Synthesis, spectroscopic characterizations, crystal structures and DFT studies of nalidixic acid carbonyl hydrazones derivatives

NASA Astrophysics Data System (ADS)

Bergamini, F. R. G.; Ribeiro, M. A.; Lancellotti, M.; Machado, D.; Miranda, P. C. M. L.; Cuin, A.; Formiga, A. L. B.; Corbi, P. P.

2016-09-01

This article describes the synthesis and characterization of the 1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazide (hzd) and six carbonyl hydrazones derivatives of the nalidixic with 1H-pyrrol-2-ylmethylidene (hpyrr), 1H-imidazol-2-ylmethylidene (h2imi), pyridin-2-ylmethylidene (h2py), pyridin-3-ylmethylidene (h3py), pyridin-4-ylmethylidene(h4py) and (2-hydroxyphenyl)methylidene (hsali). The carbonyl hydrazones were characterized by elemental and ESI-QTOF-MS analyses, IR and detailed NMR spectroscopic measurements. The 2D NMR experiments allowed the unambiguous assignment of the hydrogen, carbon and nitrogen atoms, which have not been reported for nalidixic acid carbonyl hydrazone derivatives so far. Crystal structures of hzd and the new carbonyl hydrazones h2imi, hpyrr and h3py were determined by X-ray diffraction studies. Although the synthesis of hzd was reported decades ago, the hzd crystal structure have not been reported yet. Geometric optimizations of all the characterized structures were performed with the aid of DFT studies. Despite the fact that the hydrazones with 2-pyridine carboxylic acid (h2py) and salicyl aldehyde (hsali) were already reported by literature, a detailed spectroscopic study followed by DFT studies are also reported for such compounds in this manuscript. Antimicrobial studies of the compounds are also presented.

Studies on synthesis of diamond at high pressure and temperature

NASA Astrophysics Data System (ADS)

Kailath, Ansu J.

Diamond is an essential material of modern industry and probably the most versatile abrasive available today. It also has many other industrial applications attributable to its unique mechanical, optical, thermal and electrical properties. Its usage has grown to the extent that there is hardly a production process in modern industry in which industrial diamond does not play a part. Bulk diamond production today is a major industry. Diamonds can be produced in its thermodynamically stable regions either by direct static conversion, or shock-wave conversion. The pressures and temperatures required for direct static conversion are very high. In the catalyst-solvent method, the material used establishes a reaction path with lower activation energy than for direct transformation. This helps in a quicker transformation under more benign conditions. Hence, catalyst-solvent synthesis is readily accomplished and is now a viable and successful industrial process. Diamonds produced by shock wave are very small (approximately 60mu). Therefore this diamond is limited to applications such as polishing compounds only. The quality, quantity, size and morphology of the crystals synthesized by catalyst-solvent process depend on different conditions employed for synthesis. These details, because of commercial reasons are not disclosed in published literature. Hence, systematic studies have been planned to investigate the effect of various growth parameters on the synthesized crystals. During the growth of synthetic diamond crystals, some catalyst-solvent is retained into the crystals in some form and behaves like an impurity. Several physico-mechanical properties of the crystals are found to depend on the total quantity and distribution of these inclusions. Thus, detailed investigation of the crystallization medium and inclusions in synthesized diamonds was also undertaken in the present work. The work incorporated in this thesis has been divided into seven chapters. The first chapter is a general introduction incorporating the information regarding diamond together with a brief history of diamond synthesis. It also includes the details of the high pressure synthesis of diamond, the uses of diamond grits, the advantages of the synthetic diamond grit over natural grit and an outline to elucidate the reasons which prompted to undertake the present work. The details of the technique used in the present studies for synthesis of diamond grits by high-pressure high-temperature process are included in chapter II. The hydraulic press used for synthesis, the details of the reactant materials, stacking of the high pressure cell and the details of synthesis run have been described together with the separation procedure to isolate diamond grits from the frozen slug. Different analytical and characterization techniques used in the present studies for the analysis and characterization of the reactant materials, synthesized diamonds and the crystallization medium have been illustrated in chapter III. The effect of different synthesizing parameters on synthesized diamond crystals were studied. This study includes: (a) dependence of yield of diamond on temperature and pressure, (b) dependence of crystal size on cook length, (c) effect of variation of the relative amounts of carbonaceous material and catalyst on synthesis, (d) morphological variation and (e) effect of pressure pulse on synthesized crystals. Various observations made during this study and the results obtained have been compiled in chapter IV. The synthesized diamond crystals were characterized by X-ray Powder Diffraction (XRD), Raman Spectroscopy, Scanning Electron Microscopy (SEM) and Optical Microscopy. The results obtained have been compiled in chapter V. In addition to these, the results obtained from the Infrared Spectra and the Electron Paramagnetic Spectra have also been included. Studies of crystallization medium and inclusions in the synthesized diamonds were carried out. This include: (a) X-ray diffraction study of the phase composition of crystallization medium and inclusions in synthesized diamonds, (b) metallographic examination of the initial catalyst-solvent and the frozen slug after synthesis, (c) temperature dependence of the magnetic susceptibility of the initial catalyst-solvent and the frozen catalyst-solvent after synthesis, (d) scanning electron microscopic examination of the inclusion on the mechanically polished cross-sections of the synthesized crystals, (e) EDAX analysis of these observed inclusions and the frozen catalyst-solvent matrix after growth, (f) temperature dependence of the magnetic susceptibility of the synthesized crystals and (g) the Mossbauer spectroscopic analysis of the synthesized crystals. Different observations and the results obtained from these studies have been compiled and presented in chapter VI. Chapter VII illustrates the various conclusions drawn from the present studies.

Synthesis and characterization of zinc borophosphates with ANA-zeotype framework by the microwave method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Yu, E-mail: songyu@dlpu.edu.cn; Ding, Ling; An, Qingda

2013-06-15

Zinc borophosphate (NH{sub 4}){sub 16}[Zn{sub 16}B{sub 8}P{sub 24}O{sub 96}] (denoted as ZnBP-ANA) with ANA-zeotype structure has been synthesized by employing microwave-assisted solvothermal synthesis in the reaction system ZnCl{sub 2}∙6H{sub 2}O-(NH{sub 4}){sub 2}HPO{sub 4}–H{sub 3}BO{sub 3} using ethylene glycol as a co-solvent. The influences of various experimental parameters, such as reaction temperature, solvent ratio, zinc precursors and reactive power, have been systematically investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), and so on. Small and homogeneous ZnBP-ANA single crystal with regular cube morphology are crystallized by using microwave solvothermal synthesis method withinmore » a shorter time, and its grain size decreases with power. - Graphical abstract: Tailor-made ANA zeolites with varied size can be prepared by simply changing the reaction power. - Highlights: • Zinc borophosphate zeolites with ANA-zeotype structures were prepared by microwave technique. • The size of crystals could be controlled by tuning power. • Synthesis period can be significantly reduced by raising reaction temperature.« less

Polyamides based on the renewable monomer, 1,13-tridecane diamine I: synthesis and characterization of nylon 13,T

DOE PAGES

He, Jie; Samanta, Satyabrata; Selvakumar, Sermadurai; ...

2013-06-01

Nylon 13,T was successfully synthesized and chemical composition, thermal properties, crystal structure, and moisture absorption characterized. Melting temperature and glass transition temperature were determined to be 263 °C and 90 °C, respectively, while the equilibrium melting temperature was determined to be 289 °C. Characterization of the crystallization kinetics showed that nylon 13,T exhibits very fast crystallization compared to the industrially important nylons, nylon 6 and nylon 6,6. In addition, the moisture absorption of nylon 13,T was dramatically lower than nylon 6 and nylon 6,6 which is consistent with the much lower amide content of nylon 13,T. The crystal structure wasmore » determined to be pseudohexagonal.« less

Second harmonic generation and crystal growth of new chalcone derivatives

NASA Astrophysics Data System (ADS)

Patil, P. S.; Dharmaprakash, S. M.; Ramakrishna, K.; Fun, Hoong-Kun; Sai Santosh Kumar, R.; Narayana Rao, D.

2007-05-01

We report on the synthesis, crystal structure and optical characterization of chalcone derivatives developed for second-order nonlinear optics. The investigation of a series of five chalcone derivatives with the second harmonic generation powder test according to Kurtz and Perry revealed that these chalcones show efficient second-order nonlinear activity. Among them, high-quality single crystals of 3-Br-4'-methoxychalcone (3BMC) were grown by solvent evaporation solution growth technique. Grown crystals were characterized by X-ray powder diffraction (XRD), laser damage threshold, UV-vis-NIR and refractive index measurement studies. Infrared spectroscopy, thermogravimetric analysis and differential thermal analysis measurements were performed to study the molecular vibration and thermal behavior of 3BMC crystal. Thermal analysis does not show any structural phase transition.

Synthesis, crystal growth and studies on non-linear optical property of new chalcones

NASA Astrophysics Data System (ADS)

Sarojini, B. K.; Narayana, B.; Ashalatha, B. V.; Indira, J.; Lobo, K. G.

2006-09-01

The synthesis, crystal growth and non-linear optical (NLO) property of new chalcone derivatives are reported. 4-Propyloxy and 4-butoxy benzaldehydes were made to under go Claisen-Schmidt condensation with 4-methoxy, 4-nitro and 4-phenoxy acetophenones to form corresponding chalcones. The newly synthesized compounds were characterized by analytical and spectral data. The Second harmonic generation (SHG) efficiency of these compounds was measured by powder technique using Nd:YAG laser. Among tested compounds three chalcones showed NLO property. The chalcone 1-(4-methoxyphenyl)-3-(4-propyloxy phenyl)-2-propen-1-one exhibited SHG conversion efficiency 2.7 times that of urea. The bulk crystal of 1-(4-methoxyphenyl)-3-(4-butoxyphenyl)-2-propen-1-one (crystal size 65×28×15 mm 3) was grown by slow-evaporation technique from acetone. Microhardness of the crystal was tested by Vicker's microhardness method.

Effect of the raw material type and the reaction time on the synthesis of halloysite based Zeolite Na-P1

NASA Astrophysics Data System (ADS)

Meftah, Mahdi; Oueslati, Walid; Chorfi, Nejmeddine; Ben Haj Amara, Abdesslem

Zeolites are currently one of the most important classes of inorganic materials because of their multiple applications not only as ions exchangers and molecular sieves, but also as catalysts. This works focus the synthesis and the characterization of Zeolite Na-P1 using halloysite (collected near Ain Khemouda, western Tunisia) as the starting material. Two parameters, such as the host materials type (natural or treated) and the reaction time, involved in the synthesis process are investigated. The intermediate phases and final products were characterized by X-ray diffraction, Infrared IR spectroscopy, scanning electron microscopy and high-resolution 29Si and 27Al MAS NMR. Obtained results show that the hydrothermal synthesis from natural and heated-halloysite leads to formation of homogenous Zeolite Na-P1. The difference in the crystallization/transformation time process is explained by the effect of the dissolution rate of the starting materials in sodium hydroxide solution. In the case of heated halloysite, the synthesis reaction with alkali solution occurs very readily and achieved without prior thermal activation at high temperature. The optimal conditions of Zeolite Na-P1 crystallization, from heated-halloysite, are reached at 120 °C.

Synthesis, growth, structural, spectroscopic and optical studies of a semiorganic NLO crystal: zinc guanidinium phosphate.

PubMed

Suvitha, A; Murugakoothan, P

2012-02-01

The semi-organic nonlinear optical (NLO) crystal, zinc guanidinium phosphate (ZGuP) has been grown through synthesis between zinc sulphate, guanidine carbonate and orthophosphoric acid from its aqueous solution by slow solvent evaporation technique. Solubility of the synthesized material has been determined for various temperatures using water as solvent. The grown crystal has been characterized by powder X-ray diffraction to confirm the crystal structure. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopy technique. (1)H and (13)C FT-NMR have been recorded to elucidate the molecular structure. The optical absorption study confirms the suitability of the crystal for device applications. The second harmonic generation (SHG) efficiency of ZGuP is found to be 1.825 times that of potassium dihydrogen phosphate (KDP). Thermal behavior of the grown crystals has been studied by thermogravimetric and differential thermal analysis. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester. Copyright © 2011 Elsevier B.V. All rights reserved.

2-Hydroxyethyl substituted NHC precursors: Synthesis, characterization, crystal structure and carbonic anhydrase, α-glycosidase, butyrylcholinesterase, and acetylcholinesterase inhibitory properties

NASA Astrophysics Data System (ADS)

Erdemir, Fatoş; Barut Celepci, Duygu; Aktaş, Aydın; Taslimi, Parham; Gök, Yetkin; Karabıyık, Hasan; Gülçin, İlhami

2018-03-01

This study contains novel a serie synthesis of N-heterocyclic carbene (NHC) precursors that 2-hydroxyethyl substituted. The NHC precursors have been prepared from 1-(2- hydroxyethyl)benzimidazole and alkyl halides. The novel NHC precursors have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Molecular and crystal structures of 2a, 2d, 2e, 2f and 2g were obtained with single-crystal X-ray diffraction studies. These novel NHC precursor's derivatives effectively inhibited the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms (hCA I and II), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE). Inhibition constant (Ki) were found in the range of 0.30-9.22 nM for α-glycosidase, 13.90-41.46 nM for hCA I, 12.82-49.95 nM for hCA II, 145.82-882.01 nM for BChE, and 280.92-1370.01 nM for AChE, respectively.

Synthesis and X-ray crystal structure determination of N- p-methylphenyl-4-benzoyl-3,4-diphenyl-2-azetidinone

NASA Astrophysics Data System (ADS)

Kabak, Mehmet; Şenöz, Hülya; Elmali, Ayhan; Adar, Vildan; Svoboda, Ingrid; Dušek, Michal; Fejfarová, Karla

2010-12-01

The title compound, C29H23NO2, has been characterized by single-crystal X-ray diffraction at two different temperatures (303 K and 120 K) and wavelengths (Mo K α and Cu K α). The non-centrosymmetric hexagonal crystal structure contains four-membered planar β-lactam ring with an unusually long C-C bond. The β-lactam ring is almost planar.

Synthesis, characterization and intramolecular cyclisation study of three new liquid crystals

NASA Astrophysics Data System (ADS)

Saïdat, B.; Guermouche, M. H.; Bayle, J.-P.

2004-12-01

Internal cyclization of three new phenyldiazene liquid crystals (R is an alkyl substituent with 4, 6 or 8 carbons) with activated methylene group in the ortho position to the diazo linkage was studied . The initial liquid crystals was synthesised and characterized by ^1H NMR, electrospray mass spectrometry and differential scanning calorimetry. The final compound was characterized by ^1H NMR and differential scanning calorimetry. The kinetic of cyclization was studied at different temperatures and followed by reversed phase HPLC and a UV detection. For all the temperatures used, it appeared that the cyclisation was a first order reaction for the three compounds. The Arrhenius plot (ln reaction constant k against 1000/T) gave the mean activation energy of the cyclisation.

Synthesis, crystal structure, thermal and nonlinear optical properties of new metal-organic single crystal: Tetrabromo (piperazinium) zincate (II) (TBPZ)

NASA Astrophysics Data System (ADS)

Boopathi, K.; Babu, S. Moorthy; Ramasamy, P.

2018-04-01

Tetrabromo (piperazinium) zincate, a new metal-organic crystal has been synthesized and its single crystal grown by slow evaporation method. The grown crystal has characterized by structural, spectral, thermal, linear and nonlinear optical properties. Single crystal X-ray diffractions study reveals that grown crystal belongs to orthorhombic crystal system with space group P212121. The presence of functional groups is identified by FT-IR spectral analysis. Thermal stability of the crystal was ascertained by TG-DTA measurement. The second order harmonic generation efficiency was measured using Kurtz and Perry technique and it was found to be 1.5 times that of KDP.

Synthesis, structural, optical and thermal studies of an organic nonlinear optical 4-aminopyridinium maleate single crystal.

PubMed

Pandi, P; Peramaiyan, G; Kumar, M Krishna; Kumar, R Mohan; Jayavel, R

2012-03-01

Synthesis and growth of a novel organic nonlinear optical (NLO) crystal of 4-aminopyridinium maleate (4APM) in larger size by the slow evaporation solution growth technique are reported. Single crystal and powder X-ray diffraction analyses reveal that 4APM crystallizes in monoclinic system with space group P2(1) with cell parameters a=8.140(4)Å, b=5.457(5)Å, c=10.926(10)Å and volume=481.4(7)Å(3). The grown crystal has been characterized by Fourier transform infrared and UV-visible spectral analyses. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have been carried out to study its thermal properties. Dielectric measurements have been carried out to study the distribution of charges within the crystal. The mechanical strength of the crystal has been studied by using Vickers' microhardness test. The etching studies have been carried out on the grown crystal. The Kurtz and Perry powder SHG technique confirms the NLO property of the grown crystal and the SHG efficiency of 4APM was found to be 4.8 times greater than that of KDP crystal. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures

DOE PAGES

Caskey, Christopher M.; Holder, Aaron; Shulda, Sarah; ...

2016-04-12

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here, we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experimentsmore » indicate that this novel material is N-deficient SnN with tin in the mixed ii/iv valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. Furthermore, this observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn 3N 4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of metastable materials. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.« less

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures

NASA Astrophysics Data System (ADS)

Caskey, Christopher M.; Holder, Aaron; Shulda, Sarah; Christensen, Steven T.; Diercks, David; Schwartz, Craig P.; Biagioni, David; Nordlund, Dennis; Kukliansky, Alon; Natan, Amir; Prendergast, David; Orvananos, Bernardo; Sun, Wenhao; Zhang, Xiuwen; Ceder, Gerbrand; Ginley, David S.; Tumas, William; Perkins, John D.; Stevanovic, Vladan; Pylypenko, Svitlana; Lany, Stephan; Richards, Ryan M.; Zakutayev, Andriy

2016-04-01

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here, we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experiments indicate that this novel material is N-deficient SnN with tin in the mixed ii/iv valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn3N4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of metastable materials. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures.

PubMed

Caskey, Christopher M; Holder, Aaron; Shulda, Sarah; Christensen, Steven T; Diercks, David; Schwartz, Craig P; Biagioni, David; Nordlund, Dennis; Kukliansky, Alon; Natan, Amir; Prendergast, David; Orvananos, Bernardo; Sun, Wenhao; Zhang, Xiuwen; Ceder, Gerbrand; Ginley, David S; Tumas, William; Perkins, John D; Stevanovic, Vladan; Pylypenko, Svitlana; Lany, Stephan; Richards, Ryan M; Zakutayev, Andriy

2016-04-14

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here, we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experiments indicate that this novel material is N-deficient SnN with tin in the mixed ii/iv valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn3N4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of metastable materials. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.

Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caskey, Christopher M.; Colorado School of Mines, Golden, Colorado 80401; Larix Chemical Science, Golden, Colorado 80401

2016-04-14

Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for these studies, since even simple binary non-ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here, we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experimentsmore » indicate that this novel material is N-deficient SnN with tin in the mixed II/IV valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn{sub 3}N{sub 4} spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of metastable materials. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials.« less

Placing Tighter Constraints on Mercurian Surface Fe Abundances Through the Synthesis and Characterization of Fe-Poor Silicates

NASA Astrophysics Data System (ADS)

Vander Kaaden, K. E.; McCubbin, F. M.; Rowland, R. L.; Morris, R. V.; Reppart, J. J.; Klima, R. L.

2018-05-01

We have crystallized and characterized synthetic Fe-poor minerals to make advancements towards reconciling the discrepancy between the lack of a 1-µm absorption band observed on the surface of Mercury, despite wt% levels of Fe observed by XRS.

Ionothermal synthesis, crystal structure, and magnetic study of Co2PO4OH isostructural with caminite.

PubMed

Wang, Guangmei; Valldor, Martin; Spielberg, Eike T; Mudring, Anja-Verena

2014-03-17

A new framework cobalt(II) hydroxyl phosphate, Co2PO4OH, was prepared by ionothermal synthesis using 1-butyl-4-methyl-pyridinium hexafluorophosphate as the ionic liquid. As the formation of Co2PO4F competes in the synthesis, the synthesis conditions have to be judiciously chosen to obtain well-crystallized, single phase Co2PO4OH. Single-crystal X-ray diffraction analyses reveal Co2PO4OH crystallizes with space group I41/amd (a = b = 5.2713(7) Å, c = 12.907(3) Å, V = 358.63(10) Å(3), and Z = 4). Astonishingly, it does not crystallize isotypically with Co2PO4F but rather isotypically with the hydroxyl minerals caminite Mg1.33[SO4(OH)0.66(H2O)0.33] and lipscombite Fe(2–y)PO4(OH) (0 ≤ y ≤ 2/3). Phosphate tetrahedra groups interconnect four rod-packed face-sharing ∞(1){CoO(6/2)} octahedra chains to form a three-dimensional framework structure. The compound Co2PO4OH was further characterized by powder X-ray diffraction, Fourier transform–infrared, and ultraviolet–visible spectroscopy, confirming the discussed structure. The magnetic measurement reveals that Co2PO4OH undergoes a magnetic transition and presents at low temperatures a canted antiferromagnetic spin order in the ground state.

Microfluidic approach toward continuous and ultrafast synthesis of metal-organic framework crystals and hetero structures in confined microdroplets.

PubMed

Faustini, Marco; Kim, Jun; Jeong, Guan-Young; Kim, Jin Yeong; Moon, Hoi Ri; Ahn, Wha-Seung; Kim, Dong-Pyo

2013-10-02

Herein, we report a novel nanoliter droplet-based microfluidic strategy for continuous and ultrafast synthesis of metal-organic framework (MOF) crystals and MOF heterostructures. Representative MOF structures, such as HKUST-1, MOF-5, IRMOF-3, and UiO-66, were synthesized within a few minutes via solvothermal reactions with substantially faster kinetics in comparison to the conventional batch processes. The approach was successfully extended to the preparation of a demanding Ru3BTC2 structure that requires high-pressure hydrothermal synthesis conditions. Finally, three different types of core-shell MOF composites, i.e., Co3BTC2@Ni3BTC2, MOF-5@diCH3-MOF-5, and Fe3O4@ZIF-8, were synthesized by exploiting a unique two-step integrated microfluidic synthesis scheme in a continuous-flow mode. The synthesized MOF crystals were characterized by X-ray diffraction, scanning electron microscopy, and BET surface area measurements. In comparison with bare MOF-5, MOF-5@diCH3-MOF-5 showed enhanced structural stability in the presence of moisture, and the catalytic performance of Fe3O4@ZIF-8 was examined using Knoevenagel condensation as a probe reaction. The microfluidic strategy allowed continuous fabrication of high-quality MOF crystals and composites exhibiting distinct morphological characteristics in a time-efficient manner and represents a viable alternative to the time-consuming and multistep MOF synthesis processes.

