples collected in area subjected to nuclear anthropogenic contamination. The detection of variations in these isotopic ratios of fission products represents the first application of CPE in nuclear forensic investigations of environmental samples.

  19. Toward mechanistic understanding of nuclear reprocessing chemistries by quantifying lanthanide solvent extraction kinetics via microfluidics with constant interfacial area and rapid mixing.

    PubMed

    Nichols, Kevin P; Pompano, Rebecca R; Li, Liang; Gelis, Artem V; Ismagilov, Rustem F

    2011-10-05

    The closing of the nuclear fuel cycle is an unsolved problem of great importance. Separating radionuclides produced in a nuclear reactor is useful both for the storage of nuclear waste and for recycling of nuclear fuel. These separations can be performed by designing appropriate chelation chemistries and liquid-liquid extraction schemes, such as in the TALSPEAK process (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes). However, there are no approved methods for the industrial scale reprocessing of civilian nuclear fuel in the United States. One bottleneck in the design of next-generation solvent extraction-based nuclear fuel reprocessing schemes is a lack of interfacial mass transfer rate constants obtained under well-controlled conditions for lanthanide and actinide ligand complexes; such rate constants are a prerequisite for mechanistic understanding of the extraction chemistries involved and are of great assistance in the design of new chemistries. In addition, rate constants obtained under conditions of known interfacial area have immediate, practical utility in models required for the scaling-up of laboratory-scale demonstrations to industrial-scale solutions. Existing experimental techniques for determining these rate constants suffer from two key drawbacks: either slow mixing or unknown interfacial area. The volume of waste produced by traditional methods is an additional, practical concern in experiments involving radioactive elements, both from disposal cost and experimenter safety standpoints. In this paper, we test a plug-based microfluidic system that uses flowing plugs (droplets) in microfluidic channels to determine absolute interfacial mass transfer rate constants under conditions of both rapid mixing and controlled interfacial area. We utilize this system to determine, for the first time, the rate constants for interfacial transfer of all lanthanides, minus promethium, plus yttrium, under TALSPEAK

  20. Separated Shoulder

    MedlinePlus

    Separated shoulder Overview By Mayo Clinic Staff A separated shoulder is an injury to the ligaments that hold your collarbone (clavicle) to your shoulder blade. In a mild separated shoulder, the ligaments ...

  1. Luminescent hybrid lanthanide sulfates and lanthanide sulfonate-carboxylates with 1,10-phenanthroline involving in-situ oxidation of 2-mercaptonbenzoic acid

    NASA Astrophysics Data System (ADS)

    Zhong, Jie-Cen; Wan, Fang; Sun, Yan-Qiong; Chen, Yi-Ping

    2015-01-01

    A series of lanthanide sulfates and lanthanide sulfonate-carboxylates, [Ln2(phen)2(SO4)3(H2O)2]n (I:Ln=Nd(1a), Sm(1b), Eu(1c), phen=1,10-phenanthroline) and [Ln(phen)(2-SBA)(BZA)]n (II: Ln=Sm(2a), Eu(2b), Dy(2c), 2-SBA=2-sulfobenzoate, BZA=benzoate) have been hydrothermally synthesized from lanthanide oxide, 2-mercaptonbenzoic acid with phen as auxiliary ligand and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, TG analyses and luminescence spectroscopy. Interestingly, SO4 2 - anions in I came from the in situ deep oxidation of thiol groups of 2-mercaptonbenzoic acid while 2-sulfobenzoate and benzoate ligands in II from the middle oxidation and desulfuration reactions of 2-mercaptonbenzoic acid. Compounds I are organic-inorganic hybrid lanthanide sulfates, which have rare one-dimensional column-like structures. Complexes II are binuclear lanthanide sulfonate-carboxylates with 2-sulfobenzoate and benzoate as bridges and 1,10-phenanthroline as terminal. Photoluminescence studies reveal that complexes I and II exhibit strong lanthanide characteristic emission bands in the solid state at room temperature.

  2. A series of three-dimensional architectures constructed from lanthanide-substituted polyoxometalosilicates and lanthanide cations or lanthanide-organic complexes as linkers.

    PubMed

    An, Haiyan; Zhang, Hua; Chen, Zhaofei; Li, Yangguang; Liu, Xuan; Chen, Hao

    2012-07-21

    Six 3D architectures based on lanthanide-substituted polyoxometalosilicates, KLn[(H(2)O)(6)Ln](2)[(H(2)O)(4)LnSiW(11)O(39)](2)·nH(2)O (Ln = La 1, n = 42; Ce 2, n = 40), H[(H(2)O)(6)Nd](2)[(H(2)O)(7)Nd][(H(2)O)(4)NdSiW(11)O(39)][(H(2)O)(3)NdSiW(11)O(39)]·13H(2)O (3), H(2)K(2)[(Hpic)(H(2)O)(5)Ln](2)[(H(2)O)(4)LnSiW(11)O(39)](2)·nH(2)O (Ln = La 4, n = 18.5; Ce 5, n = 35; Nd 6, n = 36; Hpic = 4-picolinic acid), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy, TG analysis, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1 and 2 are isostructural, built up of lanthanide-substituted polyoxoanions [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) linked by Ln(3+) cations to form a 3D open framework with 1D channels. The polyoxoanion [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) consists of two α(1)-type mono-Ln-substituted Keggin anions. When Nd(3+) ion was used instead of La(3+) or Ce(3+) ions, compound 3 with a different structure was obtained, containing two kinds of polyoxoanions [{(H(2)O)(4)Nd(SiW(11)O(39))}(2)](10-) and [{(H(2)O)(3)Nd(SiW(11)O(39))}(2)](10-) which are connected together by Nd(3+) ions to yield a 3D framework. When 4-picolinic acid was added to the reaction system of 1-3, isostructural compounds 4-6 were obtained, constructed from the polyoxoanions [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) linked by picolinate-chelated lanthanide centers to form a 3D channel framework. From a topological viewpoint, the 3D nets of 1, 2, 4, 5 and 6 exhibit a (3,6)-connected rutile topology, whereas the 3D structure of 3 possesses a rare (3,3,6,10)-connected topology. The magnetic properties of 2, 3, 5 and 6 have been studied by measuring their magnetic susceptibilities in the temperature range 2-300 K.

  3. Novel states of matter with ultracold magnetic lanthanides

    NASA Astrophysics Data System (ADS)

    Kotochigova, Svetlana

    2016-05-01

    Ultracold atomic physics is now poised to enter a new regime, where far-more complex atomic species can be cooled and studied. Magnetic lanthanide atoms with their large magnetic moment and large orbital momentum are extreme examples of such species. In fact, ultracold gases of magnetic lanthanides provide the opportunity to examine strongly correlated matter, creating a platform to explore exotic many-body phases such as quantum ferrofluids, quantum liquid crystals, and supersolids. Experimental advances in trapping and cooling magnetic Dy and Er atoms are paving the way towards these goals. Over the last few years we have developed a framework for understanding the complex anisotropic interactions between magnetic lanthanide atoms. Our theoretical model uses novel tools and advanced numerical treatments to describe the underlying mechanism that generates correlations and chaos in dipolar scattering and bridges the enormous conceptual gap between simple atoms and complex molecules. This allows us to explain the origin of the dense spectra and statistics of the observed Er and Dy collisional resonances due to the anisotropy of the short- and long-range interactions between the atoms. We also study the distribution of the values of the molecular wave functions to isolate Anderson-type localized states within chaotic structures and confirm the existence of an intermediate chaotic regime. In addition, our model for the three-body recombination via the formation of a resonant trimer has identified the origin of the temperature-sensitive resonance density observed in both Er and Dy collisions as due to d-wave entrance channel collisions. This work is supported by AFOSR (No. FA9550-14-1-0321) and NSF (No. PHY-1308573) grants.

  4. Centrifugal atomization of lanthanide materials for cryogenic coolers

    SciTech Connect

    Osborne, Matthew G.

    1994-01-04

    Until recently, Pb was the preferred heat exchanger matrix material used in low temperature cryocoolers; however, the heat capacity of Pb drops drastically below ~15K and new matrix materials based on the lanthanide elements have been developed. These materials magnetically order at low temperatures and the entropy change associated with ordering contributes to the materials` heat capacities. The drawback to widespread use of lanthanide intermetallic compounds in cryocoolers has been the difficulty in manufacturing high-quality particulates. The purpose of this project was to develop a technique for producing high-quality powders of lanthanide metals and lanthanide intermetallic compounds for use in cryocooler heat exchangers. A series of atomization experiments was performed using Er3Ni, Nd, Nd3Ni, and (Er0.5Nd0.5)3Ni. Atomization of these materials resulted in particles ranging from mostly spherical to extremely flattened. Analyses of size distributions for the experiments indicate that increased atomization disk speed and superheat result in smaller mean particle diameters and narrower size distributions. Chemical analyses of the atomized powders indicate that the CA/RQB technique produces particulate with much lower interstitial contamination than other techniques. The Er3Ni and Nd3Ni powders were predominantly of the desired phase and the (Er0.5Nd0.5)3Ni powder had one major and possibly three minor phases. The solidification morphology is typically fine dendritic or cellular with finer microstructure spacings near the particle surfaces. The Er3Ni powders have higher heat capacities than gas atomized powders reported in literature. The heat capacity of Nd3Ni has a peak which does not degrade dramatically with processing. The (Er0.5Nd0.5)3Ni material has a higher heat capacity compared to Er3

  5. Progress on lanthanide-based organic-inorganic hybrid phosphors.

    PubMed

    Carlos, Luís D; Ferreira, Rute A S; de Zea Bermudez, Verónica; Julián-López, Beatriz; Escribano, Purificación

    2011-02-01

    Research on organic-inorganic hybrid materials containing trivalent lanthanide ions (Ln(3+)) is a very active field that has rapidly shifted in the last couple of years to the development of eco-friendly, versatile and multifunctional systems, stimulated by the challenging requirements of technological applications spanning domains as diverse as optics, environment, energy, and biomedicine. This tutorial review offers a general overview of the myriad of advanced Ln(3+)-based organic-inorganic hybrid materials recently synthesised, which may be viewed as a major innovation in areas of phosphors, lighting, integrated optics and optical telecommunications, solar cells, and biomedicine.

  6. Status of the lanthanides and actinides in the periodic table

    SciTech Connect

    Holden, N.E.

    1985-01-01

    In extended discussions and correspondence with Ekkehard Fluck, the author was made aware of a problem with the Periodic Table, i.e., which element should be shown in the main table as the representative of the lanthanide series and the actinide series. In earlier discussion, he came to the conclusion that lanthanum and actinium are not the elements which should appear, but rather lutetium and lawrencium are more appropriate for inclusion in their place. This paper will attempt to justify the reasons for the above conclusions. 4 refs.

  7. Lanthanide luminescence for functional materials and bio-sciences.

    PubMed

    Eliseeva, Svetlana V; Bünzli, Jean-Claude G

    2010-01-01

    Recent startling interest for lanthanide luminescence is stimulated by the continuously expanding need for luminescent materials meeting the stringent requirements of telecommunication, lighting, electroluminescent devices, (bio-)analytical sensors and bio-imaging set-ups. This critical review describes the latest developments in (i) the sensitization of near-infrared luminescence, (ii) "soft" luminescent materials (liquid crystals, ionic liquids, ionogels), (iii) electroluminescent materials for organic light emitting diodes, with emphasis on white light generation, and (iv) applications in luminescent bio-sensing and bio-imaging based on time-resolved detection and multiphoton excitation (500 references).

  8. Stabilization of molecular lanthanide polysulfides by bulky scorpionate ligands.

    PubMed

    Kühling, Marcel; McDonald, Robert; Liebing, Phil; Hilfert, Liane; Ferguson, Michael J; Takats, Josef; Edelmann, Frank T

    2016-07-07

    Well-defined lanthanide polysulfide complexes containing S4(2-) and S5(2-) ligands, the samarium(iii) pentasulfide complex Sm(Tp(iPr2))(κ(1)-3,5-(i)Pr2Hpz)(S5) and the tetrasulfide-bridged binuclear ytterbium(iii) complex (μ-S4)[Yb(Tp(iPr2))(κ(1)-3,5-(i)Pr2Hpz)(κ(2)-3,5-(i)Pr2pz)]2 (Tp(iPr2) = hydro-tris(3,5-diisopropylpyrazolyl)borate), have been synthesized and structurally characterized by single-crystal X-ray diffraction.

  9. An integrated closed-tube 2-plex PCR amplification and hybridization assay with switchable lanthanide luminescence based spatial detection.

    PubMed

    Lahdenperä, Susanne; Spangar, Anni; Lempainen, Anna-Maija; Joki, Laura; Soukka, Tero

    2015-06-21

    Switchable lanthanide luminescence is a binary probe technology that inherently enables a high signal modulation in separation-free detection of DNA targets. A luminescent lanthanide complex is formed only when the two probes hybridize adjacently to their target DNA. We have now further adapted this technology for the first time in the integration of a 2-plex polymerase chain reaction (PCR) amplification and hybridization-based solid-phase detection of the amplification products of the Staphylococcus aureus gyrB gene and an internal amplification control (IAC). The assay was performed in a sealed polypropylene PCR chip containing a flat-bottom reaction chamber with two immobilized capture probe spots. The surface of the reaction chamber was functionalized with NHS-PEG-azide and alkyne-modified capture probes for each amplicon, labeled with a light harvesting antenna ligand, and covalently attached as spots to the azide-modified reaction chamber using a copper(i)-catalyzed azide-alkyne cycloaddition. Asymmetric duplex-PCR was then performed with no template, one template or both templates present and with a europium ion carrier chelate labeled probe for each amplicon in the reaction. After amplification europium fluorescence was measured by scanning the reaction chamber as a 10 × 10 raster with 0.6 mm resolution in time-resolved mode. With this assay we were able to co-amplify and detect the amplification products of the gyrB target from 100, 1000 and 10,000 copies of isolated S. aureus DNA together with the amplification products from the initial 5000 copies of the synthetic IAC template in the same sealed reaction chamber. The addition of 10,000 copies of isolated non-target Escherichia coli DNA in the same reaction with 5000 copies of the synthetic IAC template did not interfere with the amplification or detection of the IAC. The dynamic range of the assay for the synthetic S. aureus gyrB target was three orders of magnitude and the limit of detection of 8 p

  10. Ultracapacitor separator

    DOEpatents

    Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris

    2001-03-06

    An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.

  11. Thermodynamics and extraction modeling of trivalent lanthanides in the nuclear fuel cycle

    SciTech Connect

    Levitskaia, T.G.; Chatterjee, S.; Valerio, E.L.; Robinson, T.A.

    2013-07-01

    In this investigation, a combination of VPO (Vapor Pressure Osmometry) and water activity methods was applied to measure water activity and osmotic coefficients of binary lanthanide nitrate solutions at a temperature of 25 C. degrees. It was observed that the nature of the lanthanide nitrate has pronounced effect on the water activity in solution. In the solutions with the same Ln(NO{sub 3}){sub 3} molality, water activity is decreased in the order from the light to heavy lanthanides. This trend was explained by the contraction of the lanthanide ionic radii in the same order resulting in the [Ln(H{sub 2}O){sub n}]{sup 3+} (aq) hydration number of 9 for the early (La-Sm) and 8 for the late (Dy-Lu) lanthanides, with the intermediate metals exhibiting a mixture of eight and nine coordinate molecules. This results in the dissimilar effect of the light and heavy lanthanides on the water structure manifesting in the systematic changes of the water activity in the series of concentrated lanthanide solutions. Experimental water activity and osmotic coefficient data agree well with the literature for both 1:1 and 3:1 electrolyte systems. The Pitzer parameters obtained fitting these data are in an excellent agreement with the literature reported values for Ln(NO{sub 3}){sub 3} solutions.

  12. A flowsheet concept for an Am/Ln separation based on Am{sup VI} solvent extraction

    SciTech Connect

    Mincher, B.J.; Law, J.D.

    2013-07-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term radiotoxicity of material interred in a future high-level waste repository. However, a separation amenable to process scale-up remains elusive. Higher oxidation states of americium have recently been used to demonstrate solvent extraction-based separations using conventional fuel cycle ligands. Here, the successful partitioning of Am{sup VI} from the bulk of lanthanides and curium using diamyl-amyl-phosphonate (DAAP) extraction is reported. Due to the instability of Am{sup VI} in the organic phase it was readily selectively stripped to a new acidic aqueous phase to provide separation from co-extracted Ce{sup IV}. The use of NaBiO{sub 3} as an oxidant to separate Am from the lanthanides and Cm by solvent extraction has been successfully demonstrated on the bench scale. Based on these results, flowsheet concepts can be designed that result in 96 % Am recovery in the presence of a few percent of the remaining Cm and the lanthanides in two extraction contacts. Preliminary results also indicate that the DAAP extractant is robust toward γ- irradiation under realistic conditions of acidity and dissolved oxygen concentration.

  13. Equilibrium Speciation of Select Lanthanides in the Presence of Acidic Ligands in Homo- and Heterogeneous Solutions

    SciTech Connect

    Robinson, Troy A

    2011-08-01

    This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd3+), sodium (Na+), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd3+ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probed through vapor pressure osmometry, visible and Fourier Transform Infrared (FTIR) spectroscopy, 22Na and 13C labeled lactate radiotracer distribution measurements, Karl Fischer titrations, and equilibrium pH measurements. Distribution of Nd3+, Na+, lactate, and equilibrium pH were modeled using the SXLSQI software to obtain logKNd and logKNa extraction constants under selected conditions. Results showed that high Nd3+ loading of the HDEHP led to Nd3+ speciation that departs from the ion exchange mechanism and includes formation of highly aggregated, polynuclear [NdLactate(DEHP)2]x; (with x > 1). By substituting lanthanum (La3+) for Nd3+ in this system, NMR scoping experiments using 23Na, 31P nuclei and 13C labeled lactate were performed. Results indicated that this technique is sensitive to changes in system speciation, and that further experiments are warranted. In a homogeneous system representing the TALSPEAK aqueous phase, Lactate protonation behavior at various temperatures was characterized using a combination of potentiometric titration and modeling with the Hyperquad computer program. The temperature dependent deprotonation behavior of lactate showed little change with temperature at 2.0 M NaCl ionic strength. Cloud point extraction is a non-traditional separation technique that starts with a homogeneous

  14. Purification of lanthanides for double beta decay experiments

    SciTech Connect

    Polischuk, O. G.; Barabash, A. S.; Belli, P.; Bernabei, R.; Boiko, R. S.; Danevich, F. A.; Mokina, V. M.; Poda, D. V.; Tretyak, V. I.; Cappella, F.; Incicchitti, A.; Cerulli, R.; Laubenstein, M.; Nisi, S.

    2013-08-08

    There are several potentially double beta active isotopes among the lanthanide elements. However, even high purity grade lanthanide compounds contain {sup 238}U, {sup 226}Ra and {sup 232,228}Th typically on the level of ∼ (0.1 - 1) Bq/kg. The liquid-liquid extraction technique was used to remove traces of U, Ra and Th from CeO{sub 2}, Nd{sub 2}O{sub 3} and Gd{sub 2}O{sub 3}. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe γ spectrometry at the underground Gran Sasso National Laboratories of the INFN (Italy). After the purification the radioactive contamination of gadolinium oxide by Ra and Th was decreased at least one order of magnitude. The efficiency of the approach to purify cerium oxide from Ra was on same level, while the radioactive contamination of neodymium sample before and after the purification is below the sensitivity of analytical methods. The purification method is much less efficient for chemically very similar radioactive elements like lanthanum, lutetium and actinium. R and D of the methods to remove the pollutions with improved efficiency is in progress.

  15. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    PubMed

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Lanthanide(III)-polyimide nanocomposites: Enhancement of dimensional stability

    SciTech Connect

    Southward, R.E.; Thompson, D.S.; Thornton, T.A.

    1996-10-01

    The addition of lanthanide(RI) acetate and tris(2,4-pentanedionato)lanthanum(III) complexes to the soluble, low dielectric, colorless polyimides formed from 2,2-bis(3,4-dicarboxyphenyl)hexa-fluoropropanedianhydride/1,3-bis-(aminophenoxy)benzene, (6FDA/APB), and 6FDA/2,2-bis[4-4-aminophenoxy]hexa-fluoropropane, 6FDA/BDAF, was investigated with the expectation that thermal treatment of doped resin films would lead to an isotropic reduction in the linear coefficient of thermal expansion (CTE) while maintaining the essential properties of the parent polyimide. To realize visually clear metal-doped films the inorganic phase particle size, after thermal treatment, must be less than ca. 200 nm. This can only be accomplished by using Ln complexes which are soluble in the curing polymer matrix. Ln acetates gave homogeneous, visually clear films with manometer size inorganic clusters and slightly lowered CTE`s. The Ln-2,4-pentanedionates gave films with large CTE lowerings while maintaining visual clarity and acceptable mechanical and thermal properties. RI measurements indicate that the films are isotropic. TEM data are consistent with particle sizes for the lanthanide ion containing species which are in the manometer range. Dielectric constants (8-12 GHz) remain low.

  17. Purification of lanthanides for double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Polischuk, O. G.; Barabash, A. S.; Belli, P.; Bernabei, R.; Boiko, R. S.; Cappella, F.; Cerulli, R.; Danevich, F. A.; Incicchitti, A.; Laubenstein, M.; Mokina, V. M.; Nisi, S.; Poda, D. V.; Tretyak, V. I.

    2013-08-01

    There are several potentially double beta active isotopes among the lanthanide elements. However, even high purity grade lanthanide compounds contain 238U, 226Ra and 232,228Th typically on the level of ˜ (0.1 - 1) Bq/kg. The liquid-liquid extraction technique was used to remove traces of U, Ra and Th from CeO2, Nd2O3 and Gd2O3. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe γ spectrometry at the underground Gran Sasso National Laboratories of the INFN (Italy). After the purification the radioactive contamination of gadolinium oxide by Ra and Th was decreased at least one order of magnitude. The efficiency of the approach to purify cerium oxide from Ra was on same level, while the radioactive contamination of neodymium sample before and after the purification is below the sensitivity of analytical methods. The purification method is much less efficient for chemically very similar radioactive elements like lanthanum, lutetium and actinium. R&D of the methods to remove the pollutions with improved efficiency is in progress.

  18. Stabilization of actinides and lanthanides in unusually high oxidation states

    SciTech Connect

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO/sub 3/ or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF/sub 5//HF solution or Pu(VII) in Li/sub 5/PuO/sub 6/). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs.

  19. Magnetic Interactions in a Series of Homodinuclear Lanthanide Complexes.

    PubMed

    Comba, Peter; Großhauser, Michael; Klingeler, Rüdiger; Koo, Changhyun; Lan, Yanhua; Müller, Dennis; Park, Jaena; Powell, Annie; Riley, Mark J; Wadepohl, Hubert

    2015-12-07

    A series of seven isostructural homodinuclear lanthanide complexes are reported. The magnetic properties (ac and dc SQUID measurements) are discussed on the basis of the X-ray structural properties which show that the two lanthanide sites are structurally different. MCD spectroscopy of the dysprosium(III) and neodymium(III) complexes ([Dy(III)2(L)(OAc)4](+) and [Nd(III)2(L)(OAc)4](+)) allowed us to thoroughly analyze the ligand field, and high-frequency EPR spectroscopy of the gadolinium(III) species ([Gd(III)2(L)(OAc)4](+)) showed the importance of dipolar coupling in these systems. An extensive quantum-chemical analysis of the dysprosium(III) complex ([Dy(III)2(L)(OAc)4](+)), involving an ab initio (CASSCF) wave function, explicit spin-orbit coupling (RASSI-SO), and a ligand field analysis (Lines model and Stevens operators), is in full agreement with all experimental data (SQUID, HF-EPR, MCD) and specifically allowed us to accurately simulate the experimental χT versus T data, which therefore allowed us to establish a qualitative model for all relaxation pathways.

  20. Americium/curium extraction from a lanthanide borosilicate glass

    SciTech Connect

    Rudisill, T.S.; Pareizs, J.M.; Ramsey, W.G.

    1996-12-01

    A solution containing kilogram quantities of highly radioactive isotopes of americium and curium (Am/Cm) and lanthanide fission products is currently stored in a process tank at the Department of Energy`s Savannah River Site (SRS). This tank and its vital support systems are old, subject to deterioration, and prone to possible leakage. For this reason, a program has been initiated to stabilize this material as a lanthanide borosilicate (LBS) glass. The Am/Cm has commercial value and is desired for use by the heavy isotope programs at the Oak Ridge National Laboratory (ORNL). A recovery flowsheet was demonstrated using a curium containing glass to extract the Am/Cm from the glass matrix. The procedure involved grinding the glass to less than 200 mesh and dissolving in concentrated nitric acid at 110 {degrees}C. Under these conditions, the dissolution was essentially 100% after 2 hours except for the insoluble silicon. Using a nonradioactive surrogate, the expected glass dissolution rate during Am/Cm recovery was bracketed by using both static and agitated conditions. The measured rates, 0.0082 and 0.040 g/hr.sq cm, were used to develop a predictive model for the time required to dissolve a spherical glass particle in terms of the glass density, particle size, and measured rate. The calculated dissolution time was in agreement with the experimental observation that the curium glass dissolution was complete in less than 2 hrs.