Synthesis, growth and characterization of a nonlinear optical crystal: Bis l-proline hydrogen nitrate.

PubMed

Selvaraju, K; Kirubavathi, K

2013-11-01

The single crystals of bis l-proline hydrogen nitrate (BLPHN) belonging to non-centrosymmetric space group were successfully grown by the slow evaporation solution growth technique. The BLPHN crystals of size 10×7×3mm(3) were obtained in 35days. Initially, the solubility tests were carried out for two solvents such as deionized water and mixed of deionized water-acetone. Among the two solvents, the solubility of BLPHN was found to be the highest in deionized water, so crystallization of BLPHN was done from its aqueous solution. As grown, crystals were characterized by single crystal X-ray diffraction studies and optical transmission spectral studies. Infrared spectroscopy, thermo gravimetric analysis and differential thermal analysis measurements were performed to study the molecular vibration and thermal behavior of the grown BLPHN crystals. Nonlinear optical (NLO) behavior of BLPHN crystal was studied by Kurtz and Perry powder method. Copyright © 2013 Elsevier B.V. All rights reserved.

1. Innovative Relaxor-Based PiezoCrystals: Phase Diagrams, Crystal Growth, Domain Structures and Electric Properties. 2. Piezo- and Ferroelectric Materials Based on Morphotropic Phase Boundary Synthesis, Characterization and Structure - Property Relations

DTIC Science & Technology

2006-03-31

crystals by the flux method and modified Bridgman technique, the growth results were hardly reproducible, and the quality of the crystals was still a serious... growth . 2.2.1.2.2) Solution Bridgman Growth A modified Bridgman method using excess of PbO as solvent was developed for the growth of PZNT91/9 crystals ...of growth , the grown crystal can be rotated via the A120 3 rod which was driven by a motor at a speed of 0 to 30 rmp. Figure 15(b) gives the

Synthesis, high-resolution NMR spectroscopic analysis, and single-crystal X-ray diffraction of isoxazoline tetracycles.

PubMed

Fascio, Mirta L; Alvarez-Larena, Angel; D'Accorso, Norma B

2002-11-29

Three isoxazoline tetracycles were obtained enantiomerically pure by intramolecular 1,3-dipolar cycloaddition. The characterization of the new compounds was performed by high-resolution 1H and 13C NMR spectroscopy. The relative configuration of the new chiral centers was determined by NOESY experiments and confirmed by single-crystal X-ray structural analysis.

New diols with imidazoquinazoline ring

NASA Astrophysics Data System (ADS)

Szyszkowska, Agnieszka; Klasek, Antonin; Pawlędzio, Sylwia; Trzybiński, Damian; Woźniak, Krzysztof; Zarzyka, Iwona

2018-02-01

The objective of these studies was to synthesize and characterize new diols with an imidazoquinazoline ring. New diols were obtained in reactions of 2,6-bis-(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione with excess of ethylene glycol or in reaction of 1-phenyl-2H,6H-imidazo[1,5-c]quinazoline-3,5-dione with 2-M excess of ethylene oxide. The products were isolated at high yield and characterized by instrumental methods (IR, 1H- and 13C-NMR, MS-ESI, UV, TGA). The structure of 2,6-bis(2-hydroxyethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione (BEFIQ) was also investigated by single-crystal X-ray diffraction. BEFIQ crystallizes in the monoclinic P21/n space group with two molecules in the asymmetric unit of the crystal lattice. The nature of the packing of molecules in the crystal lattice of BEFIQ was investigated by Hirshfeld surface analysis. The described methods enable the synthesis of new diols with an imidazoquinazoline ring. The new diols are quite soluble in typical organic solvents. Therefore, they can be used as raw materials for the synthesis of thermally stable polymers, and they can also have biological activity.

Large-scale synthesis and growth habit of 3-D flower-like crystal of PbTe

NASA Astrophysics Data System (ADS)

Zhou, Nan; Chen, Gang; Yang, Xi; Zhang, Xiaosong

2012-02-01

In this paper, 3-D flower-like crystal of PbTe was successfully synthesized using Pb(CH3COO)2·3H2O and Na2TeO3 as precursors under hydrothermal conditions, and characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction pattern (XRD). The reaction parameters that influenced the evolution of PbTe synthesis and morphology were investigated. It was shown that the flower-like crystal of PbTe was composed of a nucleus with eight pods. A possible growth mechanism was proposed based on the calculation of the surface energies of PbTe and the SEM observation. Furthermore, the temperature-dependent transport properties of 3-D flower-like crystal of PbTe specimen have been evaluated with an average thermoelectric power of 120 S cm-1 and electrical conductivity of 220 μV K-1 at 740 K.

Synthesis of vaterite and aragonite crystals using biomolecules of tomato and capsicum

NASA Astrophysics Data System (ADS)

Chen, Long; Xu, Wang-Hua; Zhao, Ying-Guo; Kang, Yan; Liu, Shao-Hua; Zhang, Zai-Yong

2012-12-01

In this paper, biomimetic synthesis of calcium carbonate (CaCO3) in the presence of biomolecules of two vegetables-tomato and capsicum is investigated. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the CaCO3 obtained. The biomolecules in the extracts of two vegetables are determined by UV-vis or FTIR. The results indicate that a mixture of calcite and vaterite spheres constructed from small particles is produced with the extract of tomato, while aragonite rods or ellipsoids are formed in the presence of extract of capsicum. The possible formation mechanism of the CaCO3 crystals with tomato biomolecules can be interpreted by particle-aggregation based non-classical crystallization laws. The proteins and/or other biomolecules in tomato and capsicum may control the formation of vaterite and aragonite crystals by adsorbing onto facets of them.

Aerosol Route Synthesis and Applications of Doped Nanostructured Materials

NASA Astrophysics Data System (ADS)

Sahu, Manoranjan

Nanotechnology presents an attractive opportunity to address various challenges in air and water purification, energy, and other environment issues. Thus, the development of new nanoscale materials in low-cost scalable synthesis processes is important. Furthermore, the ability to independently manipulate the material properties as well as characterize the material at different steps along the synthesis route will aide in product optimization. In addition, to ensure safe and sustainable development of nanotechnology applications, potential impacts need to be evaluated. In this study, nanomaterial synthesis in a single-step gas phase reactor to continuously produce doped metal oxides was demonstrated. Copper-doped TiO2 nanomaterial properties (composition, size, and crystal phase) were independently controlled based on nanoparticle formation and growth mechanisms dictated by process control parameters. Copper dopant found to significantly affect TiO2 properties such as particle size, crystal phase, stability in the suspension, and absorption spectrum (shift from UV to visible light absorption). The in-situ charge distribution characterization of the synthesized nanomaterials was carried out by integrating a tandem differential mobility analyzer (TDMA) set up with the flame reactor synthesis system. Both singly- and doubly- charged nanoparticles were measured, with the charged fractions dependent on particle mobility and dopant concentration. A theoretical calculation was conducted to evaluate the relative importance of the two charging mechanisms, diffusion and thermo-ionization, in the flame. Nanoparticle exposure characterization was conducted during synthesis as a function of operating condition, product recovery and handling technique, and during maintenance of the reactors. Strategies were then indentified to minimize the exposure risk. The nanoparticle exposure potential varied depending on the operating conditions such as precursor feed rate, working conditions of the fume hood, ventilation system, and distance from the reactors. Nanoparticle exposure varied during product recovery and handling depending on the quantity of nanomaterial handled. Most nanomaterial applications require nanomaterials to be in solution. Thus, the role of nanomaterial physio-chemical properties (size, crystal phase, dopant types and concentrations) on dispersion properties was investigated based on hydrodynamic size and surface charge. Dopant type and concentration were found to significantly affect iso-electric point (IEP)-shifting the IEP to a high or lower pH value compared to pristine TiO2 based on the oxidation state of the dopant. The microbial inactivation effectiveness of as-synthesized nanomaterials was investigated under different light irradiation conditions. Microbial inactivation was found to strongly depend on the light irradiation condition as well as on material properties such chemical composition, crystal phase, and particle size. The potential interaction mechanisms of copper-doped TiO2 nanomaterial with microbes were also explored. The studies conducted as part of this dissertation addressed issues in nanomaterial synthesis, characterization and their potential environmental applications.

Structural and Biochemical Characterization of Chlamydia trachomatis Hypothetical Protein CT263 Supports That Menaquinone Synthesis Occurs through the Futalosine Pathway*

PubMed Central

Barta, Michael L.; Thomas, Keisha; Yuan, Hongling; Lovell, Scott; Battaile, Kevin P.; Schramm, Vern L.; Hefty, P. Scott

2014-01-01

The obligate intracellular human pathogen Chlamydia trachomatis is the etiological agent of blinding trachoma and sexually transmitted disease. Genomic sequencing of Chlamydia indicated this medically important bacterium was not exclusively dependent on the host cell for energy. In order for the electron transport chain to function, electron shuttling between membrane-embedded complexes requires lipid-soluble quinones (e.g. menaquionone or ubiquinone). The sources or biosynthetic pathways required to obtain these electron carriers within C. trachomatis are poorly understood. The 1.58Å crystal structure of C. trachomatis hypothetical protein CT263 presented here supports a role in quinone biosynthesis. Although CT263 lacks sequence-based functional annotation, the crystal structure of CT263 displays striking structural similarity to 5′-methylthioadenosine nucleosidase (MTAN) enzymes. Although CT263 lacks the active site-associated dimer interface found in prototypical MTANs, co-crystal structures with product (adenine) or substrate (5′-methylthioadenosine) indicate that the canonical active site residues are conserved. Enzymatic characterization of CT263 indicates that the futalosine pathway intermediate 6-amino-6-deoxyfutalosine (kcat/Km = 1.8 × 103 m−1 s−1), but not the prototypical MTAN substrates (e.g. S-adenosylhomocysteine and 5′-methylthioadenosine), is hydrolyzed. Bioinformatic analyses of the chlamydial proteome also support the futalosine pathway toward the synthesis of menaquinone in Chlamydiaceae. This report provides the first experimental support for quinone synthesis in Chlamydia. Menaquinone synthesis provides another target for agents to combat C. trachomatis infection. PMID:25253688

Synthesis, characterization and crystal structure of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid

NASA Astrophysics Data System (ADS)

Muche, Simon; Müller, Matthias; Hołyńska, Małgorzata

2018-03-01

The condensation reaction of ortho-vanillin and L-cysteine leads to formation of a racemic mixture of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid and not, as reported in the available literature, to a Schiff base. The racemic mixture was fully characterized by 1D and 2D NMR techniques, ESI-MS and X-ray diffraction. Addition of ZnCl2 led to formation of crystals in form of colorless needles, suitable for X-ray diffraction studies. The measured crystals were identified as the diastereomer (2R,4R)-2-(2-hydroxy-3-methoxyphenyl)thiazolidine-4-carboxylic acid 1. The bulk material is racemic. Thiazolidine exists as zwitterion in solid state, as indicated by the crystal structure.

Synthesis, characterization and single crystal x-ray analysis of a complex of iron(II) bis(2,4-dimethylphenyl)dithiophosphate with 4-ethylpyridine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Sandeep; Andotra, Savit; Kaur, Mandeep

2016-09-15

Complex of iron(II) bis(2,4-dimethylphenyl)dithiophosphate with 4-ethylpyridine [((2,4- (CH{sub 3}){sub 2}C{sub 6}H{sub 3}O)2PS2)2Fe(NC{sub 5}H{sub 4}(C{sub 2}H{sub 5})-4){sub 2}] is synthesized and characterized by elemental analysis, magnetic moment, IR spectroscopy and single crystal X-ray analysis. Complex crystallizes in the monoclinic sp. gr. P2{sub 1}/n, Z = 2. Crystal structure consists of mononuclear units with Fe(II) ion chelated by four S atoms of the two diphenyldithiophosphate ligands in bidentate manner. N atoms from two 4-ethylpyridine ligands are axially coordinated to the Fe(II) atom leading to an octahedral geometry.

Synthesis, characterization, electrical conductivity and luminescence properties of two copper(II) complexes with tridentate N2O chelating ligands containing imine bond

NASA Astrophysics Data System (ADS)

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Şahin, Onur; Serin, Selahattin

2018-03-01

In the present study, we describe the synthesis and characterization of two tridentate N2O donor ligands, namely, (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-methoxyphenol (HL1) and (E)-2-(((2-(diethylamino)ethyl)imino)methyl)-6-ethoxyphenol (HL2), and their copper(II) complexes, [Cu(L1)(CH3COO)] (1), [Cu(L2)(CH3COO)] (2). They have been synthesized under conventional methods and characterized by elemental analysis, FTIR, 1H and 13C NMR, ICP-OES, TGA and GC/MS analysis. For the morphological analysis field emission scanning electron microscopy (FESEM) was used. The geometry of the copper(II) complexes was determined by single crystal X-ray diffraction analysis. The copper(II) ions are in distorted square-pyramidal coordination environments. Complexes crystallize in monoclinic space group, P21/c. The electrical conductivity and luminescence properties of 1-2 have been investigated.

Synthesis, Characterization, Crystal Structure, and Biological Studies of a Cadmium(II) Complex with a Tridentate Ligand 4′-Chloro-2,2′:6′,2′′-Terpyridine

PubMed Central

Saghatforoush, L. A.; Valencia, L.; Chalabian, F.; Ghammamy, Sh.

2011-01-01

A new Cd(II) complex with the ligand 4′-chloro-2,2′6′,2′′-terpyridine (Cltpy), [Cd(Cltpy)(I)2], has been synthesized and characterized by CHN elemental analysis, 1H-NMR, 13C-NMR, and IR spectroscopy and structurally analyzed by X-ray single-crystal diffraction. The single-crystal X-ray analyses show that the coordination number in complex is five with three terpyridine (Cltpy) N-donor atoms and two iodine atoms. The antibacterial activities of Cltpy and its Cd(II) complex are tested against different bacteria. PMID:21738495

A facile approach towards synthesis, characterization, single crystal structure, and DFT study of 5-bromosalicylalcohol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rastogi, Rupali, E-mail: rastogirupali@ymail.com; Tarannum, Nazia; Butcher, R. J.

2016-03-15

5-Bromosalicylalcohol was prepared by the interaction of NaBH{sub 4} and 5-bromosalicylaldehyde. The use of sodium borohydride makes the reaction easy, facile, economic and does not require any toxic catalyst. The compound is characterized by FTIR, {sup 1}H NMR, {sup 13}C NMR, TEM and ESI-mass spectra. Crystal structure is determined by single crystal X-ray analysis. Quantum mechanical calculations of geometries, energies and thermodynamic parameters are carried out using density functional theory (DFT/B3LYP) method with 6-311G(d,p) basis set. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental data.

High-Pressure Synthesis and Characterization of the Ammonium Yttrium Borate (NH4)YB8O14.

PubMed

Schmitt, Martin K; Podewitz, Maren; Liedl, Klaus R; Huppertz, Hubert

2017-11-20

The first high-pressure yttrium borate (NH 4 )YB 8 O 14 was synthesized at 12.8 GPa/1300 °C using a Walker-type multianvil module. The compound crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 17.6375(9), b = 10.7160(5), and c = 4.2191(2) Å. (NH 4 )YB 8 O 14 constitutes a novel structure type but exhibits similarities to the crystal structure of β-BaB 4 O 7 . X-ray single-crystal and powder diffraction, EDX, vibrational spectroscopy as well as quantum chemical calculations were used to characterize (NH 4 )YB 8 O 14 .

Imidazolium tagged acridines: Synthesis, characterization and applications in DNA binding and anti-microbial activities

NASA Astrophysics Data System (ADS)

Raju, Gembali; Vishwanath, S.; Prasad, Archana; Patel, Basant K.; Prabusankar, Ganesan

2016-03-01

New water soluble 4,5-bis imidazolium tagged acridines have been synthesized and structurally characterized by multinuclear NMR and single crystal X-ray diffraction techniques. The DNA binding and anti-microbial activities of these acridine derivatives were investigated by fluorescence and far-UV circular dichroism studies.

Low-molecular-weight poly(alpha-methyl beta,L-malate) of microbial origin: synthesis and crystallization.

PubMed

Fernández, Carlos E; Mancera, Manuel; Holler, Eggehard; Bou, Jordi J; Galbis, Juan A; Muñoz-Guerra, Sebastián

2005-02-23

Low-molecular-weight poly(alpha-methyl beta,L-malate) made of approximately 25-30 units was prepared from microbial poly(beta,L-malic acid) by treatment with diazomethane. The thermal characterization of the polymalate methyl ester was carried out and its crystalline structure was preliminary examined. Its ability to crystallize both from solution and from the melt was comparatively evaluated.

Non-covalent interactions in 2-methylimidazolium copper(II) complex (MeImH)2[Cu(pfbz)4]: Synthesis, characterization, single crystal X-ray structure and packing analysis

NASA Astrophysics Data System (ADS)

Sharma, Raj Pal; Saini, Anju; Kumar, Santosh; Kumar, Jitendra; Sathishkumar, Ranganathan; Venugopalan, Paloth

2017-01-01

A new anionic copper(II) complex, (MeImH)2 [Cu(pfbz)4] (1) where, MeImH = 2-methylimidazolium and pfbz = pentafluorobenzoate has been isolated by reacting copper(II) sulfate pentahydrate, pentafluorobenzoic acid and 2-methylimidazole in ethanol: water mixture in 1:2:2 molar ratio. This complex 1 has been characterized by elemental analysis, thermogravimetric analysis, spectroscopic techniques (UV-Vis, FT-IR) and conductance measurements. The complex salt crystallizes in monoclinic crystal system with space group C2/c. Single crystal X-ray structure determination revealed the presence of discrete ions: [Cu(pfbz)4]2- anion and two 2-methylimidazolium cation (C4H7N2)+. The crystal lattice is stabilized by strong hydrogen bonding and F⋯F interactions between cationic-anionic and the anionic-anionic moieties respectively, besides π-π interactions.

Synthesis and Characterization of Quenched and Crystalline Phases: Q-Carbon, Q-BN, Diamond and Phase-Pure c-BN

NASA Astrophysics Data System (ADS)

Bhaumik, Anagh; Narayan, Jagdish

2018-04-01

We report the synthesis and characterization of quenched (Q-carbon and Q-BN) and crystalline (diamond and c-BN) phases using a non-equilibrium technique. These phases are formed as a result of the melting and subsequent quenching of amorphous carbon and nanocrystalline h-BN in a super undercooled state by using high-power nanosecond laser pulses. Pulsed laser annealing also leads to the formation of nanoneedles, microneedles and single-crystal thin films of diamond and c-BN. This formation is dependent on the nucleation and growth times, which are controlled by laser energy density and thermal conductivities of substrate and as-deposited thin film. The diamond nuclei present in the Q-carbon structure ( 80% sp 3) can also be grown to larger sizes using the equilibrium hot filament chemical vapor deposition process. The texture of diamond and c-BN crystals is <111> under epitaxial growth and <110> under rapid unseeded crystallization. Our nanosecond laser processing opens up a roadmap to the fabrication of novel phases on heat-sensitive substrates.

Synthesis and characterization of CuAlO(2) and AgAlO(2) delafossite oxides through low-temperature hydrothermal methods.

PubMed

Xiong, Dehua; Zeng, Xianwei; Zhang, Wenjun; Wang, Huan; Zhao, Xiujian; Chen, Wei; Cheng, Yi-Bing

2014-04-21

In this work, we present one-step low temperature hydrothermal synthesis of submicrometer particulate CuAlO2 and AgAlO2 delafossite oxides, which are two important p-type transparent conducting oxides. The synthesis parameters that affect the crystal formation processes and the product morphologies, including the selection of starting materials and their molar ratios, the pH value of precursors, the hydrothermal temperature, pressure, and reaction time, have been studied. CuAlO2 crystals have been synthesized from the starting materials of CuCl and NaAlO2 at 320-400 °C, and from Cu2O and Al2O3 at 340-400 °C, respectively. AgAlO2 crystals have been successfully synthesized at the low temperature of 190 °C, using AgNO3 and Al(NO3)3 as the starting materials and NaOH as the mineralizer. The detailed elemental compositions, thermal stability, optical properties, and synthesis mechanisms of CuAlO2 and AgAlO2 also have been studied. Noteworthy is the fact that both CuAlO2 and AgAlO2 can be stabilized up to 800 °C, and their optical transparency can reach 60%-85% in the visible range. Besides, it is believed the crystal formation mechanisms uncovered in the synthesis of CuAlO2 and AgAlO2 will prove insightful guildlines for the preparation of other delafossite oxides.

Crystal-growth kinetics of magnetite (Fe3O4) nanoparticles with Ostwald Ripening Model approach

NASA Astrophysics Data System (ADS)

Utami, S. P.; Fadli, A.; Sari, E. O.; Addabsi, A. S.

2018-04-01

Magnetite (Fe3O4) nanoparticles is a magnetic nanomaterial that have potential properties to be applied as drug delivery The purpose of this study was to determine the influence of time and temperature synthesis of magnetie characteristics and determine its crystal growth kinetics model with Ostwald ripening model approach. Magnetite nanoparticles synthesized from FeCl3, citrate, urea and polyethylene glycol with hydrothermal method at 180, 200 and 220 °C for 1,3,5,7,9 and 12 hours. Characterization by X-ray Diffraction (XRD) indicated that magnetite formed at temperatures of 200 and 220 °C. Magnetite crystallite diameter obtained was 10-29 nm. Characterization by Transmission Electron Mycroscope (TEM) shows that magnetite nanoparticles have uniform size and non-agglomerated. Core-shell shaped particles formed at 200 °C and 220 °C for 3 hours. Irregular shape obtained at 220 °C for 12 hour synthesis with particle diameter about 120 nm. Characterization using Vibrating Sample Magnetometer (VSM) shown that magnetite has super paramagnetism behaviour with the highest saturation magnetization (Ms) was 70.27 emu/g. magnetite crystal growth data at temperature of 220 °C can be fitted by Ostwald ripening growth model with growth controlled by the dissolution of surface reaction (n≈4) with the percent error of 2.53%.

Synthesis and characterization of a prominent NLO active MOF of lead with 1,5-naphthalenedisulfonic acid

NASA Astrophysics Data System (ADS)

Prasad, S. Shibu; Sudarsanakumar, M. R.; Dhanya, V. S.; Suma, S.; Kurup, M. R. Prathapachandra

2018-09-01

A new metal-organic framework of lead, [Pb(1,5-nds)(H2O)3]n (1,5-nds = 1,5-naphthalenedisulfonate) having prominent nonlinear optical property has been prepared by single gel diffusion technique at ambient condition using sodium metasilicate. The second harmonic generation efficiency was analyzed using Kurtz and Perry powder method and was found to be 30 times as large as potassium dihydrogen phosphate (KDP). Single crystal X-ray diffraction studies reveal the crystal structure. The grown crystals were further characterized by elemental analysis, powder XRD study, thermogravimetry, FT-IR and UV-visible spectral studies. The Pb2S2O4 rings in the crystal structure form a 1D channel. Hydrogen bonding and π-π interactions provide additional stability to the compound. Photoluminescence studies were also carried out.

Synthesis and characterization of iron based superconductor Nd-1111

NASA Astrophysics Data System (ADS)

Alborzi, Z.; Daadmehr, V.

2018-06-01

Polycrystalline sample of NdFeAsO0.8F0.2 was prepared by one-step solid-state reaction method. The structural and electrical properties of sample were characterized through XRD pattern and the 4-probe method. The critical temperature was obtained at 56 K. The crystal structure was tetragonal with P4/nmm:2 symmetry group.

Synthesis, characterization, antimicrobial and enzymatic activity of 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione

NASA Astrophysics Data System (ADS)

Mehdi, Sayed Hasan; Hashim, Rokiah; Ghalib, Raza Murad; Fátima C. Guedes da Silva, M.; Sulaiman, Othman; Rahman, Syed Ziaur; Murugaiyah, Vikneswaran; Marimuthu, Mani Maran

2011-12-01

The crystal structure of the title compound, 4b,9b-dihydroxy-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione has been determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P2 1/c with Z = 4. The FTIR as well as the 1H and 13C NMR spectra of the compound were also recorded and briefly discussed. The compound showed potential antimicrobial activity comparable to that of clinically used antimicrobial agents against selected microorganisms. It has selective and moderate inhibitory activity on butyryl cholinesterase enzyme and could serve as potential lead compound for synthesis of more bioactive derivatives.

Advantage of low-temperature hydrothermal synthesis to grow stoichiometric crednerite crystals

NASA Astrophysics Data System (ADS)

Poienar, Maria; Martin, Christine; Lebedev, Oleg I.; Maignan, Antoine

2018-06-01

This work reports a new approach for the growth of stoichiometric crednerite CuMnO2 crystals. The hydrothermal reaction, starting from soluble metal sulphates as precursors, is assisted by ethylene glycol and the formation of crednerite is found to depend strongly on pH and temperature. This method allows obtaining small hexagonal platelets with the larger dimension about 1.0-1.5 μm and with a composition characterized by a Cu/Mn ratio of 1. Thus, these crystals differ from the needle-like millimetric ones obtained by the flux technique for which the composition departs from the expected one and is close to Cu1.04Mn0.96. This monitoring of the cationic composition in crednerite, using hydrothermal synthesis, is important as the Cu/Mn ratio controls the low temperature antiferromagnetic ground-state.

Synthesis of renewable diesel through hydrodeoxygenation reaction from nyamplung oil (Calophyllum Inophyllum oil) using NiMo/Z and NiMo/C catalysts with rapid heating and cooling method

NASA Astrophysics Data System (ADS)

Susanto, B. H.; Prakasa, M. B.; Shahab, M. H.

2016-11-01

The synthesis of metal nanocrystal was conducted by modification preparation from simple heating method which heating and cooling process run rapidly. The result of NiMo/Z 575 °C characterizations are 33.73 m2/gram surface area and 31.80 nm crystal size. By used NiMo/C 700 °C catalyst for 30 minutes which had surface area of 263.21 m2/gram, had 31.77 nm crystal size, and good morphology, obtained catalyst with high activity, selectivity, and stability. After catalyst activated, synthesis of renewable diesel performed in hydrogenation reactor at 375 °C, 12 bar, and 800 rpm. The result of conversion was 81.99%, yield was 68.08%, and selectivity was 84.54%.

Synthesis and Characterization of Fe3O4 Nanoparticles using Polyvinyl Alcohol (PVA) as Capping Agent and Glutaraldehyde (GA) as Crosslinker

NASA Astrophysics Data System (ADS)

Budi Hutami Rahayu, Lale; Oktavia Wulandari, Ika; Herry Santjojo, Djoko; Sabarudin, Akhmad

2018-01-01

The use of polyvinyl alcohol (PVA) as a capping agent and glutaraldehyde (GA) as a crosslinker for a synthesis of magnetite (Fe3O4) nanoparticles is able to reduce agglomeration of produced Fe3O4. Additionally, oxidation of Fe3O4 by air could be avoided. The synthesis is carried out in two steps: first step, magnetite (Fe3O4) nanoparticles were prepared by dissolving the FeCl3.6H2O and FeCl2.4H2O in alkaline media (NH3.H2O). The second step, magnetite nanoparticles were coated with polyvinyl alcohol (PVA) and glutaraldehyde (GA) to obtain Fe3O4-PVA-GA. The latter material was then characterized by FTIR to determine the typical functional groups of magnetite coated with PVA-GA. X-ray Diffraction analysis was used to determine structure and size of crystal as well as the percentage of magnetite produced. It was found that the produced nanoparticles have crystal sizes around 4-9 nm with the cubic crystal structure. The percentage of magnetite phase increases when the amount of glutaraldehyde increased. SEM-EDX was employed to assess the surface morphology and elemental composition of the resulted nanoparticles. The magnetic character of the magnetite and Fe3O4- PVA-GA were studied using Electron Spin Resonance.

The Preparation and Characterization of a Sodium Tungsten Bronze

ERIC Educational Resources Information Center

Conroy, Lawrence E.

1977-01-01

Describes an experiment that utilizes the techniques of temperature synthesis, crystallization from a molten salt, oxidation-reduction in a molten salt, powder X-ray diffraction and analysis by high temperature volatilization or a specific ion electrode. (MLH)

Synthesis, characterization, and photophysical properties of a thiophene-functionalized bis(pyrazolyl) pyridine (BPP) tricarbonyl rhenium(I) complex.

PubMed

Lytwak, Lauren A; Stanley, Julie M; Mejía, Michelle L; Holliday, Bradley J

2010-09-07

A bromo tricarbonyl rhenium(I) complex with a thiophene-functionalized bis(pyrazolyl) pyridine ligand (L), ReBr(L)(CO)(3) (1), has been synthesized and characterized by variable temperature and COSY 2-D (1)H NMR spectroscopy, single-crystal X-ray diffraction, and photophysical methods. Complex 1 is highly luminescent in both solution and solid-state, consistent with phosphorescence from an emissive (3)MLCT excited state with an additional contribution from a LC (3)(pi-->pi*) transition. The single-crystal X-ray diffraction structure of the title ligand is also reported.

Synthesis, crystal structure and magnetic properties of a new B-site ordered double perovskite Sr{sub 2}CuIrO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vasala, Sami; Yamauchi, Hisao; Karppinen, Maarit, E-mail: maarit.karppinen@aalto.fi

2014-12-15

Here we synthesize and characterize a new double-perovskite oxide Sr{sub 2}CuIrO{sub 6}. The synthesis requires the use of high oxygen pressure to stabilize the VI oxidation state of iridium. The compound has a tetragonally-distorted crystal structure due to the Jahn–Teller active Cu{sup II} ion, and a high degree of B-site cation order. Magnetic transition is apparent at 15 K, but the zero-field-cooled and field-cooled susceptibilities diverge below this temperature. The high degree of cation order would exclude the possibility of a typical spin-glass, indicating that the divergence is probably due to a frustration of the magnetic interactions between Cu andmore » Ir, with a high frustration factor of f≈25. - Graphical abstract: A new member of the A{sub 2}B′B″O{sub 6} double-perovskite family with JT-active Cu{sup II} at the B′ site and Ir{sup VI} at the B″ site is synthesized through high pressure synthesis and characterized for the structural and magnetic properties. - Highlights: • New member of the A{sub 2}CuB″O{sub 6} double-perovskite family is synthesized with B″=Ir. • Stabilization of Ir{sup VI} requires the use of high oxygen pressure synthesis. • Crystal structure is tetragonally distorted due to JT-active Cu{sup II}. • Divergence of ZFC and FC curves is seen below the T{sub N} of 15 K. • This is presumably due to a frustration effect.« less

Synthesis, crystal structure and magnetic properties of a novel tetranuclear oxo-bridged iron(III) butterfly

NASA Astrophysics Data System (ADS)

Arizaga, Livia; Gancheff, Jorge S.; Faccio, Ricardo; Cañón-Mancisidor, Walter; González, Ricardo; Kremer, Carlos; Chiozzone, Raúl

2014-01-01

A novel carboxylate/picolinate oxo-bridged iron(III) cluster, namely [Na2(H2O)8][Fe4(μ-O)2(O2CPh)7(pic)2]2·2H2O (1) where pic = picolinate, has been obtained by reacting "basic iron benzoate" [Fe3O(O2CPh)6(H2O)3](O2CPh) with sodium picolinate in acetonitrile. The compound has been characterized by elemental analysis and IR spectroscopy and its crystal structure has been determined by single-crystal X-ray diffraction.

Single Crystal Synthesis and STM Studies of High Temperature Superconductors

NASA Technical Reports Server (NTRS)

Barrientos, Alfonso

1997-01-01

This is a final report for the work initiated in September of 1994 under the grant NAG8-1085 - NASA/OMU, on the fabrication of bulk and single crystal synthesis, specific heat measuring and STM studies of high temperature superconductors. Efforts were made to fabricate bulk and single crystals of mercury based superconducting material. A systematic thermal analysis on the precursors for the corresponding oxides and carbonates were carried out to synthesized bulk samples. Bulk material was used as seed in an attempt to grow single crystals by a two-step self flux process. On the other hand bulk samples were characterized by x-ray diffraction, electrical resistivity and magnetic susceptibility, We studied the specific heat behavior in the range from 80 to 300 K. Some preliminary attempts were made to study the atomic morphology of our samples. As part of our efforts we built an ac susceptibility apparatus for measuring the transition temperature of our sintered samples.

Precursor Routes to Complex Ternary Intermetallics: Single-Crystal and Microcrystalline Preparation of Clathrate-I Na8Al8Si38 from NaSi + NaAlSi.

PubMed

Dong, Yongkwan; Chai, Ping; Beekman, Matt; Zeng, Xiaoyu; Tritt, Terry M; Nolas, George S

2015-06-01

Single crystals of the ternary clathrate-I Na8Al8Si38 were synthesized by kinetically controlled thermal decomposition (KCTD), and microcrystalline Na8Al8Si38 was synthesized by spark plasma sintering (SPS) using a NaSi + NaAlSi mixture as the precursor. Na8AlxSi46-x compositions with x ≤ 8 were also synthesized by SPS from precursor mixtures of different ratios. The crystal structure of Na8Al8Si38 was investigated using both Rietveld and single-crystal refinements. Temperature-dependent transport and UV/vis measurements were employed in the characterization of Na8Al8Si38, with diffuse-reflectance measurement indicating an indirect optical gap of 0.64 eV. Our results indicate that, when more than one precursor is used, both SPS and KCTD are effective methods for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques.

Effects of ultrasonic treatment on zeolite NaA synthesized from by-product silica.

PubMed

Vaičiukynienė, Danutė; Kantautas, Aras; Vaitkevičius, Vitoldas; Jakevičius, Leonas; Rudžionis, Žymantas; Paškevičius, Mantas

2015-11-01

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects of different parameters such as crystallization time and initial materials preparation methods on the crystallinity and morphology of the synthesized zeolites were investigated. The final products were characterized by XRD and FT-IR. It was possible to obtain crystalline zeolite NaA from by-product silica in the presence of ultrasound. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis, crystal structure, NLO and Hirshfeld surface analysis of 1,2,3-triazolyl chalcone single crystal

NASA Astrophysics Data System (ADS)

Shruthi, C.; Ravindrachary, V.; Guruswamy, B.; Lokanath, N. K.; Kumara, Karthik; Goveas, Janet

2018-05-01

Needle shaped brown coloured single crystal of the title compound was grown by slow evaporation technique using methanol as solvent. The grown crystal was characterized using FT-IR, Single crystal XRD, UV-visible and NLO studies. Crystal structure was confirmed by FT-IR study and the functional groups were identified. XRD study reveals that the crystal belongs to orthorhombic crystal system with pnaa space group and the corresponding cell parameters were calculated. UV-visible spectrum shows that the crystal is transparent in the entire visible region and absorption takes place in the UV-range. NLO efficiency of the crystal obtained 0.66 times that of urea was determined by SHG test. The intermolecular interaction and percentage contribution of each individual atom in the crystal lattice was quantized using Hirshfeld surface and 2D finger print analysis.

Colloidal CdTe Nano Crystals Synthesis and Characterization

DTIC Science & Technology

2008-09-01

Nibir Dhar, and Yuanping Chen Sensors and Electron Devices Directorate, ARL Gomatam Jaganathan and Sudhir Trivedi Brimrose Corporation...POLYTECHNIC INSTITUTE ATTN I BHAT TROY NJ 12180 10 BRIMROSE CORP OF AMERICA ATTN G JAGANATHAN (5 COPIES) ATTN S TRIVEDI (5 COPIES

Synthesis, structural, thermal and Hirshfeld surface analysis of novel [1,2,4]triazolo[3,4-b][1,3,4] thiadiazine carrying 1,4-benzothiazine-3-one moiety

NASA Astrophysics Data System (ADS)

Shruthi, C.; Ravindrachary, V.; Guruswamy, B.; Lokanath, N. K.; Kumara, Karthik; Goveas, Janet

2018-05-01

Needle shaped single crystal of the title compound was grown by slow evaporation solution growth technique using ethanol as solvent. The grown single crystal was characterized using FT-IR, Single crystal XRD and Thermal analysis. The FT-IR spectrum confirms the molecular structure and identifies the different functional groups present in the compound. Single crystal XRD study reveals that the crystallized compound belongs to the monoclinic crystal system with P21/c space group and the corresponding cell parameters were identified. The thermal stability of the material was determined using both TGA and DTA analysis. The intermolecular interaction of each individual atom in the crystal lattice was estimated using Hirshfeld surface and finger print analysis.

Growth of single crystals of organic salts with large second-order optical nonlinearities by solution processes for devices

NASA Technical Reports Server (NTRS)

Leslie, Thomas M.

1995-01-01

Data obtained from the electric field induced second harmonic generation (EFISH) and Kurtz Powder Methods will be provided to MSFC for further refinement of their method. A theoretical model for predicting the second-order nonlinearities of organic salts is being worked on. Another task is the synthesis of a number of salts with various counterions. Several salts with promising SHG activities and new salts will be tested for the presence of two crystalline forms. The materials will be recrystallized from dry and wet solvents and compared for SHG efficiency. Salts that have a high SHG efficiency and no tendency to form hydrates will be documented. The synthesis of these materials are included in this report. A third task involves method to aid in the growth of large, high quality single crystals by solution processes. These crystals will be characterized for their applicability in the fabrication of devices that will be incorporated into optical computers in future programs. Single crystals of optimum quality may be obtained by crystal growth in low-gravity. The final task is the design of a temperature lowering single crystal growth apparatus for ground based work. At least one prototype will be built.

Synthesis, characterization and anti-microbial activity of pure, Cu2+ and Cd2+ doped organic NLO l-arginine trifluoroacetate single crystals

NASA Astrophysics Data System (ADS)

Prasanyaa, T.; Haris, M.; Jayaramakrishnan, V.; Amgalan, M.; Mathivanan, V.

2013-10-01

Optically transparent Cu2+ and Cd2+ doped l-arginine trifluoroacetate (LATF) single crystals were grown from its aqueous solution using the slow solvent evaporation technique. The grown crystals were characterized by powder x-ray diffraction to confirm the monoclinic crystal structure. The percentage of transmittance measured using the ultraviolet-visible-near infrared spectrophotometer was found to be more than 80% for doped crystals. The functional group analysis of the grown crystals has been made by Fourier transform infrared spectroscopy. Thermogravimetric/differential thermal analysis was performed for the grown crystals. An atomic absorption study was carried out to determine the presence of Cu2+ and Cd2+. The hardness of the grown crystals was assessed and the results show a significant variation in the hardness value between the pure and doped LATF crystals. The second harmonic generation measurements show that Cu2+ doped LATF is 2.8 times greater and Cd2+ doped is 2.6 times greater than KDP. The anti-bacterial and anti-fungal activities of the title compound were performed using the disc diffusion method against standard bacteria Escherichia coli, Xanthomonas oryzae and against the fungus Aspergillus niger and Aspergillus flavus.

Synthesis, structural, optical and thermal properties of N-methyl-N-aryl benzamide organic single crystals grown by a slow evaporation technique

NASA Astrophysics Data System (ADS)

Prabukanthan, P.; Lakshmi, R.; Harichandran, G.; Kumar, C. Sudarsana

2018-03-01

The organic materials, N-methyl-N-aryl benzamides were synthesized from benzoylation of N-methyl-4-nitrobenzenamine (MNBA) using suitably substituted benzoyl chlorides. The products were purified by recrystallization and their single crystal were grown by a slow evaporation technique. The crystals were characterized by FTIR, UV-Vis-NIR, 1H &13C NMR, and single & powder X-ray diffraction. Thermal stability of the crystals was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Dielectric and NLO properties of MNPB, FMNPB and MMNPB crystals were studied. The second harmonic generation (SHG) has been confirmed by the Kurtz powder test for all these crystals and the SHG efficiency of MMNPB crystal was found to be 2.25 times higher than that of KDP crystal.

Synthesis, growth, structural characterization, Hirshfeld analysis and nonlinear optical studies of a methyl substituted chalcone

NASA Astrophysics Data System (ADS)

Prabhu, Shobha R.; Jayarama, A.; Chandrasekharan, K.; Upadhyaya, V.; Ng, Seik Weng

2017-05-01

A new chalcone compound (2E)-3-(3-methylphenyl)-1-(4-nitrophenyl)prop-2-en-1-one (3MPNP) with molecular formula C16H13NO3 has been synthesized and crystallized by slow solvent evaporation technique. The Fourier transform infrared, Fourier transform Raman and nuclear magnetic resonance techniques were used for structural characterization. UV-visible absorption studies were carried out to study the transparency of the crystal in the visible region. Differential scanning calorimetry study shows thermal stability of crystals up to temperature 122 °C. Single crystal X-ray diffraction and powder X-ray diffraction techniques were used to study crystal structure and cell parameters. The Hirshfeld surface and 2-D fingerprint analysis were performed to study the nature of interactions and their quantitative contributions towards the crystal packing. The third order non-linear optical properties have been studied using single beam Z-scan technique and the results show that the material is a potential candidate for optical device applications such as optical limiters and optical switches.

5-phosphonato-3,4-dihydropyrimidin-2(1H)-ones: Zinc triflate-catalyzed one-pot multi-component synthesis, X-ray crystal structure and anti-inflammatory activity

NASA Astrophysics Data System (ADS)

Essid, Idris; Lahbib, Karima; Kaminsky, Werner; Ben Nasr, Cherif; Touil, Soufiane

2017-08-01

Herein we report a simple and efficient one-pot three-component synthesis of 5-phosphonato-3,4-dihydropyrimidin-2(1H)-ones, through the zinc triflate-catalyzed Biginelli-type reaction of β-ketophosphonates, aldehydes and urea. The compounds obtained were characterized by various spectroscopic tools including IR, NMR (1H, 31P, 13C) spectroscopy, mass spectrometry and single crystal X-ray diffraction. All the synthesized compounds were screened, for the first time, for anti-inflammatory activity by carrageenan-induced hind paw edema method, using female Wister rats and they showed significant anti-inflammatory activity in some cases higher than the standard indomethacin.

Utilization of biogenic tea waste silver nanoparticles for the reduction of organic dyes

NASA Astrophysics Data System (ADS)

Kaur, H.; Jaryal, N.

2018-05-01

Eco-friendly synthesis of nanoparticles is the need of the society today. Present study has been undertaken to investigate the greener approach for the preparation of medicinally and chemically important nanoparticles. Tea waste has been taken to synthesis silver nanoparticles. The nanoparticles are characterized by x-ray Diffraction, and Transmission Emission Microscopy studies. The particle size varied from 2 to 34 nm. These silver nanoparticles were evaluated for their reducing activity against four organic dyes viz crystal violet, methylene blue, Congo red and brilliant green. The particles exhibited good catalytic activity against crystal violet, methylene blue and brilliant green but no activity was visible for Congo red. Furthermore, AgNPs shows very promising and prominent antioxidant activity.

Structural and physicochemical studies of two key intermediates and the impurity in the new synthesis route of vitamin MK-7

NASA Astrophysics Data System (ADS)

Łaszcz, Marta; Trzcińska, Kinga; Kubiszewski, Marek; Krajewski, Krzysztof

2018-05-01

The MK-7 homologues of vitamin K2 are characterized by the best bioavailability among other K vitamins and act effectively in the treatment of osteoporosis and cardiovascular diseases. In this article comprehensive structural studies of two intermediates 1,4-diethoxy-2-methylnaphtalene (M2) and 1,4-diethoxy-2-methyl-3-[(2E)-3-methyl-4-(phenylsulfonyl)-2-buten-1-yl]naphtalene (M3) from the multi-step synthesis of MK-7 vitamin were described. The compounds crystallize in a monoclinic system in P21/n and P21/c for M2 and M3, respectively. Also, the isomer (2E)-4-chloro-3-methyl-1-(phenylsulfonyl)but-2-ene (M1-E verso) was isolated and the single crystal studies were performed. These three compounds were fully characterized by the 1D and 2D NMR technique as well as by Fourier-transformed infrared and Raman spectroscopies.