  1. Pyridinophane platform for stable lanthanide(III) complexation.

    PubMed

    Castro, Goretti; Bastida, Rufina; Macías, Alejandro; Pérez-Lourido, Paulo; Platas-Iglesias, Carlos; Valencia, Laura

    2013-05-20

    A detailed investigation of the solid state and solution structures of lanthanide(III) complexes with the macrocyclic ligand 2,11,20-triaza[3.3.3](2,6)pyridinophane (TPP) is reported. The solid state structures of 14 different Ln(3+) complexes have been determined using X-ray crystallography. The ligand is coordinating to the Ln(3+) ion by using its six nitrogen atoms, while nitrate or triflate anions and water molecules complete the metal coordination environments. The structure of the complexes in solution has been investigated by (1)H and (13)C NMR spectroscopy, as well as by DFT calculations (TPSSh model) performed in aqueous solution. The structures obtained from these calculations for the complexes with the lightest Ln(3+) ions (La-Sm) are in very good agreement with those determined by the analysis of the Ln(3+)-induced paramagnetic shifts. A structural change occurs across the lanthanide series at Sm(3+); the complexes of the large Ln(3+) ions (La-Nd) are chiral due to the nonplanar conformation of the macrocycle, and present effective C3v symmetries in solution as a consequence of a fast interconversion of two enantiomeric forms with C3 symmetry. The activation free energy for this enantiomerization process, as estimated by using DFT calculations, amounts to 33.0 kJ·mol(-1). The TPP ligand in the complexes of the heaviest Ln(3+) ions (Eu-Lu) presents a half-chair conformation, which results in C(s) symmetries in solution.

  2. Methods to increase the luminescence of lanthanide (III) macrocyclic complexes

    NASA Astrophysics Data System (ADS)

    Quagliano, John R.; Leif, Robert C.; Vallarino, Lidia M.; Williams, Steven A.

    2000-04-01

    Simultaneous detection of both a Eu(III) and a Sm(III) Quantum Dye is now possible because the enhanced luminescence of the Eu(III) and Sm(III) macrocycles occurs in the same solution and with excitation at the same wavelengths between 350 to 370 nm. Since DAPI is also excited between 350 to 370 nm, it is possible to use common excitation optics and a single dichroic mirror for measuring two molecular species and DNA. The narrow emissions of these macrocycles can be detected with negligible overlap between themselves or with DAPI-stained DNA. This will permit precise pixel by pixel ratio measurements of the Eu(III) macrocycle to Sm(III) macrocycle, and of each macrocycle to DNA> This technology should be applicable to antibodies, FISH, comparative genomic hybridization, and chromosome painting. Cofluorescence of the Tb(III)-macrocycle has also been obtained under different conditions. The luminescence of these lanthanide macrocycles can be observed with conventional fluorescence instrumentation previously unattainable low levels. Thus, it will be possible to employ narrow bandwidth lanthanide luminescent tags to identify three molecular species with a conventional microscope.

  3. Features of the reaction of heterocyclic analogs of chalcone with lanthanide shift reagents

    SciTech Connect

    Turov, A.V.; Khilya, V.P.

    1994-10-01

    The PMR spectra of heterocyclic analogs of 2-hydroxychalcone containing thiazole, benzofuran, triazole, imidazole, benzodioxane, or pyridine rings in the presence of lanthanide shift reagents are studied. It is found that the most effective reagent for modifying the spectra of these compounds is Yb(fod)3. The broadening of the spectra of 2-hydroxy chalcones in the presence of lanthanide shift reagents is explained by the dynamic effects of complex formation. An example is given of the determination of the conformation of molecules of 2-hydroxychalcone by the simultaneous use of lanthanide shift reagents and the homonuclear Overhauser effect. 9 refs., 1 fig., 1 tab.

  4. Sol-Gel Electrolytes Incorporated by Lanthanide Luminescent Materials and Their Photophysical Properties

    NASA Astrophysics Data System (ADS)

    Yu, Chufang; Zhang, Zhengyang; Fu, Meizhen; Gao, Jinwei; Zheng, Yuhui

    2017-10-01

    A group of silica gel electrolytes with lanthanide luminescent hybrid materials were assembled and investigated. Photophysical studies showed that terbium and europium hybrids displayed characteristic green and red emissions within the electrolytes. The influence of different concentration of the lanthanide hybrids on the electrochemical behavior of a gelled electrolyte valve-regulated lead-acid battery were studied through cyclic voltammograms, electrochemical impedance spectroscopy, water holding experiments and mobility tests. The morphology and particle size were analyzed by scanning electron microscopy. The results proved that lanthanide (Tb3+/Eu3+) luminescent materials are effective additives which will significantly improve the electrochemical properties of lead-acid batteries.

  5. Fluoride Binding and Crystal-Field Analysis of Lanthanide Complexes of Tetrapicolyl-Appended Cyclen.

    PubMed

    Blackburn, Octavia A; Kenwright, Alan M; Jupp, Andrew R; Goicoechea, Jose M; Beer, Paul D; Faulkner, Stephen

    2016-06-20

    Lanthanide complexes of tetrapicolyl cyclen displayed remarkably high affinities for fluoride (log K≈5) in water, and were shown to form 1:1 complexes. The behaviour of these systems can be rationalised by changes to the magnitude of the crystal-field parameter, B20 . However, such changes are not invariably accompanied by a change in sign of this parameter: for early lanthanides, the N8 donor set with a coordinated axial water molecule ensures that the magnetic anisotropy has the opposite sense to that observed in the analogous dehydrated lanthanide complexes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Lanthanide-stimulated glucose and proline transport across rabbit intestinal brush-border membranes.

    PubMed

    Stevens, B R; Kneer, C

    1988-07-07

    Trivalent cations of the lanthanide series (La3+----Yb3+) stimulated uptake of proline or glucose in rabbit small intestinal brush-border membrane vesicles. The lanthanides stimulated uptake to an extent greater than Al3+, choline, and in many cases, Na+. A time-course of Er3+-stimulated glucose uptake gave initial rates and overshoots greater than Na+ stimulation. The best activators were Sm3+, Eu3+ and Tm3+, which stimulated proline initial uptakes by 400-600%, and stimulated glucose uptake by 120-150%, compared to Na+. The best lanthanide cotransport activators possessed high third ionization potentials.

  7. Correlation between Pi-Orbital Overlap and Conductivity Bis- Phthalocyaninato Lanthanides

    DTIC Science & Technology

    1991-06-10

    Overlap and Conductivity Bis-Phthalo- cyaninato Lanthanides 12. PERSONAL AUTHOR(S) Juan Padilla and William E. Hatfield 13a. TYPE OF REPORT 13b TIME COVERED...phthalocyanine ligands. Conductivity measurements on the iodine-doped bis-phthalocyaninato lanthanides , H[M(Pc)l2 1, show an average increase of four...18. Continued: bis-phthalocyaninato lanthanides mobility model OFFICE OF NAVAL RESERACH Just if o1 Contract N0014-89-J-1734 * R&T Code .135007---05 0

  8. Mixed Micelle-mediated Extraction and Separation of Scandium from Yttrium and Some Lanthanide Ions.

    PubMed

    Khalifa, Magdi E; Kenawy, Ibrahim M M; Hassanien, Mohamed M; Elnagar, Mohamed M

    2016-01-01

    A simple mixed-micelle mediated extraction was elaborated for the preconcentration and determination of scandium(III) by inductively coupled plasma optical emission spectrometry. Scandium(III) was complexed with Alizarin Red S and cetyltrimethylammonium bromide at pH 3 to form hydrophobic chelates, which could be extracted with Triton X-114 at room temperature (25°C) in the presence of KI as a salting-out electrolyte. The main parameters of the extraction procedure were investigated in regard to the extraction efficiency of scandium(III). Under the optimum conditions, a linear range of 0.5 - 150 ng mL(-1) and a detection limit of 0.2 ng mL(-1), along with a preconcentration factor of 100, were achieved. Furthermore, the interference of diverse ions accompanying scandium(III) was extensively studied. The obtained results indicate the high selectivity of the proposed procedure. The accuracy of the procedure was verified through recovery experiments on spiked water samples and synthetic mixtures. The procedure was successfully applied to a scandium(III) determination in clay samples.

  9. Understanding the Chemistry of Uncommon Americium Oxidation States for Application to Actinide/Lanthanide Separations

    SciTech Connect

    Leigh Martin; Bruce J. Mincher; Nicholas C. Schmitt

    2007-09-01

    A spectroscopic study of the stability of Am(V) and Am(VI) produced by oxidizing Am(III) with sodium bismuthate is presented, varying the initial americium concentration, temperature and length of the oxidation was seen to have profound effects on the resultant solutions.

  10. Preparation of N,N-dialkylcarbamato lanthanide complexes by extraction of lanthanide ions from aqueous solution into hydrocarbons.

    PubMed

    Armelao, Lidia; Belli Dell'Amico, Daniela; Biagini, Paolo; Bottaro, Gregorio; Chiaberge, Stefano; Falvo, Paola; Labella, Luca; Marchetti, Fabio; Samaritani, Simona

    2014-05-19

    Lanthanides are easily extracted as N,N-dibutylcarbamato complexes from aqueous solutions of their chlorides into heptane solutions of dibutylamine saturated with CO2. The products are recovered in high yields and are soluble in hydrocarbons. The derivatives [Ln(O2CNBu2)3]n [Ln = Nd (1), Eu (2), Tb (3)], [NH2Bu2]2[Ln4(CO3)(O2CNBu2)12] [Ln = Tb (4), Sm (5), Eu (6)], and [Sm4(CO3)(O2CNBu2)10], 7, have thus been obtained. The crystal and molecular structure of 4 has been solved; the samarium and europium complexes 5 and 6 were found to be isostructural. Mass spectra of the complexes 1-3, 4, and 7 (in MeCN/toluene) reveal that equilibria are present in solution. Compound 2 has been reacted in toluene with NHBz2 in the presence of CO2 affording [NH2Bz2][Eu(O2CNBz2)4], 8, through a ligand exchange process. By thermal treatment, 8 afforded [Eu(O2CNBz2)3]n, 9. With a similar procedure [Sm(O2CNBz2)3]n, 10, was obtained from 5. According to the photoluminescence study carried out on solid samples of 2, 4, 5, 7, and 8, the metal centered f-f transitions represent the only effective way to induce lanthanide luminescence in these complexes.

  11. Design and Development of Selective Extractants for An/Ln Separations

    SciTech Connect

    Robert T. Paine

    2009-12-04

    This study has succeeded in further developing phosphinoylmethyl pyridine compounds as selective recognition and separations agents for trivalent lanthanide and actinide ions present in nuclear materials. The parameters for efficient separations have been further elucidated and factors important to further development have been identified. Further development will lead to optimal extractant design for effective actinide ion partitioning under process practical conditions. The primary objective of the project involved the design, synthesis, and characterization of the extraction performance of 2,6-bis(phosphinomethyl)pyridine N,P,P{prime}-trioxides (NOPOPO) as potential reagents for the separation of Am, Cm, and fission product lanthanides from other transuranics and fission products and for acting as a separations 'platform' for the mutual separation of Am/Cm from the lanthanides. The secondary but critical objective of the project focused on the characterization of aqueous acid and radiation stability of NOPOPO ligands. Further, the project served as a interdisciplinary training vehicle for new, young investigators in actinide separations chemistry.

  12. DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING

    SciTech Connect

    Marra, J.; Billings, A.

    2009-06-24

    The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

  13. Bioadsorption of rare earth elements through cell surface display of lanthanide binding tags

    SciTech Connect

    Park, Dan M.; Reed, David W.; Yung, Mimi C.; Eslamimanesh, Ali; Lencka, Malgorzata M.; Anderko, Andrzej; Fujita, Yoshiko; Riman, Richard E.; Navrotsky, Alexandra; Jiao, Yongqin

    2016-02-02

    In this study, with the increasing demand for rare earth elements (REEs) in many emerging clean energy technologies, there is an urgent need for the development of new approaches for efficient REE extraction and recovery. As a step toward this goal, we genetically engineered the aerobic bacterium Caulobacter crescentus for REE adsorption through high-density cell surface display of lanthanide binding tags (LBTs) on its S-layer. The LBT-displayed strains exhibited enhanced adsorption of REEs compared to cells lacking LBT, high specificity for REEs, and an adsorption preference for REEs with small atomic radii. Adsorbed Tb3+ could be effectively recovered using citrate, consistent with thermodynamic speciation calculations that predicted strong complexation of Tb3+ by citrate. No reduction in Tb3+ adsorption capacity was observed following citrate elution, enabling consecutive adsorption/desorption cycles. The LBT-displayed strain was effective for extracting REEs from the acid leachate of core samples collected at a prospective rare earth mine. Our collective results demonstrate a rapid, efficient, and reversible process for REE adsorption with potential industrial application for REE enrichment and separation.

  14. Bioadsorption of rare earth elements through cell surface display of lanthanide binding tags

    DOE PAGES

    Park, Dan M.; Reed, David W.; Yung, Mimi C.; ...

    2016-02-02

    In this study, with the increasing demand for rare earth elements (REEs) in many emerging clean energy technologies, there is an urgent need for the development of new approaches for efficient REE extraction and recovery. As a step toward this goal, we genetically engineered the aerobic bacterium Caulobacter crescentus for REE adsorption through high-density cell surface display of lanthanide binding tags (LBTs) on its S-layer. The LBT-displayed strains exhibited enhanced adsorption of REEs compared to cells lacking LBT, high specificity for REEs, and an adsorption preference for REEs with small atomic radii. Adsorbed Tb3+ could be effectively recovered using citrate,more » consistent with thermodynamic speciation calculations that predicted strong complexation of Tb3+ by citrate. No reduction in Tb3+ adsorption capacity was observed following citrate elution, enabling consecutive adsorption/desorption cycles. The LBT-displayed strain was effective for extracting REEs from the acid leachate of core samples collected at a prospective rare earth mine. Our collective results demonstrate a rapid, efficient, and reversible process for REE adsorption with potential industrial application for REE enrichment and separation.« less

  15. Anti-HCV immunoassays based on a multiepitope antigen and fluorescent lanthanide chelate reporters.

    PubMed

    Salminen, Teppo; Juntunen, Etvi; Khanna, Navin; Pettersson, Kim; Talha, Sheikh M

    2016-02-01

    There is a need for simple to produce immunoassays for hepatitis C virus (HCV) antibody capable of detecting all genotypes worldwide. Current commonly used third generation immunoassays use three to six separate recombinant proteins or synthetic peptides. We have developed and expressed in Escherichia coli a single recombinant antigen incorporating epitopes from different HCV proteins. This multiepitope protein (MEP) was used to develop two types of HCV antibody immunoassays: a traditional antibody immunoassay using a labeled secondary antibody (indirect assay) and a double-antigen assay with the same MEP used as capture binder and labeled binder. The secondary antibody assay was evaluated with 171 serum/plasma samples and double-antigen assay with 148 samples. These samples included an in-house patient sample panel, two panels of samples with different HCV genotypes and a seroconversion panel. The secondary antibody immunoassay showed 95.6% sensitivity and 100% specificity while the double-antigen assay showed 91.4% sensitivity and 100% specificity. Both assays detected samples from all six HCV genotypes. The results showed that combining a low-cost recombinant MEP binder antigen with a high sensitivity fluorescent lanthanide reporter can provide a sensitive and specific immunoassay for HCV serology. The results also showed that the sensitivity of HCV double-antigen assays may suffer from the low avidity immune response of acute infections.

  16. Bioadsorption of Rare Earth Elements through Cell Surface Display of Lanthanide Binding Tags.

    PubMed

    Park, Dan M; Reed, David W; Yung, Mimi C; Eslamimanesh, Ali; Lencka, Malgorzata M; Anderko, Andrzej; Fujita, Yoshiko; Riman, Richard E; Navrotsky, Alexandra; Jiao, Yongqin

    2016-03-01

    With the increasing demand for rare earth elements (REEs) in many emerging clean energy technologies, there is an urgent need for the development of new approaches for efficient REE extraction and recovery. As a step toward this goal, we genetically engineered the aerobic bacterium Caulobacter crescentus for REE adsorption through high-density cell surface display of lanthanide binding tags (LBTs) on its S-layer. The LBT-displayed strains exhibited enhanced adsorption of REEs compared to cells lacking LBT, high specificity for REEs, and an adsorption preference for REEs with small atomic radii. Adsorbed Tb(3+) could be effectively recovered using citrate, consistent with thermodynamic speciation calculations that predicted strong complexation of Tb(3+) by citrate. No reduction in Tb(3+) adsorption capacity was observed following citrate elution, enabling consecutive adsorption/desorption cycles. The LBT-displayed strain was effective for extracting REEs from the acid leachate of core samples collected at a prospective rare earth mine. Our collective results demonstrate a rapid, efficient, and reversible process for REE adsorption with potential industrial application for REE enrichment and separation.

  17. Neptunium separations

    SciTech Connect

    Wild, J.F.

    1983-05-09

    Two procedures for the separation of Np are presented; the first involves separation of /sup 239/Np from irradiated /sup 238/U, and the second involves separation of /sup 237/Np from a solution representing that from a dissolved fuel element.

  18. Structurally characterized luminescent lanthanide zinc carboxylate precursors for Ln-Zn-O nanomaterials.

    PubMed

    Boyle, Timothy J; Raymond, Rebecca; Boye, Daniel M; Ottley, Leigh Anna M; Lu, Ping

    2010-09-14

    A novel family of lanthanide zinc carboxylate compounds was synthesized, characterized (structural determination and luminescent behavior), and investigated for utility as single-source precursors to Ln-Zn-O nanoparticles. Carboxylic acids [H-ORc = H-OPc (H-O(2)CCH(CH(3))(2), H-OBc (H-O(2)CC(CH(3))(3), H-ONc (H-O(2)CCH(2)C(CH(3))(3))] were individually reacted with diethyl zinc (ZnEt(2)) to yield a set of previously unidentified zinc carboxylates: (i) [Zn(mu-ORc)(3)Zn(mu-ORc)](n) [ORc = OPc (1), ONc (2)], (ii) [(py)Zn](2)(mu-ORc)(4) [ORc = OBc (3), ONc (4), and py = pyridine], or (iii) Zn(ORc)(2)(solv)(2) [ORc/solv = OPc/py (5), O(c)Nc/H(2)O (6) (O(c)Rc = chelating)]. Introduction of lanthanide cation [Ln[N(SiMe(3))(2)](3), ZnEt(2), and HOBc in py] yielded the mixed cationic species structurally characterized as: (i) (O(c)Bc)Ln[(mu-OBc)(3)Zn(py)](2) [Ln = Pr (7), Nd (8), Sm (9)] or (ii) (py)(2)Zn(mu-OBc)(3)Ln(O(c)Bc)(2)(py) [Ln = Tb (10), Dy (11), Er (12), Y (13), Yb (14)]. Exploration of alternative starting materials [Ln(NO(3))(3).nH(2)O, Zn(O(2)CCH(3))(2), HOBc in py] led to the isolation of (NO(3)(c))Ln[(mu-OBc)(3)Zn(py)](2) [Ln = La (15), Ce (16), Pr (17), Nd (18), Sm (19), Eu (20), Gd (21), Tb (22) Dy (23), and Er (24); NO(3)(c) = chelating]. The UV-vis spectra of 7-24 revealed standard absorption spectra for the Ln cations. Representative compounds were used to generate nanoparticles from an established 1,4-butanediol-based solution precipitation route. The nanoproducts isolated adopted either a mixed zincite/lanthanum oxide (18n or 22n) or pure zincite (8n or 10n) phase dependent on NO(3) or OBc moiety. Fluorescence was not observed for any of these nanomaterials possibly due to phase separation, low crystallinity, surface traps, and/or quenching based on elevated Ln cation content.

  19. Ditopic CMPO-pillar[5]arenes as unique receptors for efficient separation of americium(III) and europium(III).

    PubMed

    Fang, Yuyu; Yuan, Xiangyang; Wu, Lei; Peng, Zhiyong; Feng, Wen; Liu, Ning; Xu, Dingguo; Li, Shoujian; Sengupta, Arijit; Mohapatra, Prasanta K; Yuan, Lihua

    2015-03-11

    A unique host-guest recognition process involving a new class of homoditopic CMPO-pillar[5]arenes and lanthanides was revealed to proceed in a stepwise manner, and correlated with the efficient separation of americium(III) and europium(III) under acidic feed conditions.

  20. Engineering bacterial two-component system PmrA/PmrB to sense lanthanide ions.

    PubMed

    Liang, Haihua; Deng, Xin; Bosscher, Mike; Ji, Quanjiang; Jensen, Mark P; He, Chuan

    2013-02-13

    The Salmonella PmrA/PmrB two-component system uses an iron(III)-binding motif on the cell surface to sense the environmental or host ferric level and regulate PmrA-controlled gene expression. We replaced the iron(III)-binding motif with a lanthanide-binding peptide sequence that is known to selectively recognize trivalent lanthanide ions. The newly engineered two-component system (PmrA/PmrB) can effectively sense lanthanide ion and regulate gene expression in E. coli . This work not only provides the first known lanthanide-based sensing and response in live cells but also demonstrates that the PmrA/PmrB system is a suitable template for future synthetic biology efforts to construct bacteria that can sense and respond to other metal ions in remediation or sequestration.

  1. Patterns in the stability of the lower oxidation states of the actinides and lanthanides

    SciTech Connect

    Mikheev, N.B.; Auerman, L.N.; Ionova, G.V.; Korshunov, B.G.; Spitsyn, V.I.

    1986-09-01

    The authors compare the first half of the lanthanides and the second half of the actinides by considering the specifics of the electronic structure of the valence atoms of the f-, d-, and s-orbitals, consisting of he following: The lanthanides from praseodymium to europium and from dysprosium to ytterbium, as well as the actinides from californium to nobelium, have the same electronic configuration f /SUP n/ s/sub 2/ in the state of free neutral atoms, which corresponds to their divalent state. On the basis of a consideration of the energy characteristics of the valence orbitals of the elements of the lanthanide and actinide famililies and as a result of an experimental determination of the standard oxidation potential of these elements, the authors consider the profound similarity between the elements of the first half of the lanthanide family and the second half of the actinide family to be established.

  2. Lanthanide salts solutions: representation of osmotic coefficients within the binding mean spherical approximation.

    PubMed

    Ruas, Alexandre; Moisy, Philippe; Simonin, Jean-Pierre; Bernard, Olivier; Dufrêche, Jean-François; Turq, Pierre

    2005-03-24

    Osmotic coefficients of aqueous solutions of lanthanide salts are described using the binding mean spherical approximation (BIMSA) model based on the Wertheim formalism for association. The lanthanide(III) cation and the co-ion are allowed to form a 1-1 ion pair. Hydration is taken into account by introducing concentration-dependent cation size and solution permittivity. An expression for the osmotic coefficient, derived within the BIMSA, is used to fit data for a wide variety of lanthanide pure salt aqueous solutions at 25 degrees C. A total of 38 lanthanide salts have been treated, including perchlorates, nitrates, and chlorides. For most solutions, good fits could be obtained up to high ionic strengths. The relevance of the fitted parameters has been discussed, and a comparison with literature values has been made (especially the association constants) when available.

  3. The interactions between the sterically demanding trimesitylphosphine oxide and trimesityphosphine with scandium and selected lanthanide ions

    NASA Astrophysics Data System (ADS)

    Platt, Andrew W. G.; Singh, Kuldip

    2016-05-01

    The reactions between lanthanide nitrates, Ln(NO3)3 and scandium and lanthanide trifluoromethane sulfonates, Ln(Tf)3 with trimesitylphosphine oxide, Mes3PO show that coordination to the metal ions does not lead to crystalline complexes. Investigation of the reactions by 31-P NMR spectroscopy shows that weak complexes are formed in solution. The crystal structures of Mes3PO·0.5CH3CN (1) and [Mes3PO]3H3O·2CH3CN·Tf (2), formed in the reaction between ScTf3 and Mes3PO, are reported. Trimesitylphosphine, Mes3P, is protonated by scandium and lanthanide trifluoromethane sulfonates and lanthanide nitrates in CD3CN and the structure of [Mes3PH]Cl·HCl·2H2O (3) is reported.

  4. Pentavalent Lanthanide Compounds: Formation and Characterization of Praseodymium(V) Oxides.

    PubMed

    Zhang, Qingnan; Hu, Shu-Xian; Qu, Hui; Su, Jing; Wang, Guanjun; Lu, Jun-Bo; Chen, Mohua; Zhou, Mingfei; Li, Jun

    2016-06-06

    The chemistry of lanthanides (Ln=La-Lu) is dominated by the low-valent +3 or +2 oxidation state because of the chemical inertness of the valence 4f electrons. The highest known oxidation state of the whole lanthanide series is +4 for Ce, Pr, Nd, Tb, and Dy. We report the formation of the lanthanide oxide species PrO4 and PrO2 (+) complexes in the gas phase and in a solid noble-gas matrix. Combined infrared spectroscopic and advanced quantum chemistry studies show that these species have the unprecedented Pr(V) oxidation state, thus demonstrating that the pentavalent state is viable for lanthanide elements in a suitable coordination environment.

  5. Lanthanide ecotoxicity: first attempt to measure environmental risk for aquatic organisms.

    PubMed

    González, Verónica; Vignati, Davide A L; Pons, Marie-Noelle; Montarges-Pelletier, Emmanuelle; Bojic, Clément; Giamberini, Laure

    2015-04-01

    The geochemical cycles of lanthanides are being disrupted by increasing global production and human use, but their ecotoxicity is not fully characterized. In this study, the sensitivity of Aliivibrio fischeri and Pseudokirchneriella subcapitata to lanthanides increased with atomic number, while Daphnia magna, Heterocypris incongruens, Brachionus calyciflorus and Hydra attenuata were equally sensitive to the tested elements. In some cases, a marked decrease in exposure concentrations was observed over test duration and duly considered in calculating effect concentrations and predicted no effect concentrations (PNEC) for hazard and risk assessment. Comparison of PNEC with measured environmental concentrations indicate that, for the present, environmental risks deriving from lanthanides should be limited to some hotspots (e.g., downstream of wastewater treatment plants). However, considering the increasing environmental concentrations of lanthanides, the associated risks could become higher in the future. Ecotoxicological and risk assessment studies, along with monitoring, are required for properly managing these emerging contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. An ionic liquid based synthesis method for uniform luminescent lanthanide fluoride nanoparticles

    NASA Astrophysics Data System (ADS)

    Nuñez, Nuria O.; Ocaña, Manuel

    2007-11-01

    We describe a facile procedure for the synthesis of uniform lanthanide fluoride nanophosphors by homogeneous precipitation in ethylene glycol solutions containing lanthanide precursors and an ionic liquid (1-butyl, 2-methylimidazolium tetrafluoroborate). It is shown that the use of this ionic liquid as a fluoride source, an appropriate choice of the solvent and the lanthanide precursor, and the adjustment of reaction temperature, are essential to obtain uniform nanoparticles. This method is applied to the preparation of pure YF3, EuF3 and TbF3 nanoparticles as well as of Eu-doped YF3 and Tb-doped YF3. In most cases, highly uniform nanoparticles were obtained, the size of which could be tuned in the nanometer range by adjusting the nature and concentration of the starting lanthanide precursor. The luminescent properties of the synthesized materials are also evaluated.

  7. From antenna to assay: lessons learned in lanthanide luminescence.

    PubMed

    Moore, Evan G; Samuel, Amanda P S; Raymond, Kenneth N

    2009-04-21

    Ligand-sensitized, luminescent lanthanide(III) complexes are of considerable importance because their unique photophysical properties (microsecond to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts) make them well suited as labels in fluorescence-based bioassays. The long-lived emission of lanthanide(III) cations can be temporally resolved from scattered light and background fluorescence to vastly enhance measurement sensitivity. One challenge in this field is the design of sensitizing ligands that provide highly emissive complexes with sufficient stability and aqueous solubility for practical applications. In this Account, we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in homogeneous time-resolved fluorescence (HTRF) technology. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms and using multichromophore chelates to increase molar absorptivity; earlier examples utilized a single pendant chromophore (that is, a single "antenna"). Ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to approximately 60% that are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM chromophore and time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of these chromophores as a tool to guide ligand design. Additionally, we have investigated chiral IAM ligands that yield Tb(III) complexes possessing both high quantum yield values and strong circularly

  8. A Ratiometric Luminescent Thermometer Co-doped with Lanthanide and Transition Metals.

    PubMed

    Li, Zhiqiang; Hou, Zhaohui; Ha, Denghui; Li, Huanrong

    2015-12-01

    Herein, we report the fabrication of a sensitive ratiometric and colorimetric luminescent thermometer with a wide operating-temperature range, from cryogenic temperatures up to high temperatures, through the combination of lanthanide and transition metal complexes. Benefiting from the transition metal complex as a self-reference, the lanthanide content in the mixed-coordination complex, Eu0.05(Mebip-mim bromine)0.15Zn0.95(Mebip-mim bromine)1.9, was lowered to 5%.

  9. Complications in complexation kinetics for lanthanides with DTPA using dye probe molecules in aqueous solution

    DOE PAGES

    Larsson, K.; Cullen, T. D.; Mezyk, S. P.; ...

    2017-05-17

    The complexation kinetics for the polyaminopolycarboxylic ligand DTPA to lanthanides in acidic aqueous solution were investigated using the dye ligand displacement technique and stopped-flow spectroscopy. Significant rate differences were obtained for different dye probes used, indicating that the kinetics of the dissociation of the dye molecule significantly impacts the overall measured kinetics when using this common methodology. The conditions of the solution also influenced the dye-lanthanide-DTPA interactions, which reconciled previously disparate data in the literature.

  10. Novel materials based on DNA-CTMA and lanthanide (Ce(3+) , Pr(3+) ).

    PubMed

    Lazar, Cosmina Andreea; Kajzar, François; Mihaly, Maria; Rogozea, Adina Elena; Petcu, Adina Roxana; Olteanu, Nicoleta Liliana; Rau, Ileana

    2016-09-01

    New, deoxyribonucleic acid (DNA) based compounds, functionalized with hexadecyltrimethylammonium chloride (CTMA) and lanthanide hydroxide nanoparticles were synthesized. The spectral measurements suggest that between the DNA-CTMA complex and the lanthanide (III) ions a chemical interaction takes place. The obtained materials exhibit an improved fluorescence efficiency, showing a potential interest for application in photonics, and more particularly, in light emitting devices. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 613-617, 2016. © 2016 Wiley Periodicals, Inc.

  11. Rare Earth Ion-Host Lattice Interactions. 12. Lanthanides in Y3Ga5O12.

    DTIC Science & Technology

    1977-07-01

    YGG ). A smooth set of B sub km are obtained and are used to calculate energy levels for the ground configurations for all the lanthanides in YGG by...are obtained by a sum over the YGG lattice. The D2d approximated parameters are used to calculate squared-matrix elements of the electric dipole...operator between the Stark-split energy levels for the lanthanides in YGG . (Author)

  12. Purely heterometallic lanthanide(III) macrocycles through controlled assembly of disulfide bonds for dual color emission.

    PubMed

    Lewis, David J; Glover, Peter B; Solomons, Melissa C; Pikramenou, Zoe

    2011-02-02

    Lanthanide complexes based on bis(amides) of diethylenetriaminepentaacetic acid with thiol functionalities are modified with 2,2'-dipyridyl disulfide to give activated complexes that can selectively react with thiol-functionalized complexes to form heterometallic lanthanide macrocycles. The preparation and full characterization of the polyaminocarboxylate ligands N,N''-bis[p-thiophenyl(aminocarbonyl)]diethylenetriamine-N,N',N''-triacetic acid (H(3)L(x)) and the activated N,N''-bis[p-(pyridyldithio)[phenyl(aminocarbonyl)

  13. Nitrite-Templated Synthesis of Lanthanide-Containing [2]Rotaxanes for Anion Sensing**

    PubMed Central

    Langton, Matthew J; Blackburn, Octavia A; Lang, Thomas; Faulkner, Stephen; Beer, Paul D

    2014-01-01

    The first anion-templated synthesis of a lanthanide-containing interlocked molecule is demonstrated by utilizing a nitrite anion to template initial pseudorotaxane formation. Subsequent stoppering of the interpenetrated assembly allows for the preparation of a lanthanide-functionalized [2]rotaxane in high yield. Following removal of the nitrite anion template, the europium [2]rotaxane host is demonstrated to recognize and sense fluoride selectively. PMID:24989322

  14. Lanthanide alkyl and silyl compounds: Synthesis, reactivity and catalysts for green

    SciTech Connect

    Pindwal, Aradhana

    2016-01-01

    The last few decades have witnessed enormous research in the field of organometallic lanthanide chemistry. Our research group has developed a few rare earth alkyl compounds containing tris(dimethylsilyl)methyl ligand and explored their reactivity. This thesis focusses on extending the study of lanthanide alkyl and silyl compounds to develop strategies for their synthesis and explore their reactivity and role as catalysts in processes such as hydrosilylation and cross-dehydrocoupling.

  15. Separation of Cf, Es, and Fm by eluative chromatography using ammonium. cap alpha. -hydroxyisobutyrate

    SciTech Connect

    Mikheev, N.B.; Kamenskaya, A.N.; Auerman, L.N.; Kulyukhin, S.A.; Rumer, I.A.; Novichenko, V.L.

    1987-11-01

    The method of separation of californium, einsteinium, fermium, and certain lanthanides, based on the use of ammonium ..cap alpha..-hydroxyisobutyrate as the eluent, has been improved. The use of a 0.10-0.14 M solution of this reagent and columns (9 x 0.5 cm) filled with the resin Aminex SB with particle size 20-25 ..mu.., permitted the production of about 0.5 ..mu..g of einsteinium-253 from irradiated californium-252 with coefficient of purification of einsteinium from californium in two cycles of adsorption and elution of approx. 10/sup 10/. The coefficient of separation of californium and einsteinium is equal to 1.6 and that of einsteinium and fermium 1.9. The behavior of certain lanthanides in the separation of californium, einsteinium, and fermium using a 0.010 M solution of ammonium ..cap alpha..-hydroxyisobutyrate is discussed.

  16. Formation and stability of lanthanide complexes and their encapsulation into polymeric microspheres

    SciTech Connect

    Mumper, R.J.; Jay, M.

    1992-10-15

    The complexation of lanthanides (Ln) with dicarbonyl compounds (acetylacetone, acac; ethyl acetoacetate; 3-ethyl-2,4-pentanedione; 2,4-hexanedione; 3-methyl-2,4-pentanedione; and diethyl malonate) was investigated using a potentiometric titration technique. The ability of a dicarbonyl compound to complex with the lanthanide elements was greatly dependent on its pK{sub a} and on the pH of the titrated solution. Selected lanthanide complexes (Ln complexes) were incorporated into spherical poly(L-lactic acid)(PLA) matrices and irradiated in a nuclear reactor with neutrons to produce short-lived high-energy {Beta}-particle-emitting radioisotopes. The lanthanides investigated (Ho, Dy, Sm, and La) were chosen on the basis of their physical and nuclear properties. A transition element (Re) was also studied. The small decrease in the ionic radii of the lanthanides with increasing atomic number led to (a) greater ability to extract and complex from an aqueous solution with complexing agents, (b) larger formation and stability constants for the Ln complexes, (c) increased solubility of the Ln complexes in chloroform, and (d) increase in the maximum percent incorporation of the stable lanthanides in PLA spheres. Ho(aca) was found to be the most promising candidate of the complexes studied on the basis of the above observations and due to the favorable physical properties of {sup 165}Ho and nuclear properties of {sup 166}Ho. 21 refs., 5 figs., 4 tabs.

  17. Selectivity enhancement of Arsenazo(III) reagent towards heavier lanthanides using polyaminocarboxylic acids: A spectrophotometric study

    NASA Astrophysics Data System (ADS)

    Matharu, Komal; Mittal, Susheel K.; Ashok Kumar, S. K.; Sahoo, Suban K.

    2015-06-01

    A new study has been conducted to quantify lanthanide(III) ions using Arsenazo III-polyaminocarboxylic acid (PACA) system. The study disclosed two different analytically important information: (i) λmax of lanthanide-Arsenazo III complexes for lighter lanthanides like Ce(III) and Nd(III) did not shift from its original position on addition of PACA and (ii) for heavier lanthanides like Dy(III), Tm(III) and Lu(III) a new λmax at 538 nm was observed, while wavelengths at 610 nm and 654 nm were disappeared in presence of ethylenediaminetertracetic acid (EDTA) and trans-1,2-Diaminocyclohexane-N,N,N‧,N‧-tetraacetic acid (DCTA), further the intensity of peak decreased with increase in lanthanide(III) ion concentration. Effect of ethylene glycol-bis(2-aminoethylether)-N,N,N‧,N‧-tetraacetic acid (EGTA) and N-(2-hydroxyethyl) ethylenediamine-N,N‧,N‧-triacetic acid (EDTA-OH) on Arsenzo(III)-Ln(III) complex is very weak and there is no analytically importance of such interaction. Moreover, this work confirms that Nd(III) and heavy lanthanides can be successfully determined with high accuracy in the working range of concentration of these metal ions.

  18. Fourier transform infrared characterization of the acidic phosphoric extractant system containing lanthanide

    NASA Astrophysics Data System (ADS)

    Shen, Y.-H.; Yao, S.-K.; Wang, D.-J.; Zhou, Weijin; Li, Ying Xue; Peng, Q.; Wu, JinGuang; Xu, Guang-Xian

    1994-01-01

    The aggregation states and FTIR spectra of the extractive organic phases of saponified HDEHP [di(2-ethylhexyl) phosphoric acid] (1). DMHPA [di(1-methylheptyl) phosphoric acid] (2) and (HDEHP + DMHPA) (3) containing lanthanides were studied, respectively. Transparent solution formed in system (1) while transparent gel formed in system (2) when the loading of lanthanides was more than 50%. The aggregation state of system (3) depends on the molar ratio of HDEHP:DMHPA and the loading percentage of lanthanide. From their FTIR spectra, it can be seen that the P equals O band of gel split into 1164, 1199, and 1232 cm-1, and the P-O-C band split into 1015, 1076, and 1083 cm-1 as well. The results suggested that the aggregation state of lanthanide complex changes considerably in the three systems, and multiple coordination states of p equals o with lanthanide result in the band split. Multiple interactions between P equals O, P-O-C and lanthanide ions form 3-D network in the gel.

  19. A bridge to coordination isomer selection in lanthanide(III) DOTA-tetraamide complexes.

    PubMed

    Vipond, Jeff; Woods, Mark; Zhao, Piyu; Tircsó, Gyula; Ren, Jimin; Bott, Simon G; Ogrin, Doug; Kiefer, Garry E; Kovacs, Zoltan; Sherry, A Dean

    2007-04-02

    Interest in macrocyclic lanthanide complexes such as DOTA is driven largely through interest in their use as contrast agents for MRI. The lanthanide tetraamide derivatives of DOTA have shown considerable promise as PARACEST agents, taking advantage of the slow water exchange kinetics of this class of complex. We postulated that water exchange in these tetraamide complexes could be slowed even further by introducing a group to sterically encumber the space above the water coordination site, thereby hindering the departure and approach of water molecules to the complex. The ligand 8O2-bridged DOTAM was synthesized in a 34% yield from cyclen. It was found that the lanthanide complexes of this ligand did not possess a water molecule in the inner coordination sphere of the bound lanthanide. The crystal structure of the ytterbium complex revealed that distortions to the coordination sphere were induced by the steric constraints imposed on the complex by the bridging unit. The extent of the distortion was found to increase with increasing ionic radius of the lanthanide ion, eventually resulting in a complete loss of symmetry in the complex. Because this ligand system is bicyclic, the conformation of each ring in the system is constrained by that of the other; in consequence, inclusion of the bridging unit in the complexes means only a twisted square, antiprismatic coordination geometry is observed for lanthanide complexes of 8O2-bridged DOTAM.

  20. Preparation and Properties of Transparent Ultrathin Lanthanide-Complex Films.

    PubMed

    Li, Yali; Xu, Yang; Wang, Yige

    2016-07-25

    Highly transparent ultrathin films (UTFs) based on alternative layer-by-layer assembly of Eu- and Tb-based lanthanide complexes (LCs) and Mg-Al-layered double hydroxide (LDH) nanosheets are reported herein. UV-visible absorption and fluorescence spectroscopy showed an orderly growth of the two types of ultrathin films upon increasing the number of deposition cycles. AFM and SEM measurements indicate that the films feature periodic layered structures as well as uniform surface morphology. Luminescent investigations reveal that (LCs/LDH)n UTFs can detect Fe(3+) with relative selectivity and high sensitivity (Stern-Volmer constant KSV =8.43×10(3)  L mol(-1) ); this suggests that (LCs/LDH)n UTFs could be a promising luminescent probe for selectively sensing Fe(3+) ion.

  1. Lanthanides in molecular magnetism: old tools in a new field.

    PubMed

    Sorace, Lorenzo; Benelli, Cristiano; Gatteschi, Dante

    2011-06-01

    In this tutorial review we discuss some basic aspects concerning the magnetic properties of rare-earth ions, which are currently the subject of a renovated interest in the field of molecular magnetism, after the discovery that slow relaxation of the magnetization at liquid nitrogen temperature can occur in mononuclear complexes of these ions. Focusing on Dy(III) derivatives a tutorial discussion is given of the relation of the crystal field parameters, which determine the anisotropy of these systems and consequently their interesting magnetic properties, with the geometry of the coordination sphere around the lanthanide centre and with the pattern of f orbitals. The problem of systems of low point symmetry is also addressed by showing how detailed single crystal investigation, coupled to more sophisticated calculation procedures, is an absolute necessity to obtain meaningful structure-property relationships in these systems.

  2. Pulsed photothermal spectroscopy applied to lanthanide and actinide speciation

    SciTech Connect

    Berg, J.M.; Morris, D.E.; Clark, D.L.; Tait, C.D.; Woodruff, W.H. ); Ven Der Sluys, W.G. . Dept. of Chemistry)

    1991-01-01

    Several key elements important for the application of laser-based photothermal spectroscopies to the study of the complexation chemistry of lanthanides and actinides in solution have been demonstrated. The sensitivity of f-f electronic transition energies and band intensities to subtle changes in complexation was illustrated through comparison of visible and near infra-red absorption spectra of well-characterized U(IV) dimers with alkoxide ligands. Significant improvements in spectroscopic band resolution and energy measurement precision for solution species were shown to be achievable through work in frozen glasses at 77 K using a very simple cryogenic apparatus. A pulsed-laser photothermal spectroscopy apparatus was constructed and shown to be sensitive to optical density changes of 10{sup {minus}5} in an aqueous Nd{sup 3+} solution. In addition, the capability of obtaining photothermal lensing spectra of dilute actinide solutions in frozen glasses at 77 K was demonstrated. 6 refs., 5 figs.

  3. Kinetic behavior of lanthanide extraction with acidic phosphorus extractants

    SciTech Connect

    Ma, E.; Muralidharan, S.; Freiser, H.

    1995-12-01

    The kinetics of the formation of the complexes of tervalent lanthanides with several organophosphorus extractants in the octane-H{sub 2}O phase pair have been characterized by competition kinetics. The kinetic studies were conducted by the extraction of the EDTA complexes of Y{sup 3+}, Nd{sup 3+}, Gd{sup 3+}, Ho{sup 3+} and Lu{sup 3+} by bis(2-ethylhexyl)phosphoric acid (HDEHP), 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) in octane. The observed rate constants bore an inverse relationship to the stability constants of the metal-EDTA complexes. For a given metal the rate constants as a function of ligand followed the order HDEHP > HEH[EHP] > Cyanex 272. The mechanistic details of the competition kinetics and the implications of the kinetic results will be discussed.

  4. Reactivity of Lanthanide Ferrite SOFC Cathodes with YSZ Electrolyte

    SciTech Connect

    Anderson, Michael D; Stevenson, Jeffry W; Simner, Steve P

    2004-04-22

    The reactivity of yttria-stabilized zirconia (YSZ) with compounds of the form Ln0.8Sr0.2FeO3 (Ln=Sm, Pr, Nd and a mixed lanthanide precursor) and La0.8M0.2FeO3 (M=Ba, Ca) was investigated, and compared to the comprehensively studied La0.8Sr0.2FeO3 (LSF-20) composition. With the exception of Ca, all variants showed either increased reactivity with YSZ (compared to the base LSF-20), or a lack of phase purity after calcination at 1200-1300°C

  5. Evolution of photoluminescence across dimensionality in lanthanide silicates.

    PubMed

    Kostova, Mariya H; Ananias, Duarte; Paz, Filipe A Almeida; Ferreira, Artur; Rocha, João; Carlos, Luís D

    2007-04-12

    The dehydratation process of layered lanthanide silicates K3[LnSi3O8(OH)2], Ln = Y, Eu, Tb, and Er, and the structural characterization of the obtained small-pore framework K3LnSi3O9, Ln = Y, Eu, Tb, and Er solids, named AV-23, have been reported. The structure of AV-23 has been solved by single-crystal X-ray diffraction (XRD) methods and further characterized by chemical analysis, thermogravimetry, scanning electron microscopy, and 29Si MAS NMR. The photoluminescence (PL), radiance, and lifetime values of AV-23 have been studied and compared with those of AV-22. Both materials have a similar chemical makeup and structures sharing analogous building blocks, hence providing a unique opportunity for rationalizing the evolution of the PL properties of lanthanide silicates across dimensionality. Although Tb-AV-23 contains a single crystallographic Tb(3+) site, PL spectroscopy indicates the presence of Ln(3+) centers in regular framework positions and in defect regions. PL evidence suggests that Eu-AV-23 contains a third type of Ln(3+) environment, namely, Eu(3+) ions replacing K(+) ions in the micropores. The radiance values of the Tb-AV-22 and Tb-AV-23 samples are of the same order of magnitude as those of standard Tb(3+) green phosphors. For the samples K3(Y1-aEraSi3O9), a = 0.005-1, efficient emission and larger 4I13/2 lifetimes (ca. 7 ms) are detected for low Er(3+) content, indicating that the Er(3+)-Er(3+) interactions become significant as the Er(3)+ content increases.

  6. Lanthanide-based laser-induced phosphorescence for spray diagnostics.

    PubMed

    van der Voort, D D; Maes, N C J; Lamberts, T; Sweep, A M; van de Water, W; Kunnen, R P J; Clercx, H J H; van Heijst, G J F; Dam, N J

    2016-03-01

    Laser-induced phosphorescence (LIP) is a relatively recent and versatile development for studying flow dynamics. This work investigates certain lanthanide-based molecular complexes for their use in LIP for high-speed sprays. Lanthanide complexes in solutions have been shown to possess long phosphorescence lifetimes (∼1-2 ms) and to emit light in the visible wavelength range. In particular, europium and terbium complexes are investigated using fluorescence/phosphorescence spectrometry, showing that europium-thenoyltrifluoracetone-trioctylphosphineoxide (Eu-TTA-TOPO) can be easily and efficiently excited using a standard frequency-tripled Nd:YAG laser. The emitted spectrum, with maximum intensity at a wavelength of 614 nm, is shown not to vary strongly with temperature (293-383 K). The decay constant of the phosphorescence, while independent of ambient pressure, decreases by approximately 12 μs/K between 323 and 373 K, with the base level of the decay constant dependent on the used solvent. The complex does not luminesce in the gas or solid state, meaning only the liquid phase is visualized, even in an evaporating spray. By using an internally excited spray containing the phosphorescent complex, the effect of vaporization is shown through the decrease in measured intensity over the length of the spray, together with droplet size measurements using interferometric particle imaging. This study shows that LIP, using the Eu-TTA-TOPO complex, can be used with different solvents, including diesel surrogates. Furthermore, it can be easily handled and used in sprays to investigate spray breakup and evaporation.

  7. Interaction between lanthanide ions and Saccharomyces cerevisiae cells.

    PubMed

    Ene, Cristian D; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Iordache, Virgil; Neagoe, Aurora D; Farcasanu, Ileana C

    2015-10-01

    Lanthanides are a group of non-essential elements with important imaging and therapeutic applications. Although trivalent lanthanide ions (Ln³⁺) are used as potent blockers of Ca²⁺ channels, the systematic studies correlating Ln³⁺ accumulation and toxicity to Ca²⁺ channel blocking activity are scarce. In this study, we made use of the eukaryotic model Saccharomyces cerevisiae to investigate the correlation between Ln³⁺ accumulation, their toxicity and their capacity to block the exogenous stress-induced Ca²⁺ influx into the cytosol. It was found that the Ln³⁺ blocked the Ca²⁺ entry into the yeast cells only when present at concentration high enough to allow rapid binding to cell surface. At lower concentrations, Ln³⁺ were taken up by the cell, but Ca²⁺ blockage was no longer achieved. At 1 mM concentration, all ions from the Ln³⁺ series could block Ca²⁺ entry into cytosol with the exception of La³⁺, and to a lesser extent, Pr³⁺ and Nd³⁺. The plasma membrane Ca²⁺-channel Cch1/Mid1 contributed to La³⁺ and Gd³⁺ entry into the cells, with a significant preference for La³⁺. The results open the possibility to obtain cells loaded with controlled amounts and ratios of Ln³⁺.

  8. Lanthanide-based laser-induced phosphorescence for spray diagnostics

    SciTech Connect

    Voort, D. D. van der Water, W. van de; Kunnen, R. P. J.; Clercx, H. J. H.; Heijst, G. J. F. van; Maes, N. C. J.; Sweep, A. M.; Dam, N. J.; Lamberts, T.

    2016-03-15

    Laser-induced phosphorescence (LIP) is a relatively recent and versatile development for studying flow dynamics. This work investigates certain lanthanide-based molecular complexes for their use in LIP for high-speed sprays. Lanthanide complexes in solutions have been shown to possess long phosphorescence lifetimes (∼1-2 ms) and to emit light in the visible wavelength range. In particular, europium and terbium complexes are investigated using fluorescence/phosphorescence spectrometry, showing that europium-thenoyltrifluoracetone-trioctylphosphineoxide (Eu-TTA-TOPO) can be easily and efficiently excited using a standard frequency-tripled Nd:YAG laser. The emitted spectrum, with maximum intensity at a wavelength of 614 nm, is shown not to vary strongly with temperature (293-383 K). The decay constant of the phosphorescence, while independent of ambient pressure, decreases by approximately 12 μs/K between 323 and 373 K, with the base level of the decay constant dependent on the used solvent. The complex does not luminesce in the gas or solid state, meaning only the liquid phase is visualized, even in an evaporating spray. By using an internally excited spray containing the phosphorescent complex, the effect of vaporization is shown through the decrease in measured intensity over the length of the spray, together with droplet size measurements using interferometric particle imaging. This study shows that LIP, using the Eu-TTA-TOPO complex, can be used with different solvents, including diesel surrogates. Furthermore, it can be easily handled and used in sprays to investigate spray breakup and evaporation.

  9. Temperature dependent NIR emitting lanthanide-PMO/silica hybrid materials.

    PubMed

    Kaczmarek, Anna M; Esquivel, Dolores; Ouwehand, Judith; Van Der Voort, Pascal; Romero-Salguero, Francisco J; Van Deun, Rik

    2017-06-28

    Two materials - a mesoporous silica (MS) and a periodic mesoporous organosilica (PMO) functionalized with dipyridyl-pyridazine (dppz) units were grafted with near-infrared (NIR) emitting lanthanide (Nd(3+), Er(3+), Yb(3+)) complexes in an attempt to obtain hybrid NIR emitting materials. The parent materials: dppz-vSilica and dppz-ePMO were prepared by a hetero Diels-Alder reaction between 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (dptz) and the double bonds of either ethenylene-bridged PMO (ePMO) or vinyl-silica (vSilica) and subsequent oxidation. The dppz-vSilica is reported here for the first time. The prepared lanthanide-PMO/silica hybrid materials were studied in depth for their luminescence properties at room temperature and chosen Nd(3+) and Yb(3+) samples also at low temperature (as low as 10 K). We show that both the dppz-vSilica and dppz-ePMO materials can be used as "platforms" for obtaining porous materials showing NIR luminescence. To obtain NIR emission these materials can be excited either in the UV or Vis region (into the π→π* transitions of the ligands or directly into the f-f transitions of the Ln(3+) ions). More interestingly, when functionalized with Nd(3+) or Yb(3+)β-diketonate complexes these materials showed interesting luminescence properties over a wide temperature range (10-360 K). The Yb(3+) materials were investigated for their potential use as ratiometric temperature sensors.