Synthesis, characterization, and application of two Al(OR(F))3 Lewis superacids.

PubMed

Kraft, Anne; Trapp, Nils; Himmel, Daniel; Böhrer, Hannes; Schlüter, Peter; Scherer, Harald; Krossing, Ingo

2012-07-23

We report herein the synthesis and full characterization of the donor-free Lewis superacids Al(OR(F))(3) with OR(F) = OC(CF(3))(3) (1) and OC(C(5)F(10))C(6)F(5) (2), the stabilization of 1 as adducts with the very weak Lewis bases PhF, 1,2-F(2)C(6)H(4), and SO(2), as well as the internal C-F activation pathway of 1 leading to Al(2)(F)(OR(F))(5) (4) and trimeric [FAl(OR(F))(2)](3) (5, OR(F) = OC(CF(3))(3)). Insights have been gained from NMR studies, single-crystal structure determinations, and DFT calculations. The usefulness of these Lewis acids for halide abstractions has been demonstrated by reactions with trityl chloride (NMR; crystal structures). The trityl salts allow the introduction of new, heteroleptic weakly coordinating [Cl-Al(OR(F))(3)](-) anions, for example, by hydride or alkyl abstraction reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis,and structural characterization of [(CH3(C5H4N))Ga(SCH2(CO)O)]-[(4-MepyH)]+, a novel Ga(III) five coordinate complex.

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K.; Duraj, Stan A.; Fanwic, Phillp E.; Hepp, Aloysius F.; Martuch, Robert A.

2003-01-01

The synthesis and structural characterization of a novel ionic Ga(III) five coordinate complex [{CH3(C5H4N)}Ga(SCH2(CO)O)2]-[(4-MepyH)]+, (4-Mepy = CH3(C5H5N)) from the reaction between Ga2Cl4 with sodium mercapto-acetic acid in 4-methylpyridine is described. Under basic reaction conditions the mercapto ligand is found to behave as a 2e- bidentate ligand. Single crystal X-ray diffraction studies show the complex to have a distorted square pyramidal geometry with the [(-SCH2(CO)CO-)] ligands in a trans conformation. The compound crystallizes in the P2(sub 1)/c (No. 14) space group with a = 7.7413(6) A, b = 16.744(2) A, c = 14.459(2) A, V = 1987.1(6) A(sup 3), R(F) = 0.032 and R(sub w) = 0.038.

Synthesis, structural characterization and antitumor activity of a Ca(II) coordination polymer based on 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tai, Xi-Shi, E-mail: taixs@wfu.edu.cn; Wang, Xin

2017-03-15

A new Ca(II) coordination polymer, ([CaL(H{sub 2}O){sub 4}] · (H{sub 2}O){sub 4}){sub n} (L = 4-formyl-1,3-benzenedisulfonate-2-furoic acid hydrazide) has been prepared by one-pot synthesis method. And it was characterized by elemental analysis, IR and thermal analysis. The result of X-ray single-crystal diffraction analysis shows that the Ca(II) complex molecules form one-dimensional chain structure by the bridging oxygen atoms. The anti-tumor activity of L ligand and the Ca(II) coordination polymer has also been studied.

Polyamides based on the renewable monomer, 1,13-tridecane diamine II: Synthesis and characterization of nylon 13,6

DOE PAGES

Samanta, Satyabrata; He, Jie; Selvakumar, Sermadurai; ...

2012-12-19

The nylon 13,6 was successfully synthesized and its chemical composition, thermal properties, crystal structure, and moisture absorption characterized. Melting temperature and glass transition temperature were determined to be 206 °C and 60 °C, respectively, while the equilibrium melting temperature was determined to be 248 °C. Characterization of the crystallization kinetics showed that nylon 13,6 exhibits very fast crystallization compared to the industrially important nylons, nylon 6 and nylon 6,6. Additionally, the moisture absorption of nylon 13,6 was dramatically lower than nylon 6 and nylon 6,6 which is consistent with the much lower amide content of nylon 13,6. The crystal structuremore » was determined to be different from the expected γ-form, which possess a pseudohexagonal unit cell. Instead, the x-ray scattering pattern was more similar to the α-form. Furthermore, a similar result has been obtained for other odd–even nylons including nylon 5,6, nylon 5,10, nylon 9,2, nylon 11,10, and nylon 11,12.« less

Synthesis, structural, thermal and optical studies of 1-ethyl-2,6-dimethyl-4-hydroxy pyridinium halides.

PubMed

Dhanuskodi, S; Manivannan, S; Kirschbaum, K

2006-05-15

1-Ethyl-2,6-dimethyl-4-hydroxy pyridinium chloride dihydrate and bromide dihydrate salts have been synthesized and their single crystals were grown by the slow evaporation of aqueous solution at 30 degrees C. The grown crystals were characterized by elemental analysis, FT-NMR and FT-IR techniques to confirm the formation of the expected compound. Optical transmittance window in aqueous solution was found to be 275-1100 nm by UV-vis-NIR technique. Thermogravimetric and differential thermal analyses reveal thermal stability and the presence of two water molecules in the crystal lattices. The crystal structure of chloride salt was also determined by X-ray diffraction method.

Synthesis of mesoporous zeolite single crystals with cheap porogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao Haixiang; Li Changlin; Ren Jiawen

2011-07-15

Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals have been successfully synthesized by adding soluble starch or sodium carboxymethyl cellulose (CMC) to a conventional zeolite synthesis system. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption analysis, {sup 27}Al magic angle spinning nuclear magnetic resonance ({sup 27}Al MAS NMR), temperature-programmed desorption of ammonia (NH{sub 3}-TPD) and ultraviolet-visible spectroscopy (UV-vis). The SEM images clearly show that all zeolite crystals possess the similar morphology with particle size of about 300 nm, the TEM images reveal that irregular intracrystalmore » pores are randomly distributed in the whole crystal. {sup 27}Al MAS NMR spectra indicate that nearly all of the Al atoms are in tetrahedral co-ordination in ZSM-5, UV-vis spectra confirm that nearly all of titanium atoms are incorporated into the framework of TS-1. The catalytic activity of meso-ZSM-5 in acetalization of cyclohexanone and meso-TS-1 in hydroxylation of phenol was also studied. The synthesis method reported in this paper is cost-effective and environmental friendly, can be easily expended to prepare other hierarchical structured zeolites. - Graphical abstract: Mesoporous zeolite single crystals were synthesized by using cheap porogens as template. Highlights: > Mesoporous zeolite (silicalite-1, ZSM-5, TS-1) single crystals were synthesized. > Soluble starch or sodium carboxymethyl cellulose (CMC) was used as porogens. > The mesoporous zeolites had connected mesopores although closed pores existed. > Higher catalytic activities were obtained.« less

Hydrothermal synthesis, crystal structures, and enantioselective adsorption property of bis(L-histidinato)nickel(II) monohydrate

NASA Astrophysics Data System (ADS)

Ramos, Christian Paul L.; Conato, Marlon T.

2018-05-01

Despite the numerous researches in metal-organic frameworks (MOFs), there are only few reports on biologically important amino acids, histidine in particular, on its use as bridging ligand in the construction of open-framework architectures. In this work, hydrothermal synthesis was used to prepare a compound based on Ni2+ and histidine. The coordination assembly of imidazole side chain of histidine with divalent nickel ions in aqueous condition yielded purple prismatic solids. Single crystal X-ray diffraction (XRD) analysis of the product revealed structure for Ni(C6H8N3O2)2 • H2O that has a monoclinic (C2) structure with lattice parameters, a = 29.41, b = 8.27, c = 6.31 Å, β = 90.01 ˚. Circular dichroism - optical rotatory dispersion (CD-ORD), Powder X-ray diffraction (PXRD) and Fourier transform - infrared spectroscopy (FT-IR) analyses are conducted to further characterize the crystals. Enantioselective adsorption analysis using racemic mixture of 2-butanol confirmed bis(L-histidinato)nickel(II) monohydrate MOF crystal's enantioselective property preferentially favoring the adsorption of (S)-2-butanol isomer.

Tetraphenylphosphonium allyldithiocarbimates derived from Morita-Baylis-Hillman adducts: Synthesis, characterization, crystal structure and antifungal activity

NASA Astrophysics Data System (ADS)

Tavares, Eder C.; Rubinger, Mayura M. M.; Filho, Eclair V.; Oliveira, Marcelo R. L.; Piló-Veloso, Dorila; Ellena, Javier; Guilardi, Silvana; Souza, Rafael A. C.; Zambolim, Laércio

2016-02-01

Botrytis blight is a very destructive disease caused by Botrytis spp., infecting flowers, trees, vegetables and fruits. Twelve new compounds were prepared by the reaction of potassium N-aryl-sulfonyldithiocarbimates with Morita-Baylis-Hillman derivatives bearing phenyl and furyl groups. These are the first examples of allyldithiocarbimate anions and were isolated as tetraphenylphosphonium salts. The new compounds were characterized by HRMS, NMR and Infrared spectroscopy. Further, the structures of three allyldithiocarbimates were determined by single crystal X-ray diffraction. The compounds are isostructural and crystallize in the space group P21/c of the monoclinic system, and the allyldithiocarbimate anions present Z configuration. All the compounds were active against Botrytis cinerea. The best results were achieved with the tetraphenylphosphonium (Z)-3-(furan-2-yl)-2-(methoxycarbonyl)allyl-(4-chlorophenylsulfonyl)dithiocarbimate (IC50 38 μM).

Synthesis, Structural and Antioxidant Studies of Some Novel N-Ethyl Phthalimide Esters

PubMed Central

Chandraju, Siddegowda; Win, Yip-Foo; Tan, Weng Kang; Quah, Ching Kheng; Fun, Hoong-Kun

2015-01-01

A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity. PMID:25742494

Synthesis, structural and antioxidant studies of some novel N-ethyl phthalimide esters.

PubMed

Chidan Kumar, C S; Loh, Wan-Sin; Chandraju, Siddegowda; Win, Yip-Foo; Tan, Weng Kang; Quah, Ching Kheng; Fun, Hoong-Kun

2015-01-01

A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity.

Semiconductor neutron detectors

NASA Astrophysics Data System (ADS)

Gueorguiev, Andrey; Hong, Huicong; Tower, Joshua; Kim, Hadong; Cirignano, Leonard; Burger, Arnold; Shah, Kanai

2016-09-01

Lithium Indium Selenide (LiInSe2) has been under development in RMD Inc. and Fisk University for room temperature thermal neutron detection due to a number of promising properties. The recent advances of the crystal growth, material processing, and detector fabrication technologies allowed us to fabricate large detectors with 100 mm2 active area. The thermal neutron detection sensitivity and gamma rejection ratio (GRR) were comparable to 3He tube with 10 atm gas pressure at comparable dimensions. The synthesis, crystal growth, detector fabrication, and characterization are reported in this paper.

Selective synthesis of FAU-type zeolites

NASA Astrophysics Data System (ADS)

Garcia, Gustavo; Cabrera, Saúl; Hedlund, Jonas; Mouzon, Johanne

2018-05-01

In the present work, parameters influencing the selectivity of the synthesis of FAU-zeolites from diatomite were studied. The final products after varying synthesis time were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and gas adsorption. It was found that high concentrations of NaCl could completely inhibit the formation of zeolite P, which otherwise usually forms as soon as maximum FAU crystallinity is reached. In the presence of NaCl, the FAU crystals were stable for extended time after completed crystallization of FAU before formation of sodalite. It was also found that addition of NaCl barely changed the crystallization kinetics of FAU zeolite and only reduced the final FAU particle size and SiO2/Al2O3 ratio slightly. Other salts containing either Na or Cl were also investigated. Our results suggest that there is a synergistic effect between Na+ and Cl-. This is attributed to the formation of (Na4Cl)3+ clusters that stabilize the sodalite cages. This new finding may be used to increase the selectivity of syntheses leading to FAU-zeolites and avoid the formation of undesirable by-products, especially if impure natural sources of aluminosilica are used.

Synthesis, characterization, crystal structures and DFT studies of some new 1,2,4-triazole and triazolidin derivatives

NASA Astrophysics Data System (ADS)

Abosadiya, Hamza M.; Anouar, El Hassane; Abusaadiya, Salima M.; Hasbullah, Siti Aishah; Yamin, Bohari M.

2018-01-01

A simple efficient method for synthesis of some new 1,2,4-Triazole and Triazolidin derivatives namely, 5-(4-methoxyphenyl)-2-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1a), (2-chlorophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1b) and (2-iodophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1c) have been synthesized in high yields from the reaction of carbonoyl isothiocyanate with phenyl hydrazine. The final products were characterized by FT-IR, 1H and 13C NMR spectroscopic techniques. X-ray crystallographic studies showed that 1a crystallized in triclinic crystal system with space group Pī, while both 1b and 1c crystallized in orthorhombic crystal system with space group Pna21. The asymmetric unit of 1a consists two crystallographically independent molecules, while only one molecule in asymmetric unit for both 1b and 1c compounds. All molecules possess Csbnd H ….S intramolecular hydrogen bonds which formed a pseudo-six-membered ring. Experimental results have been confirmed by the state-of-art density functional theory (DFT) in gas and solvent phase by using five different hybrid functionals B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0 combined with 6-311++G(d, p) basis set. The experimental data are relatively well produced, and relatively good correlations are obtained between the predicted and experimental data.

Synthesis, characterization, and ion-exchange properties of colloidal zeolite nanocrystals

NASA Astrophysics Data System (ADS)

Jawor, Anna; Jeong, Byeong-Heon; Hoek, Eric M. V.

2009-10-01

Here, we present physical-chemical properties of Linde type A (LTA) zeolite crystals synthesized via conventional hydrothermal and microwave heating methods. Both heating methods produced LTA crystals that were sub-micron in size, highly negatively charged, super-hydrophilic, and stable when dispersed in water. However, microwave heating produced relatively narrow crystal size distributions, required much shorter heating times, and did not significantly change composition, crystallinity, or surface chemistry. Moreover, microwave heating allowed systematic variation of crystal size by varying heating temperature and time during the crystallization reaction, thus producing a continuous gradient of crystal sizes ranging from about 90 to 300 nm. In ion-exchange studies, colloidal zeolites exhibited excellent sorption kinetics and capacity for divalent metal ions, suggesting their potential for use in water softening, scale inhibition, and scavenging of toxic metal ions from water.

Supramolecular Cocrystals of Gliclazide: Synthesis, Characterization and Evaluation.

PubMed

Chadha, Renu; Rani, Dimpy; Goyal, Parnika

2017-03-01

To prepare the supramolecular cocrystals of gliclazide (GL, a BCS class II drug molecule) via mechanochemical route, with the goal of improving physicochemical and biopharmaceutical properties. Two cocrystals of GL with GRAS status coformers, sebacic acid (GL-SB; 1:1) and α-hydroxyacetic acid (GL-HA; 1:1) were screened out using liquid assisted grinding. The prepared cocrystals were characterized using thermal and analytical techniques followed by evaluation of antidiabetic activity and pharmacokinetic parameters. The generation of new, single and pure crystal forms was characterized by DSC and PXRD. The crystal structure determination from PXRD revealed the existence of both cocrystals in triclinic (P-1) crystal system. The hydrogen bonded network, determined by material studio was well supported by shifts in FTIR and SSNMR. Both the new solid forms displayed improved solubility, IDR, antidiabetic activity and pharmacokinetic parameters as compared to GL. The improvement in these physicochemical and biopharmaceutical properties corroborated the fact that the supramolecular cocrystallization may be useful in the development of pharmaceutical crystalline materials with interesting network and properties.

Synthesis and characterization of new complexes of nickel (II), palladium (II) and platinum(II) with derived sulfonamide ligand: Structure, DFT study, antibacterial and cytotoxicity activities

NASA Astrophysics Data System (ADS)

Bouchoucha, Afaf; Zaater, Sihem; Bouacida, Sofiane; Merazig, Hocine; Djabbar, Safia

2018-06-01

The synthesis, characterization and biological study of new nickel (II), palladium (II), and platinum (II) complexes with sulfamethoxazole ligand used in pharmaceutical field, were reported. [MLCl2].nH2O is the general formula obtained for Pd(II) and Pt(II) complexes. These complexes have been prepared and characterized by elemental analysis, FTIR, 1HNMR spectral, magnetic measurements, UV-Visible spectra, and conductivity. The DFT calculation was applied to optimize the geometric structure of the Pd(II) and Pt(II) complexes. A new single-crystal X-ray structure of the Ni(II) complex has been determined. It crystallized in monoclinic system with P 21/c space group and Z = 8. The invitro antibacterial activity of ligand and complexes against Escherichia coli, P. aeruginosa, Klebsiella pneumoniae, S. aureus, Bacillus subtilis species has been carried out and compared using agar-diffusion method. The Pd(II) and Pt(II) complexes showed a remarkable inhibition against bacteria tested. The invitro cytotoxicity assay of the complexes against three cell lines chronic myelogenous leukaemia (K562), human colon adenocarcinoma (HT-29) and breast cancer (MCF-7) was also reported.

Synthesis, growth and characterization of 3-nitroacetanilide—A new organic nonlinear optical crystal by Bridgman technique

NASA Astrophysics Data System (ADS)

Lenin, M.; Ramasamy, P.

2008-10-01

Single crystals of 3-nitroacetanilide, an organic nonlinear optical material has been grown by the Bridgman-Stockbarger method. The single crystal X-ray diffraction (XRD) data revealed the noncentrosymmetric crystal structure, which is an essential criterion for second harmonic generation. The crystalline nature of the grown crystals was confirmed using powder XRD techniques. The functional group of the compound is identified by FTIR spectrum. The thermal stability and its tendency to grow as single crystal in solution and in melt have been identified for the new title compound. The UV-vis spectrum of mNAA shows the lower optical cut off at 400 nm and was transparent in the visible region. The second harmonic generation efficiency was found using Kurtz powder technique. The dielectric constant and dielectric loss of the crystal were measured as a function of frequency and temperature, and the results are discussed.

Hydrothermal Synthesis, Crystal Structure, and Photoluminescent Properties of Li[UO2(CH3COO)3]3[Co(H2O)6

NASA Astrophysics Data System (ADS)

AlDamen, Murad A.; Juwhari, Hassan K.; Al-zuheiri, Aya M.; Alnazer, Louy A.

2017-12-01

Single crystal of Li[UO2(CH3COO)3]3[Co(H2O)6] was prepared and found to crystallize in the monoclinic crystal system in the sp. gr. C2/ c, with Z = 2, and unit cell parameters a = 22.1857(15) Å, b = 13.6477(8) Å, c = 15.6921(10) Å, β = 117.842(9)°, V = 4201.3(4) Å3. The crystal was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The single crystal X-ray diffraction analysis revealed that the crystal has a lamellar structure in which a cobalt hydrate is sandwiched within the Li[UO2(CH3COO)3]3 2- chains. Furthermore, the room temperature photoluminescence spectrum of the complex was investigated in the solid state.

Crystallization of sodium chloride from a concentrated calcium chloride-potassium chloride-sodium chloride solution in a CMSMPR crystallizer: Observation of crystal size distribution and model validation

NASA Astrophysics Data System (ADS)

Choi, Byung Sang

Compared to overwhelming technical data available in other advanced technologies, knowledge about particle technology, especially in particle synthesis from a solution, is still poor due to the lack of available equipment to study crystallization phenomena in a crystallizer. Recent technical advances in particle size measurement such as Coulter counter and laser light scattering have made in/ex situ study of some of particle synthesis, i.e., growth, attrition, and aggregation, possible with simple systems. Even with these advancements in measurement technology, to grasp fully the crystallization phenomena requires further theoretical and technical advances in understanding such particle synthesis mechanisms. Therefore, it is the motive of this work to establish the general processing parameters and to produce rigorous experimental data with reliable performance and characterization that rigorously account for the crystallization phenomena of nucleation, growth, aggregation, and breakage including their variations with time and space in a controlled continuous mixed-suspension mixed-product removal (CMSMPR) crystallizer. This dissertation reports the results and achievements in the following areas: (1) experimental programs to support the development and validation of the phenomenological models and generation of laboratory data for the purpose of testing, refining, and validating the crystallization process, (2) development of laboratory well-mixed crystallizer system and experimental protocols to generate crystal size distribution (CSD) data, (3) the effects of feed solution concentration, crystallization temperature, feed flow rate, and mixing speed, as well as different types of mixers resulting in the evolution of CSDs with time from a concentrated brine solution, (4) with statistically designed experiments the effects of processing variables on the resultant particle structure and CSD at steady state were quantified and related to each of those operating conditions by studying the detailed crystallization processes, such as nucleation, growth, and breakage, as well as agglomeration. The purification of CaCl2 solution involving the crystallization of NaCl from the solution mixture of CaCl2, KCl, and NaCl as shipped from Dow Chemical, Ludington, in a CMSMPR crystallizer was studied as our model system because of its nucleation and crystal growth tendencies with less agglomeration. This project also generated a significant body of experimental data that are available at URL that is http://www.che.utah.edu/˜ring/CrystallizationWeb.

Synthesis, Characterization, and Theoretical Considerations of 1,2-bis(oxyamino)ethane Salts

NASA Technical Reports Server (NTRS)

Crake, Greg; Hawkins, Tom; Hall, Leslie; Tollison, Kerri; Brand, Adam

2003-01-01

The synthesis, characterization, theoretical calculations, and safety studies of energetic salts of 1,2- bis(oxyamino) ethane, (H2N-O-CH2-CH2-O-NH2), were carried out. The salts were characterized by vibrational (infrared, Raman), multinuclear nmr studies (1H, 13C), differential scanning calorimetry (DSC); elemental analysis; and initial safety testing (impact and friction sensitivity) . Theoretical calculations on the neutral, monoprotonated, and doubly protonated species of ethylene bisoxyamine were carried out using xxxx level of theory for the lowest energy structure and these theoretical results compared with the experimentally observed bond distances and vibrational (ir, Raman) frequency values. The single crystal X-ray diffraction study was carried out on the mono-perchlorate salt revealing a high degree of hydrogen bonding with an unexpected structure.