  10. Americium/curium extraction from a lanthanide borosilciate glass

    SciTech Connect

    Rudisill, T.S.; Pareizs, J.M.; Ramsey, W.G.

    1996-12-31

    A solution containing kilogram quantities of highly radioactive isotopes of americium and curium (Am/Cm) and lanthanide fission products is currently stored in a process tank at the Department of Energy`s Savannah River Site (SRS). This tank and its vital support systems are old, subject to deterioration, and prone to possible leakage. For this reason, a program has been initiated to immobilize this material as a lanthanide borosilicate glass for safe long-term storage. The Am/Cm has commercial value and is desired for use by the heavy isotope programs at the Oak Ridge National Laboratory (ORNL). Therefore, a flowsheet was demonstrated using a curium-containing glass to extract these elements from the glass matrix. The method involved grinding the glass to less than 200 mesh and dissolving in concentrated nitric acid at 110{degrees}C. Under these conditions, the dissolution was essentially 100% after 2 hours except for silicon which remained mostly insoluble. Since the actual process conditions at ORNL could not be exactly simulated, the dissolution rate of a surrogate glass was measured using static and agitated conditions to bracket the expected rate. The measured rates, 0.040 to 0.0082 grams/hour-centimeter, were constant which allowed development of a predictive model for the time required to dissolve a glass particle of spherical geometry in terms of the glass density, particle size, and experimentally measured rate. The calculated time required to dissolve an idealized curium glass particle was in agreement with the experimental observation that dissolution was complete in less than 2 hours.

  11. X-ray spectral diagnostics of synthetic lanthanide silicates

    NASA Astrophysics Data System (ADS)

    Kravtsova, A. N.; Guda, A. A.; Soldatov, A. V.; Goettlicher, J.; Taroev, V. K.; Kashaev, A. A.; Suvorova, L. F.; Tauson, V. L.

    2015-12-01

    Potassium and rare-earth (Eu, Sm, Yb, Ce) silicate and aluminosilicate crystals are hydrothermally synthesized under isothermal conditions at 500°C and a pressure of 100 MPa. The chemical and structural formulas of the synthesized compounds HK6Eu[Si10O25], K7Sm3[Si12O32], K2Sm[AlSi4O12] · 0.375H2O, K4Yb2[Si8O21], and K4Ce2[Al2Si8O24] are determined. In addition, a synthesis product with Eu, in which the dominant phase is assumed to be K3Eu3+[Si6O15] · 2H2O, is studied. The oxidation state of lanthanides in the silicates under study is determined based on X-ray absorption near-edge structure spectroscopy. The Eu L 3-, Sm L 3-, Yb L 3-, and Ce L 3-edge X-ray absorption spectra of the studied silicates and reference samples are recorded using a Rigaku R-XAS laboratory spectrometer. As reference samples, Eu2+S, Eu3+F3, Eu 2 3+ O3, Sm 2 3+ O3, Yb 2 3+ O3, Yb3+F3, Yb3+Cl3, Ce 2 3+ O3, and Ce4+O2 are used. Comparison of the absorption edge energies of lanthanide silicates and reference samples shows that Eu, Sm, Yb, and Ce in all the samples studied are in the oxidation state 3+. The synthesized silicates will supplement our knowledge of possible rare-earth minerals existing in hydrothermal systems, which is important for analyzing the distribution spectra of rare elements, which are widely used for diagnostics of geochemical processes and determination of sources of ore materials.

  12. Insertion of Trivalent Lanthanides into Uranyl Vanadate Layers and Frameworks.

    PubMed

    Wang, Yaxing; Yin, Xuemiao; Zhao, Yanyan; Gao, Yang; Chen, Lanhua; Liu, Zhiyong; Sheng, Daopeng; Diwu, Juan; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Wang, Shuao

    2015-09-08

    Two new uranyl vanadates have been prepared from hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction. The structure of (H3O)UO2VO4 (UVO-1) consists of anionic layers containing UO2(2+) pentagonal bipyramids coordinated by edge-sharing VO5 square pyramids, with the charge balanced by interlaminar H3O(+) cations. Vanadium in (UO2)3(VO4)2(H2O)3 (UVO-2) exists as monomeric VO4 tetrahedra coordinating to UO2(2+) pentagonal bipyramids, forming a 3D uranyl(VI) vanadate framework. Similar reactions with the addition of Ln(NO3)3 (Ln = Nd, Eu) afford the three heterobimetallic lanthanide uranyl vanadate frameworks Nd(UO2)3(VO4)3(H2O)11 (NdUVO-1), Eu(UO2)3(VO4)3(H2O)10 (EuUVO-1), and Eu2(UO2)12(VO4)10(H2O)24 (EuUVO-2). In NdUVO-1 and EuUVO-1, Ln(3+) cations are inserted into the interlayer space of UVO-1 substituting for H3O(+) and further bridging adjacent layers into 3D frameworks. Similarly, EuUVO-2 adopts the same sheet topology as UVO-2, with Eu(3+) ions replacing some of the interlayer uranyl ions in UVO-2. Our work has demonstrated that uranyl vanadate extended structures are excellent hosts for further incorporation of trivalent lanthanide/actinide cations and has provided a new way to create new heterobimetallic 4f-5f and 5f-5f compounds.

  13. Anisotropic lanthanide-based nano-clusters for imaging applications.

    PubMed

    Yang, Xiaoping; Wang, Shiqing; King, Tyler L; Kerr, Christopher J; Blanchet, Clement; Svergun, Dmitri; Pal, Robert; Beeby, Andrew; Vadivelu, Jamuna; Brown, Katherine A; Jones, Richard A; Zhang, Lijie; Huang, Shaoming

    2016-10-06

    We have developed a new class of lanthanide nano-clusters that self-assemble using flexible Schiff base ligands. Cd-Ln and Ni-Ln clusters, [Ln8Cd24(L(1))12(OAc)39Cl7(OH)2] (Ln = Nd, Eu), [Eu8Cd24(L(1))12(OAc)44], [Ln8Cd24(L(2))12(OAc)44] (Ln = Nd, Yb, Sm) and [Nd2Ni4(L(3))2(acac)6(NO3)2(OH)2], were constructed using different types of flexible Schiff base ligands. These molecular nano-clusters exhibit anisotropic architectures that differ considerably depending upon the presence of Cd (nano-drum) or Ni (square-like nano-cluster). Structural characterization of the self-assembled particles has been undertaken using crystallography, transmission electron microscopy and small-angle X-ray scattering. Comparison of the metric dimensions of the nano-drums shows a consistency of size using these techniques, suggesting that these molecules may share similar structural features in both solid and solution states. Photophysical properties were studied by excitation of the ligand-centered absorption bands in the solid state and in solution, and using confocal microscopy of microspheres loaded with the compounds. The emissive properties of these compounds vary depending upon the combination of lanthanide and Cd or Ni present in these clusters. The results provide new insights into the construction of novel high-nuclearity nano-clusters and offer a promising foundation for the development of new functional nanomaterials.

  14. Lanthanide-based laser-induced phosphorescence for spray diagnostics

    NASA Astrophysics Data System (ADS)

    van der Voort, D. D.; Maes, N. C. J.; Lamberts, T.; Sweep, A. M.; van de Water, W.; Kunnen, R. P. J.; Clercx, H. J. H.; van Heijst, G. J. F.; Dam, N. J.

    2016-03-01

    Laser-induced phosphorescence (LIP) is a relatively recent and versatile development for studying flow dynamics. This work investigates certain lanthanide-based molecular complexes for their use in LIP for high-speed sprays. Lanthanide complexes in solutions have been shown to possess long phosphorescence lifetimes (˜1-2 ms) and to emit light in the visible wavelength range. In particular, europium and terbium complexes are investigated using fluorescence/phosphorescence spectrometry, showing that europium-thenoyltrifluoracetone-trioctylphosphineoxide (Eu-TTA-TOPO) can be easily and efficiently excited using a standard frequency-tripled Nd:YAG laser. The emitted spectrum, with maximum intensity at a wavelength of 614 nm, is shown not to vary strongly with temperature (293-383 K). The decay constant of the phosphorescence, while independent of ambient pressure, decreases by approximately 12 μs/K between 323 and 373 K, with the base level of the decay constant dependent on the used solvent. The complex does not luminesce in the gas or solid state, meaning only the liquid phase is visualized, even in an evaporating spray. By using an internally excited spray containing the phosphorescent complex, the effect of vaporization is shown through the decrease in measured intensity over the length of the spray, together with droplet size measurements using interferometric particle imaging. This study shows that LIP, using the Eu-TTA-TOPO complex, can be used with different solvents, including diesel surrogates. Furthermore, it can be easily handled and used in sprays to investigate spray breakup and evaporation.

  15. Chiral Separations

    NASA Astrophysics Data System (ADS)

    Stalcup, A. M.

    2010-07-01

    The main goal of this review is to provide a brief overview of chiral separations to researchers who are versed in the area of analytical separations but unfamiliar with chiral separations. To researchers who are not familiar with this area, there is currently a bewildering array of commercially available chiral columns, chiral derivatizing reagents, and chiral selectors for approaches that span the range of analytical separation platforms (e.g., high-performance liquid chromatography, gas chromatography, supercritical-fluid chromatography, and capillary electrophoresis). This review begins with a brief discussion of chirality before examining the general strategies and commonalities among all of the chiral separation techniques. Rather than exhaustively listing all the chiral selectors and applications, this review highlights significant issues and differences between chiral and achiral separations, providing salient examples from specific classes of chiral selectors where appropriate.

  16. Battery separators.

    PubMed

    Arora, Pankaj; Zhang, Zhengming John

    2004-10-01

    The ideal battery separator would be infinitesimally thin, offer no resistance to ionic transport in electrolytes, provide infinite resistance to electronic conductivity for isolation of electrodes, be highly tortuous to prevent dendritic growths, and be inert to chemical reactions. Unfortunately, in the real world the ideal case does not exist. Real world separators are electronically insulating membranes whose ionic resistivity is brought to the desired range by manipulating the membranes thickness and porosity. It is clear that no single separator satisfies all the needs of battery designers, and compromises have to be made. It is ultimately the application that decides which separator is most suitable. We hope that this paper will be a useful tool and will help the battery manufacturers in selecting the most appropriate separators for their batteries and respective applications. The information provided is purely technical and does not include other very important parameters, such as cost of production, availability, and long-term stability. There has been a continued demand for thinner battery separators to increase battery power and capacity. This has been especially true for lithiumion batteries used in portable electronics. However, it is very important to ensure the continued safety of batteries, and this is where the role of the separator is greatest. Thus, it is essential to optimize all the components of battery to improve the performance while maintaining the safety of these cells. Separator manufacturers should work along with the battery manufacturers to create the next generation of batteries with increased reliability and performance, but always keeping safety in mind. This paper has attempted to present a comprehensive review of literature on separators used in various batteries. It is evident that a wide variety of separators are available and that they are critical components in batteries. In many cases, the separator is one of the major factors

  17. Water separator

    NASA Technical Reports Server (NTRS)

    Dunn, W. F.; Austin, I. G. (Inventor)

    1964-01-01

    An apparatus for separating liquids from gases or gaseous fluids is described. Features of the apparatus include: (1) the collection and removal of the moisture in the fluid is not dependent upon, or affected by gravity; (2) all the collected water is cyclically drained from the apparatus irrespective of the attitude of the separator; and (3) a fluid actuator is utilized to remove the collected water from the separator.

  18. Structural study of trivalent lanthanide and actinide complexes formed upon solvent extraction.

    PubMed

    Gannaz, Benoît; Antonio, Mark R; Chiarizia, Renato; Hill, Clément; Cote, Gérard

    2006-10-14

    The coordination of the trivalent 4f ions, Ln = Nd3+, Eu3+ and Yb3+, as well as the trivalent 5f ion, Am3+, with diamide and dialkylphosphoric acid extractants, individually and in combination, was studied by use of X-ray absorption spectroscopy. These studies provide metrical information about the interatomic interactions between the f-ions (M3+) and the ligands, dihexylphosphoric acid (HDHP) and N,N'-dimethyl-N,N'-dioctylhexylethoxymalonamide (DMDOHEMA), that is of practical relevance to the control of metal-ligand binding in liquid-liquid extraction systems for the separation of trivalent actinide ions, An3+, from trivalent lanthanide ions, Ln3+. Through systematic variations of extraction conditions and extractant combinations, we have found that the HDHP complexes with M3+ involve MO6 coordination and distant M...P interactions, whereas the DMDOHEMA complexes with M3+ involve MO8 coordination. The combination of the EXAFS results with ancillary extraction data and IR results facilitates descriptions of the stoichiometries and structures of the molecular species formed in solution upon liquid-liquid extraction and leads to a new understanding of the binary extraction systems in terms of the strength and selectivity of An3+- vs. Ln3+-ligand interactions. This fundamental structure information affords insight into solvent extraction processes that are of contemporary and practical importance in heavy element chemistry and to environmentally related issues arising from the separation and disposal of radioactive materials, particularly actinides and selected fission products, in the field of nuclear waste reprocessing research.

  19. Synergistic selective extraction of actinides(III) over lanthanides from nitric acid using new aromatic diorganyldithiophosphinic acids and neutral organophosphorus compounds

    SciTech Connect

    Modolo, G.; Odoj, R.

    1999-01-01

    New aromatic dithiophosphinic acids (R{sub 2}PSSH) with R = C{sub 6}H{sub 5{sup {minus}}}, ClC{sub 6}H{sub 4{sup {minus}}}, FC{sub 6}H{sub 4{sup {minus}}} and CH{sub 3}C{sub 6}H{sub 4{sup {minus}}} were synthesized, characterized and tested as potential separating agents for trivalent actinides over lanthanides. The extraction of Am(III), Eu(III) and other lanthanides was carried out from nitric acid medium with mixtures of R{sub 2}PSSHs and neutral organophosphorus compounds. There was no detectable extraction when R{sub 2}PSSHs were used alone as extractants for either Am(III) or Eu(III) (D{sub Am,Eu} < 10{sup {minus}3}) under the experimental conditions used in this study. High separation factors (D{sub Am}/D{sub Eu} > 20) with D{sub Am} > 1 were achieved in the nitric acid range 0.1--1 mol/L by means of a synergistic mixture of bis(chlorophenyl)dithiophosphinic acid + tributylphosphate (TBP), trioctylphosphine oxide (TOPO) or tributylphosphine oxide (TBPO). The high radiation resistance (up to 10{sup 6} Gy absorbed {gamma}-doses) of the extractants was also demonstrated.

  20. Increasing the luminescence of lanthanide(III) macrocyclic complexes by the use of polymers and lanthanide enhanced luminescence

    NASA Astrophysics Data System (ADS)

    Leif, Robert C.; Becker, Margie C.; Bromm, Alfred J., Jr.; Vallarino, Lidia M.; Williams, Steven A.; Yang, Sean

    2001-05-01

    A Eu (III)-macrocycle-isothiocyanate, Quantum DyeTM, has been reacted with lysine homo- and hetero-peptides to give polymers with multiple luminescent side chains. Contrary to the concentration quenching that occurs with conventional organic fluorophores, the attachment of multiple Quantum Dyes to a polymer results in a concomitant increase in luminescence. The emission intensity of the peptide-bound Quantum Dye units is approximately linearly related to their number. The attachment of peptides containing multiple lanthanide (III) macrocycles to analyte-binding species is facilitated by employing solid-phase technology. Bead-bound peptides are first labeled with multiple Quantum Dye units, then conjugated to an antibody, and finally released from the bead by specific cleavage with Proteinase K unedr physiological conditions. Since the luminescence of lanthanide(III) macrocycles is enhanced by the presence of GD(III) or Y(III) ions in a micellar system, a significant increase in signal can be achieved by attaching a polymer labeled with multiple Quantum Dye units to an analyte- binding species, such as a monoclonal antibody, or by taking advantage of the luminescence enhancing effects of Gd(III) or Y(III), or by both approaches concomitantly. A comparison between the integrated intensity and lifetime measurements of the Eu(III)-macrocycle under a variety of conditions show that the signal increase caused by Gd(III) can not be explained solely by the increase in lifetime, and must result in significant part from an energy transfer process invloving donors not directly bound to the Eu(III).

  1. In the Bottlebrush Garden: The Structural Aspects of Coordination Polymer Phases formed in Lanthanide Extraction with Alkyl Phosphoric Acids.

    PubMed

    Ellis, Ross J; Demars, Thomas; Liu, Guokui; Niklas, Jens; Poluektov, Oleg G; Shkrob, Ilya A

    2015-09-03

    Coordination polymers (CPs) of metal ions are central to a large variety of applications, such as catalysis and separations. These polymers frequently occur as amorphous solids that segregate from solution. The structural aspects of this segregation remain elusive due to the dearth of the spectroscopic techniques and computational approaches suitable for probing such systems. Therefore, there is a lacking of understanding of how the molecular building blocks give rise to the mesoscale architectures that characterize CP materials. In this study we revisit a CP phase formed in the extraction of trivalent lanthanide ions by diesters of the phosphoric acid, such as the bis(2-ethylhexyl)phosphoric acid (HDEHP). This is a well-known system with practical importance in strategic metals refining and nuclear fuel reprocessing. A CP phase, referred to as a "third phase", has been known to form in these systems for half a century, yet the structure of the amorphous solid is still a point of contention, illustrating the difficulties faced in characterizing such materials. In this study, we follow a deductive approach to solving the molecular structure of amorphous CP phases, using semiempirical calculations to set up an array of physically plausible models and then deploying a suite of experimental techniques, including optical, magnetic resonance, and X-ray spectroscopies, to consecutively eliminate all but one model. We demonstrate that the "third phase" consists of hexagonally packed linear chains in which the lanthanide ions are connected by three O-P-O bridges, with the modifying groups protruding outward, as in a bottlebrush. The tendency to yield linear polynuclear oligomers that is apparent in this system may also be present in other systems yielding the "third phase", demonstrating how molecular geometry directs polymeric assembly in hybrid materials. We show that the packing of bridging molecules is central to directing the structure of CP phases and that by

  2. Selective self-assembly of hexameric homo- and heteropolymetallic lanthanide wheels: synthesis, structure, and photophysical studies.

    PubMed

    Chen, Xiao-Yan; Bretonnière, Yann; Pécaut, Jacques; Imbert, Daniel; Bünzli, Jean-Claude; Mazzanti, Marinella

    2007-02-05

    A rational approach to the formation of pure heteropolymetallic lanthanide complexes that uses a two-step assembly strategy and exploits the different size requirements of the two metals included in the final structure is described. The investigation of the assembly of [LnL2](Otf) (L = 2,2':6',2' '-terpyridine-6-carboxylate) complexes into hexametallic rings hosting an additional hexacoordinated lanthanide cation was crucial for the development of this strategy. The formation and size of the cyclic assembly are controlled by the ionic radius and by the coordination number of the lanthanides. The rather high luminescence quantum yield of the heptaeuropium complex (25%) indicates that the ring structure is well adapted to include highly luminescent lanthanide complexes in nanosized architecture. The use of a stepwise synthetic strategy leads to the selective assembly of large heteropolymetallic rings. The addition of a smaller lanthanide ion to the [EuL2](Otf) complex in anhydrous acetonitrile leads selectively to heterometallic species with the Eu ions located on the peripheral sites and the smaller ion occupying only the central site. The high selectivity is the result of the different size requirements of the two metal sites present in the cyclic structure. The heterometallic structure of the isolated [Lu subset (EuL2)6](Otf)9 complex was confirmed by X-ray diffraction and by high resolution solid-state photophysical studies. The described synthetic approach allowed us to obtain the first example of selective assembly of two different lanthanide ions in a large polymetallic structure characterized in solution and in the solid state and will make the isolation of planned dimetallic combinations presenting different lanthanide emitters in the peripheral sites possible.

  3. CENTRIFUGAL SEPARATORS

    DOEpatents

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  4. Fluorescence quenching studies of tryptophan by trivalent lanthanide ions in aqueous media. Evidence for a lanthanide-induced intersystem crossing singlet-to-triplet mechanism

    NASA Astrophysics Data System (ADS)

    Gaye-Seye, M. D.; Aaron, J. J.

    1999-09-01

    The quenching of tryptophan fluorescence by trivalent lanthanide ions is studied at room temperature in aqueous non buffered (pH 5.8) and in 0.05 M HEPES pH 7.5 and acetate pH 5.8 buffered solutions. Bimolecular quenching rate constants ranged between 0.9× 109 and 24.4×109 M-1s-1 in HEPES buffer, and 1.8×109 and 20.7×109 in acetate buffer and between 2.0×109 and 22×109 M-1s-1 in non buffered aqueous solution, according to the nature of the ions. A mechanism involving a lanthanide-induced intersystem crossing singlet-to-triplet process is proposed. The induced intersystem crossing rate constants (kiscind) range from 2.0×107 to 4.7×107 M-1s-1. In aqueous media, kiscind are correlated with the molecular weight of the lanthanide ions under study. L'effet de l'extinction de la fluorescence du tryptophane par des ions lanthanides trivalents a été étudié à 298 K en milieu aqueux (pH 5.8) et en solutions tampon HEPES 0.05 M pH 7.5 et acétate pH 5.8. Les constantes de vitesse bimoléculaires d'extinction varient suivant la nature des ions lanthanides et sont comprises entre 0.9× 109 et 24.4×109 M-1s-1 en tampon HEPES, et 1.8×109 et 20.7×109 en tampon acétate et entre 2.0×109 et 22×109 M-1s-1 en milieu aqueux non tamponné. Un mécanisme comprenant un processus de croisement intersystème singulet-triplet induit par les ions lanthanides est proposé. Les constantes de vitesse de croisement intersystéme induit (kiscind) varient entre 2.0×107 et 4.7×107 M-1s-1. En milieu aqueux, les valeurs de kiscind se corrèlent bien avec la masse molaire des ions lanthanides étudiés.

  5. Coupling of the 4f Electrons in Lanthanide Molecules

    SciTech Connect

    Kazhdan, Daniel

    2008-09-01

    (C5Me5)2LnOTf where Ln = La, Ce, Sm, Gd, and Yb have been synthesized and these derivatives are good starting materials for the synthesis of (C5Me5)2LnX derivatives. (C5Me5)2Ln(2,2'-bipyridine), where Ln = La, Ce, Sm, and Gd, along with several methylated bipyridine analogues have been synthesized and their magnetic moments have been measured as a function of temperature. In lanthanum, cerium, and gadolinium complexes the bipyridine ligand ligand is unequivocally the radical anion, and the observed magnetic moment is the result of intramolecular coupling of the unpaired electron on the lanthanide fragment with the unpaired electron on the bipyridine along with the intermolecular coupling between radicals. Comparison with the magnetic moments of the known compounds (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine) leads to an understanding of the role of the SmII/SmIII and YbII/YbIII couple in the magnetic properties of (C5Me5)2Sm(2,2'-bipyridine) and (C5Me5)2Yb(2,2'-bipyridine). In addition, crystal structures of (C5Me5)2Ln(2,2'-bipyridine) and [(C5Me5)2Ln(2,2'-bipyridine)][BPh4](Ln= Ce and Gd), where the lanthanide is unequivocally in the +3 oxidation state, give the crystallographic characteristics of bipyridine as an anion and as a neutral ligand in the same coordination environment, respectively. Substituted bipyridine ligands coordinated to (C5Me5)2Yb are studied to further understand how the magnetic coupling in (C5Me5)2Yb(2,2'-bipyridine) changes with substitutions. In the cases of (C5Me5)2Yb(5,5'-dimethyl-2,2'-bipyridine) and (C5Me5

  6. Stereoisomers Separation

    NASA Astrophysics Data System (ADS)

    Wieczorek, Piotr

    The use of capillary electrophoresis for enantiomer separation and optical purity determination is presented. The contents start with basic information about the nature of stereoizomers and the mechanism of enantioseparation using capillary electrophoresis techniques. The molecules to be separated show identical chemical structure and electrochemical behavior. Therefore, the chiral recognition of enantiomers is possible only by bonding to chiral selector and the separation based on very small differences in complexation energies of diastereomer complexes formed. This method is useful for this purpose due to the fact that different compounds can be used as chiral selectors. The mostly used chiral selectors like cyclodextrins, crown ethers, chiral surfactants, macrocyclic antibiotics, transition metal complexes, natural, and synthetic polymers and their application for this purpose is also discussed. Finally, examples of practical applications of electromigration techniques for enantiomers separation and determination are presented.

  7. Mist separator

    SciTech Connect

    Moran, T.M.

    1984-04-17

    An apparatus for the removal of particulates from a flowing gas stream and a process for its use are provided. A perforated screen separator formed as a plate having parallel rows of perforations formed by pushing alternating strips of the plate material forward and backward from the plane of the plate is used. The perforated screen separator may be used alone or with a fiber bed mist eliminator for increased particulate removal.