Precipitation method for barium metaborate (BaB2O4) synthesis from borax solution

NASA Astrophysics Data System (ADS)

Akşener, Eymen; Figen, Aysel Kantürk; Pişkin, Sabriye

2013-12-01

In this study, barium metaborate (BaB2O4, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also β-BaB2O4 single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na2B4O7ṡ10H2O, BDH) and barium chloride (BaCI2ṡ2H2O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.

Synthesis, crystal growth, structural, thermal and optical properties of naphthalene picrate an organic NLO material.

PubMed

Chandramohan, A; Bharathikannan, R; Kandavelu, V; Chandrasekaran, J; Kandhaswamy, M A

2008-12-01

Crystalline substance of naphthalene picrate (NP) was synthesized and single crystals were grown using slow evaporation solution growth technique. The solubility of the naphthalene picrate complex was estimated using different solvents such as chloroform and benzene. The material was characterized by elemental analysis, powder X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and fourier transform-infrared (FT-IR) techniques. The electronic absorption was studied through UV-vis spectrophotometer. Thermal behavior and stability of the crystal were studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The second harmonic generation (SHG) of the material was confirmed using Nd:YAG laser.

Colorimetric detection of hydrogen peroxide by dioxido-vanadium(V) complex containing hydrazone ligand: synthesis and crystal structure

NASA Astrophysics Data System (ADS)

Kurbah, Sunshine D.; Syiemlieh, Ibanphylla; Lal, Ram A.

2018-03-01

Dioxido-vanadium(V) complex has been synthesized in good yield, the complex was characterized by IR, UV-visible and 1H NMR spectroscopy. Single crystal X-ray crystallography techniques were used to assign the structure of the complex. Complex crystallized with monoclinic P21/c space group with cell parameters a (Å) = 39.516(5), b (Å) = 6.2571(11), c (Å) = 17.424(2), α (°) = 90, β (°) = 102.668(12) and γ (°) = 90. The hydrazone ligand is coordinate to metal ion in tridentate fashion through -ONO- donor atoms forming a distorted square pyramidal geometry around the metal ion.

Synthesis and structural characterization of Li3K3Y7(BO3)9

NASA Astrophysics Data System (ADS)

Bräuchle, Sebastian; Huppertz, Hubert

2017-09-01

Li3K3Y7(BO3)9 was prepared by high-temperature solid state synthesis at 900 °C in a platinum crucible from lithium carbonate, potassium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes in the orthorhombic space group Pca21 (no. 29) (Z = 4). The structure was refined from single-crystal X-ray diffraction data: a = 20.743(8), b = 6.387(4), c = 17.474(4) Å, V = 2315.2(2) Å3, R1 = 0.0473, and wR2 = 0.0637 for all data. The crystal structure of Li3K3Y7(BO3)9 consists of isolated BO3 groups forming [Li3B4O21] units in combination with LiO6 octahedra in the ac plane, which are interconnected to each other by additional planar BO3 groups. The Y3+ and K+ cations are arranged in layers along the a-axis.

Ionic liquid catalyzed one-pot multi-component synthesis, characterization and antibacterial activity of novel chromeno[2,3-d]pyrimidin-8-amine derivatives

NASA Astrophysics Data System (ADS)

Kanakaraju, Sankari; Prasanna, Bethanamudi; Basavoju, Srinivas; Chandramouli, G. V. P.

2012-06-01

An efficient, simple and convenient method for the one-pot multi-component synthesis of novel chromeno[2,3-d]pyrimidin-8-amine derivatives has been accomplished by starting from α-naphthol, aryl aldehydes, malononitrile and NH4Cl. The reaction has been catalyzed by 1-butyl-3-methylimidazolium tetrafluoroborate [bmim]BF4 ionic liquid. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, mass spectra, and elemental analysis. The structure of compound 4a was confirmed by single-crystal X-ray diffraction. All the synthesized compounds were evaluated for their in vitro antibacterial activity.

Synthesis, characterization and biological activities of copper(II) complex of 2-Benzimidazolyl-urea and the nitrate salt of 2-Benzimidazolyl-urea

NASA Astrophysics Data System (ADS)

Poyraz, Mehmet; Sari, Musa; Banti, Christina N.; Hadjikakou, Sotiris K.

2017-10-01

The synthesis of the complex {[Cu(BZIMU)2](NO3)2} (1) (BZIMU = 2-Benzimidazolyl-urea) is reported here. The complex 1 was characterized by elemental analysis, FT-IR, magnetic susceptibility and molar conductance measurements. The crystal structures of 1 and of the nitrate salt of [(BZIMUH+)(NO3)-] (2) were determined by X-ray diffraction analysis. The copper complex 1 and [(BZIMUH+)(NO3)-] (2) were evaluated for their in vitro cytotoxic activity (cell viability) against human cervix adenocarcinoma (HeLa) and human breast adenocarcinoma (MCF-7) cell line and normal human fetal lung fibroblast cells (MRC-5) with SRB assay.

Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torre-Fernández, Laura; Khainakova, Olena A.; Espina, Aránzazu

2015-05-15

A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2{sub 1}/c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D), was also isolated and the crystal structure was determined (monoclinic P2{sub 1}/c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N)more » analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal structure of 1D metastable phase was also determined. • Thermal behavior of 2D compound is strongly dependent on the selected heating rate. • Magnetic measurements show no magnetic ordering down to 4 K.« less

Synthesis and Characterization of a New Co-Crystal Explosive with High Energy and Good Sensitivity

NASA Astrophysics Data System (ADS)

Gao, Han; Jiang, Wei; Liu, Jie; Hao, Gazi; Xiao, Lei; Ke, Xiang; Chen, Teng

2017-10-01

A new energetic co-crystal consisting of one of the most powerful explosive molecules 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and the military explosive cyclotrimethylenetrinitramine (RDX) was prepared with a simple solvent evaporation method. Scanning electron microscopy (SEM) revealed the morphology of the bar-shaped product, which differed greatly from the morphology of the individual components. Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction spectrum (XRD), and differential scanning calorimetry (DSC) proved the formation of the co-crystal at the molecular level. The result of mechanical sensitivity test indicated the sensitivity was effectively reduced compared to raw CL-20. Finally, a possible crystallization mechanism was discussed.

Additive-mediated electrochemical synthesis of platelike copper crystals for methanol electrooxidation.

PubMed

Venkatasubramanian, Rajesh; He, Jibao; Johnson, Michael W; Stern, Ilan; Kim, Dae Ho; Pesika, Noshir S

2013-10-29

A room-temperature electrochemical approach to synthesizing anisotropic platelike copper microcrystals and nanocrystals in the presence of potassium bromide is presented. Morphological and elemental characterization was performed using SEM, TEM, and XRD to confirm the anisotropic morphology and crystal structure of the synthesized copper particles. A possible mechanism for explaining the anisotropic crystal growth is proposed on the basis of the preferential adsorption of bromide ions to selective crystal faces. The shape-dependent electrocatalytic property of copper particles is demonstrated by its enhanced catalytic activity for methanol oxidation. Further development of such anisotropic copper particles localized on an electrode surface will lead us to find a suitable alternative for noble metal-based electrocatalysts for the methanol oxidation reaction relevant to fuel cells.

High temperature hydrothermal synthesis of rare-earth titanates: synthesis and structure of RE5Ti4O15(OH) (RE = La, Er), Sm3TiO5(OH)3, RE5Ti2O11(OH) (RE = Tm-Lu) and Ce2Ti4O11.

PubMed

Fulle, Kyle; Sanjeewa, Liurukara D; McMillen, Colin D; Kolis, Joseph W

2018-05-15

Reactions of rare-earth oxides with TiO2 were performed in high temperature (650-700 °C) hydrothermal fluids. Two different mineralizer fluids were examined, 20 M KOH and 30 M CsF, and their respective products analyzed. When concentrated KOH fluids were used, single crystals of a variety of new OH- containing species were isolated and structurally characterized: RE5Ti4O15(OH) (RE = La, Er) I, Sm3TiO5(OH)3II and RE5Ti2O11(OH) (RE = Tm-Lu) III. La5Ti4O15(OH) I crystallizes in the orthorhombic space group Pnnm with unit cell dimensions of a = 30.5152(12) Å, b = 5.5832(2) Å, c = 7.7590(3) Å and V = 1321.92(9) Å3, Z = 4. Sm3TiO5(OH)3II crystallizes in the monoclinic space group P21/m with unit cell parameters of a = 5.6066(2) Å, b = 10.4622(4) Å, c = 6.1258(2) Å and β = 104.7390(10)°, V = 347.50(2) Å3, Z = 2. Lu5Ti2O11(OH) III crystallizes in the monoclinic space group C2/m with unit cell dimensions of a = 12.1252(9) Å, b = 5.8243(4) Å, c = 7.0407(5) Å, β = 106.939(3)° and V = 475.65(6) Å3, Z = 2. When concentrated fluoride solutions are used, mostly RE2Ti2O7 type compounds were isolated in either cubic or monoclinic phases. In the case of cerium, Ce2Ti4O11IV was isolated that crystallizes in the monoclinic space group C2/c with unit cell parameters of a = 13.6875(7) Å, b = 5.0955(3) Å, c = 12.8592(7) Å, β = 108.964(2)° and V = 848.18(8) Å3, Z = 4. The synthesis, structural characterization, and supporting characterization are reported for all compounds. The work highlights the complementary nature of hydroxide and fluoride fluids in studying the reactivity of refractory oxides.

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

PubMed Central

Hagmann, Joseph A.; Le, Son T.; Richter, Curt A.; Seiler, David G.

2016-01-01

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T. PMID:26863449

Synthesis, crystal growth and characterization of a phase matchable nonlinear optical single crystal: p-chloro dibenzylideneacetone

NASA Astrophysics Data System (ADS)

Ravindra, H. J.; John Kiran, A.; Nooji, Satheesha Rai; Dharmaprakash, S. M.; Chandrasekharan, K.; Kalluraya, Balakrishna; Rotermund, Fabian

2008-05-01

Good quality single crystals of p-chloro dibenzylideneacetone (CDBA) of size 13 mm×8 mm×2 mm were grown by slow evaporation solution growth technique. The grown crystals were confirmed by elemental analysis, Fourier transform infrared (FTIR) analysis and single crystal X-ray diffraction techniques. From the thermo gravimetric/differential thermal (TG/DT) analysis, the CDBA was found to be thermally stable up to 250 °C. The mechanical stability of the crystal is comparable with that of the other reported chalcones. The lower optical cut-off wavelength for this crystal was observed at 440 nm. The laser damage threshold of the crystal was 0.6 GW/cm 2 at 532 nm. The second harmonic generation conversion efficiency of the powder sample of CDBA was found to be 4.5 times greater than that of urea. We also demonstrate the existence of the phase matching property in this crystal using Kurtz powder technique.

Synthesis and characterization of barium hexaferrite with manganese (Mn) doping material as anti-radar

NASA Astrophysics Data System (ADS)

Susilawati, Doyan, Aris; Khalilurrahman

2017-01-01

Have been successfully synthesized barium powder doping Manganese hexaferrite with the expected potential as anti-radar material. Synthesis was done by using the co-precipitation method, the variation of the variable x concentrations used were 0; 0.2; 0.4; and 0.6 and calcined at temperatures of 400, 600 and 800°C. Characterization powders of hexaferrite have used XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), LCR (inductance, capacitance, and resistance) meter, and VSM (Vibrating Sample Magnetometer). The higher the concentration and temperature of calcinations given affect the color of the powder. The test results using XRD indicates that it has formed barium hexaferrite phase with a hexagonal crystal structure. Tests using SEM showed that all the constituent elements barium powder hexaferrite by doping Manganese powders have been spread evenly. XRD test results were confirmed by a test using a TEM showing the crystal structure and the powder was sized nano particles. The results from the LCR meter showed that the barium powder hexaferrite by doping Manganese that has been synthesized classified in semiconductor materials. The result from VSM showed that the value of coercivity magnetic powder doped barium hexaferrite Manganese is smaller when compared with barium hexaferrite without doping and belong to the soft magnetic. Based on the results of the synthesis and characterization, we can conclude that the barium powder heksaferrite by doping Manganese potential as a material anti-radar.

Screening and Characterization of Hydrate Forms of T-3256336, a Novel Inhibitor of Apoptosis (IAP) Protein Antagonist.

PubMed

Takeuchi, Shoko; Kojima, Takashi; Hashimoto, Kentaro; Saito, Bunnai; Sumi, Hiroyuki; Ishikawa, Tomoyasu; Ikeda, Yukihiro

2015-01-01

Different crystal packing of hydrates from anhydrate crystals leads to different physical properties, such as solubility and stability. Investigation of the potential of varied hydrate formation, and understanding the stability in an anhydrous/hydrate system, are crucial to prevent an undesired transition during the manufacturing process and storage. Only one anhydrous form of T-3256336, a novel inhibitor of apoptosis (IAP) protein antagonist, was discovered during synthesis, and no hydrate form has been identified. In this study, we conducted hydrate screening such as dynamic water vapor sorption/desorption (DVS), and the slurry experiment, and characterized the solid-state properties of anhydrous/hydrate forms to determine the most desirable crystalline form for development. New hydrate forms, both mono-hydrate and hemi-hydrate forms, were discovered as a result of this hydrate screening. The characterization of two new hydrate forms was conducted, and the anhydrous form was determined to be the most desirable development form of T-3256336 in terms of solid-state stability. In addition, the stability of the anhydrous form was investigated using the water content and temperature controlled slurry experiment to obtain the desirable crystal form in the crystallization process. The water content regions of the stable phase of the desired form, the anhydrous form, were identified for the cooling crystallization process.

Purification, characterization and crystallization of the human 80S ribosome

PubMed Central

Khatter, Heena; Myasnikov, Alexander G.; Mastio, Leslie; Billas, Isabelle M. L.; Birck, Catherine; Stella, Stefano; Klaholz, Bruno P.

2014-01-01

Ribosomes are key macromolecular protein synthesis machineries in the cell. Human ribosomes have so far not been studied to atomic resolution because of their particularly complex structure as compared with other eukaryotic or prokaryotic ribosomes, and they are difficult to prepare to high homogeneity, which is a key requisite for high-resolution structural work. We established a purification protocol for human 80S ribosomes isolated from HeLa cells that allows obtaining large quantities of homogenous samples as characterized by biophysical methods using analytical ultracentrifugation and multiangle laser light scattering. Samples prepared under different conditions were characterized by direct single particle imaging using cryo electron microscopy, which helped optimizing the preparation protocol. From a small data set, a 3D reconstruction at subnanometric resolution was obtained showing all prominent structural features of the human ribosome, and revealing a salt concentration dependence of the presence of the exit site tRNA, which we show is critical for obtaining crystals. With these well-characterized samples first human 80S ribosome crystals were obtained from several crystallization conditions in capillaries and sitting drops, which diffract to 26 Å resolution at cryo temperatures and for which the crystallographic parameters were determined, paving the way for future high-resolution work. PMID:24452798

A novel coordination polymer of Ni(II) based on 1,3,5-benzenetricarboxylic acid synthesis, characterization, crystal structure, thermal study, and luminescent properties

NASA Astrophysics Data System (ADS)

Saheli, Sania; Rezvani, Alireza

2017-01-01

A new metal-organic framework (MOF) formulated as [Ni(H2btc)(OH)(H2O)2] (1) (H3btc = 1,3,5-benzenetricarboxylic acid) was synthesized using the hydrothermal technique. The complex 1 was characterized by elemental analysis, infrared spectroscopy, and powder X-ray diffraction in addition to single crystal X-ray diffraction. X-ray crystal structural analysis displayed that the compound belonged to the monoclinic space group P21/n with cell parameters a = 6.8658(14) Å, b = 18.849(4) Å, c = 8.5608(17) Å. In the title complex, ligand is linked to metal centers through two μ-oxo bridges and forming a 2D layer which is led to form an interesting geometry. The thermal stability and fluorescence property of 1 have also been investigated.

Hydrothermal synthesis and structural characterization of a novel three-dimensional supramolecular framework constructed by zinc salt and pyridine-2,5-dicarboxylate

NASA Astrophysics Data System (ADS)

Wang, Xinlong; Qin, Chao; Wang, Enbo; Hu, Changwen; Xu, Lin

2004-07-01

A novel metal-organic coordination polymer, [Zn(PDB)(H 2O) 2] 4 n (H 2PDB=pyridine-2,5-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. Colorless crystals crystallized in the triclinic system, space group P-1, a=7.0562(14) Å, b=7.38526(15) Å, c=18.4611(4) Å, α=90.01(3)°, β=96.98(3)°, γ=115.67(3)°, V=859.1(3) Å 3, Z=1 and R=0.0334. The structure of the compound exhibits a novel three-dimensional supramolecular network, mainly based on multipoint hydrogen bonds originated from within and outside of a large 24-membered ring. Interestingly, the three-dimensional network consists of one-dimensional parallelogrammic channels in which coordinated water molecules point into the channel wall.

Synthesis and crystal structure of an oxovanadium(IV) complex with a pyrazolone ligand and its use as a heterogeneous catalyst for the oxidation of styrene under mild conditions.

PubMed

Parihar, Sanjay; Pathan, Soyeb; Jadeja, R N; Patel, Anjali; Gupta, Vivek K

2012-01-16

1-Phenyl-3-methyl-4-touloyl-5-pyrazolone (ligand) was synthesized and used to prepare an oxovanadium(IV) complex. The complex was characterized by single-crystal X-ray analysis and various spectroscopic techniques. The single-crystal X-ray analysis of the complex shows that the ligands are coordinated in a syn configuration to each other and create a distorted octahedral environment around the metal ion. A heterogeneous catalyst comprising an oxovanadium(IV) complex and hydrous zirconia was synthesized, characterized by various physicochemical techniques, and successfully used for the solvent-free oxidation of styrene. The influence of the reaction parameters (percent loading, molar ratio of the substrate to H(2)O(2), amount of catalyst, and reaction time) was studied. The catalyst was reused three times without any significant loss in the catalytic activity.

Synthesis of gold nanoparticles using silk fibroin and their characterization

NASA Astrophysics Data System (ADS)

Gowda, Mahadeva; Harisha, K. S.; Ranjana, T.; Harish, K. V.; Narayana, B.; Byrappa, K.; Sangappa, Y.

2018-05-01

The synthesis of metal nanoparticales by environmentally friendly processes is an important aspect of nanotechnology today. One such approach that shows immense potential is based on the in situ synthesis of gold nanoparticles (AuNPs) using naturally available materials such as aqueous silk fibroin (SF) obtained from Bombyx mori silk. The UV-visible absorption study revealed the formation of AuNPs by showing characteristic surface plasmon resonance (SPR) band at 525 nm. The X-ray diffraction (XRD) analysis study suggests the synthesized gold nanoparticles are FCC crystal structure. The transmission electron microscopy (TEM) images showed that the formed AuNPs are spherical in shape with smooth edges.

Synthesis, structural characterization, DFT studies and in-vitro antidiabetic activity of new mixed ligand oxovanadium(IV) complex with tridentate Schiff base

NASA Astrophysics Data System (ADS)

Patel, R. N.; Singh, Yogendra Pratap

2018-02-01

The mixed ligand oxovanadium(IV) complex [VO(L1)(L2)] [L1 = N'-[(Z)-phenyl(pyridin-2-yl)methylidene]benzohydrazide and L2 = Benzohydrazide] has been synthesized in aerobic condition. The complex was characterized by elemental analysis spectroscopic (UV-vis, IR, epr) and electrochemical methods. X-ray diffraction pattern was also used to characterize this complex, which has a distorted octahedral structure. Single crystal diffraction analysis reveals that Csbnd H⋯π (aryl/metal chelate rings) interactions contribute to the stabilization of the crystal structure in given dimension. The room temperature magnetic susceptibility data shows paramagnetic nature of the complex. The complex was also tested for in-vitro antidiabetic activity. Moderate α-glucosidase inhibition is shown by this complex, which may be considered as α-glucosidase inhibitors.

Synthesis of formamidinium lead iodide perovskite bulk single crystal and its optical properties

NASA Astrophysics Data System (ADS)

Zheng, Hongge; Duan, Junjie; Dai, Jun

2017-07-01

Formamidinium lead iodide (FAPbI3) is a promising hybrid perovskite material for optoelectronic devices. We synthesized bulk single crystal FAPbI3 by a rapid solution crystallization method. X-ray diffraction (XRD) was performed to characterize the crystal structure. Temperature-dependent photoluminescence (PL) spectra of the bulk single crystal FAPbI3 were measured from 10 to 300 K to explain PL recombination mechanism. It shows that near band edge emission blueshifts with the temperature increasing from 10 to 120 K and from 140 K to room temperature, a sudden emission band redshift demonstrates near 140 K because of the phase transition from orthorhombic phase to cubic phase. From the temperature-dependent PL spectra, the temperature coefficients of the bandgap and thermal activation energies of FAPbI3 perovskite are fitted.

Synthesis, crystal structure and redox properties of dihydropyrazole-bridged ferrocene-based derivatives

NASA Astrophysics Data System (ADS)

Li, Heng-Dong; Ma, Zai-He; Yang, Kun; Xie, Li-Li; Yuan, Yao-Feng

2012-09-01

Dihydropyrazole-bridged ferrocene-based derivatives were prepared by corresponding chalcones with hydrazine hydrate, then acylation with 3-(ethoxycarbonyl)propionyl chloride directly in high yields and purity. All of these compounds were characterized by MS, IR, 1H NMR, 13C NMR and elemental analysis. The relationship between the structure and redox properties was investigated based on the results of single crystal X-ray structure determinations and cyclic voltammetry. The mechanism of the electron transfer for representative compound 4b was verified by density functional theory (DFT) calculations.

Synthesis and crystal structure of (S, S, S, S)-N, N′-bis[N-(P-toluenesulfonamido)-1,2-diphenylethyl]ethylenediamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X.-G.; Zhang, T.; Hu, Y.-Y.

2013-12-15

(S, S, S, S)-N,N′-bis[N-(p-toluenesulfonamido)-1,2-diphenylethyl] ethylenediamine (C{sub 44}H{sub 46}N{sub 4}O{sub 4}S{sub 2}), has been synthesized and structurally characterized by elemental analysis, {sup 1}H-NMR, MS, IR and single-crystal X-ray diffraction. The title compound contains four chiral centers with C atoms in S configuration. Molecules are connected to one another by hydrogen bonds between sulfonamide nitrogen and sulfonyl oxygen to form chains alone a axis.