  8. Effect of lanthanide contraction on the mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien): Syntheses and characterizations of lanthanide complexes with a tetraelenidoantimonate ligand

    SciTech Connect

    Zhao Jing; Liang Jingjing; Pan Yingli; Zhang Yong; Jia Dingxian

    2011-06-15

    Mixed polyamine systems Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) (Ln=lanthanide, en=ethylenediamine, dien=diethylenetriamine, trien=triethylenetetramine) were investigated under solvothermal conditions, and novel mixed-coordinated lanthanide(III) complexes [Ln(en){sub 2}(dien)({eta}{sup 2}-SbSe{sub 4})] (Ln=Ce(1a), Nd(1b)), [Ln(en){sub 2}(dien)(SbSe{sub 4})] (Ln=Sm(2a), Gd(2b), Dy(2c)), [Ln(en)(trien)({mu}-{eta}{sup 1},{eta}{sup 2}-SbSe{sub 4})]{sub {infinity}} (Ln=Ce(3a), Nd(3b)) and [Sm(en)(trien)({eta}{sup 2}-SbSe{sub 4})] (4a) were prepared. Two structural types of lanthanide selenidoantimonates were obtained across the lanthanide series in both en+dien and en+trien systems. The tetrahedral anion [SbSe{sub 4}]{sup 3-} acts as a monodentate ligand mono-SbSe{sub 4}, a bidentate chelating ligand {eta}{sup 2}-SbSe{sub 4} or a tridentate bridging ligand {mu}-{eta}{sup 1},{eta}{sup 2}-SbSe{sub 4} to the lanthanide(III) center depending on the Ln{sup 3+} ions and the mixed ethylene polyamines, indicating the effect of lanthanide contraction on the structures of the lanthanide(III) selenidoantimonates. The lanthanide selenidoantimonates exhibit semiconducting properties with E{sub g} between 2.08 and 2.51 eV. - Graphical Abstract: Two structural types of lanthanide(III) selenidoantimonates are formed in both en-dien and en-trien mixed polyamines across lanthanide series, indicating the lanthanide contraction effect on the structures of the lanthanide(III) selenidoantimonates. Highlights: > Two structural types of lanthanide selenidoantimonates are prepared across the lanthanide series in both Ln/Sb/Se/(en+dien) and Ln/Sb/Se/(en+trien) systems. > The [SbSe{sub 4}]{sup 3-} anion acts as a mono-SbSe{sub 4}, a {eta}{sup 2}-SbSe{sub 4} or a {mu}-{eta}{sup 1},{eta}{sup 2}-SbSe{sub 4} ligand to the Ln{sup 3+} ions. > The soft base ligand [SbSe{sub 4}]{sup 3-} can be controlled to coordinate to the Ln{sup 3+} ions with en+dien and en+trien as co-ligands.

  9. Pentanuclear Lanthanide Mono-organophosphates: Synthesis, Structure, and Magnetism.

    PubMed

    Gupta, Sandeep K; Langley, Stuart K; Sharma, Kamna; Murray, Keith S; Murugavel, Ramaswamy

    2017-04-03

    Research on rare-earth phosphates has recently received substantial interest because of their unique physical and chemical properties. In recent years, because of their low solubility, research interest has been built on developing methodologies to prepare nanostructures and grow single crystals of inorganic rare-earth phosphates. The chemistry of rare-earth organophosphates, however, is still at a latent stage. Contrary to the traditional hydrothermal route, we report rare examples of discrete pentanuclear lanthanide(III) organophosphate clusters assembled from a sterically encumbered monoester of phosphoric acid under mild reaction conditions. Single-crystal X-ray analysis revealed that all of the compounds possess a similar core structure, [Ln5(μ3-OH)(dipp)6(NO3)x(CH3OH)y(H2O)z](2+) [Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6), Ho (7), Er (8), Tm (9); dipp = 2,6-diisopropylphenylphosphate], where the anionic charge balance is maintained by the presence of chelating nitrate anions (in the case of 9, x = 0), protonated tmeda, or dipp(2-) ligands. The vacant coordination sites on the metal ions are satisfied by coordinated methanol or water molecules. The core structure of these clusters is built on a [Ln3(μ3-OH)(dipp)6] triangle where the phosphate ligands bridge to two further Ln(III) ions. The complexes display lanthanide contraction along the series, with Ln(III) ions displaying different coordination environments/geometries as we move along the series. All of the compounds have been characterized by both analytical and spectroscopic techniques. Magnetic studies revealed the presence of weak antiferromagnetic exchange through the bridging μ3-hydroxo moiety and organophosphate groups for the {Gd(III)5} analogue, with a significant magnetic entropy change (25.8 J kg(-1) K(-1), ΔH = 7 T). The anisotropic complexes reveal an absence of slow relaxation of magnetization, except for Nd (1), Dy (6), and Er (8), which show slow relaxation in an applied DC

  10. Macrocyclic receptor exhibiting unprecedented selectivity for light lanthanides.

    PubMed

    Roca-Sabio, Adrián; Mato-Iglesias, Marta; Esteban-Gómez, David; Tóth, Eva; de Blas, Andrés; Platas-Iglesias, Carlos; Rodríguez-Blas, Teresa

    2009-03-11

    We report a new macrocyclic ligand, N,N'-bis[(6-carboxy-2-pyridil)methyl]-4,13-diaza-18-crown-6 (H(2)bp18c6), designed for complexation of lanthanide ions in aqueous solution. Potentiometric measurements evidence an unprecedented selectivity of bp18c6 for the large Ln(III) ions. Among the different Ln(III) ions, La(III) and Ce(III) show the highest log K(ML) values, with a dramatic drop of the stability observed from Ce(III) to Lu(III) as the ionic radius of the Ln(III) ions decreases (log K(CeL) - log K(LuL) = 6.9). The X-ray crystal structures of the Gd(III) and Yb(III) complexes show that the metal ion is directly bound to the 10 donor atoms of the bp18c6 ligand. The structure of the complexes in solution has been investigated by (1)H and (13)C NMR spectroscopy, as well as by theoretical calculations performed at the DFT (B3LYP) level. Our results indicate that a conformational change occurs around the middle of the lanthanide series: for the larger Ln(III) ions the most stable conformation is Delta(deltalambdadelta)(deltalambdadelta), while for the smallest Ln(III) ions (Gd-Lu) our calculations predict the Delta(lambdadeltalambda)(lambdadeltalambda) form being the most stable one. This structural change was confirmed by the analysis of the Ce(III)-, Pr(III)-, and Yb(III)-induced paramagnetic (1)H shifts. The selectivity that bp18c6 shows for the large Ln(III) ions can be attributed to a better fit between the light Ln(III) ions and the relatively large crown fragment of the ligand. Indeed, our DFT calculations indicate that the interaction between the Ln(III) ion and several donor atoms of the crown moiety is weakened as the ionic radius of the metal ion decreases.

  11. Anion and solvent induced chirality inversion in macrocyclic lanthanide complexes.

    PubMed

    Gerus, Aleksandra; Slepokura, Katarzyna; Lisowski, Jerzy

    2013-11-04

    A series of the lanthanide(III) or yttrium(III) complexes of the type [LnL(NO3)(H2O)2](NO3)2, [LnL(NO3)(H2O)](NO3)2, [LnL(H2O)2](NO3)3, and [LnLCl(H2O)2]Cl2 where L is an all-R or all-S enantiomer (L(R) or L(S)) of the chiral hexaaza macrocycle, 2(R),7(R),18(R),23(R)- or 2(S),7(S),18(S),23(S)-1,8,15,17,24,31-hexaazatricyclo[25.3.1.1.0.0]-dotriaconta-10,12,14,26,28,30-hexaene, and Ln(III) = Sm(III), Tb(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III), or Y(III), have been synthesized and structurally characterized. The crystal structure of the free macrocycle shows a highly twisted molecule, preorganized for the formation of helical complexes. The crystal structures of the lanthanide(III) complexes show two different diastereomeric forms of the macrocycle with different configurations at the stereogenic amine nitrogen atoms: (RRRR) or (RSRS) (denoted as L(RI) and L(RII), respectively). The L(RI) diastereomeric form of the nitrate derivatives [LnL(NO3)(H2O)](NO3)2 (Ln = Ho, Er) and [LnL(H2O)2](NO3)3 (Ln = Tm, Yb, Lu) convert slowly to the L(RII) form in methanol or acetonitrile solutions, while this process is not observed for the L(RI) diastereomers of analogous chloride derivatives [LnL(H2O)2]Cl3 (Ln = Tm, Yb, Lu). On the other hand, the L(RI) → L(RII) conversion for these Tm(III), Yb(III), and Lu(III) chloride derivatives can be triggered by the addition of external nitrate anions. The circular dichroism (CD) and (1)H NMR data indicate initial fast exchange of axial chloride for axial nitrate ligand, followed by slow chirality inversion of the equatorial macrocyclic ligand.

  12. Modeling lanthanide series binding sites on humic acid.

    PubMed

    Pourret, Olivier; Martinez, Raul E

    2009-02-01

    Lanthanide (Ln) binding to humic acid (HA) has been investigated by combining ultrafiltration and ICP-MS techniques. A Langmuir-sorption-isotherm metal-complexation model was used in conjunction with a linear programming method (LPM) to fit experimental data representing various experimental conditions both in HA/Ln ratio (varying between 5 and 20) and in pH range (from 2 to 10) with an ionic strength of 10(-3) mol L(-1). The LPM approach, not requiring prior knowledge of surface complexation parameters, was used to solve the existing discrepancies in LnHA binding constants and site densities. The application of the LPM to experimental data revealed the presence of two discrete metal binding sites at low humic acid concentrations (5 mg L(-1)), with log metal complexation constants (logK(S,j)) of 2.65+/-0.05 and 7.00 (depending on Ln). The corresponding site densities were 2.71+/-0.57x10(-8) and 0.58+/-0.32x10(-8) mol of Ln(3+)/mg of HA (depending on Ln). Total site densities of 3.28+/-0.28x10(-8), 4.99+/-0.02x10(-8), and 5.01+/-0.01x10(-8) mol mg(-1) were obtained by LPM for humic acid, for humic acid concentrations of 5, 10, and 20 mg L(-1), respectively. These results confirm that lanthanide binding occurs mainly at weak sites (i.e., ca. 80%) and second at strong sites (i.e., ca. 20%). The first group of discrete metal binding sites may be attributed to carboxylic groups (known to be the main binding sites of Ln in HA), and the second metal binding group to phenolic moieties. Moreover, this study evidences heterogeneity in the distribution of the binding sites among Ln. Eventually, the LPM approach produced feasible and reasonable results, but it was less sensitive to error and did not require an a priori assumption of the number and concentration of binding sites.

  13. Product separator

    DOEpatents

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  14. Lanthanide metals adsorbed in an open-cage Fullerene: first-principles calculations.

    PubMed

    Jun, Guo; Zhiguo, Liu; Xuehui, Zhao; Kelong, Huang

    2012-02-01

    In this paper, the properties of a 12-membered-ring open-cage fullerene, which encapsulate La, Ce, Pr, Nd, Pm, Sm, Eu or Gd, as a guest atom, were calculated using first-principle calculations. Calculations show that La etc. lanthanide metal atoms can be stably adsorbed on the openings of the fullerenes. The average adsorption energy is about -3.65 eV in which Pr and Nd have relatively large adsorption energy with -4.75 eV and -4.63 eV, respectively. The Gd is stably adsorbed on the side wall near bottom of the fullerene with adsorption energy of -3.05 eV. The PDOS of adsorbed lanthanides were analyzed, respectively. Magnetic property of adsorbed lanthanides was also discussed. From the calculation, it is proved that most of the adsorbed lanthanides keep good magnetic property. Finally, vertical ionization potential and vertical electron affinity of the complex compounds were researched. The results show that the possibility of donating electrons of the 12-membered-ring open-cage fullerene is significantly affected by the endohedral lanthanide metals. From our calculations, it is believed that the complex compounds could be promising candidates for medicine-carrier.

  15. A Bridge to Coordination Isomer Selection in Lanthanide(III) DOTA-tetraamide Complexes

    PubMed Central

    Vipond, Jeff; Woods, Mark; Zhao, Piyu; Tircso, Gyula; Ren, Jimin; Bott, Simon G.; Ogrin, Doug; Kiefer, Garry E.; Kovacs, Zoltan; Sherry, A.Dean

    2008-01-01

    Interest in macrocyclic lanthanide complexes such as DOTA is driven largely through interest in their use as contrast agents for MRI. The lanthanide tetraamide derivatives of DOTA have shown considerable promise as PARACEST agents, taking advantage of the slow water exchange kinetics of this class of complex. We postulated that water exchange in these tetraamide complexes could be slowed even further by introducing a group to sterically encumber the space above the water coordination site, thereby hindering the departure and approach of water molecules to the complex. The ligand 8O2-bridged-DOTAM was synthesized in a 34% yield from cyclen. It was found that the lanthanide complexes of this ligand did not possess a water molecule in the inner coordination sphere of the bound lanthanide. The crystal structure of the ytterbium complex revealed that distortions to the coordination sphere were induced by the steric constraints imposed on the complex by the bridging unit. The extent of the distortion was found to increase with increasing ionic radius of the lanthanide ion, eventually resulting in a complete loss of symmetry in the complex. Because this ligand system is bicyclic, the conformation of each ring in the system is constrained by that of the other, in consequence inclusion of the bridging unit in the complexes means only a twisted square antiprismatic coordination geometry is observed for complexes of 8O2-bridged-DOTAM. PMID:17295475

  16. Ultrastrong Alkali-Resisting Lanthanide-Zeolites Assembled by [Ln60] Nanocages.

    PubMed

    Dong, Jie; Cui, Ping; Shi, Peng-Fei; Cheng, Peng; Zhao, Bin

    2015-12-30

    Zeolites, as one of the most important porous materials, are most widely utilized in sorbents, catalysis, and ion-exchange fields. However, the multi-functional lanthanide-zeolites constructed exclusively by lanthanide ions and oxygen linkers are to our knowledge unknown hitherto. Herein, we, for the first time, report the unique structure and multifunctions of lanthanide zeolites (1·Gd, 1·Tb, 1·Dy), featuring 60 nuclear [Ln60] nanocages as building blocks and ultrastrong alkali-resisting. These compounds possess extremely high stability and still retain single crystallinity after treatment in boiling water, 0.1 M HCl, and 20 M NaOH aqueous solutions. Magnetic studies revealed 1·Gd has large magnetocaloric effect with -ΔSm(max) = 66.5 J kg(-1) K(-1), falling among the largest values known to date. Importantly, these lanthanide-zeolites themselves can efficiently catalyze the cycloaddition of CO2 with epoxides under mild conditions. Our finding extends the conventional zeolites to lanthanide counterparts, opening a new space for seeking novel and/or multifunctional zeolites.

  17. Microbial formation of lanthanide-substituted magnetites by Thermoanaerobacter sp. TOR-39

    SciTech Connect

    Moon, Ji Won; Roh, Yul; Yeary, Lucas W; Lauf, Robert J; Rawn, Claudia J; Love, Lonnie J; Phelps, Tommy Joe

    2007-01-01

    Lanthanide (Nd, Gd, Tb, Ho, and Er)-substituted magnetites, LyFe3-yO4 (L, lanthanide) were microbially synthesized using L-mixed precursors, LxFe1-xOOH, where x was between 0.01 and 0.2. By combining lanthanides (normally considered toxic to microorganisms) into the akaganeite precursor phase, we were able to mitigate some of the toxicity enabling the microorganisms to produce L-substituted magnetites. A metal reducing bacterium, Thermoanaerobacter ethanolicus successfully converted the mixed akaganeite to L-substituted magnetite while avoiding the potentially toxic effects of soluble L-ions. At higher mixing levels (0.02 < x <0.05) the poor crystallinity of L-mixed precursors increased the concentration of soluble toxic L-ions in the media. Nevertheless, using L-mixed precursors enabled production of microbially synthesized L-substituted magnetite with considerably higher L-concentration than could be obtained when the lanthanides were added as soluble salts. This method can therefore be used to extend the application for nanofermentation to fields where there is a need for nanoscale materials that involve elements such as lanthanides that are toxic or inhibitory to bacterial growth.

  18. The Construction of Homochiral Lanthanide Quadruple-Stranded Helicates with Multiresponsive Sensing Properties toward Fluoride Anions.

    PubMed

    Chen, Wanmin; Tang, Xiaoliang; Dou, Wei; Wang, Bei; Guo, Lirong; Ju, Zhenghua; Liu, Weisheng

    2017-07-21

    A series of unique homochiral lanthanide tetranuclear quadruple-stranded helicates have been self-assembled controllably by using the intrinsic advantages of chiral bridging ligands, (S)-H2 L and (R)-H2 L, and lanthanide ions with high coordination numbers. The self-assembly process of these chiral helicates not only ensures the structural stability and quadruple-stranded feature of lanthanide cluster in the solid state and solution, but also achieves effective transfer and amplification of the chirality code from the ligand to a higher supramolecular level. Moreover, through using optical rotation, circular dichroism spectra analysis, and luminescence measurements, we demonstrate that these chiral lanthanide helicates could serve as sensitive and multi-responsive sensors to recognize and detect F(-) anions based on the change of chiral signal and NIR luminescence simultaneously, which represents a meaningful exploration for developing functional lanthanide-based polynuclear clusters. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Distribution, speciation, and bioavailability of lanthanides in the Rhine-Meuse estuary, The Netherlands.

    PubMed

    Moermond, C T; Tijink, J; van Wezel, A P; Koelmans, A A

    2001-09-01

    Changing environmental conditions may influence the fate and bioavailability of lanthanides (part of the rare earth elements [Ln]) in estuaries. The aim of this study was to quantify the variation in estuarine lanthanide solid/water distribution, speciation, and bioaccumulation. The latter was studied in the amphipod Corophium volutator under field and laboratory conditions. Calculations with the chemical equilibrium model MINEQL+ indicate that dissolved lanthanides are complexed mainly to carbonates and dissolved organic matter. In the water phase, the relative abundance of the free ion, LnCO3, and humic complexes decreases from lanthanum to lutetium, whereas the relative abundance of Ln(CO3)2 increases. Cerium and europium anomalies were found in the water. Europium anomalies were also found in some biota. The biota sediment accumulation factors (BSAFs) decreased across the series from lanthanum to lutetium. Regression analysis revealed that alkalinity correlated negatively with lanthanide uptake. This suggests that increasing complexation reduced bioavailability under the prevailing conditions. The BSAFs did not depend on salinity or pH, which may simplify sediment-quality criteria for fresh versus saline waters. Field BSAFs were significantly lower than laboratory values for the same sediments, which is explained by adaptation of the organisms to lanthanides.

  20. Fluorescence Quenching of Two Coumarin-3-carboxylic Acids by Trivalent Lanthanide Ions.

    PubMed

    Cisse, Lamine; Djande, Abdoulaye; Capo-Chichi, Martine; Delattre, François; Saba, Adama; Brochon, Jean-Claude; Sanouski, Serguei; Tine, Alphonse; Aaron, Jean-Jacques

    2017-03-01

    The effects of various trivalent lanthanide ions (acetates of Ce(3+), Er(3+), Eu(3+), Nd(3+)) on the electronic absorption and fluorescence spectra of un-substituted coumarin-3-carboxylic acid (CCA) and 7-N,N-diethylamino-coumarin-3-carboxylic acid (DECCA) have been investigated in dimethylsulfoxide (DMSO) at room temperature. Depending on the lanthanide ion nature and concentration, significant spectral changes of absorption bands occurred for both coumarin derivatives. These spectral changes were attributed to the formation of ground-state complexes between the coumarin carboxylate derivatives and lanthanide ions. The fluorescence quenching of CCA and DECCA upon increasing the lanthanide ion concentration was studied. Different quantitative treatments, including the Stern-Volmer equation, the Perrin equation and a polynomial equation, were applied and compared in order to determine the nature of the quenching mechanisms for both coumarin derivatives. The results suggested the contribution of both dynamic and static quenching. Significant differences of CCA and DECCA fluorescence quenching efficiency were also observed, depending on the lanthanide ion. DECCA fluorescence lifetime measurements, performed in the absence and in the presence of Ln(3+), confirmed a contribution of static quenching.

  1. Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta)

    PubMed Central

    Goecke, Franz; Jerez, Celia G.; Zachleder, Vilém; Figueroa, Félix L.; Bišová, Kateřina; Řezanka, Tomáš; Vítová, Milada

    2015-01-01

    Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations. PMID:25674079

  2. Determination of lanthanides in rock samples by inductively coupled plasma mass spectrometry using thorium as oxide and hydroxide correction standard

    NASA Astrophysics Data System (ADS)

    Raut, Narendra M.; Huang, Li-Shing; Aggarwal, Suresh K.; Lin, King-Chuen

    2003-05-01

    Determination of lanthanides by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) using modified mathematical correction method has been studied. Normally, the ICP-MS analysis of middle and heavier lanthanides becomes difficult by severe spectroscopic overlap of M +, MO + or MOH + ions from lighter lanthanides and Ba. A correction method based on a single element oxide yield measurement, is a simple approach to correct for the above spectroscopic overlaps. But the uncertainty in the oxide and hydroxide yields measurement of lanthanides and barium over a long period of time can lead to inaccurate results even under fixed plasma conditions. To correct this, thorium was adopted as an oxide and hydroxide correction standard. Using a ratio of lanthanide oxide yield to thorium oxide yield, the lanthanide correction factors (LCF) were established and incorporated in the mathematical correction scheme. The same factors were also established for hydroxide correction. The proposed modified correction scheme was applied to the determination of lanthanides by ICP-MS from the USGS Standard Rock samples AGV-1 and G-2. The results are in good agreement with the reported values. The method also proved to be useful in isotopic ratio measurement of lanthanides having severe isobaric overlaps.

  3. Rapid hydrolytic cleavage of the mRNA model compound HPNP by glycine based macrocyclic lanthanide ribonuclease mimics.

    PubMed

    Gunnlaugsson, Thorfinnur; Davies, R Jeremy H; Nieuwenhuyzen, Mark; Stevenson, Clarke S; Viguier, Romain; Mulready, Sinead

    2002-09-21

    The lanthanide ion based macrocyclic complexes 1.Ln mimic the hydrophobic nature of ribonucleases, where the lanthanide ions induce the formation of a hydrophobic cavity for 1, giving rise to a large order of magnitude enhancement in the hydrolytic cleavage of HPNP.

  4. Metal induced folding: synthesis and conformational analysis of the lanthanide complexes of two 44-membered hydrazone macrocycles.

    PubMed

    Klein, Jörg M; Clegg, Jack K; Saggiomo, Vittorio; Reck, Lisa; Lüning, Ulrich; Sanders, Jeremy K M

    2012-04-07

    Six new lanthanide complexes of two 44-membered macrocycles have been prepared and characterised in solution. An analysis of the conformations of the free macrocycles and their lanthanide complexes both in solution (2D NMR) and in solid state (X-ray crystallography) demonstrate that the complexation induces changes in folding of the macrocycles.

  5. Barcoded materials based on photoluminescent hybrid system of lanthanide ions-doped metal organic framework and silica via ion exchange.

    PubMed

    Shen, Xiang; Yan, Bing

    2016-04-15

    A multicolored photoluminescent hybrid system based on lanthanide ions-doped metal organic frameworks/silica composite host has potential in display and barcode applications. By controlling the stoichiometry of the lanthanides via cation exchange, proportional various lanthanide ions are successfully introduced into metal organic frameworks, whose emission intensity is correspondingly proportional to its amount. The resulting luminescent barcodes depend on the lanthanide ions ratios and compositions. Subsequently, the lanthanide ions located in the channels of metal organic frameworks are protected from any interaction with the environment after the modification of silica on the surface. The optical and thermal stability of the hybrid materials are improved for technological application. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Effect of inclining strain on the crystal lattice along an extended series of lanthanide hydroxysulfates Ln(OH)SO4 (Ln = Pr-Yb, except Pm).

    PubMed

    Zehnder, Ralph A; Wilson, Christopher S; Christy, Hunter T; Harris, Kenneth S; Chauhan, Varun; Schutz, Victor; Sullivan, Matthew; Zeller, Matthias; Fronczek, Frank R; Myers, Jacob A; Dammann, Kyle; Duck, James; Smith, Peter M; Okuma, Antony; Johnson, Kristin; Sovesky, Robert; Stroudt, Cameron; Renn, Robert A

    2011-02-07

    A series of trivalent lanthanide hydroxysulfates, Ln(OH)SO(4), (Ln = Pr through Yb, except radioactive Pm) has been synthesized via hydrothermal methods from Ln(2)(SO(4))(3)·8H(2)O by reaction with aqueous NaOH at 170 °C in Teflon lined Parr steel autoclaves, and were characterized by single crystal X-ray diffraction and FT-IR spectroscopy. Two types of arrangements were found in the solid state. The lighter (Ln = Pr-Nd, Sm-Gd) and heavier lanthanide(III) hydroxysulfates (Tb-Yb) are each isostructural. Both structure types exhibit the monoclinic space group P2(1)/n, but the unit cell content is doubled with two crystallographically distinct LnO(8) polyhedra for the heavier lanthanide compounds. The lighter complexes maintain the coordination number 9, forming a three-dimensional extended lattice. The heavier counterparts exhibit the coordination number 8, and arrange as infinite columns of two crystallographically different LnO(8) polyhedra, while extending along the "c" axis. These columns of LnO(8) polyhedra are surrounded and separated by six columns of sulfate ions, also elongating in the "c" direction. The rigid sulfate entities seem to obstruct the closing in of the lighter LnO(9) polyhedra, and show an inclining degree of torsion into the "ac" layers. The crystal lattice of the lighter 4f complexes can sufficiently withstand the tension buildup, caused by the decreasing Ln(3+) radius, up to Gd(OH)SO(4). The energy profile of this structural arrangement then seems to exceed levels at which this structure type is favorable. The lattice arrangement of the heavier Ln-analogues seems to offer a lower energy profile. This appears to be the preferred arrangement for the heavier lanthanide hydroxysulfates, whose crystal lattice exhibits more flexibility, as the coordination sphere of these analogues is less crowded. The IR absorbance frequencies of the hydroxide ligands correlate as a function of the Ln(3+) ionic radius. This corresponds well with the X-ray single

  7. Map Separates

    USGS Publications Warehouse

    ,

    2001-01-01

    U.S. Geological Survey (USGS) topographic maps are printed using up to six colors (black, blue, green, red, brown, and purple). To prepare your own maps or artwork based on maps, you can order separate black-and-white film positives or negatives for any color printed on a USGS topographic map, or for one or more of the groups of related features printed in the same color on the map (such as drainage and drainage names from the blue plate.) In this document, examples are shown with appropriate ink color to illustrate the various separates. When purchased, separates are black-and-white film negatives or positives. After you receive a film separate or composite from the USGS, you can crop, enlarge or reduce, and edit to add or remove details to suit your special needs. For example, you can adapt the separates for making regional and local planning maps or for doing many kinds of studies or promotions by using the features you select and then printing them in colors of your choice.

  8. Valence calculations of binding energies of mid-row lanthanides

    NASA Astrophysics Data System (ADS)

    O'Malley, Steven M.; Beck, Donald R.

    2008-05-01

    Binding energies of mid-row lanthanides have been calculated by taking advantage of the >90% LS purity of the 4f^n subgroups of their neutral ground states ootnotetextAtomic Energy Levels -- The Rare-Earth Elements, edited by W. C. Martin, R. Zalubas, and L. Hagan, Natl. Bur. Stand. Ref. Data Ser. Natl. Bur. Stand. (U.S.) Circ. No. 60 (U.S. GPO, Washington, D.C., 1978).. As described in our recent work on Nd^- ootnotetextS. M. O'Malley and D. R. Beck, Phy. Rev. A 77, 012505 (2008)., the 4f^n electrons were treated as core-like and restricted to a single LS term throughout all Dirac-Fock and correlation configurations, resulting in manageable relativistic configuration-interaction calculations for these computationally complex systems. Several weakly bound 6p attachments (<200 meV) were found for each negative ion, and these were carefully analyzed with respect to approximate LS total configuration as well as the j's of the the 4f^n subgroup and 6p electron.

  9. Unexpected magnetism, and transport properties in mixed lanthanide compound

    NASA Astrophysics Data System (ADS)

    Pathak, Arjun; Gschneidner, Karl, Jr.; Pecharsky, Vitalij; Ames Laboratory Team

    For intelligent materials design it is desirable to have compounds which have multiple functionalities such as a large magnetoresistance, ferromagnetic and ferrimagnetic states, and field-induced first-order metamagnetic transitions. Here, we discuss one such example where we have combined two lanthanide elements Pr and Er in Pr0.6Er0.4Al2. This compound exhibits multiple functionalities in magnetic fields between 1 and 40 kOe. It undergoes only a trivial ferrimagnetism to paramagnetism transition in a zero magnetic field, but Pr0.6Er0.4Al2 exhibits a large positive magnetoresistance (MR) for H >=40 kOe, a small but non negligible negative MR for H <=30 kOe, and a clear Griffiths-like phase behavior at <1 kOe. The compound also exhibits an asymmetry of hysteresis loop, or exchange bias (EB) effect after field cooling from the paramagnetic state. These phenomena are attributed to the competition between single-ion anisotropies of Pr and Er ions coupled with the opposite nearest-neighbor and next-nearest-neighbor exchange interactions. This work was supported by the US Department of Energy, Office of Basic Energy Science, Division of Material Sciences and Engineering. The research was performed at the Ames Laboratory. The Ames Laboratory is operated by Iowa State University for the US D.

  10. PLUTONIUM FEED IMPURITY TESTING IN A LANTHANIDE BOROSILICATE (LABS) GLASS

    SciTech Connect

    Marra, J; Kevin Fox, K; Elizabeth Hoffman, E; Tommy Edwards, T; Charles Crawford, C

    2007-08-29

    A vitrification technology utilizing a lanthanide borosilicate (LaBS) glass is a viable option for dispositioning excess weapons-useable plutonium that is not suitable for processing into mixed oxide (MOX) fuel. A significant effort to develop a glass formulation and vitrification process to immobilize plutonium was completed in the mid-1990s. The LaBS glass formulation was found to be capable of immobilizing in excess of 10 wt % Pu and to be tolerant of a range of impurities. A more detailed study is now needed to quantify the ability of the glass to accommodate the anticipated impurities associated with the Pu feeds now slated for disposition. The database of Pu feeds was reviewed to identify impurity species and concentration ranges for these impurities. Based on this review, a statistically designed test matrix of glass compositions was developed to evaluate the ability of the LaBS glass to accommodate the impurities. Sixty surrogate LaBS glass compositions were prepared in accordance with the statistically designed test matrix. The heterogeneity (e.g. degree of crystallinity) and durability (as measured by the Product Consistency Test - Method A (PCT-A)) of the glasses were used to assess the effects of impurities on glass quality.

  11. Effect of Lanthanide Complex Structure on Cell Viability and Association

    PubMed Central

    2015-01-01

    A systematic study of the effect of hydrophobicity and charge on the cell viability and cell association of lanthanide metal complexes is presented. The terbium luminescent probes feature a macrocyclic polyaminocarboxylate ligand (DOTA) in which the hydrophobicity of the antenna and that of the carboxyamide pendant arms are independently varied. Three sensitizing antennas were investigated in terms of their function in vitro: 2-methoxyisophthalamide (IAM(OMe)), 2-hydroxyisophthalamide (IAM), and 6-methylphenanthridine (Phen). Of these complexes, Tb-DOTA-IAM exhibited the highest quantum yield, although the higher cell viability and more facile synthesis of the structurally related Tb-DOTA-IAM(OMe) platform renders it more attractive. Further modification of this latter core structure with carboxyamide arms featuring hydrophobic benzyl, hexyl, and trifluoro groups as well as hydrophilic amino acid based moieties generated a family of complexes that exhibit high cell viability (ED50 > 300 μM) regardless of the lipophilicity or the overall complex charge. Only the hexyl-substituted complex reduced cell viability to 60% in the presence of 100 μM complex. Additionally, cellular association was investigated by ICP-MS and fluorescence microscopy. Surprisingly, the hydrophobic moieties did not increase cell association in comparison to the hydrophilic amino acid derivatives. It is thus postulated that the hydrophilic nature of the 2-methoxyisophthalamide antenna (IAM(OMe)) disfavors the cellular association of these complexes. As such, responsive luminescent probes based on this scaffold would be appropriate for the detection of extracellular species. PMID:24901440

  12. Pyrolytic synthesis and luminescence of porous lanthanide Eu-MOF.

    PubMed

    Jin, Guangya; Liu, Zhijian; Sun, Hongfa; Tian, Zhiyong

    2016-02-01

    A lanthanide metal coordination polymer [Eu2(BDC)3(DMSO)(H2O)] was synthesized by the reaction of europium oxide with benzene-1,3-dicarboxylic acid (H2BDC) in a mixed solution of dimethyl sulfoxide (DMSO) and water under hydrothermal conditions. The crystal structure of Eu2(BDC)3(DMSO)(H2O) was characterized by X-ray diffraction (XRD). Thermo-gravimetric analysis of Eu2(BDC)3(DMSO)(H2O) indicated that coordinated DMSO and H2O molecules could be removed to create Eu2(BDC)3(DMSO)(H2O)-py with permanent microporosity, which was also verified by powder XRD (PXRD) and elemental analysis. Both Eu2(BDC)3(DMSO)(H2O) and Eu2(BDC)3(DMSO)(H2O)-py showed mainly Eu-based luminescence and had characteristic emissions in the range 550-700 nm. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Ultrasmall lanthanide-doped nanoparticles as multimodal platforms

    NASA Astrophysics Data System (ADS)

    Yust, Brian G.; Pedraza, Francisco J.; Sardar, Dhiraj K.

    2014-03-01

    Recently, there has been a great amount of interest in nanoparticles which are able to provide a platform with high contrast for multiple imaging modalities in order to advance the tools available to biomedical researchers and physicians. However, many nanoparticles do not have ideal properties to provide high contrast in different imaging modes. In order to address this, ultrasmall lanthanide doped oxide and fluoride nanoparticles with strong NIR to NIR upconversion fluorescence and a strong magnetic response for magnetic resonance imaging (MRI) have been developed. Specifically, these nanoparticles incorporate gadolinium, dysprosium, or a combination of both into the nano-crystalline host to achieve the magnetic properties. Thulium, erbium, and neodymium codopants provide the strong NIR absorption and emission lines that allow for deeper tissue imaging since near infrared light is not strongly absorbed or scattered by most tissues within this region. This also leads to better image quality and lower necessary excitation intensities. As a part of the one pot synthesis, these nanoparticles are coated with peg, pmao, or d-glucuronic acid to make them water soluble, biocompatible, and bioconjugable due to the available carboxyl or amine groups. Here, the synthesis, morphological characterization, magnetic response, NIR emission, and the quantum yield will be discussed. Cytotoxicity tested through cell viability at varying concentrations of nanoparticles in growth media will also be discussed.

  14. Thermodynamic properties of lanthanide metals in liquid bismuth

    NASA Astrophysics Data System (ADS)

    Yamana, Hajimu; Sheng, Jiawei; Souda, Naohiko; Moriyama, Hirotake

    2001-04-01

    Thermodynamic quantities of La, Gd, Tb, and Dy in liquid bismuth were experimentally determined by electromotive force (EMF) measurement using a cell consisting of molten alkaline chloride and liquid bismuth. Excess Gibbs energy changes and activity coefficients were determined at varying concentrations and temperatures. Through their temperature dependence, corresponding enthalpy changes and entropy changes were determined. The excess enthalpy changes of La, Gd, Tb, and Dy in liquid bismuth in a temperature range from 850 to 1100 K were evaluated to be, -221.54±2.31, -202.25±1.80, -199.83±0.55, and -193.80±0.99 kJ/mol, respectively. The systematic variation of excess enthalpy change of lanthanides along the 4f-series was discussed. As a result, it was found that the excess enthalpy changes of La, Gd, Tb, Dy, and Er are likely to depend linearly on the 2/3 power of their metallic volume.

  15. Highly Luminescent Lanthanide Complexes of 1 Hydroxy-2-pyridinones

    SciTech Connect

    University of California, Berkeley; Lawrence National Laboratory; Raymond, Kenneth; Moore, Evan G.; Xu, Jide; Jocher, Christoph J.; Castro-Rodriguez, Ingrid; Raymond, Kenneth N.

    2007-11-01

    The synthesis, X-ray structure, stability, and photophysical properties of several trivalent lanthanide complexes formed from two differing bis-bidentate ligands incorporating either alkyl or alkyl ether linkages and featuring the 1-hydroxy-2-pyridinone (1,2-HOPO) chelate group in complex with Eu(III), Sm(III) and Gd(III) are reported. The Eu(III) complexes are among some of the best examples, pairing highly efficient emission ({Phi}{sub tot}{sup Eu} {approx} 21.5%) with high stability (pEu {approx} 18.6) in aqueous solution, and are excellent candidates for use in biological assays. A comparison of the observed behavior of the complexes with differing backbone linkages shows remarkable similarities, both in stability and photophysical properties. Low temperature photophysical measurements for a Gd(III) complex were also used to gain insight into the electronic structure, and were found to agree with corresponding TD-DFT calculations for a model complex. A comparison of the high resolution Eu(III) emission spectra in solution and from single crystals also revealed a more symmetric coordination geometry about the metal ion in solution due to dynamic rotation of the observed solid state structure.

  16. Establishing the Structural Integrity of Core-Shell Nanoparticles against Elemental Migration using Luminescent Lanthanide Probes.

    PubMed

    Chen, Bing; Peng, Dengfeng; Chen, Xian; Qiao, Xvsheng; Fan, Xianping; Wang, Feng

    2015-10-19

    Core-shell structured nanoparticles are increasingly used to host luminescent lanthanide ions but the structural integrity of these nanoparticles still lacks sufficient understanding. Herein, we present a new approach to detect the diffusion of dopant ions in core-shell nanostructures using luminescent lanthanide probes whose emission profile and luminescence lifetime are sensitive to the chemical environment. We show that dopant ions in solution-synthesized core-shell nanoparticles are firmly confined in the designed locations. However, annealing at certain temperatures (greater than circa 350 °C) promotes diffusion of the dopant ions and leads to degradation of the integrity of the nanoparticles. These insights into core-shell nanostructures should enhance our ability to understand and use lanthanide-doped luminescent nanoparticles.

  17. White-Light-Emitting Lanthanide Metallogels with Tunable Luminescence and Reversible Stimuli-Responsive Properties.

    PubMed

    Chen, Pangkuan; Li, Qiaochu; Grindy, Scott; Holten-Andersen, Niels

    2015-09-16

    We have developed model light-emitting metallogels functionalized with lanthanide metal-ligand coordination complexes via a terpyridyl-end-capped four-arm poly(ethylene glycol) polymer. The optical properties of these highly luminescent polymer networks are readily modulated over a wide spectrum, including white-light emission, simply by tuning of the lanthanide metal ion stoichiometry. Furthermore, the dynamic nature of the Ln-N coordination bonding leads to a broad variety of reversible stimuli-responsive properties (mechano-, vapo-, thermo-, and chemochromism) of both sol-gel systems and solid thin films. The versatile functional performance combined with the ease of assembly suggests that this lanthanide coordination polymer design approach offers a robust pathway for future engineering of multi-stimuli-responsive polymer materials.

  18. Lanthanide-doped upconversion materials: emerging applications for photovoltaics and photocatalysis.

    PubMed

    Yang, Weifeng; Li, Xiyan; Chi, Dongzhi; Zhang, Hongjie; Liu, Xiaogang

    2014-12-05

    Photovoltaics and photocatalysis are two significant applications of clean and sustainable solar energy, albeit constrained by their inability to harvest the infrared spectrum of solar radiation. Lanthanide-doped materials are particularly promising in this regard, with tunable absorption in the infrared region and the ability to convert the long-wavelength excitation into shorter-wavelength light output through an upconversion process. In this review, we highlight the emerging applications of lanthanide-doped upconversion materials in the areas of photovoltaics and photocatalysis. We attempt to elucidate the fundamental physical principles that govern the energy conversion by the upconversion materials. In addition, we intend to draw attention to recent technologies in upconversion nanomaterials integrated with photovoltaic and photocatalytic devices. This review also provides a useful guide to materials synthesis and optoelectronic device fabrication based on lanthanide-doped upconversion materials.

  19. Effectiveness of a dopant in U-Zr metallic fuel to prevent lanthanide migration

    SciTech Connect

    Kim, Yeon Soo; Wieneck, T.; O'Hare, E.; Fortner, J.

    2013-07-01

    The advanced fast reactor concepts to achieve ultra-high burnup (about 50%) without requiring refueling by way of using metallic alloy fuel have gained interest. Fission product lanthanide accumulation at high burnup is substantial and its migration to cladding and reaction with cladding is a potential life-limiting phenomenon. As a means to solve this problem, adding an element that forms stable compounds with lanthanides to immobilize them has been proposed. The theoretical assessment shows that indium, thallium, gallium, and antimony are good candidates. Except for Sb, because these elements are low-melting temperature elements, liquid metal embrittlement of cladding is a concern if large sized agglomerates exist contacting the cladding. Alloy characterization of as-fabricated samples was performed to examine the effectiveness of the dopant addition method using optical microscopy and scanning electron microscopy. Although preliminary, the present results showed that indium is a better dopant to immobilize lanthanides.

  20. Realizing up-conversion fluorescence tuning in lanthanide-doped nanocrystals by femtosecond pulse shaping method

    PubMed Central

    Zhang, Shian; Yao, Yunhua; Shuwu, Xu; Liu, Pei; Ding, Jingxin; Jia, Tianqing; Qiu, Jianrong; Sun, Zhenrong

    2015-01-01

    The ability to tune color output of nanomaterials is very important for their applications in laser, optoelectronic device, color display and multiplexed biolabeling. Here we first propose a femtosecond pulse shaping technique to realize the up-conversion fluorescence tuning in lanthanide-doped nanocrystals dispersed in the glass. The multiple subpulse formation by a square phase modulation can create different excitation pathways for various up-conversion fluorescence generations. By properly controlling these excitation pathways, the multicolor up-conversion fluorescence can be finely tuned. This color tuning by the femtosecond pulse shaping technique is realized in single material by single-color laser field, which is highly desirable for further applications of the lanthanide-doped nanocrystals. This femtosecond pulse shaping technique opens an opportunity to tune the color output in the lanthanide-doped nanocrystals, which may bring a new revolution in the control of luminescence properties of nanomaterials. PMID:26290391

  1. Hybrid lanthanide nanoparticles with paramagnetic shell coated on upconversion fluorescent nanocrystals.

    PubMed

    Li, Zhengquan; Zhang, Yong; Shuter, Borys; Muhammad Idris, Niagara

    2009-10-20

    Nanoparticles comprising of fluorescent probes and MRI contrast agents are highly desirable for biomedical applications due to their ability to be detected at different modes, optically and magnetically. However, most fluorescent probes in such nanoparticles synthesized so far are down-conversion phosphors such as organic dyes and quantum dots, which are known to display many intrinsic limitations. Here, we report a core-shell hybrid lanthanide nanoparticle consisting of an upconverting lanthanide nanocrystal core and a paramagnetic lanthanide complex shell. These nanoparticles are uniform in size, stable in water, and show both high MR relaxivities and upconversion fluorescence, which may have the potential to serve as a versatile imaging tool for smart detection or diagnosis in future biomedical engineering.

  2. Poly (acrylic acid)-capped lanthanide-doped BaFCl nanocrystals: synthesis and optical properties.

    PubMed

    Ju, Qiang; Luo, Wenqin; Liu, Yongsheng; Zhu, Haomiao; Li, Renfu; Chen, Xueyuan

    2010-07-01

    Water-soluble lanthanide-doped BaFCl nanophosphors with the surface functionalized by a layer of poly (acrylic acid) are synthesized via a facile one-step solvothermal method. Intense long-lived luminescence is realized from visible to near-infrared (NIR) by doping with different lanthanide ions. The emission and excitation spectra of Eu(3+) indicate that the doped lanthanide ions occupy a site close to the surface of the nanoparticles. Strong NIR emissions of Nd(3+) and green luminescence of Tb(3+) using Ce(3+) as sensitizers are also achieved in BaFCl nanoparticles. The synthesized nanoparticles featuring long-lived luminescence in either visible or NIR regions may have potential applications as luminescent labels for biological applications.

  3. Survey of factors determining the circularly polarised luminescence of macrocyclic lanthanide complexes in solution.

    PubMed

    Bruce, James I; Parker, David; Lopinski, Stefan; Peacock, Robert D

    2002-07-01

    The development of emissive lanthanide complexes as structural or reactive probes to signal changes in their local chiral or ionic environment has been inhibited by the lack of understanding of correlating structural and electronic spectral information. The definition of relatively rigid enantiopure macrocyclic lanthanide complexes, whose inter- and intramolecular exchange dynamics have been defined, offers scope for remedying this situation. Chiral axially symmetric lanthanide complexes in solution give rise to large emission dissymmetry values (g(em)) in CPL spectra. The sign and magnitude of g(em) are determined by the degree of twist about the principal axis, which is predicted to be a maximum at +/-22.5 degrees, and by the site symmetry and local ligand field. In particular, the polarisability of the ligand donor atoms, especially for any axial donor, is very important. Examples of each case are discussed for structurally related cationic Eu(III) complexes.

  4. Isotope separation

    DOEpatents

    Bartlett, Rodney J.; Morrey, John R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated.

  5. ISOTOPE SEPARATORS

    DOEpatents

    Bacon, C.G.

    1958-08-26

    An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.

  6. Separator sub

    SciTech Connect

    Hayatdavoudi, A.

    1984-10-09

    Apparatus and methods are disclosed for drilling a well. A separator sub is used to separate a stream of drilling mud into a less dense first portion and more dense second portion. The less dense first portion of the stream of drilling mud is directed downward to a drill bit so that the drilling mud adjacent the drill bit has a density less than an initial density of the stream of drilling mud. The more dense second portion of the stream of drilling mud is ejected into a well annulus with an upward component of velocity and thereby reduces a hydrostatic drilling mud pressure adjacent the drill bit.

  7. Isotopic separation

    SciTech Connect

    Chen, C.

    1981-03-10

    Method and apparatus for separating isotopes in an isotopic mixture of atoms or molecules by increasing the mass differential among isotopic species. The mixture containing a particular isotope is selectively irradiated so as to selectively excite the isotope. This preferentially excited species is then reacted rapidly with an additional preselected radiation, an electron or another chemical species so as to form a product containing the specific isotope, but having a mass different than the original species initially containing the particular isotope. The product and the remaining balance of the mixture is then caused to flow through a device which separates the product from the mixture based upon the increased mass differential.

  8. Inductively coupled plasma mass spectrometry in comparison with neutron activation and ion chromatography with UV/VIS detection for the determination of lanthanides in plant materials.

    PubMed

    Bulska, Ewa; Danko, Bożena; Dybczyński, Rajmund S; Krata, Agnieszka; Kulisa, Krzysztof; Samczyński, Zbigniew; Wojciechowski, Marcin

    2012-08-15

    Analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for determination of lanthanides in plant materials was investigated and compared with neutron activation analysis (NAA) as well as ion chromatography (IC) with UV-VIS detection. Two sample preparation protocols were tested: (i) microwave assisted digestion by concentrated nitric acid; (ii) microwave digestion involving silica and fluoride removal, followed by the selective and quantitative lanthanides group separation from the plant matrix. Several Certified Reference Materials (CRM) of plant origin were used for the evaluation of the accuracy of the applied analytical procedures. The consistency of results, obtained by various methods, enabled to establish the tentative recommended values (TRV) for several missing elements in one of CRMs. The ICP-MS, due to its very high sensitivity, has the potential to contribute to this aim. The discrepancy of the results obtained by various methods was discussed in a view of possible matrix effects related to the composition of investigated materials. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Solid-state and solution-state coordination chemistry of lanthanide(III) complexes with (pyrazol-1-yl)acetic acid.

    PubMed

    Chen, Xiao-Yan; Goff, George S; Scott, Brian L; Janicke, Michael T; Runde, Wolfgang

    2013-03-18

    As a precursor of carboxyl-functionalized task-specific ionic liquids (TSILs) for f-element separations, (pyrazol-1-yl)acetic acid (L) can be deprotonated as a functionalized pyrazolate anion to coordinate with hard metal cations. However, the coordination chemistry of L with f-elements remains unexplored. We reacted L with lanthanides in aqueous solution at pH = 5 and synthesized four lanthanide complexes of general formula [Ln(L)3(H2O)2]·nH2O (1, Ln = La, n = 2; 2, Ln = Ce, n = 2; 3, Ln = Pr, n = 2; 4, Ln = Nd, n = 1). All complexes were characterized by single crystal X-ray diffraction analysis revealing one-dimensional chain formations. Two distinct crystallographic structures are governed by the different coordination modes of carboxylate groups in L: terminal bidentate and bridging tridentate (1-3); terminal bidentate, bridging bidentate, and tridentate coordination in 4. Comparison of the solid state UV-vis-NIR diffuse reflectance spectra with solution state UV-vis-NIR spectra suggests a different species in solution and solid state. The different coordination in solid state and solution was verified by distinctive (13)C NMR signals of the carboxylate groups in the solid state NMR.

  10. Multi-modal imaging and cancer therapy using lanthanide oxide nanoparticles: current status and perspectives.

    PubMed

    Park, J Y; Chang, Y; Lee, G H

    2015-01-01

    Biomedical imaging is an essential tool for diagnosis and therapy of diseases such as cancers. It is likely true that medicine has developed with biomedical imaging methods. Sensitivity and resolution of biomedical imaging methods can be improved with imaging agents. Furthermore, it will be ideal if imaging agents could be also used as therapeutic agents. Therefore, one dose can be used for both diagnosis and therapy of diseases (i.e., theragnosis). This will simplify medical treatment of diseases, and will be also a benefit to patients. Mixed (Ln(1x)Ln(2y)O3, x + y = 2) or unmixed (Ln2O3) lanthanide (Ln) oxide nanoparticles (Ln = Eu, Gd, Dy, Tb, Ho, Er) are potential multi-modal imaging and cancer therapeutic agents. The lanthanides have a variety of magnetic and optical properties, useful for magnetic resonance imaging (MRI) and fluorescent imaging (FI), respectively. They also highly attenuate X-ray beam, useful for X-ray computed tomography (CT). In addition gadolinium-157 ((157)Gd) has the highest thermal neutron capture cross section among stable radionuclides, useful for gadolinium neutron capture therapy (GdNCT). Therefore, mixed or unmixed lanthanide oxide nanoparticles can be used for multi-modal imaging methods (i.e., MRI-FI, MRI-CT, CT-FI, and MRICT- FI) and cancer therapy (i.e., GdNCT). Since mixed or unmixed lanthanide oxide nanoparticles are single-phase and solid-state, they can be easily synthesized, and are compact and robust, which will be beneficial to biomedical applications. In this review physical properties of the lanthanides, synthesis, characterizations, multi-modal imagings, and cancer therapy of mixed and unmixed lanthanide oxide nanoparticles are discussed.

  11. Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide

    SciTech Connect

    Di Bernardo, Plinio; Zanonato, Pier Luigi; Melchior, Andrea; Portanova, Roberto; Tolazzi, Marilena; Choppin, Gregory R.; Wang, Zheming

    2008-01-01

    The thermodynamic parameters of complexation of Ln(III) cations with tris(2-aminoethyl)amine (tren) and tetraethylenepentamine (tetren) were determined in dimethyl sulfoxide (DMSO) by potentiometry and calorimetry. The excitation and emission spectra and luminescence decay constants of Eu3+ and Tb3+ complexed by tren and tetren, as well as those of the same lanthanides(III) complexed with diethylenetriamine (dien) and triethylenetetramine (trien), were also obtained in the same solvent. The combination of thermodynamic and spectroscopic data showed that, in the 1:1 complexes, all nitrogens of the ligands bound to the lanthanides except in the case of tren, in which only pendant N bound. For the larger ligands (trien, tren, tetren) in the higher complexes (ML2), there was less complete binding by available donors, presumably due to steric crowding. FT-IR studies were carried out in an acetonitrile/DMSO mixture, suitably chosen in order to follow the changes in the primary solvation sphere of lanthanide(III) due to complexation of amine ligands. Results show that the mean number of molecules of DMSO removed from the inner coordination sphere of lanthanides(III) is lower than ligand denticity and that the coordination number of the metal ions increases with amine complexation from ~8 to ~10. Independently of the number and structure of the amines, linear trends, similar for all lanthanides, were obtained by plotting the values of ΔGj°, ΔHj° and TΔSj° for the complexation of ethylenediamine (en), dien, trien, tren and tetren as a function of the number of amine metal-coordinated nitrogen atoms. The main factors on which the thermodynamic functions of lanthanide(III) complexation reactions in DMSO depend are discussed.