Hydrothermal synthesis, characterization, and thermal properties of alumino silicate azide sodalite, Na8[AlSiO4]6(N3)2

NASA Astrophysics Data System (ADS)

Borhade, A. V.; Wakchaure, S. G.; Dholi, A. G.; Kshirsagar, T. A.

2017-07-01

First time we report the synthesis, structural characterization and thermal behavior of an unusual N3 - containing alumino-silicate sodalite mineral. Azide sodalite, Na8[AlSiO4]6(N3)2 has been synthesized under hydrothermal conditions at 433 K in steel lined Teflon autoclave. The structural and microstructural properties of azide sodalite mineral was characterized by various methods including FT-IR, XRD, SEM, TGA, and MAS NMR. Crystal structure have been refined by Rietveld method in P\\bar 43n space group, indicating that the N3 - sodalite has cubic in lattice. High temperature study was carried out to see the effect of thermal expansion on cell dimension ( a o) of azide sodalite. Thermal behavior of sodalite was also assessed by thermogravimetric method.

Synthesis and performance characterization of 2-(dinitromethylene)-1-nitro-1, 3-diazacyclopentane

NASA Astrophysics Data System (ADS)

Liu, Pan; Qin, Weiyan

2018-04-01

The present paper described an new effort to synthesis 2-(dinitromethylene)-l-nitro-1, 3-diaza-cyclopentane (iv), characterization an thermal studies of (iv) are also reported. 2-(dinitromethylene)-1, 3-diazacyclo-pentane (i) was synthesized from the nucleophilic substitution of ethylenediamine and 1,1-diamino-2,2-dinitroethylene (FOX-7) catalyzed by Mg(OAc)2. Then i was transformed to iv through reactions of nitration, reduction and hydrolysis. The structure of iv was characterized by IR, NMR, MS and elemental analysis. Thermal stability of iv was investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC) which revealed that decomposed at 131 °C. The experimentally determined sensitivity parameters indicated that iv is sensitive towards external stimuli. The performance of iv had been calculated using VLW equation and its crystal morphology was investigated by scanning electron microscopy (SEM).

Synthesis and characterization of gillespite

NASA Astrophysics Data System (ADS)

Bloise, A.

2018-04-01

The synthesis of gillespite BaFeSi4O10 was investigated under various experimental conditions: temperature 300-400 °C; pressure 0.1-1 kbar; duration of treatment 92-160 h. The run products were characterized by X-ray powder diffraction, scanning and transmission electron microscopy with an energy-dispersive spectrometer and differential scanning calorimetry (DSC). At 1 kbar for 160 h of treatment, an increase in temperature from 300 to 400 °C was found to increase the abundance and degree of crystallinity of gillespite even if a further decrease in pressure or reaction time may hinder gillespite formations. The effects of experimental conditions on the presence of other accessory phases and the yield and size of gillespite crystals were also discussed. Further characterization by DSC was carried out to determine the thermal stability of synthesized gillespite.

Synthesis, Crystal Structure, and Magnetic Properties of the YbFeTi2O7 Compound

NASA Astrophysics Data System (ADS)

Drokina, T. V.; Petrakovskii, G. A.; Molokeev, M. S.; Velikanov, D. A.

2018-03-01

We report on the synthesis conductions and results of experimental investigations of the crystal structure and magnetic properties of a new magnetic compound YbFeTi2O7. According to the X-ray diffractometry data, the crystal structure of the investigated compound is described by the rhombic space group Pcnb with unit cell parameters of a = 9.8115(1) Å, b = 13.5106(2) Å, and c = 7.31302(9) Å and atomic disordering in the distribution of iron ions Fe3+ over five structural sites. The magnetic measurements in the lowtemperature region revealed a kink in the temperature dependence of the magnetic moment and its dependence on the sample magnetic prehistory. The experimental results obtained suggest that with a decrease in temperature the sample passes from the paramagnetic state to the spin-glass-like magnetic state characterized by a freezing temperature of T f = 4.5 K at the preferred antiferromagnetic exchange coupling in the sample spin system. The chemical pressure variation upon replacement of rare-earth ion R by Yb in the RFeTi2O7 system does not change the crystal lattice symmetry and magnetic state.

Combinatorial synthesis of bimetallic complexes with three halogeno bridges.

PubMed

Gauthier, Sébastien; Quebatte, Laurent; Scopelliti, Rosario; Severin, Kay

2004-06-07

Methods for the synthesis of bimetallic complexes in which two different metal fragments are connected by three chloro or bromo bridges are reported. The reactions are general, fast, and give rise to structurally defined products in quantitative yields. Therefore, they are ideally suited for generating a library of homo- and heterobimetallic complexes in a combinatorial fashion. This is of special interest for applications in homogeneous catalysis. Selected members of this library were synthesized and comprehensively characterized; single-crystal X-ray analyses were performed for 15 new bimetallic compounds.

Ionic Liquid Crystals: Versatile Materials.

PubMed

Goossens, Karel; Lava, Kathleen; Bielawski, Christopher W; Binnemans, Koen

2016-04-27

This Review covers the recent developments (2005-2015) in the design, synthesis, characterization, and application of thermotropic ionic liquid crystals. It was designed to give a comprehensive overview of the "state-of-the-art" in the field. The discussion is focused on low molar mass and dendrimeric thermotropic ionic mesogens, as well as selected metal-containing compounds (metallomesogens), but some references to polymeric and/or lyotropic ionic liquid crystals and particularly to ionic liquids will also be provided. Although zwitterionic and mesoionic mesogens are also treated to some extent, emphasis will be directed toward liquid-crystalline materials consisting of organic cations and organic/inorganic anions that are not covalently bound but interact via electrostatic and other noncovalent interactions.

Synthesis and characterization of Ni doped ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Tamgadge, Y. S.; Gedam, P. P.; Ganorkar, R. P.; Mahure, M. A.; Pahurkar, V. G.; Muley, G. G.

2018-05-01

In this paper, we present synthesis of L-valine assisted surface modification of Ni doped ZnO nanoparticles (NPs) using chemical precipitation method. Samples were calcined at 500oC for 2h. Uncalcined and calcined samples were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultraviolet-visible (UV-vis) spectroscopy. Ni doped ZnO NPs with average particle size of 8 nm have been successfully obtained using L-valine as surface modifying agent. Increase in the particle size was observed after the calcination. XRD and TEM studies confirmed the purity, surface morphology and hexagonal wurtzite crystal structure of ZnO NPs. UV-vis spectroscopy indicated the blue shift of excitons absorption wavelength and surface modification by L-valine.

Synthesis and crystal structure determination of yttrium ultraphosphate YP 5O 14

NASA Astrophysics Data System (ADS)

Mbarek, A.; Graia, M.; Chadeyron, G.; Zambon, D.; Bouaziz, J.; Fourati, M.

2009-03-01

The crystal structure of monoclinic YP 5O 14 (space group C2/ c, a=12.919(2) Å, b=12.796(4) Å, c=12.457(2) Å, β=91.30(1)°, Z=8) has been refined from single-crystal X-ray diffraction data. Full-matrix least-squares refinement on F2 using 2249 independent reflections for 183 refinable parameters results in a final R value of 0.027 ( ωR=0.069). The structure is isotypic with HoP 5O 14. This structure is built up from infinite layers of PO 4 tetrahedra linked through isolated YO 8 polyhedra. The three-dimensional cohesion of the framework results from Y-O-P bridges. This crystal structure refinement leads to the calculated X-ray diffraction powder pattern of this monoclinic polymorph, which has been the starting point of a thorough study of the solid-state synthesis of this ultraphosphate. This investigation further leads to a better outstanding of features observed during the synthesis of powdered samples. The thermal behavior of this ultraphosphate has been studied by DTA and TGA analyses. The infrared and Raman spectroscopic characterizations have been carried out on polycrystalline samples. The luminescence properties of the Eu 3+ ion incorporated in the monoclinic C2/ c polymorph of YP 5O 14 as local structural probe show that in YP 5O 14: 5% Eu 3+ sample, the Eu 3+ ions are distributed over the two Y 3+ crystallographic sites of C 2 symmetry of this structure.

Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

NASA Technical Reports Server (NTRS)

1988-01-01

The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

Precipitation method for barium metaborate (BaB{sub 2}O{sub 4}) synthesis from borax solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akşener, Eymen; Figen, Aysel Kantürk; Pişkin, Sabriye

2013-12-16

In this study, barium metaborate (BaB{sub 2}O{sub 4}, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also β−BaB{sub 2}O{sub 4} single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na{sub 2}B{sub 4}O{sub 7⋅}10H{sub 2}O, BDH) and barium chloride (BaCI{sub 2⋅}2H{sub 2}O, Ba) in the glass-batch reactor with stirring.more » The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.« less

Controllable Growth of Monolayer MoS2 and MoSe2 Crystals Using Three-temperature-zone Furnace

NASA Astrophysics Data System (ADS)

Zheng, Binjie; Chen, Yuanfu

2017-12-01

Monolayer molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2) have attracted a great attention for their exceptional electronic and optoelectronic properties among the two dimensional family. However, controllable synthesis of monolayer crystals with high quality needs to be improved urgently. Here we demonstrate a chemical vapor deposition (CVD) growth of monolayer MoS2 and MoSe2 crystals using three-temperature-zone furnace. Systematical study of the effects of growth pressure, temperature and time on the thickness, morphology and grain size of crystals shows the good controllability. The photoluminescence (PL) characterizations indicate that the as-grown monolayer MoS2 and MoSe2 crystals possess excellent optical qualities with very small full-width-half-maximum (FWHM) of 96 me V and 57 me V, respectively. It is comparable to that of exfoliated monolayers and reveals their high crystal quality. It is promising that our strategy should be applicable for the growth of other transition metal dichalcogenides (TMDs) monolayer crystals.

Synthesis, characterization, nucleic acid interactions and photoluminescent properties of methaniminium hydrazone Schiff base and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes

NASA Astrophysics Data System (ADS)

Sennappan, M.; Murali Krishna, P.; Hosamani, Amar A.; Hari Krishna, R.

2018-07-01

An environmental benign and efficient reaction was carried out via amine exchange and condensation reaction in water and methanol mixture (3:1) and absence of catalyst between 1-[3-(2-hydroxy benzylidene)amine)phenyl]ethanone and benzhydrazide yields methaniminium hydrazone Schiff base in high yield. The prepared ligand was structurally characterized by using single crystal XRD, elemental analysis and spectroscopy (UV-Vis, FT-IR, LC-MS and NMR) techniques. The crystal data indicates the ligand crystallizes in orthorhombic system with Pna21 space group. Further, the ligand was used in synthesis of mononuclear Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes and were characterized by elemental analysis, magnetic moment and spectroscopy (UV-Vis, FT-IR and ESR) studies. The spectral data showed that ligand is coordinated to the metal ion through azomethine nitrogen and methaniminium nitrogen. The DNA binding absorption titrations reveals that, ligand, L and its metal complexes, 1-6 are avid binders to CT- DNA. The apparent binding constant values of compounds are in the order of 106 M-1. The nuclease activity of ligand, L and its metal complexes, 1-6 were investigated by gel electrophoresis method using pUC18 DNA. The photoluminescent properties of the methaniminium hydrazone ligand, L and its various metal complexes, 1-6 were investigated. The emission spectra of both ligand (L) and metal complexes (1-6) exhibits emission in the range of blue to red.

Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

NASA Astrophysics Data System (ADS)

Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

2018-03-01

The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

Thermodynamic Investigation of Carbamazepine-Saccharin Co-Crystal Polymorphs.

PubMed

Pagire, Sudhir K; Jadav, Niten; Vangala, Venu R; Whiteside, Benjamin; Paradkar, Anant

2017-08-01

Polymorphism in active pharmaceutical ingredients can be regarded as critical for the potential that crystal form can have on the quality, efficacy, and safety of the final drug product. The current contribution aims to characterize thermodynamic interrelationship of a dimorphic co-crystal, FI and FII, involving carbamazepine (CBZ) and saccharin (SAC) molecules. Supramolecular synthesis of CBZ-SAC FI and FII has been performed using thermokinetic methods and systematically characterized by differential scanning calorimetry, powder X-ray diffraction, solubility, and slurry measurements. According to the heat of fusion rule by Burger and Ramberger, FI (ΔH fus  = 121.1 J/g; melting point, 172.5°C) and FII (ΔH fus  = 110.3 J/g; melting point, 164.7°C) are monotropically related. The solubility and van't Hoff plot results suggest FI stable and FII metastable forms. This study reveals that CBZ-SAC co-crystal phases, FI or FII, could be stable to heat-induced stresses; however, FII converts to FI during solution-mediated transformation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

N-2-Hydroxy-4-methoxyacetophenone- N'-4-nitrobenzoyl hydrazine: Synthesis and structural characterization

NASA Astrophysics Data System (ADS)

Bessy Raj, B. N.; Kurup, M. R. Prathapachandra

2007-04-01

A new aroyl hydrazone, N-2-hydroxy-4-methoxyacetophenone- N'-4-nitrobenzoyl hydrazine was prepared by the condensation reaction of 2-hydroxy-4-methoxyacetophenone and 4-nitrobenzoyl hydrazine. Characterization of the compound was done by elemental analysis and electronic, infrared and NMR spectral analyses. The complete structural assignment of the compound was done by NMR studies by using COSY homonuclear and HSQC heteronuclear techniques. The crystal and molecular structure was determined by single crystal X-ray diffraction studies: crystallized in the monoclinic system, space group P2 1/ n, Z = 4, a = 7.3343(9) Å, b = 20.3517(9) Å, c = 10.1375(5) Å, α = 90.00°, β = 95.735(7)° and γ = 90.00°. From the crystal structure, it is concluded that the compound exists as the keto isomer in the solid state. There is a completely extended conformation in the central part of the molecule C5 sbnd C8 dbnd N1 sbnd N2 sbnd C10 dbnd O2 with an E configuration at the double bond of the hydrazinic bridge.

An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures

DOE PAGES

Bergquist, Leah; Zhang, Cuiyu; Ribeiro de Almeida, Roberta R.; ...

2017-02-07

Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterizedmore » and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.« less

An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergquist, Leah; Zhang, Cuiyu; Ribeiro de Almeida, Roberta R.

Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterizedmore » and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.« less

5-(1-Aryl-3-(thiophen-2-yl)-1H-pyrazol-4-yl)-1H-tetrazoles: Synthesis, structural characterization, Hirshfeld analysis, anti-inflammatory and anti-bacterial studies

NASA Astrophysics Data System (ADS)

Kumbar, Mahadev N.; Kamble, Ravindra R.; Dasappa, Jagadeesh Prasad; Bayannavar, Praveen K.; Khamees, Hussien Ahmed; Mahendra, M.; Joshi, Shrinivas D.; Dodamani, Suneel; Rasal, V. P.; Jalalpure, Sunil

2018-05-01

A series of novel 5-(1-aryl-3-(thiophen-2-yl)-1H-pyrazol-4-yl)-1H-tetrazoles 7(h-s) were designed and synthesized. Structural characterization was done by spectral and single crystal X-ray studies. The intermolecular interactions of compound 7n were quantified and visualized using Hirshfeld surface analysis. Structures of newly synthesized compounds were docked into active site of COX-2 enzyme PDB:

Ion dynamics in nanocrystalline LiMnPO{sub 4} synthesised by novel template free hydrothermal approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vijayan, Lakshmi, E-mail: lakshmivijayan@gmail.com; Cheruku, Rajesh; Govindaraj, G.

A dense core rectangular shaped nanocrystalline LiMnPO{sub 4} material was synthesized by template free sucrose assisted hydrothermal synthesis. The material possess orthorhombic crystal structure with Pnma, space group having four formula units. The structural characterization was accomplished through X-ray diffraction, thermo gravimetry/differential thermal analysis. Morphology was identified by the SEM, VSM was used to verify the magnetic behavior of the material and electrical characterization was done through impedance spectroscopy and the results were reported.

Synthesis of Copper-Antimony-Sulfide Nanocrystals for Solution-Processed Solar Cells.

PubMed

Suehiro, Satoshi; Horita, Keisuke; Yuasa, Masayoshi; Tanaka, Tooru; Fujita, Katsuhiko; Ishiwata, Yoichi; Shimanoe, Kengo; Kida, Tetsuya

2015-08-17

The p-type nanocrystals (NCs) of copper-based chalcogenides, such as CuInSe2 and Cu2ZnSnS4, have attracted increasing attention in photovoltaic applications due to their potential to produce cheap solution-processed solar cells. Herein, we report the synthesis of copper-antimony-sulfide (CAS) NCs with different crystal phases including CuSbS2, Cu3SbS4, and Cu12Sb4S13. In addition, their morphology, crystal phase, and optical properties were characterized using transmission electron microscopy, X-ray diffractometry, UV-vis-near-IR spectroscopy, and photoemission yield spectroscopy. The morphology, crystal phase, and electronic structure were significantly dependent on the chemical composition in the CAS system. Devices were fabricated using particulate films consisting of CAS NCs prepared by spin coating without a high-temperature treatment. The CAS NC-based devices exhibited a diode-like current-voltage characteristic when coupled with an n-type CdS layer. In particular, the CuSbS2 NC devices exhibited photovoltaic responses under simulated sunlight, demonstrating its applicability for use in solution-processed solar cells.

Synthesis and formation mechanism of pinnoite in sulfated-type boron concentrated brine by dilution method

NASA Astrophysics Data System (ADS)

Peng, Jiaoyu; Bian, Shaoju; Lin, Feng; Wang, Liping; Dong, Yaping; Li, Wu

2017-10-01

The synthesis of pinnoite (MgB2O(OH)6) in boron-containing brine was established with a novel dilution method. Effects of temperature, precipitation time, boron concentration and mass dilution ratio on the formation of pinnoite were investigated. The products obtained were characterized by X-ray diffraction (XRD), Raman, thermogravimetric and differential scanning calorimeter (TG-DSC), and scanning electron microscopy. The transformation mechanism of pinnoite with different dilution ratios was assumed by studying the crystal growth of pinnoite. The results showed that pinnoite was synthesized above 60 °C in the diluted brine. There were two reaction steps - precipitation of amorphous solid and the formation of pinnoite crystals - during the whole reaction process of pinnoite when the dilution ratio is more than 1.0 at 80 °C. While in the 0.5 diluted brine, only one reaction step of pinnoite crystal formation was observed and its transformation mechanism was discussed based on dissociation of polyborates in brine. Besides, the origin of pinnoite mineral deposited on salt lake bottom was proposed.

Synthesis, crystal structure and characterization of chiral, three-dimensional anhydrous potassium tris(oxalato)ferrate(III)

NASA Astrophysics Data System (ADS)

Saritha, A.; Raju, B.; Ramachary, M.; Raghavaiah, P.; Hussain, K. A.

2012-11-01

The synthesis, crystal structure and physical properties of chiral, three-dimensional anhydrous potassium tris(oxalato)ferrate(III) [K3Fe(C2O4)3] are described. X-ray analysis reveals that the compound crystallized in the chiral space group P4132 of cubic system with a=b=c=13.5970(2), Z=4. The structure of the complex consists of infinite anionic [Fe(C2O4)3]3- units with distorted octahedral environment of iron surrounded by six oxygen atoms of three oxalato groups. The anionic units are interlinked through K+ ions of three different coordination environments of distorted octahedral, bicapped trigonal prismatic and trigonal prismatic yielding a three-dimensional motif. The two broad absorption bands at 644 and 924 nm from UV-vis-NIR transmittance spectra were ascribed to a ligand-to-metal charge transfer. The room temperature crystalline EPR spectra indicate the high-spin (S=5/2) of Fe(III) ion. The vibrating sample magnetometer measurement shows the paramagnetic nature at room temperature. Thermal studies of the compound confirm the absence of water molecule.

Facile synthesis of gold nanomaterials with unusual crystal structures.

PubMed

Fan, Zhanxi; Huang, Xiao; Chen, Ye; Huang, Wei; Zhang, Hua

2017-11-01

Gold (Au) nanomaterials have attracted wide research attention, owing to their high chemical stability, promising catalytic properties, excellent biocompatibility, unique electronic structure and outstanding localized surface plasmon resonance (LSPR) absorption properties; all of which are closely related to their size and shape. Recently, crystal-phase-controlled synthesis of noble metal nanomaterials has emerged as a promising strategy to tune their physicochemical properties. This protocol describes the detailed experimental procedures for the crystal-phase-controlled syntheses of Au nanomaterials with unusual crystal structures under mild conditions. Briefly, pure hexagonal close-packed (hcp) Au square sheets (AuSSs) with a thickness of ∼2.4 nm are synthesized using a graphene-oxide-assisted method in which HAuCl 4 is reduced by oleylamine in a mixture of hexane and ethanol. By using pure hexane as the solvent, well-dispersed ultrathin hcp/face-centered cubic (fcc) Au nanowires with a diameter of ∼1.6 nm on graphene oxide can be obtained. Meanwhile, hcp/fcc Au square-like plates with a side length of 200-400 nm are prepared via the secondary growth of Au on the hcp AuSSs. Remarkably, hexagonal (4H) Au nanoribbons with a thickness of 2.0-6.0 nm can be synthesized with a one-pot colloidal method in which HAuCl 4 is reduced by oleylamine in a mixed solvent of hexane and 1,2-dichloropropane. It takes 17-37 h for the synthesis of these Au nanomaterials with unusual crystal structures. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) are used to characterize the resultant Au nanomaterials, which could have many promising applications, such as biosensing, near-IR photothermal therapy, catalysis and surface-enhanced Raman scattering (SERS).

Effect of synthesis conditions on the nanopowder properties of Ce{sub 0.9}Zr{sub 0.1}O{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimicz, M.G.; Fabregas, I.O.; Lamas, D.G.