  12. Plasma separation

    NASA Technical Reports Server (NTRS)

    Steurer, Wolfgang

    1992-01-01

    This process employs a thermal plasma for the separation and production of oxygen and metals. It is a continuous process that requires no consumables and relies entirely on space resources. The almost complete absence of waste renders it relatively clean. It can be turned on or off without any undesirable side effects or residues. The prime disadvantage is its high power consumption.

  13. SEPARATION PROCESS

    DOEpatents

    Stoughton, R.W.

    1961-10-24

    A process for separating tetravalent plutonium from aqueous solutions and from niobium and zirconium by precipitation on lanthanum oxalate is described. The oxalate ions of the precipitate may be decomposed by heating in the presence of an oxidizing agent, forming a plutonium compound readily soluble in acid. (AEC)

  14. Lanthanide(III)/pyrimidine-4,6-dicarboxylate/oxalate extended frameworks: a detailed study based on the lanthanide contraction and temperature effects.

    PubMed

    Cepeda, Javier; Balda, Rolindes; Beobide, Garikoitz; Castillo, Oscar; Fernández, Joaquín; Luque, Antonio; Pérez-Yáñez, Sonia; Román, Pascual; Vallejo-Sánchez, Daniel

    2011-09-05

    Detailed structural, magnetic, and luminescence studies of six different crystalline phases obtained in the lanthanide/pyrimidine-4,6-dicarboxylate/oxalate system have been afforded: {[Ln(μ-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·3H(2)O}(n) (1-Ln), {[Ln(μ-pmdc)(μ-ox)(0.5)(H(2)O)(3)]·2H(2)O}(n) (2-Ln), {[Ln(μ(3)-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·~2.33H(2)O}(n) (3-Ln), {[Ln(2)(μ(3)-pmdc)(μ(4)-pmdc)(μ-ox)(H(2)O)(3)]·5H(2)O}(n) (4-Ln), {[Ln(μ(3)-pmdc)(μ-ox)(0.5)(H(2)O)(2)]·H(2)O}(n) (5-Ln), and [Ln(pmdc)(1.5)(H(2)O)(2.5)] (6-Ln). The slow generation of the oxalate (ox) anion, obtained from the in situ partial hydrothermal decomposition of the pyrimidine-4,6-dicarboxylate (pmdc) ligand, allows us to obtain good shaped single crystals, while direct addition of potassium oxalate provides the same compounds but as polycrystalline samples. The crystal structures of all compounds are based on the double chelation established by the pmdc and ox ligands to provide distorted 2D honeycomb layers that, in some cases, are fused together, leading to 3D systems, by replacing some of the coordinated water molecules that complete the coordination sphere of the lanthanide by uncoordinated carboxylate oxygen atoms of the pmdc. The presence of channels occupied by crystallization water molecules is also a common feature with the exception of compounds 5-Ln. It is worth noting that compounds 3-Ln present a commensurate crystal structure related to the partial occupancy of the crystallization water molecules placed within the channels. Topological analyses have been carried out, showing a previously nonregistered topology for compounds 4-Ln, named as jcr1. The crystal structures are strongly dependent on the lanthanide ion size and the temperature employed during the hydrothermal synthesis. The lanthanide contraction favors crystal structures involving sterically less hindranced coordination environments for the final members of the lanthanide series. Additionally, reinforcement of the

  15. Lanthanide mixed ligand chelates for DNA profiling and latent fingerprint detection

    NASA Astrophysics Data System (ADS)

    Menzel, E. R.; Allred, Clay

    1997-02-01

    It is our aim to develop a universally applicable latent fingerprint detection method using lanthanide (rare-earth) complexes as a source of luminescence. Use of these lanthanide complexes offers advantages on several fronts, including benefits from large Stokes shifts, long luminescence lifetimes, narrow emissions, ability of sequential assembly of complexes, and chemical variability of the ligands. Proper exploitation of these advantages would lead to a latent fingerprint detection method superior to any currently available. These same characteristics also lend themselves to many of the problems associated with DNA processing in the forensic science context.

  16. Nature of chiral-induced equilibrium shifts in racemic labile lanthanide complexes

    SciTech Connect

    Wu, Shuguang; Hilmes, G.L.; Riehl, J.P. )

    1989-03-23

    An analysis of the chiral-induced equilibrium shift of racemic D{sub 3} tris-terdendate complexes of lanthanides with 2,6-pyridinedicarboxylate is presented in terms of the associated/dissociated models of Schipper. Results are presented which indicate that the so-called Pfeiffer effect in these lanthanide complexes is best described by the dissociated model, as was determined for similar labile transition-metal complexes. The nature of the chiral discriminatory interaction is shown to be largely electrostatic by measurements in mixed solvents of varying dielectric constant.

  17. Luminescent trimethoprim-polyaminocarboxylate lanthanide complex conjugates for selective protein labeling and time-resolved bioassays

    PubMed Central

    Reddy, D. Rajasekhar; Pedró Rosa, Laura E.; Miller, Lawrence W.

    2011-01-01

    Labeling proteins with long-lifetime emitting lanthanide (III) chelate reporters enables sensitive, time-resolved luminescence bioaffinity assays. Heterodimers of trimethoprim (TMP) covalently linked to various cs124-sensitized, polyaminocarboxylate chelates stably retain lanthanide ions and exhibit quantum yields of europium emission up to 20% in water. A time-resolved, luminescence resonance energy transfer (LRET) assay showed that TMP-polyaminocarboxylates bind to Escherichia coli dihydrofolate reductase (eDHFR) fusion proteins with nanomolar affinity in purified solutions and in bacterial lysates. The ability to selectively impart terbium or europium luminescence to fusion proteins in complex physiological mixtures bypasses the need for specific antibodies and simplifies sample preparation. PMID:21619068

  18. Synthesis and characterisation of bis-cyclen based dinuclear lanthanide complexes.

    PubMed

    Gunnlaugsson, Thorfinnur; Harte, Andrew J

    2006-04-21

    The design and synthesis of several bis-macrocyclic cyclen (1,4,7,10-tetraazacyclododecane) ligands and their corresponding lanthanum or europium complexes is described; these dinuclear lanthanide systems were made by connecting two macrocyclic cyclen moieties through a rigid, covalent, p-xylylenediamide bridge or a flexible aliphatic hexane bridge. These ligands were subsequently functionalised with six acetamide pendant arms (CONR1R2: R1 = R2 = H or CH3, or R1 = H, R2 = CH3). The corresponding lanthanide bis-complexes were then formed by reaction with La(III) and Eu(III) triflates, yielding overall cationic (+VI charged) complexes.

  19. Syntheses and structural analyses of four isostructural lanthanide dimers derived from thiourea-based carboxylato ligands

    NASA Astrophysics Data System (ADS)

    Wang, Wenyue; Guo, Mengwei; Guo, Xiaofang; Lu, Huijie; Li, Gang

    2011-05-01

    From the reactions of 2-(3-benzoylthioureido)ethanoic acid (H 3L) and 1,10-phenanthroline (phen) with lanthanide ions, four crystalline isostructural homodinuclear complexes [Ln 2( μ2- η2-H 2L) 2( μ2-H 2L) 2(phen) 2(NO 3) 2] 2CH 3OH (Ln = Eu ( 1), Sm ( 2), Tb ( 3) and Dy ( 4)) have been produced. In these complexes, two neighboring lanthanide ions are connected by carboxylate groups in μ2- η2- or μ2-bridging modes. The four complexes present similar themostabilities. Their solid-state fluorescence properties have been investigated at room temperature.

  20. From Antenna to Assay: Lessons Learned in Lanthanide Luminescence

    SciTech Connect

    Moore, Evan; Samuel, Amanda; Raymond, Kenneth

    2008-09-25

    Ligand-sensitized luminescent lanthanide(III) complexes are of considerable current interest due to their unique photophysical properties (micro- to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts), which make them well suited to serve as labels in fluorescence-based bioassays. The long-lived Ln(III) emission can be temporally resolved from scattered light and background fluorescence, resulting in vastly enhanced measurement sensitivity. One of the challenges in this field is the design of sensitizing ligands that provide highly emissive Ln(III) complexes that also possess sufficient stability and aqueous solubility required for practical applications. In this account we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in Homogeneous Time Resolved Fluorescence (HTRF) technology, the requirements and current use of which will be briefly discussed. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms as well as using multi-chromophore chelates to increase molar absorptivity compared to earlier examples that utilize a single pendant antenna chromophore. We have found that ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to ca. 60%. Solution thermodynamic studies have indicated that these complexes are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM-chromophore, in conjunction with time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of

  1. Gas separating

    DOEpatents

    Gollan, Arye Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  2. Gas separating

    DOEpatents

    Gollan, Arye

    1988-01-01

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing.

  3. Dust separator

    SciTech Connect

    Borow, H.

    1987-01-27

    This patent describes a gas filter apparatus for separating solids from a gas stream comprising a housing having a top, base, and side walls defining a chamber, a partition wall extending across the chamber and separating the chamber into an upper compartment and a lower compartment. A gas inlet conveyor tube in the chamber passes downwardly of the partition and into the lower compartment, the portion of the conveyor tube passing through the upper compartment being impervious and the portion of the conveyor tube extending downwardly into the lower compartment being provided with exit means including exit apertures at least in the area of the conveyor tube adjacent the partition wall. The partition wall is provided with openings surrounding the conveyor tube and communicates the lower compartment with the upper compartment. A filter means in the form of filter tubes covers each opening in the partition wall and extends downwardly in the lower compartment and parallel to the conveyor tube, at least one gas outlet communicating with the upper compartment. A suction means is associated with the gas outlet to provide a reduced pressure within the chamber. A discharge means at the base of the housing is associated with the lower compartment for discharging solid matter separated from the gas stream. The solid laden gas is conveyed into the lower compartment downwardly by the conveying tube and the gas of the stream is drawn from the conveyor tube immediately past the partition, through the surrounding filter tubes in order to prevent the formation of counter gas flows to the gravity discharge of the solids being separated from the gas stream.

  4. Theoretical, spectral characterization and antineoplastic activity of new lanthanide complexes.

    PubMed

    Kostova, Irena; Trendafilova, Natasha; Momekov, Georgi

    2008-01-01

    The new cerium(III), lanthanum(III) and neodymium(III) complexes were synthesized in view of their application as cytotoxic agents. The complexes were characterized by different physicochemical methods: elemental analysis, mass spectrometry, (1)H NMR, (13)C NMR and IR spectroscopy. The spectra of the complexes were interpreted on the basis of comparison with the spectrum of the free ligand. The vibrational analysis showed that in the complexes the ligand coordinates to the metal ion through both deprotonated hydroxyl groups, however participation of the carbonyl groups in the coordination to the metal ion was also suggested. Geometry optimization of 3,3'-(ortho-pyridinomethylene)di-[4-hydroxycoumarin] H(2)(o-pyhc), (H(2)L) and its dianionic forms, o-pyhc(2-), (L(2-)) were carried out at AM1 and PM3 levels as well as using density functional theory with Becke's three parameter hybrid method and correlation functional of Lee, Yang and Parr (B3LYP) with 6-31G(d) basis set. The optimized geometries of the neutral ligand isomers were stabilized by two asymmetrical intramolecular O-H...O hydrogen bonds (HBs). The conformational search showed four low-energy dianionic species (o-pyhc(2-)) on the potential energy surface. Molecular electrostatic potential calculations showed that the most preferred sites for electrophilic attack in H(2)(o-pyhc) and o-pyhc(2-) are the carbonyl oxygen atoms. The evaluation of the cytotoxic activity of the novel lantanide complexes on HL-60 myeloid cells revealed, that they are potent cytotoxic agents. The cerium complex was found to exhibit superior activity in comparison to the lanthanum, and neodymium species, the latter being the least active. Taken together our data give us a reason to conclude that the newly synthesized lanthanide complexes should be a subset to further more detailed pharmacological and toxicological evaluation.

  5. Luminescence of Lanthanide-Dimethyl Sulfoxide Compound Solutions

    SciTech Connect

    Yao, Mingzhen; Li, Yuebin; Hossu, Marius; Joly, Alan G.; Liu, Zhongxin; Liu, Zuli; Chen, Wei

    2011-08-04

    Dimethyl sulfoxide (DMSO) has the ability to penetrate living tissues without causing significant damage. Of foremost importance to our understanding of the possible functions of DMSO in biological systems is its ability to replace some of the water molecules associated with the cellular constituents, or to affect the structure of the omnipresent water. Luminescence probes have been widely used for biological studies such as labeling, imaging and detection. Luminescence probes formed in DMSO may find new applications. Here, luminescence compounds formed by refluxing lanthanide nitrates of Ce, La, Tb, Yb, Nd, Gd and Eu in DMSO are reported and their luminescence properties investigated. Based on their luminescence spectral properties, the compounds can be classified into four classes. For compounds-I with Yb, Ce, and La, the excitation and emission spectra are very broad and their excitation or emission peaks are shifted to longer wavelengths when the monitored emission or excitation wavelength is longer . For compounds-II with Gd and Nd, both the excitation and emission spectra are very broad but their emission wavelengths change little at different excitation wavelengths. For Tb-DMSO as compound-III, both the typical emissions from the f - f transitions of Tb3+ and a broad emission at 445 nm are observed. At low temperatures of reaction, the f - f emissions are dominant, while at high temperatures such as 180 oC of reaction, the broad emission at 445 nm is dominant. For compound-IV with Eu-DMSO compounds, the dominant emissions are from the f - f transitions of Eu3+ and only a weak broad emission is observed, which is likely from the d - f transition of Eu2+ rather than from the metal to ligand charge transfer states.

  6. Efficient electroluminescence from new lanthanide (Eu3+, Sm3+) complexes.

    PubMed

    Yu, Jiangbo; Zhou, Liang; Zhang, Hongjie; Zheng, Youxuan; Li, Huanrong; Deng, Ruiping; Peng, Zeping; Li, Zhefeng

    2005-03-07

    The syntheses, structures, and electroluminescent properties are described for two new lanthanide complexes Ln(HFNH)3phen [HFNH = 4,4,5,5,6,6,6-heptafluoro-1-(2-naphthyl)hexane-1,3-dione; phen = 1,10-phenanthroline; Ln = Eu3+ (1), Sm3+ (2)]. Both complexes exhibit bright photoluminescence at room temperature (RT) due to the characteristic emission of Eu3+ and Sm3+ ion. Several devices using the two complexes as emitters were fabricated. The performances of these devices are among the best reported for devices using europium complex and samarium complex as emitters. The device based on 1 with the structure ITO/TPD (50 nm)/1:CBP (10%, 40 nm)/BCP (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (200 nm) exhibits the maximum brightness of 957 cd/m2, current efficiency of 4.14 cd/A, and power efficiency of 2.28 lm/W with a pure red Eu3+ ion emission. Especially, at the high brightness of 200 cd/m2, the device of 1 still has a high current efficiency of 2.15 cd/A. The device of 2 with a three-layer structure of ITO/TPD (50 nm)/2 (50 nm)/BCP (20 nm)/LiF (1 nm)/Al (200 nm) gives the maximum brightness of 42 cd/m2, current efficiency of 0.18 cd/A. By the comparison of the electroluminescent properties of devices based on Eu(TTA3phen (TTA = 2-thenoyltrifluoroacteonate) and 1, we conclude that the polyfluoration on the alkyl group of the ligand and the introduction of the long conjugate naphthyl group into the ligand improve the efficiency of 1-doped devices, especially at high current densities.

  7. Separation system

    DOEpatents

    Rubin, Leslie S.

    1986-01-01

    A separation system for dewatering radioactive waste materials includes a disposal container, drive structure for receiving the container, and means for releasably attaching the container to the drive structure. Separation structure disposed in the container adjacent the inner surface of the side wall structure retains solids while allowing passage of liquids. Inlet port structure in the container top wall is normally closed by first valve structure that is centrifugally actuated to open the inlet port and discharge port structure at the container periphery receives liquid that passes through the separation structure and is normally closed by second valve structure that is centrifugally actuated to open the discharge ports. The container also includes coupling structure for releasable engagement with the centrifugal drive structure. Centrifugal force produced when the container is driven in rotation by the drive structure opens the valve structures, and radioactive waste material introduced into the container through the open inlet port is dewatered, and the waste is compacted. The ports are automatically closed by the valves when the container drum is not subjected to centrifugal force such that containment effectiveness is enhanced and exposure of personnel to radioactive materials is minimized.

  8. Component separations.

    PubMed

    Heller, Lior; McNichols, Colton H; Ramirez, Oscar M

    2012-02-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-cm wide defects in the midline area. Since its original description, components separation technique underwent multiple modifications with the ultimate goal to decrease the morbidity associated with the traditional procedure. The extensive subcutaneous lateral dissection had been associated with ischemia of the midline skin edges, wound dehiscence, infection, and seroma. Although the current trend is to proceed with minimally invasive component separation and to reinforce the fascia with mesh, the basic principles of the techniques as described by Ramirez et al in 1990 have not changed over the years. Surgeons who deal with the management of abdominal wall defects are highly encouraged to include this technique in their collection of treatment options.

  9. First examples of ternary lanthanide 5-aminoisophthalate complexes: Hydrothermal syntheses and structures of lanthanide coordination polymers with 5-aminoisophthalate and oxalate

    NASA Astrophysics Data System (ADS)

    Liu, Chong-Bo; Wen, Hui-Liang; Tan, Sheng-Shui; Yi, Xiu-Guang

    2008-05-01

    Two new lanthanide coordination polymers with mixed-carboxylates, [Ln(OX)(HAPA)(H 2O)] n[Ln = Eu ( 1), Ho ( 2); H 2APA = 5-aminoisophthalic acid; OX = oxalate] were obtained by hydrothermal reactions, and characterized by single crystal X-ray diffraction, elemental analysis and IR spectra. Complexes 1 and 2 are both 3-D supramolecular structure, in which lanthanide ions are bridged by oxalate and 5-aminoisophthalate ligands forming 2-D metal-organic framework, and 2-D networks are further architectured to form 3-D supramolecular structures by hydrogen bonds. The two carboxylate groups of H 2APA ligand are all deprotonated and exhibit chelating and bridging bidentate coordination modes, respectively, and the amino group in HAPA presents - NH3+ in the titled complexes. The thermogravimetric analysis was carried out to examine the thermal stability of the titled complexes. And the photoluminescence property of 1 was investigated.

  10. Evolution of Luminescent Supramolecular Lanthanide M2nL3n Complexes from Helicates and Tetrahedra to Cubes.

    PubMed

    Li, Xiao-Zhen; Zhou, Li-Peng; Yan, Liang-Liang; Yuan, Da-Qiang; Lin, Chen-Sheng; Sun, Qing-Fu

    2017-06-21

    Lanthanide-containing molecules have many potential applications in material science and biology, that is, luminescent sensing/labling, MRI, magnetic refrigeration, and catalysis among others. Coordination-directed self-assembly has shown great power in the designed construction of well-defined supramolecular systems. However, application of this strategy to the lanthanide edifices is challenging due to the complicated and greatly labile coordination numbers and geometries for lanthanides. Here we demonstrate a sensitive structural switching phenomenon during the stereocontrolled self-assembly of a group of Ln2nL3n (Ln for lanthanides, L for organic ligands, and n = 1, 2, 4) compounds. Systematic variation of the offset distances between the two chelating arms on the bis(tridentate) ligands dictated the final outcomes of the lanthanide assembly, ranging from Ln2L3 helicates and Ln4L6 tetrahedra to Ln8L12 cubes. Remarkably, the borderline case leading to the formation of a mixture of the helicate and the tetrahedron was clearly revealed. Moreover, the concentration-dependent self-assembly of an unprecedented cubic Ln8L12 complex was also confirmed. The luminescent lanthanide cubes can serve as excellent turn-off sensors in explosives detection, featuring high selectivity and sensitivity toward picric acid. All complexes were confirmed by NMR, ESI-TOF-MS, and single crystal X-ray diffraction studies. Our results provide valuable design principles for the coordination self-assembly of multinuclear functional lanthanide architectures.

  11. Discrete site surface complexation constants for lanthanide adsorption to bacteria as determined by experiments and linear free energy relationships.

    PubMed

    Ngwenya, Bryne T; Magennis, Marisa; Olive, Valerie; Mosselmans, J Fred W; Ellam, Robert M

    2010-01-15

    Bacteria are abundant in many natural and engineered environments where they are thought to exert important controls on the cycling, mobility, bioavailability, and toxicity of metal contaminants. In order to probe their role in moderating the behavior of lanthanides, pH-dependent adsorption edges of 13 individual lanthanides and yttrium to the Gram-negative bacterium Pantoea agglomerans were used to generate discrete site surface complexation constants. The calculated surface complexation constants were compared with stability constants estimated using linear free energy relationships based on a number of hydroxyl-containing ligands. The experimental data suggests that lanthanide adsorption edges below pH 6.5 are consistent with adsorption to phosphate groups for the light and some of the middle lanthanides (La to Gd), whereas some of the middle and heavy lanthanides appear to favor carboxyl co-ordination (Tb to Yb), although exceptions occur in each grouping. The experimentally derived surface complexation constants for carboxyl coordination were of similar magnitude to stability constants estimated from linear free energy correlations using fulvic acid stability constants. The implication is that the adsorption of lanthanides to bacterial surfaces could be modeled reasonably well using lanthanide stability constants for natural organic matter, except perhaps at low pH where phosphate binding dominates.

  12. Energy transfer in coumarin-sensitised lanthanide luminescence: investigation of the nature of the sensitiser and its distance to the lanthanide ion.

    PubMed

    Andres, Julien; Chauvin, Anne-Sophie

    2013-10-14

    A series of lanthanide complexes [Ln(dpxCy)3](3-) have been synthesised. The ligands are composed of a coordinating dipicolinic acid backbone decorated with a polyoxyethylene arm fitted with a coumarin moiety at its extremity. The nature of the coumarin as well as the length of the linker have been varied. Upon excitation at 320 nm, the coumarin exclusively acts as an antenna while the dipicolinic acid core is not excited. Upon excitation below 300 nm, both parts are excited. With europium as a metal centre, the relaxation of the europium ion (intrinsic quantum yield Φ(Eu)(Eu) and radiative lifetime τr) is constant for all the studied ligands. Therefore, the observed differences in overall quantum yield (Φ(Eu)(L)) in such systems come exclusively from the variation of the terminal coumarin. The overall quantum yields of the studied complexes are low (Φ(Eu)(L) < 2% in aqueous solution). In order to rationalise the mechanism of the energy transfer and to improve the sensitisation efficiency (ηsens), the distance between the coumarin sensitiser and the lanthanide centre was explored in solution and compared to the solid state. In the solid state, a dramatic effect was confirmed, with an improvement of 80% in the quantum yield Φ(Eu)(L) for short linkers ((-CH2CH2O-)n with n = 1 compared to n = 3). By monitoring the lifetime decay of the excited state of the lanthanide cation with nanosecond vs. microsecond time-resolved spectroscopy at low temperature, the sensitisation of the lanthanide ions by coumarin derivatives was demonstrated to mainly occur through the singlet excited state of the coumarin and not via the usual triplet pathway. No evidence of a different behaviour at room temperature was found by transient triplet-triplet absorption spectroscopy.

  13. APPLICATIONS OF SOLVENT EXTRACTION IN THE HIGH-YIELD MULTI-PROCESS REDUCTION/SEPARATION OF Eu FROM EXCESS Sm

    SciTech Connect

    Schwantes, Jon M.; Sudowe, Ralf; Nitsche, Heino; Hoffman, Darleane C.

    2008-05-15

    A novel multi-process method for separating Eu from neighbouring lanthanides (Ln) has been developed that chemically reduces Eu(III) to Eu(II) prior to solvent extraction of Ln(III) with thenoyltrifluoroacetone in benzene. This method is capable of achieving higher purities (>99%) and separation yields than previously published multi-process methods that stabilize and separate the reduced Eu(II) as a sulphate solid and is ideal for enriching materials of high-value. Results from a variety of combinations of a chemical or electrochemical reduction process preceding a separation process using either ion exchange chromatography, reversed phase chromatography, or solvent extraction are discussed.

  14. Sigma Team for Minor Actinide Separation: PNNL FY 2010 Status Report

    SciTech Connect

    Lumetta, Gregg J.; Sinkov, Sergey I.; Neiner, Doinita; Levitskaia, Tatiana G.; Braley, Jenifer C.; Carter, Jennifer C.; Warner, Marvin G.; Pittman, Jonathan W.; Rapko, Brian M.