Graphical abstract: . The synthesis of nanocrystalline Ce{sub 0.9}Zr{sub 0.1}O{sub 2} powders via the gel-combustion method, using different fuels, and following either stoichiometric or non-stoichiometric pH-controlled routes is investigated. Research highlights: {yields} All samples exhibited the fluorite-type crystal structure, nanometric average crystallite size and negligible carbon content. {yields} Synthesis conditions strongly affect the average crystallite size, the degree of agglomeration, the specific surface area and the pore volume. {yields} Our results indicate that, by controlling the synthesis conditions it is possible to obtain solids with custom-made morphological properties. -- Abstract: In this work, the synthesis of nanocrystalline Ce{sub 0.9}Zr{sub 0.1}O{submore » 2} powders via the gel-combustion method, using different fuels, and following either stoichiometric or non-stoichiometric pH-controlled routes is investigated. The objective is to evaluate the effect of synthesis conditions on the textural and morphological properties, and the crystal structure of the synthesized materials. The solids were characterized by nitrogen physisorption, Scanning Electron Microscopy (SEM), X-ray powder diffraction (XPD), and Carbon-Hydrogen-Nitrogen Elemental Analysis (CHN). All the powders exhibited nanometric crystallite size, fluorite-type structure and negligible carbon content. Synthesis conditions strongly affect the average crystallite size, the degree of agglomeration, the specific surface area and the pore volume. Our results indicate that, by controlling the synthesis conditions it is possible to obtain solids with custom-made morphological properties.« less

Synthesis and structural characterization of two half-sandwich nickel(II) complexes with the scorpionate ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G.-F., E-mail: wgf1979@126.com, E-mail: s-shuwen@163.com; Zhang, X., E-mail: zhangx@hit.edu.cn; Sun, S.-W.

The synthesis and characterization of two new halfsandwich mononuclear nickel(II) complexes with the scorpionate ligands, [k{sup 3}-N, N',N''-Tp{sup t-Bu}, {sup Me}NiI] (1) and [k{sup 3}-N,N',N''-Tp{sup t-Bu}, {sup Me}NiNO{sub 3}] (2), are reported. These complexes have been fully characterized by elemental analyses and infrared spectra. Their molecular structures were determined by single crystal X-ray diffraction. The nickel(II) ion of complex 1 is in a four-coordinate environment, in which the donor atoms are provided by three nitrogen atoms of a hydrotris(pyrazolyl) borate ligand and one iodide atom, while that of complex 2 is in a five-coordinate environment with three nitrogen atoms frommore » a hydrotris(pyrazolyl)borate ligand and two oxygen atoms from a nitrate ion.« less

Synthesis, Structure, and Rigid Unit Mode-like Anisotropic Thermal Expansion of BaIr 2 In 9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calta, Nicholas P.; Han, Fei; Kanatzidis, Mercouri G.

2015-09-08

This Article reports the synthesis of large single crystals of BaIr 2In 9 using In flux and their characterization by variable-temperature single-crystal and synchrotron powder X-ray diffraction, resistivity, and magnetization measurements. The title compound adopts the BaFe 2Al 9-type structure in the space group P6/mmm with room temperature unit cell parameters a = 8.8548(6) angstrom and c = 4.2696(4) A. BaIr 2In 9 exhibits anisotropic thermal expansion behavior with linear expansion along the c axis more than 3 times larger than expansion in the ab plane between 90 and 400 K. This anisotropic expansion originates from a rigid unit mode-likemore » mechanism similar to the mechanism of zero and negative thermal expansion observed in many anomalous thermal expansion materials such as ZrW 2O 8 and ScF 3.« less

Synthesis, Structure, and Rigid Unit Mode-like Anisotropic Thermal Expansion of BaIr2In9.

PubMed

Calta, Nicholas P; Han, Fei; Kanatzidis, Mercouri G

2015-09-08

This Article reports the synthesis of large single crystals of BaIr2In9 using In flux and their characterization by variable-temperature single-crystal and synchrotron powder X-ray diffraction, resistivity, and magnetization measurements. The title compound adopts the BaFe2Al9-type structure in the space group P6/mmm with room temperature unit cell parameters a = 8.8548(6) Å and c = 4.2696(4) Å. BaIr2In9 exhibits anisotropic thermal expansion behavior with linear expansion along the c axis more than 3 times larger than expansion in the ab plane between 90 and 400 K. This anisotropic expansion originates from a rigid unit mode-like mechanism similar to the mechanism of zero and negative thermal expansion observed in many anomalous thermal expansion materials such as ZrW2O8 and ScF3.

Synthesis and characterization of a novel schiff base of 1,2-diaminopropane with substituted salicyaldehyde and its transition metal complexes: Single crystal structures and biological activities

NASA Astrophysics Data System (ADS)

Tadavi, Samina K.; Yadav, Abhijit A.; Bendre, Ratnamala S.

2018-01-01

A novel schiff base H2L derived from simple condensation of 2-hydroxy-6-isopropyl-3-methyl benzaldehyde and 1,2-diaminopropane in 2:1 M ratio and its [MnL], [CoL] and [NiL]2 complexes have been prepared and characterized by spectroscopic technique, elemental analysis, SEM-EDX analysis, and cyclic voltammetry. Additionally, single crystal X-ray diffraction technique has been applied to the schiff base ligand H2L and its nickel complex. The structure of nickel complex exhibited dimeric form with formula [NiL]2 with distorted square planar geometry around each nickel center. Furthermore, all the synthesized compounds were screened for their antimicrobial and antioxidant and DNA cleavage activities.

Synthesis, spectroscopic characterization and structural investigations of new adduct compound of carbazole with picric acid: DNA binding and antimicrobial studies

NASA Astrophysics Data System (ADS)

Saravanabhavan, Munusamy; Sathya, Krishnan; Puranik, Vedavati G.; Sekar, Marimuthu

2014-01-01

Carbazole picrate (CP), a new organic compound has been synthesized, characterized by various analytical and spectroscopic technique such as FT-IR, UV-Vis, 1H and 13C NMR spectroscopy. An orthorhombic geometry was proposed based on single crystal XRD study. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it was stable up to 170 °C. Further, the newly synthesized title compound was tested for its in vitro antibacterial and antifungal activity against various bacterial and fungal species. Also, the compound was tested for its binding activity with Calf thymus (CT) DNA and the results show a considerable interaction between CP and CT-DNA.

Synthesis, crystal structure and antioxidant evaluation of C-4-acetamidophenylcalix[4]pyrogallolarene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M.

2015-09-25

C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibitsmore » good antioxidant activity of about 72%.« less

Hydrogen bonds directed 2D → 3D interdigitated Cd(II) compound: Synthesis, crystal structure and dual-emission luminescent properties

NASA Astrophysics Data System (ADS)

Yu, Yuanyuan

2017-06-01

A new Cd(II) compound, namely [Cd2(btc)(phen)2Cl]n·n(H2O)·n(DMA) (1, H3btc = 1, 3, 5-benzenetricarboxylic acid, phen = 1,10-phenanthroline, DMA = N,N'-dimethylacetamide) has been synthesized and structurally characterized by single-crystal X-ray diffraction analysis. This compound crystallizes in monoclinic P21/n space group with a = 13.5729(7) Å, b = 20.1049(7) Å, c = 13.9450(6) Å, β = 104.671(4)°, Z = 4. Single-crystal X-ray diffraction analysis reveals that compound 1 features a 2D → 3D interdigitated framework directed by the intermolecular hydrogen bonds. In addition, the luminescent properties of compound 1 were also investigated in the solid state at room temperature.

The dual role of sulfur-containing amino acids in the synthesis of IV-VI semiconductor nanocrystals: a mechanochemical approach.

PubMed

Baláž, Peter; Baláž, Matej; Caplovičová, Mária; Zorkovská, Anna; Caplovič, Lubomír; Psotka, Miroslav

2014-01-01

PbS@cystine nanocrystals were synthesized mechanochemically, with lead acetate and L-cystine being used as the lead and sulfur precursors, respectively. The resulting nanocrystals are 22-34 nm in size, well-faceted and octahedral in shape. Characterization by XRD, FT-IR, NMR, FE-SEM, EDS, TEM (HRTEM) and surface area measurement methods showed that the particles are single, defect-free crystals with a high crystallinity. Furthermore, the crystals were prepared using a solvent-free procedure that was performed under ambient temperature and atmospheric pressure.

Crystal structure of phosphoethanolamine methyltransferase from Plasmodium falciparum in complex with amodiaquine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Soon Goo; Alpert, Tara D.; Jez, Joseph M.

2012-07-17

Phosphoethanolamine N-methyltransferase (PMT) is essential for phospholipid biogenesis in the malarial parasite Plasmodium falciparum. PfPMT catalyzes the triple methylation of phosphoethanolamine to produce phosphocholine, which is then used for phosphatidylcholine synthesis. Here we describe the 2.0 {angstrom} resolution X-ray crystal structure of PfPMT in complex with amodiaquine. To better characterize inhibition of PfPMT by amodiaquine, we determined the IC{sub 50} values of a series of aminoquinolines using a direct radiochemical assay. Both structural and functional analyses provide a possible approach for the development of new small molecule inhibitors of PfPMT.

Crystal growth and characterization of Hg-based chalcogenide compounds (Conference Presentation)

NASA Astrophysics Data System (ADS)

He, Yihui; Lin, Wenwen; Syrigos, Jonathan C.; Wang, Peng Li; Islam, Saiful M.; McCall, Kyle M.; Kostina, Svetlana S.; Liu, Zhifu; Wessels, Bruce W.; Kanatzidis, Mercouri G.

2016-09-01

In this work, two Hg-based chalcogenides were investigated in detail to reveal their potential capability of radiation detection at room temperature (RT). Cs2Hg6S7, with a bandgap of 1.63 eV, which is designed by the dimensional reduction theory proposed by our group, were prepared and characterized. α-HgS, with a bandgap of 2.10 eV, as a precursor used for the ternary compound synthesis, was also proposed and further investigated. For Cs2Hg6S7, the crystals tended to crystallize into needle form with small grains. Here, the conditions of Bridgman melt growth were optimized to obtain relatively large single crystals. The slight excess of Cs2S as a fluxing agent during growth was found to facilitate better crystallization and large grains. Interestingly, no inclusion or secondary phase was found in the as-grown single crystals. The improvement of bulk resistivity from 10^6 Ωcm to 10^8 Ωcm was also achieved through the control of stoichiometry during crystal growth. For α-HgS crystals, both physical vapor transport and chemical vapor transport methods have been applied. By modifying the transport temperature and transport agent, single crystal with size about 3x1.5 mm^2 was grown with resistivity higher than 10^11 Ωcm. Photoluminescence (PL) revealed that multiple peaks observed in the 1.6-2.3 eV range and excitonic peak from for α-HgS single crystals were observed indicating good crystalline quality. Finally, the planar detectors for both crystals were tested under Co57 gamma ray source. Both of the crystals showed reasonable gamma ray response, while α-HgS crystals could respond at a relatively higher counting rate.

Synthesis, crystal growth and characterization of bioactive material: 2-amino-1H-benzo[d]imidazol-3-ium salicylate single crystal-a proton transfer molecular complex

NASA Astrophysics Data System (ADS)

Fathima, K. Saiadali; Anitha, K.

2017-05-01

The 1:1 molecular adducts 2-aminobenzimidazolium salicylate (ABIS) single crystal was synthesized and grown from 2-aminobenzimidazole (ABI) as a donor and salicylic acid (SA) as an acceptor. The cell parameter was determined using single crystal X-Ray diffraction method and the complex ABIS belongs to monoclinic system. The spectroscopic studies showed that ABIS crystal was an ion pair complex. The FTIR and Raman spectra showed that the presence of O-H, C=N, C=O vibration which confirms the proton transfer from SA to ABI. The UV-Vis spectrum exhibited a visible band at 359nm for ABIS due to the salicylate anion of the molecule. Further the antimicrobial activity of ABIS complex against Staphylococcus aureus, klebsiella pneumonia, Pseudomonas eruginos and E.coli pathogens was investigated. So the complex molecule inhibits both Gram positive and Gram negative bacterial. It is found that benzimidazole with aminogroup at position 2 increases the general antimicrobial activities of ABIS crystal.

Synthesis, structure and characterization of a hybrid centrosymmetric material (4-dimethylaminopyridinium nitrate gallic acid monohydrate) well-designed for non-linear optics

NASA Astrophysics Data System (ADS)

Ennaceur, Nasreddine; Jalel, Boutheina; Henchiri, Rokaya; Cordier, Marie; Ledoux-Rak, Isabelle

2018-01-01

Hybrid material: 4-Dimethylaminopyridinium nitrate gallic acid monohydrate abbreviated DNGA monohydrate has been successfully synthesized by slow evaporation method at room temperature. X-ray diffraction (XRD) on a single crystal showed that the latter was crystallized in P-1 space group. Likewise, thermal analyses demonstrated the stability of our crystal up to 80 °C. Besides, the analysis of the infrared spectrum (FTIR), allowed us to confirm the presence of the different groups present in the structure. Furthermore, by studying the UV-Visible spectrum, the transparency of our crystal was proven. Despite the fact that of having a centrosymmetric structure, the nonlinear optical properties of our single crystal, which was tested by Kurtz-Perry technique, proved that its second harmonic generation efficiency was 1.22 times more than that of KDP (potassium dihydrogen phosphate) single crystal. This nonlinear optical behavior of the studied compound was also determined through the calculations of polarizability and first hyperpolarizability values.

Ferromagnetism in CVT grown tungsten diselenide single crystals with nickel doping

NASA Astrophysics Data System (ADS)

Habib, Muhammad; Muhammad, Zahir; Khan, Rashid; Wu, Chuanqiang; Rehman, Zia ur; Zhou, Yu; Liu, Hengjie; Song, Li

2018-03-01

Two dimensional (2D) single crystal layered transition materials have had extensive consideration owing to their interesting magnetic properties, originating from their lattices and strong spin-orbit coupling, which make them of vital importance for spintronic applications. Herein, we present synthesis of a highly crystalline tungsten diselenide layered single crystal grown by chemical vapor transport technique and doped with nickel (Ni) to tailor its magnetic properties. The pristine WSe2 single crystal and Ni-doped crystal were characterized and analyzed for magnetic properties using both experimental and computational aspects. It was found that the magnetic behavior of the 2D layered WSe2 crystal changed from diamagnetic to ferromagnetic after Ni-doping at all tested temperatures. Moreover, first principle density functional theory (DFT) calculations further confirmed the origin of room temperature ferromagnetism of Ni-doped WSe2, where the d-orbitals of the doped Ni atom promoted the spin moment and thus largely contributed to the magnetism change in the 2D layered material.

Supramolecular complexes of Co(II), Ni(II) and Zn(II) p-hydroxybenzoates with caffeine: Synthesis, spectral characterization and crystal structure

NASA Astrophysics Data System (ADS)

Taşdemir, Erdal; Özbek, Füreya Elif; Sertçelik, Mustafa; Hökelek, Tuncer; Çelik, Raziye Çatak; Necefoğlu, Hacali

2016-09-01

Three novel complexes Co(II), Ni(II) and Zn(II) containing p-hydroxybenzoates and caffeine ligands were synthesized and characterized by elemental analysis, FT-IR and UV-vis Spectroscopy, molar conductivity and single crystal X-ray diffraction methods. The thermal properties of the synthesized complexes were investigated by TGA/DTA. The general formula of the complexes is [M(HOC6H4COO)2(H2O)4]·2(C8H10N4O2)·8H2O (where: M: Co, Ni and Zn). The IR studies showed that carboxylate groups of p-hydroxybenzoate ligands have monodentate coordination mode. The M2+ ions are octahedrally coordinated by two p-hydroxybenzoate ligands, four water molecules leading to an overall MO6 coordination environment. The medium-strength hydrogen bondings involving the uncoordinated caffeine ligands and water molecules, coordinated and uncoordinated water molecules and p-hydroxybenzoate ligands lead to three-dimensional supramolecular networks in the crystal structures.

Synthesis, characterization, crystal structure and solution studies of a novel proton transfer (charge transfer) complex of 2,2‧-dipyridylamine with 2,6-pyridine dicarboxylic acid

NASA Astrophysics Data System (ADS)

Ghasemi, Khaled; Rezvani, Ali Reza; Shokrollahi, Ardeshir; Zarghampour, Fereshteh; Moghimi, Abolghasem; García-Granda, Santiago; Mendoza-Meroño, Rafael

2015-06-01

Reaction between 2,2‧-dipyridylamine (DPA) and 2,6-pyridine dicarboxylic acid (dipicolinic acid, dipicH2), in water results in the formation of a proton transfer or charge transfer (CT) complex, (DPAH)+(dipicH)-·H2O, 1. The characterization was performed using 1H NMR and FTIR spectroscopy, elemental analysis and X-ray crystallography. The crystal system is triclinic with space group P1. The structural investigations exhibit that the hydrogen bonds and π-π stacking interactions stabilize the crystal structure of proton transfer complex. The protonation constants of 2,6-pyridine dicarboxylic acid, 2,2‧-dipyridylamine and the equilibrium constants for dipic-DPA (1:1) proton transfer system were calculated by potentiometric pH titration method using Hyperquad2008 program. The stoichiometries of the proton transfer species in solution was in agreement with the solid state result.

Green synthesis, characterization and some physico-chemical studies on a novel intermolecular compound; 4-nitro-o-phenylenediamine-N, N-dimethylaminobenzaldehyde system

NASA Astrophysics Data System (ADS)

Rai, U. S.; Singh, Manjeet; Rai, R. N.

2017-09-01

An inter-molecular compound (IMC) L1 was synthesized by taking 1:1 molar ratio of p-nitro-o-phenylenediamine (NOPDA) and N, N-dimethylaminobenzaldehyde (DMAB) via thermally initiated solid state reaction. It was characterized by X-ray diffraction, spectral and optical studies. The single crystal of the (L1) was grown from saturated solution of ethanol using slow evaporation technique at 29 °C. From the single crystal X-ray diffraction analysis, it can be inferred that it crystallizes in triclinic unit cell with P-1 space group (CCDC No 1422765). Absorption spectrum of IMC (L1) shows a band at 318 nm attributed to the intra-molecular charge-transfer (ICT) excited state absorption and the other band at 376 nm is due to n→π* transition. The IMC (L1) shows a strong fluorescence at 418 nm with a Stokes shift (≈100 nm) and quantum efficiency (0.22) upon excitation in methyl alcohol at 318 nm.

Synthesis, structure, spectral characterization and thermal analysis of the tetraaquabis (isothiocyanato-κN) cobalt (II)-bis(caffeine)-tetrahydrate complex

NASA Astrophysics Data System (ADS)

EL Hamdani, H.; EL Amane, M.; Duhayon, C.

2018-04-01

The complex 2(C8H10N4O2).[Co(H2O)4(NCS)2].4H2O was prepared in the water-ethanol solution at room temperature and characterized by the single crystal X-ray diffraction analysis, 1H, 13C NMR, TGA/DTA and IR spectroscopy. This complex was crystallized in the monoclinic system (P 21/c). The unit cell parameters are a = 10.65854 (19) A°, b = 8.16642 (14) A°, c = 18.0595 (3) A° with β = 96.4701° (15). The cobalt (II) cation is coordinated by four oxygen atoms of the water molecules and two nitrogen in isothiocyanato a trans octahedral geometry, stabilized by hydrogen bonds with caffeine molecule and free water molecule, The intermolecular hydrogen bonds: Osbnd H⋯N, Osbnd H⋯O, Csbnd H⋯S, π···π interactions are together playing a vital role in the stabilization of the crystal packing.

Mesomorphic behaviors of a series of heterocyclic thiophene-imine-ester-based liquid crystals

NASA Astrophysics Data System (ADS)

Foo, K.-L.; Ha, S.-T.; Yeap, G. Y.; Lee, S. L.

2018-05-01

The synthesis and characterization of a series of heterocyclic liquid crystal, 4-{[(thiophen-2-yl)methylidene]amino}phenyl 4-alkoxybenzoates possessing even number of carbon atoms at the alkoxy chain (CnH2n+1O-, n = 6, 8, 10, 12, 14, 16, 18) are reported. The molecular structures of title compounds were elucidated using Fourier-transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopic techniques along with mass spectrometric analysis. The phase behavior of these compounds was characterized and studied by differential scanning calorimetry and polarizing optical microscopy. All members exhibited enantiotropic nematic phase except for the highest member (n = 18) which is a non-mesogen. Influence of alkoxy chain length on the transition temperatures of crystal-to-nematic (melting point) and nematic-to-isotropic (clearing point) was studied. Nematic phase range was found to increase from n = 6 to n = 10, then it started to descend from n = 12 to n = 16 and finally the nematic phase disappeared when n changed to 18.

Sulfaguanidine cocrystals: Synthesis, structural characterization and their antibacterial and hemolytic analysis.

PubMed

Abidi, Syed Sibte Asghar; Azim, Yasser; Khan, Shahper Nazeer; Khan, Asad U

2018-02-05

Sulfaguanidine (SG), belongs to the class of sulfonamide drug used as an effective antibiotic. In the present work, using crystal engineering approach two novel cocrystals of SG were synthesized (SG-TBA and SG-PT) with thiobarbutaric acid (TBA) and 1,10-phenanthroline (PT), characterized by solid state techniques viz., powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and the crystal structures were determined by single crystal X-ray diffraction studies. A comparative antibacterial activity and hemolytic potential was done on SG drug, coformers and their cocrystals. The tested cocrystals formulations showed almost two fold higher antibacterial activity against the tested strains of bacteria Gram-positive bacteria (S. mutans and E. faecalis) and Gram-negative bacteria (E. coli, K. pneumonia and E. clocae) over SG alone and their coformers. Cocrystal SG-TBA showed better antibacterial activity and reduced hemolysis, thereby, reduced cytotoxicity than SG-PT. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and characterization of a BaGdF5:Tb glass ceramic as a nanocomposite scintillator for x-ray imaging.

PubMed

Lee, Gyuhyon; Struebing, Christian; Wagner, Brent; Summers, Christopher; Ding, Yong; Bryant, Alex; Thadhani, Naresh; Shedlock, Daniel; Star-Lack, Josh; Kang, Zhitao

2016-05-20

Transparent glass ceramics with embedded light-emitting nanocrystals show great potential as low-cost nanocomposite scintillators in comparison to single crystal and transparent ceramic scintillators. In this study, cubic structure BaGdF5:Tb nanocrystals embedded in an aluminosilicate glass matrix are reported for potential high performance MeV imaging applications. Scintillator samples with systematically varied compositions were prepared by a simple conventional melt-quenching method followed by annealing. Optical, structural and scintillation properties were characterized to guide the design and optimization of selected material systems, aiming at the development of a system with higher crystal volume and larger crystal size for improved luminosity. It is observed that enhanced scintillation performance was achieved by tuning the glass matrix composition and using GdF3 in the raw materials, which served as a nucleation agent. A 26% improvement in light output was observed from a BaGdF5:Tb glass ceramic with addition of GdF3.