    2010-08-24

    Work conducted at Pacific Northwest National Laboratory (PNNL) in FY 2010 addressed two lines of inquiry. The two hypotheses put forth were: 1. The extractants from the TRUEX( ) process (CMPO)( ) and from the TALSPEAK( ) process (HDEHP)( ) can be combined into a single process solvent to separate 1) the lanthanides and actinides from acidic high-level waste and 2) the actinides from the lanthanides in a single solvent extraction process. (Note: This combined process will hereafter be referred to as the TRUSPEAK process.) A series of empirical measurements performed (both at PNNL and Argonne National Laboratory) in FY 2009 supported this hypothesis, but also indicated some nuances to the chemistry. Lanthanide/americium separation factors of 12 and higher were obtained with a prototypic TRUSPEAK solvent when extracting the lanthanides from a citrate-buffered DTPA( ) solution. Although the observed separation factors are sufficiently high to design an actinide/lanthanide separation process, a better understanding of the chemistry is expected to lead to improved solvent formulations and improved process performance. Work in FY 2010 focused on understanding the synergistic extraction behavior observed for Nd(III) and Am(III) when extracted into mixtures of CMPO and HDEHP. The interaction between CMPO and HDEHP in dodecane was investigated by 31P NMR spectroscopy, and an adduct of the type CMPO•HDEHP was found to form. The formation of this adduct will reduce the effective extractant concentrations and must be taken into account when modeling metal ion extraction data in this system. Studies were also initiated to determine the Pitzer parameters for Nd(III) in lactate media. 2. Higher oxidation states (e.g., +5 and +6) of Am can be stabilized in solution by complexation with uranophilic ligands, and this chemistry can be exploited to separate Am from Cm. To test this hypothesis, the previously reported stereognostic uranophilic ligands NPB( ) and ETAC(e) were

  15. Realgar as a building block for lanthanide clusters: encapsulation of a copper cluster by a lanthanide cluster.

    PubMed

    Arleth, Nicholas; Bestgen, Sebastian; Gamer, Michael T; Roesky, Peter W

    2014-10-08

    The reactions of the divalent lanthanide metallocenes [Cp*2Ln(thf)2] (Cp* = η(5)-C5Me5; Ln = Sm, Yb) with realgar (As4S4) gave the open cage tetrametallic complex [(Cp*2Sm)(Cp*Sm)3AsS3(Cp*AsS2)2(thf)3] (1) or the trimetallic cage compound [(Cp*Yb)3As2S4(Cp*AsS2)(thf)2] (2), respectively, by reductive cleavage of the inorganic cage. As result of a Cp* transfer, the novel Cp*AsS2(2-) anion is formed. Moreover, the As2S4(4-) anion, which is bound in 2, is observed for the first time in coordination chemistry. Closed cage compounds are formed by either using bulkier ligands or a different As/S cage. The reaction of [Cp‴2Sm] (Cp‴ = (1,2,4-(t-Bu)3C5H2)) with As4S4 and the reaction of [Cp*2Yb(thf)2] with dimorphite (As4S3) gave the closed 11-vertex cage clusters [(Cp‴Sm)3(AsS3)2] (3) and [(Cp*Yb)3(AsS3)2] (4), respectively. The reaction of 3 with [CuMes] resulted in the formation of the Sm/S/Cu cluster [(Cp‴Sm(thf))4Cu4S6] (5), in which the Sm atoms encapsulate a classical Cu4S6(8-) cluster core. This is the first transition metal chalcogenide cluster encapsulated by f-elements. Alternatively, the endohedral cluster can thus be described as [Cu4@{(Cp‴Sm(thf))4S6}], in which a Cu4 tetrahedron is encapsulated by the samarium sulfido cluster {(Cp‴Sm(thf))4S6}.

  16. Gas separating

    DOEpatents

    Gollan, A.Z.

    1990-12-25

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  17. Gas separating

    DOEpatents

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  18. Method of loading organic materials with group III plus lanthanide and actinide elements

    DOEpatents

    Bell, Zane W.; Huei-Ho, Chuen; Brown, Gilbert M.; Hurlbut, Charles

    2003-04-08

    Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.

  19. Hot-pressed silicon nitride with various lanthanide oxides as sintering additives

    NASA Technical Reports Server (NTRS)

    Ueno, K.; Toibana, Y.

    1984-01-01

    The effects of addition of various lanthanide oxides and their mixture with Y2O3 on the sintering of Si3N4 were investigated. The addition of simple and mixed lanthanide oxides promoted the densification of Si3N4 in hot-pressing at 1800 C under 300-400kg/ centimeters squared for 60 min. The crystallization of yttrium and lanthanide-silicon oxynitrides which was observed inn the sintered body containing yttrium-lanthanide mixed oxides as additives led to the formation of a highly refractory Si3N4 ceramic having a bending strength of 82 and 84 kg/millimeters squared at room temperature and 1300 C respectively. In a Y2O3+La2O3 system, a higher molar ratio of La2O3 to Y2O3 gave a higher hardness and strength at high temperatures. It was found that 90 min was an optimum sintering time for the highest strength.

  20. MxaY regulates the lanthanide-mediated methanol dehydrogenase switch in Methylomicrobium buryatense

    PubMed Central

    Chu, Frances; Beck, David A.C.

    2016-01-01

    Many methylotrophs, microorganisms that consume carbon compounds lacking carbon–carbon bonds, use two different systems to oxidize methanol for energy production and biomass accumulation. The MxaFI methanol dehydrogenase (MDH) contains calcium in its active site, while the XoxF enzyme contains a lanthanide in its active site. The genes encoding the MDH enzymes are differentially regulated by the presence of lanthanides. In this study, we found that the histidine kinase MxaY controls the lanthanide-mediated switch in Methylomicrobium buryatense 5GB1C. MxaY controls the transcription of genes encoding MxaFI and XoxF at least partially by controlling the transcript levels of the orphan response regulator MxaB. We identify a constitutively active version of MxaY, and identify the mutated residue that may be involved in lanthanide sensing. Lastly, we find evidence to suggest that tight control of active MDH production is required for wild-type growth rates. PMID:27651996

  1. Molecular spectrum of lanthanide complexes with 2,3-dichlorobenzoic acid and 2,2-bipyridine.

    PubMed

    He, Shu-Mei; Sun, Shu-Jing; Zheng, Jun-Ru; Zhang, Jian-Jun

    2014-04-05

    With 2,3-dichlorobenzoic acid as the first ligands and 2,2'-bipyridine as the second ligands, the lanthanide complexes [Ln(2,3-DClBA)3bipy]2 [Ln=Nd(a), Sm(b), Eu(c), Tb(d), Dy(e), Ho(f)] have been synthesized. By using Infrared (IR) and Raman (R) spectra, the characteristics of the groups can be identified. The bands of lanthanide complexes have been analyzed and attributed, and clearly demonstrated with the use of the complementarity of IR and R. The experiment reveals that the bands of complexes are affected by lanthanide elements (Ln). The frequency of stretching vibration and breathing vibration of ring, together with the stretching vibration of the carbonyl group (νCO), tends to be rising as the atomic number of lanthanide increasing. Meanwhile, crystallography data demonstrate that the six carbonyl groups have different bond length and bond angle, which can lead to different vibration frequency. The second derivatives of IR show that there are multiple vibration frequencies existing in the symmetrical stretching vibration of the carbonyl group (νsCO). Therefore the second derivative of IR spectrum is a characteristic band of different coordination modes of carbonyl group.

  2. Rapid homogeneous immunoassay for cardiac troponin I using switchable lanthanide luminescence.

    PubMed

    Päkkilä, Henna; Malmi, Eeva; Lahtinen, Satu; Soukka, Tero

    2014-12-15

    Homogeneous assays are advantageous because of their simplicity and rapid kinetics but typically their performance is severely compromised compared to heterogeneous assay formats. Here, we report a homogeneous immunoassay utilizing switchable lanthanide luminescence for detection and site-specifically labeled recombinant antibody fragments as binders to improve the assay performance. Switchable lanthanide luminescence enabled elimination of assay background due to division of the luminescent lanthanide chelate into two non-luminescent label moieties. Simultaneous biomolecular recognition of model analyte cardiac troponin I by two antibody fragments brought the label moieties together and resulted in self-assembly of luminescent mixed chelate complex. The assay was very rapid as maximal signal-to-background ratios were achieved already after 6 min of incubation. Additionally, the limit of detection was 0.38 ng/mL (16 pM), which was comparable to the limit of detection for the heterogeneous reference assay based on the same binders (0.26 ng/mL or 11 pM). This is the first study to apply switchable lanthanide luminescence in immunoassays and demonstrates the versatile potential of the technology for rapid and sensitive homogeneous assays.

  3. Two types of lanthanide selenidostannates(IV) first prepared under the same solvothermal conditions.

    PubMed

    Zhou, Jian; Xiao, Hong; Xiao, Hong-Ping; Yang, Tao; Zou, Hua-Hong; Liu, Xing; Zhao, Rong-Qing; Tang, Qiuling

    2015-01-21

    Two types of lanthanide selenidostannates(iv) [Ln2(tepa)2(μ-OH)2Sn2Se6] {Ln = Y(), Pr (), Dy (), Er (), Tm (); tepa = tetraethylenepentamine} and [Ln2(tepa)2(μ2-OH)2Cl2]2[Sn4Se10]·4H2O {Ln = Y (), Dy (), Er (), Tm ()} have been synthesized under identical solvothermal conditions and characterized structurally. Type I (, , , and ) displays 1-D neutral chains [Ln2(tepa)2(μ-OH)2Sn2Se6]n, while type II (, , and ) contains discrete adamantane-like [Sn4Se10](4-) ions with binuclear lanthanide complex [Ln2(tepa)2(μ-OH)2Cl2](2+) ions as counterions. Although the solvothermal synthetic methods could result in the formation of various transition-metal chalcogenidometalates, such identical experimental conditions usually result in the only stable phases of lanthanide chalcogenidometalates. Hence, two different lanthanide selenidostannates(iv), obtained under same solvothermal conditions and starting materials, have been first observed in this work. The optical properties of all the compounds have been investigated by UV-vis spectra.

  4. Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout.

    PubMed

    Censi, P; Tamburo, E; Speziale, S; Zuddas, P; Randazzo, L A; Punturo, R; Cuttitta, A; Aricò, P

    2011-02-28

    Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corresponding to the depletion of elements from Nd to Tb when compared to the variable enrichments of heavy lanthanides, Y, La and Ce. These features and concurrent thermodynamic simulations suggest that phosphate precipitation can occur in lungs due to interactions between volcanic particles and fluids. We propose that patterns of yttrium and lanthanides can represent a viable explanation of some pathology observed in patients after prolonged exposure to atmospheric fallout and are suitable to become a diagnostic parameter of chemical environmental stresses.

  5. Lanthanide-Containing Cyclophanes for the Detection of Explosives and Propellants

    DTIC Science & Technology

    2006-05-01

    transition to the terbium centers is evident by the emission spectrum of Tb-4, Figure 3 . The emission spectrum with λmax of 545 nm is indicative of...MAY 2006 2. REPORT TYPE 3 . DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE Lanthanide-Containing Cyclophanes for the Detection of...BACKGROUND ..................................................................................................................................... 3 3

  6. Controlled synthesis of bright and compatible lanthanide-doped upconverting nanocrystals

    DOEpatents

    Cohen, Bruce E.; Ostrowski, Alexis D.; Chan, Emory M.; Gargas, Daniel J.; Katz, Elan M.; Schuck, P. James; Milliron, Delia J.

    2017-01-31

    Certain nanocrystals possess exceptional optical properties that may make them valuable probes for biological imaging, but rendering these nanoparticles biocompatible requires that they be small enough not to perturb cellular systems. This invention describes a phosphorescent upconverting sub-10 nm nanoparticle comprising a lanthanide-doped hexagonal .beta.-phase NaYF.sub.4 nanocrystal and methods for making the same.

  7. Self-assembly and photophysical properties of lanthanide dinuclear triple-helical complexes

    SciTech Connect

    Piguet, C.; Bernardinelli, G.; Williams, A.F. ); Buenzli, J.C.G. ); Hopfgartner, G. )

    1993-09-08

    The dinucleating ligand bis[1-methyl-2-(6[prime]-[1[double prime]-(3,5-dimethoxybenzyl)benzimidazol-2[double prime]-yl]pyrid-2[prime]-yl)benzimidazol-5-yl]methane (L) reacts with lanthanide perchlorates to give dinuclear 2:3 complexes [Ln[sub 2](L)[sub 3

  8. Sorption speciation of lanthanides/actinides on minerals by TRLFS, EXAFS and DFT studies: a review.

    PubMed

    Tan, Xiaoli; Fang, Ming; Wang, Xiangke

    2010-11-17

    Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory (DFT) is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the methods are concisely presented. Examples of recent research results of lanthanide/actinide speciation and local atomic structures using TRLFS, EXAFS and DFT are discussed. The interaction of lanthanides/actinides with oxides and minerals as well as their uptake are also of common interest in radionuclide chemistry. Especially the sorption and inclusion of radionuclides into several minerals lead to an improvement in knowledge of minor components in solids. In the solid-liquid interface, the speciation and local atomic structures of Eu(III), Cm(III), U(VI), and Np(IV/VI) in several natural and synthetic minerals and oxides are also reviewed and discussed. The review is important to understand the physicochemical behavior of lanthanides/actinides at a molecular level in the natural environment.

  9. The remarkable efficiency of N-heterocyclic carbenes in lanthanide(III)/actinide(III) differentiation.

    PubMed

    Mehdoui, Thouraya; Berthet, Jean-Claude; Thuéry, Pierre; Ephritikhine, Michel

    2005-06-14

    The capacity of NHC molecules to discriminate between trivalent lanthanide and actinide ions was revealed by competition reactions of analogous U(III) and Ce(III) compounds with C3Me4N2 and a comparison of the crystal structures of the corresponding carbene adducts.

  10. Interaction between multi-component lanthanide alloy and ferritic-martensitic steel

    NASA Astrophysics Data System (ADS)

    Kim, Jun Hwan; Cheon, Jin Sik; Kim, June Hyung; Lee, Byoung Oon; Lee, Chan Bock

    2014-09-01

    Studies were carried out to evaluate the effect of lanthanide elements which are generated during the fission process on the interaction between metal fuel and cladding material. Quartenary lanthanide alloy as Nd-Ce-Pr-La and Sm-contained quintenary alloy were manufactured by vacuum arc remelting and a diffusion couple test with HT9 (12Cr1MoWV) alloy was carried out at 660 and 700 °C for up to 231 h followed by microstructural analysis. The results showed that interdiffusion between lanthanide element (Nd, Ce) and Fe took place as the diffusion couple test proceeds to form intermetallic compounds as an RE2(Fe,Cr)17 (RE=Nd, Ce, Pr, La) type. As the number of alloying elements increased, the reaction layer thickness increased, but a deviation of the theoretical non-linear relationship as well as an increase in the rate exponent occurred. Instantaneous diffusion of Fe into a lanthanide side and its associated Fe depletion beneath the interface acted as the major driving force in forming the reaction layer. The addition of Ce enhanced the Nd diffusion and increased the layer growth when compared to pure Nd alone.

  11. MxaY regulates the lanthanide-mediated methanol dehydrogenase switch in Methylomicrobium buryatense

    DOE PAGES

    Chu, Frances; Beck, David A. C.; Lidstrom, Mary E.

    2016-09-07

    Many methylotrophs, microorganisms that consume carbon compounds lacking carbon–carbon bonds, use two different systems to oxidize methanol for energy production and biomass accumulation. The MxaFI methanol dehydrogenase (MDH) contains calcium in its active site, while the XoxF enzyme contains a lanthanide in its active site. The genes encoding the MDH enzymes are differentially regulated by the presence of lanthanides. In this study, we found that the histidine kinase MxaY controls the lanthanide-mediated switch in Methylomicrobium buryatense 5GB1C. MxaY controls the transcription of genes encoding MxaFI and XoxF at least partially by controlling the transcript levels of the orphan response regulatormore » MxaB. We identify a constitutively active version of MxaY, and identify the mutated residue that may be involved in lanthanide sensing. Finally, we find evidence to suggest that tight control of active MDH production is required for wild-type growth rates.« less

  12. Characterization and Catalytic Performance of Montmorillonites with Mixed Aluminium/Lanthanide Pillars

    NASA Astrophysics Data System (ADS)

    González, F.; Pesquera, C.; Blanco, C.

    Pillared montmorillonites with mixed Al/lanthanide pillars were prepared. The materials present characteristics that are very different from montmorillonite pillared with only aluminium. Nuclear magnetic resonance studies indicated total absence of tetrahedral aluminium in the pillars when lanthanide cations are incorporated between the clay layers. They have a high thermal stability, high specific surface area and porosity, with pores at the limit between the microporosity and mesoporosity. The textural parameters maintained high values up to 700 °C. The number and the strength of the acid sites in these materials were also high. The increase of the conversion in dehydration of 1-butanol as in hydroisomerization of n-heptane shows their better behaviour as acid catalysts. The Al/lanthanide-pillared samples showed increased conversion and improved the selectivity towards the products of cracking. The study of 1-butanol dehydration showed that there is an increase in the acidity, thermal stability and smaller deactivation by carbonaceous deposits in the Al/lanthanide-pillared sample.

  13. Lanthanide-doped upconversion nano-bioprobes: electronic structures, optical properties, and biodetection.

    PubMed

    Zheng, Wei; Huang, Ping; Tu, Datao; Ma, En; Zhu, Haomiao; Chen, Xueyuan

    2015-03-21

    Lanthanide-doped upconversion nanoparticles (UCNPs) have attracted considerable interest due to their superior physicochemical features, such as large anti-Stokes shifts, low autofluorescence background, low toxicity and high penetration depth, which make them extremely suitable for use as alternatives to conventional downshifting luminescence bioprobes like organic dyes and quantum dots for various biological applications. A fundamental understanding of the photophysics of lanthanide-doped UCNPs is of vital importance for discovering novel optical properties and exploring their new applications. In this review, we focus on the most recent advances in the development of lanthanide-doped UCNPs as potential luminescent nano-bioprobes by means of our customized lanthanide photophysics measurement platforms specially designed for upconversion luminescence, which covers from their fundamental photophysics to bioapplications, including electronic structures (energy levels and local site symmetry of emitters), excited-state dynamics, optical property designing, and their promising applications for in vitro biodetection of tumor markers. Some future prospects and efforts towards this rapidly growing field are also envisioned.

  14. Site-selective hydrolysis of tRNA by lanthanide metal complexes

    SciTech Connect

    Hayashi, Nobuhiro ); Takeda, Naoya; Yashiro, Morio; Watanabe, Kimitsuna; Komiyama, Makoto ); Shiiba, Tetsuro )

    1993-12-22

    tRNA[sup Phe] is site-selectively hydrolyzed by lanthanide metal complexes (Ce(III), Eu(III), La(III)) of hexaimine macrocyclic ligands. The selectivities of the complexes are much higher than those of the metal ions and are strongly dependent on the ligand structure. The tertiary structure of tRNA is essential for the site-selective scission.

  15. An aryl-phosphonate appended macrocyclic platform for lanthanide based bimodal imaging agents.

    PubMed

    Placidi, Matteo P; Engelmann, Jörn; Natrajan, Louise S; Logothetis, Nikos K; Angelovski, Goran

    2011-11-07

    Four ligand systems have been prepared whose characteristics are well suited to the design of bimodal MRI and luminescence probes. The lanthanide complexes display high relaxivities and luminescence quantum yields. These properties are retained at higher magnetic fields and in a range of competitive environments including model extracellular medium and cultured cells.

  16. Materials and methods for the separation of oxygen from air

    DOEpatents

    MacKay, Richard; Schwartz, Michael; Sammells, Anthony F.

    2003-07-15

    Metal oxides particularly useful for the manufacture of catalytic membranes for gas-phase oxygen separation processes having the formula: O.sub.5+z where: x and x' are greater than 0; y and y' are greater than 0; x+x' is equal to 2; y+y' is less than or equal to 2; z is a number that makes the metal oxide charge neutral; A is an element selected from the lanthanide elements; A' is an element selected from Be, Mg, Ca, Sr, Ba and Ra; A" is an element selected from the f block lanthanides, Be, Mg, Ca, Sr, Ba and Ra; B is an element selected from the group consisting of Al, Ga, In or mixtures thereof and B" is Co or Mg, with the exception that when B" is Mg, A' and A" are not Mg. The metal oxides are useful for preparation of dense membranes which may be formed from dense thin films of the mixed metal oxide on a porous metal oxide element. The invention also provides methods and catalytic reactors for oxygen separation and oxygen enrichment of oxygen deficient gases which employ mixed conducting metal oxides of the above formula.

  17. Selective recognition of uranyl ions from bulk of thorium(iv) and lanthanide(iii) ions by tetraalkyl urea: a combined experimental and quantum chemical study.

    PubMed

    Vats, Bal Govind; Das, Debasish; Sadhu, Biswajit; Kannan, S; Pius, I C; Noronha, D M; Sundararajan, Mahesh; Kumar, Mukesh

    2016-06-21

    The selective separation of uranyl ions from an aqueous solution is one of the most important criteria for sustainable nuclear energy production. We report herein a known, but unexplored extractant, tetraalkyl urea, which shows supreme selectivity for uranium in the presence of interfering thorium and other lanthanide ions from a nitric acid medium. The structural characterization of the uranyl complex (UO2X2·2L, where X = NO3(-), Cl(-) and Br(-)) by IR, NMR and single crystal X-ray diffraction provides insight into the strong interaction between the uranyl ion and the ligand. The origin of this supreme selectivity for uranyl ions is further supported by electronic structure calculations. Uranyl binding with the extractant is thermodynamically more favourable when compared to thorium and the selectivity is achieved through a combination of electronic and steric effects.

  18. Intrinsic and Carrier Colloid-facilitated transport of lanthanides through discrete fractures in chalk

    NASA Astrophysics Data System (ADS)

    Weisbrod, N.; Tran, E. L.; Klein-BenDavid, O.; Teutsch, N.

    2015-12-01

    Geological disposal of high-level radioactive waste is the long term solution for the disposal of long lived radionuclides and spent fuel. However, some radionuclides might be released from these repositories into the subsurface as a result of leakage, which ultimately make their way into groundwater. Engineered bentonite barriers around nuclear waste repositories are generally considered sufficient to impede the transport of radionuclides from their source to the groundwater. However, colloidal-sized mobile bentonite particles ("carrier" colloids) originating from these barriers have come under investigation as a potential transport vector for radionuclides sorbed to them. As lanthanides are generally accepted to have the same chemical behaviors as their more toxic actinide counterparts, lanthanides are considered an acceptable substitute for research on radionuclide transportation. This study aims to evaluate the transport behaviors of lanthanides in colloid-facilitated transport through a fractured chalk matrix and under geochemical conditions representative the Negev desert, Israel. The migration of Ce both with and without colloidal particles was explored and compared to the migration of a conservative tracer (bromide) using a flow system constructed around a naturally fractured chalk core. Results suggest that mobility of Ce as a solute is negligible. In experiments conducted without bentonite colloids, the 1% of the Ce that was recovered migrated as "intrinsic" colloids in the form of carbonate precipitates. However, the total recovery of the Ce increased to 9% when it was injected into the core in the presence of bentonite colloids and 13% when both bentonite and precipitate colloids were injected. This indicates that lanthanides are essentially immobile in chalk as a solute but may be mobile as carbonate precipitates. Bentonite colloids, however, markedly increase the mobility of lanthanides through fractured chalk matrices.

  19. A new class of macrocyclic lanthanide complexes for cell labeling and magnetic resonance imaging applications.

    PubMed

    Zheng, Quan; Dai, Houquan; Merritt, Matthew E; Malloy, Craig; Pan, Cai Yuan; Li, Wen-Hong

    2005-11-23

    Lanthanide complexes have wide applications in biochemical research and biomedical imaging. We have designed and synthesized a new class of macrocyclic lanthanide chelates, Ln/DTPA-PDA-C(n), for cell labeling and magnetic resonance imaging (MRI) applications. Two lipophilic Gd3+ complexes, Gd/DTPA-PDA-C(n) (n = 10, 12), labeled a number of cultured mammalian cells noninvasively at concentrations as low as a few micromolar. Cells took up these agents rapidly and showed robust intensity increases in T1-weighed MR images. Labeled cells showed normal morphology and doubling time as control cells. In addition to cultured cells, these agents also labeled primary cells in tissues such as dissected pancreatic islets. To study the mechanism of cellular uptake, we applied the technique of diffusion enhanced fluorescence resonance energy transfer (DEFRET) to determine the cellular localization of these lipophilic lanthanide complexes. After loading cells with a luminescent complex, Tb/DTPA-PDA-C10, we observed DEFRET between the Tb3+ complex and extracellular, but not intracellular, calcein. We concluded that these cyclic lanthanide complexes label cells by inserting two hydrophobic alkyl chains into cell membranes with the hydrophilic metal binding site facing the extracellular medium. As the first imaging application of these macrocyclic lanthanide chelates, we labeled insulin secreting beta-cells with Gd/DTPA-PDA-C12. Labeled cells were encapsulated in hollow fibers and were implanted in a nude mouse. MR imaging of implanted beta-cells showed that these cells could be followed in vivo for up to two weeks. The combined advantages of this new class of macrocyclic contrast agents ensure future imaging applications to track cell movement and localization in different biological systems.

  20. Lanthanide amidinates and guanidinates in catalysis and materials science: a continuing success story.

    PubMed

    Edelmann, Frank T

    2012-12-07

    Today the rare-earth elements play a critical role in numerous high-tech applications. This is why various areas of rare-earth chemistry are currently thriving. In organolanthanide chemistry the search for new ligand sets which are able to satisfy the coordination requirements of the large lanthanide cations continues to be a hot topic. Among the most successful approaches in this field is the use of amidinate and guanidinate ligands of the general types [RC(NR')(2)](-) (R = H, alkyl, aryl; R' = alkyl, cycloalkyl, aryl, SiMe(3)) and [R(2)NC(NR')(2)](-) (R = alkyl, SiMe(3); R' = alkyl, cycloalkyl, aryl, SiMe(3)), which can both be regarded as steric cyclopentadienyl equivalents. Mono-, di- and trisubstituted lanthanide amidinate and guanidinate complexes are all readily available. Various rare earth amidinates and guanidinates have turned out to be very efficient homogeneous catalysts e.g. for the polymerization of olefins and dienes, the ring-opening polymerization of cyclic esters or the guanylation of amines. Moreover, certain alkyl-substituted lanthanide tris(amidinates) and tris(guanidinates) were found to be highly volatile and are thus promising precursors for ALD (= atomic layer deposition) and MOCVD (= metal-organic chemical vapor deposition) processes in materials science, e.g. for the production of lanthanide nitride thin layers. This tutorial review covers the continuing success story of lanthanide amidinates and guanidinates which have undergone an astonishing transition from mere laboratory curiosities to efficient homogeneous catalysts as well as ALD and MOCVD precursors within the past 10 years.