Synthesis, characterization, and pharmacological studies of ferrocene-1H-1,2,3-triazole hybrids

NASA Astrophysics Data System (ADS)

Haque, Ashanul; Hsieh, Ming-Fa; Hassan, Syed Imran; Haque Faizi, Md. Serajul; Saha, Anannya; Dege, Necmi; Rather, Jahangir Ahmad; Khan, Muhammad S.

2017-10-01

A series of ferrocene-1H-1,2,3-triazole hybrids namely 1-(4-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (1), 1-(4,4‧-dinitro-2-biphenyl)-4-ferrocenyl-1H-1,2,3-triazole (2), 1-(3-chloro-4-fluorophenyl)-4-ferrocenyl-1H-1,2,3-triazole (3), 1-(4-bromophenyl)-4-ferrocenyl-1H-1,2,3-triazole (4) and 1-(2-nitrophenyl)-4-ferrocenyl-1H-1,2,3-triazole (5) were designed and synthesized by copper-catalyzed azide alkyne cycloaddition (CuAAC) reaction. All the new hybrids were characterized by microanalyses, NMR (1H and 13C), UV-vis, IR, ESI-MS and electrochemical techniques. Crystal structure of the compound (3) was solved by single crystal X-ray diffraction method. The structural (single crystal) and spectroscopic (UV-Vis. and IR) properties of the compound 3 have been analyzed and compared by complementary quantum modeling. Hybrids 1-5 exhibited low toxicity and demonstrated neuroprotective effect.

Synthesis, crystal growth, characterization and theoretical studies of 4-aminobenzophenonium picrate

NASA Astrophysics Data System (ADS)

Aditya Prasad, A.; Muthu, K.; Rajasekar, M.; Meenatchi, V.; Meenakshisundaram, S. P.

2015-01-01

Single crystals of 4-aminobenzophenonium picrate (4ABPP) were grown by slow evaporation of a mixed solvent system methanol-acetone (1:1,v/v) containing equimolar quantities of picric acid and 4-aminobenzophenone. The proton and carbon signals are confirmed by nuclear magnetic resonance spectroscopy. The various functional groups present in the molecule are identified by FT-IR analysis. Optimized geometry, first-order molecular hyperpolarizability (β), polarizability (α), bond length, bond angles and excited state energy from theoretical UV were derived by Hartree-Fock calculations. The complete assignment of the vibrational modes for 4-aminobenzophenonium picrate was performed by the scaled quantum mechanics force field (SQMFF) methodology using potential energy distribution. Natural bond orbital (NBO) calculations were employed to study the stabilities arising from charge delocalization and intermolecular interactions of 4ABPP. The atomic charge distributions of the various atoms present in 4ABPP are obtained by Mulliken charge population analysis. The as-grown crystal is further characterized by thermal and optical absorbance studies.

A Novel Coordination Polymer Based on Trinuclear Cobalt Building Blocks Cluster: Synthesis, Crystal Structure, and Properties

NASA Astrophysics Data System (ADS)

Lu, J. F.; Tang, Z. H.; Shi, J.; Ge, H. G.; Jiang, M.; Song, J.; Jin, L. X.

2017-12-01

The title compound {[Co3(μ3-OH)(μ2-H2O)2(H2O)5(BTC)2] · 6H2O} n (H3BTC is a 1,3,5-benzenetricarboxylic acid) was prepared and characterized by single crystal and powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and elemental analyses. The single crystal X-ray diffraction reveals that the title compound consists of 1D infinite zigzag chains which were constructed by trinuclear cobalt cluster and BTC3- ligand. Neighbouring above-mentioned 1D infinite zigzag chains are further linked by intermolecular hydrogen bonding to form a 3D supermolecular structure. In addition, the luminescent properties of the title compound were investigated.

Synthesis and Doping of Silicon Nanocrystals for Versatile Nanocrystal Inks

NASA Astrophysics Data System (ADS)

Kramer, Nicolaas Johannes

The impact of nanotechnology on our society is getting larger every year. Electronics are becoming smaller and more powerful, the "Internet of Things" is all around us, and data generation is increasing exponentially. None of this would have been possible without the developments in nanotechnology. Crystalline semiconductor nanoparticles (nanocrystals) are one of the latest developments in the field of nanotechnology. This thesis addresses three important challenges for the transition of silicon nanocrystals from the lab bench to the marketplace: A better understanding of the nanocrystal synthesis was obtained, the electronic properties of the nanocrystals were characterized and tuned, and novel silicon nanocrystal inks were formed and applied using simple coating technologies. Plasma synthesis of nanocrystals has numerous advantages over traditional solution-based synthesis methods. While the formation of nanoparticles in low pressure nonthermal plasmas is well known, the heating mechanism leading to their crystallization is poorly understood. A combination of comprehensive plasma characterization with a nanoparticle heating model presented here reveals the underlying plasma physics leading to crystallization. The model predicts that the nanoparticles reach temperatures as high as 900 K in the plasma as a result of heating reactions on the nanoparticle surface. These temperatures are well above the gas temperature and sufficient for complete nanoparticle crystallization. Moving the field of plasma nanoparticle synthesis to atmospheric pressures is important for lowering its cost and making the process attractive for industrial applications. The heating and charging model for silicon nanoparticles was adapted in Chapter 3 to study plasmas maintained over a wide range of pressures (10 -- 105 Pa). The model considers three collisionality regimes and determines the dominant contribution of each regime under various plasma conditions. Strong nanoparticle cooling at atmospheric pressures necessitates high plasma densities to reach temperatures required for crystallization of nanoparticles. Using experimentally determined plasma properties from the literature, the model estimates the nanoparticle temperature that is achieved during synthesis at atmospheric pressures. It was found that temperatures well above those required for crystallization can be achieved. Now that the synthesis of nanocrystals is understood, the second half of this thesis will focus on doping of the nanocrystals. The doping of semiconductor nanocrystals, which is vital for the optimization of nanocrystal-based devices, remains a challenge. Gas phase plasma approaches have been very successful in incorporating dopant atoms into nanocrystals by simply adding a dopant precursor during synthesis. However, little is known about the electronic activation of these dopants. This was investigated with field-effect transistor measurements using doped silicon nanocrystal films. It was found that, analogous to bulk silicon, boron and phosphorous electronically dope silicon nanocrystals. However, the dopant activation efficiency remains low as a result of self-purification of the dopants to the nanocrystal surface. Next the plasmonic properties of heavily doped silicon nanocrystals was explored. While the synthesis method was identical, the plasmonic behavior of phosphorus-doped and boron-doped nanocrystals was found the be significantly different. Phosphorus-doped nanocrystals exhibit a plasmon resonance immediately after synthesis, while boron-doped nanocrystals require a post-synthesis annealing or oxidation treatment. This is a result of the difference in dopant location. Phosphorus is more likely to be incorporated into the core of the nanocrystal, while the majority of boron is placed on the surface of the nanocrystal. The oxidized boron-doped particles exhibit stable plasmonic properties, and therefore this allows for the production of air-stable silicon-based plasmonic materials which is very interesting for certain applications. Finally the boron atoms were used to form a Lewis acidic nanocrystal surface chemistry allowing for the creation of ligand-less silicon nanocrystal solutions. This represents an immense step towards an abundant, non-toxic alternative to Pb and Cd-based nanocrystal technologies. The lack of long ligand chains enables the production of dense films with excellent electrical conductivity. This was demonstrated by forming uniform nanocrystal thin-films using simple and inexpensive spray coating techniques.

Development and characterization of Mn2+-doped MgO nanoparticles by solution combustion synthesis

NASA Astrophysics Data System (ADS)

Basha, Md. Hussain; Gopal, N. O.; Rao, J. L.; Nagabhushana, H.; Nagabhushana, B. M.; Chakradhar, R. P. S.

2015-06-01

Mn doped MgO Nanoparticles have been prepared by Solution Combustion Synthesis. The synthesized sample is characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). The prepared MgO:Mn (1 mol%) nano crystals appear to be of simple cubic crystalline phase with lattice parameters a = 4.218(2) Å and cell volume = 74.98 (7) Å3. SEM micrograph of powders show highly porous, many agglomerates with irregular morphology, large voids, cracks and pores. EPR spectrum of the sample at room temperature exhibit an isotropic sextet hyperfine pattern, centered at g=1.99, characteristic if Mn2+ ions with S=I=5/2.The observed g value and the hyperfine value reveal the ionic bonding between Mn2+ and its surroundings.

Synthesis and x-ray characterization of cobalt phosphide (Co₂P) nanorods for the oxygen reduction reaction

DOE PAGES

Doan-Nguyen, Vicky V.T.; Su, Dong; Zhang, Sen; ...

2015-07-14

Low temperature fuel cells are clean, effective alternative fuel conversion technology. Oxygen reduction reaction (ORR) at the fuel cell cathode has required Pt as the electrocatalyst for high activity and selectivity of the four-electron reaction pathway. Targeting a less expensive, earth abundant alternative, we have developed the synthesis of cobalt phosphide (Co₂P) nanorods for ORR. Characterization techniques that include total X-ray scattering and extended X-ray absorption fine structure revealed a deviation of the nanorods from bulk crystal structure with a contraction along the b orthorhombic lattice parameter. The carbon supported nanorods have comparable activity but are remarkably more stable thanmore » conventional Pt catalysts for the oxygen reduction reaction in alkaline environments.« less

Synthesis and characterization of monodispersed polymer/polydiacetylene nanocrystal composite particles.

PubMed

Wei, Zhong; Ujiiye-Ishii, Kento; Masuhara, Akito; Kasai, Hitoshi; Okada, Shuji; Matsune, Hideki; Asahi, Tsuyoshi; Masuhara, Hiroshi; Nakanishi, Hachiro

2005-06-01

Monodispersed polymer/polydiacetylenecomposite particles were synthesized by soap-free seeded emulsion polymerization of styrene andmethyl methacrylate; the products were characterized by XRD, SEM, TEM, UV-visible spectroscopy, and single particle scattering spectroscopy. In the synthesis process, polydiacetylene nanocrystals were found to act as inhibitor, and consequently a relatively low concentration was necessary. Different monomers lead to the differences in reaction condition and particle morphology; the PMMA composite particles were simpler in preparation than polystyrene particles, but the latter havebetter spherical morphology. The composite particles were composed of polymer shells and polydiacetylene cores, which kept their crystal structure and optical properties. A high percentage of cored particles could be achieved with optimized reaction conditions where the amount of seed was sufficient and the oily oligomer by-product was suppressed.

Polynitrogen Chemistry, Synthesis, Characterization, and Crystal Structure of Surprisingly Stable Fluoroantimonate Salts of N5(+)

DTIC Science & Technology

2001-03-01

Ber. 1966, 99, 1589. (6) Pankratov , V. A.; Savenkova, N. I. Zhur. Neorg. Khim. 1968, 13, 2610. (7) Christe, K. 0.; Wilson, R. D.; Sawodny, W, J. Mol...Structure 1971, 8, 245. Christe, K. 0.; Wilson, R. D.; Wilson, W. W.; Bau, R.; Sukumar, S.; Dixon, D. A. J. Am. Chem. Soc. 1991 , 113, 1991 . (8

Infrared fiber optic materials

NASA Technical Reports Server (NTRS)

Feigelson, Robert S.

1987-01-01

The development of IR fiber optics for use in astronomical and other space applications is summarized. Candidate materials were sought for use in the 1 to 200 micron and the 200 to 1000 micron wavelength range. Synthesis and optical characterization were carried out on several of these materials in bulk form. And the fabrication of a few materials in single crystal fiber optic form were studied.

Metal–organic coordination architectures of tetrazole heterocycle ligands bearing acetate groups: Synthesis, characterization and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Bo-Wen, E-mail: bowenhu@hit.edu.cn; Zheng, Xiang-Yu; Ding, Cheng

2015-12-15

Two new coordination complexes with tetrazole heterocycle ligands bearing acetate groups, [Co(L){sub 2}]{sub n} (1) and [Co{sub 3}(L){sub 4}(N{sub 3}){sub 2}·2MeOH]{sub n} (2) (L=tetrazole-1-acetate) have been synthesized and structurally characterized. Single crystal structure analysis shows that the cobalt-complex 1 has the 3D 3,6-connected (4{sup 2}.6){sub 2}(4{sup 4}.6{sup 2}.8{sup 8}.10)-ant topology. By introducing azide in this system, complex 2 forms the 2D network containing the [Co{sub 3}] units. And the magnetic properties of 1 and 2 have been studied. - Graphical abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with tetrazole heterocycle ligands bearing acetate groupsmore » are reported. - Highlights: • Two novel Cobalt(II) complexes with tetrazole acetate ligands were synthesized. • The magnetic properties of two complexes were studied. • Azide as co-ligand resulted in different structures and magnetic properties. • The new coordination mode of tetrazole acetate ligand was obtained.« less

Synthesis, Crystal Structure, and Topology-Symmetry Analysis of a New Modification of NaIn[IO3]4

NASA Astrophysics Data System (ADS)

Belokoneva, E. L.; Karamysheva, A. S.; Dimitrova, O. V.; Volkov, A. S.

2018-01-01

Crystals of new iodate NaIn[IO3]4 were prepared by the hydrothermal synthesis. The unit cell parameters are a = 7.2672(2) Å, b = 15.2572(6) Å, c = 15.0208(6) Å, β = 101.517(3)°, sp. gr. P21/ c. The formula was determined during the structure determination and refinement of a twinned crystal based on a set of reflections from the atomic planes of the major individual. The refinement with anisotropic displacement parameters was performed for both twin components to the final R factor of 0.050. The In and Na atoms are in octahedral coordination formed by oxygen atoms. The oxygen octahedra are arranged into columns by sharing edges, and the columns are connected by isolated umbrella-like [IO3]- groups to form layers. The new structure is most similar to the isoformular iodate NaIn[IO3]4, which crystallizes in the same sp. gr. P21/ c and is structurally similar, but has a twice smaller unit cell and is characterized by another direction of the monoclinic axis. The structural similarity and difference between the two phases were studied by topologysymmetry analysis. The formation of these phases is related to different combinations of identical one-dimensional infinite chains of octahedra.

Synthesis, structural and optical characterization of APbX{sub 3} (A=methylammonium, dimethylammonium, trimethylammonium; X=I, Br, Cl) hybrid organic-inorganic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mancini, Alessandro; Quadrelli, Paolo; Amoroso, Giuseppe

2016-08-15

In this paper we report the synthesis, the crystal structure and the optical response of APbX{sub 3} (A=MA, DMA, and TMA; X=I, Br) hybrid organic-inorganic materials including some new phases. We observe that as the cation group increases in size, the optical absorption edge shifts to higher energies with energy steps which are systematic and independent on the anion. A linear correlation between the optical bad gap and the tolerance factor has been shown for the series of samples investigated. - Graphical abstract: The crystal structure and the optical response of the two series of hybrid organic-inorganic materials APbX{sub 3}more » (A=MA, DMA, and TMA; X=I, Br), which include some new phases, are reported. A dependence of crystal structure and band-gap with tolerance factor is shown. Display Omitted - Highlights: • DMAPbI{sub 3}, TMAPbI{sub 3} and TMAPbBr{sub 3} are reported as new hybrid organic-inorganic compounds. • Crystal structure and optical properties as a function of the number of methyl groups are provided. • Correlation between structure and optical properties are given as a function of tolerance factor.« less

Mechanochemical Synthesis of Carbon Nanothread Single Crystals.

PubMed

Li, Xiang; Baldini, Maria; Wang, Tao; Chen, Bo; Xu, En-Shi; Vermilyea, Brian; Crespi, Vincent H; Hoffmann, Roald; Molaison, Jamie J; Tulk, Christopher A; Guthrie, Malcolm; Sinogeikin, Stanislav; Badding, John V

2017-11-15

Synthesis of well-ordered reduced dimensional carbon solids with extended bonding remains a challenge. For example, few single-crystal organic monomers react under topochemical control to produce single-crystal extended solids. We report a mechanochemical synthesis in which slow compression at room temperature under uniaxial stress can convert polycrystalline or single-crystal benzene monomer into single-crystalline packings of carbon nanothreads, a one-dimensional sp 3 carbon nanomaterial. The long-range order over hundreds of microns of these crystals allows them to readily exfoliate into fibers. The mechanochemical reaction produces macroscopic single crystals despite large dimensional changes caused by the formation of multiple strong, covalent C-C bonds to each monomer and a lack of reactant single-crystal order. Therefore, it appears not to follow a topochemical pathway, but rather one guided by uniaxial stress, to which the nanothreads consistently align. Slow-compression room-temperature synthesis may allow diverse molecular monomers to form single-crystalline packings of polymers, threads, and higher dimensional carbon networks.

The effect of adding CTAB template in ZSM-5 synthesis

NASA Astrophysics Data System (ADS)

Widayat, Widayat; Annisa, Arianti Nuur

2017-11-01

In general, ZSM-5 synthesis is performed using a hydrothermal process that takes place at high temperature and high pressure (> 373 K,> 1 bar). The synthesis of ZSM-5 is influenced by the organic template used. The organic template serves as a determinant of the zeolite crystal structure formation. CTAB is an easily found organic template and the price is cheap so the production cost of ZSM-5 synthesis would be more efficient. In this research, ZSM-5 is synthesized by varying temperature and crystallization time. The result showed the optimal condition of ZSM-5 synthesis was at 363 K for the crystallization temperature with 8 hours of crystallization time. The crystalline product had 60.07% of crystallinity with an aluminosilicate composition of 72% w/w.

Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN) 4

DOE PAGES

Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; ...

2013-01-01

This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN) 4], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P2 1/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å 3, Z = 4, D c = 1.46 g cm -1. Ni(bpene)[Ni(CN) 4] assumes a pillared layer structure with layers defined by Ni[Ni(CN) 4] n nets and bpene ligands acting as pillars. With the present crystallization technique which involvesmore » the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN) 4](1/2)bpene∙DMSO 2H 2O, or Ni 2N 7C 24H 25SO 3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO 2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO 2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO 2 per unit cell was obtained.« less

Synthesis and characterization of nanosized MgxMn1-xFe2O4 ferrites by both sol-gel and thermal decomposition methods

NASA Astrophysics Data System (ADS)

De-León-Prado, Laura Elena; Cortés-Hernández, Dora Alicia; Almanza-Robles, José Manuel; Escobedo-Bocardo, José Concepción; Sánchez, Javier; Reyes-Rdz, Pamela Yajaira; Jasso-Terán, Rosario Argentina; Hurtado-López, Gilberto Francisco

2017-04-01

This work reports the synthesis of MgxMn1-xFe2O4 (x=0-1) nanoparticles by both sol-gel and thermal decomposition methods. In order to determine the effect of synthesis conditions on the crystal structure and magnetic properties of the ferrites, the synthesis was carried out varying some parameters, including composition. By both methods it was possible to obtain ferrites having a single crystalline phase with cubic inverse spinel structure and a behavior near to that of superparamagnetic materials. Saturation magnetization values were higher for materials synthesized by sol-gel. Furthermore, in both cases particles have a spherical-like morphology and nanometric sizes (11-15 nm). Therefore, these materials can be used as thermoseeds for the treatment of cancer by magnetic hyperthermia.

Accessibility of selenomethionine proteins by total chemical synthesis: structural studies of human herpesvirus-8 MIP-II.

PubMed

Shao, W; Fernandez, E; Wilken, J; Thompson, D A; Siani, M A; West, J; Lolis, E; Schweitzer, B I

1998-12-11

The determination of high resolution three-dimensional structures by X-ray crystallography or nuclear magnetic resonance (NMR) is a time-consuming process. Here we describe an approach to circumvent the cloning and expression of a recombinant protein as well as screening for heavy atom derivatives. The selenomethionine-modified chemokine macrophage inflammatory protein-II (MIP-II) from human herpesvirus-8 has been produced by total chemical synthesis, crystallized, and characterized by NMR. The protein has a secondary structure typical of other chemokines and forms a monomer in solution. These results indicate that total chemical synthesis can be used to accelerate the determination of three-dimensional structures of new proteins identified in genome programs.

Synthesis, structural characterization, and thermal stability studies of heteroleptic cadmium(II) dithiocarbamate with different pyridyl groups

NASA Astrophysics Data System (ADS)

Onwudiwe, Damian C.; Hosten, Eric C.

2018-01-01

The synthesis, characterization and crystal structures of three chloroform solvated adducts of cadmium with mixed ligands of N-alkyl-N-phenyldithiocarbamate and pyridine, 2,2-bipyridine and 1, 10 phenanthroline represented as [CdL1L2 (py)2]·CHCl3(1), [CdL1L2bpy]•CHCl3(2), and [CdL1L2phen]•CHCl3(3) (LI = N-methyl-N-phenyldithiocarbamate, L2 = N-ethyl-N-phenyldithiocarbamate, py = pyridine, bpy = 2,2-bipyridine and phen = 1,10-phenanthroline) respectively are reported. Complex 1, which crystallized in the monoclinic space group P-1, is a centrosymmetric dimeric structure where each Cd center is bonded to two monodentate pyridine, a bidentate terminal dithiocarbamate, and another bidentate bridging dithiocarbamate to form a four-membered ring. Complex 2 crystallized in the monoclinic space group P21/c, with four discrete monomeric molecules in the asymmetric unit. The structure presents a cadmium atom coordinated by two sulphur atoms of a dithiocarbamate ligand and two nitrogen atoms of the 2,2‧-bipyridine to form a CdS4N2 fragment, thus giving the structure around the Cd atom a distorted trigonal prism geometry. Complex 3 contains two discrete monomeric molecules of (phenanthroline) (N, N-methyl phenyl-N, N-ethyl phenyl dithiocarbamato)cadmium (II) per unit cell, and the complex crystallized in the triclinic space group P-1. The structure showed that the Cd atom is bonded to two bidentate dithiocarbamate ligands and to one bidentate phenanthroline ligand in a distorted trigonal prism geometry. All the compounds resulted in CdS as residue upon thermal decomposition process conducted under inert atmosphere.

Synthesis, characterization and computational studies of 3-{(E)-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol and molecular structure of its zwitterionic form

NASA Astrophysics Data System (ADS)

Ezeorah, Julius Chigozie; Ossai, Valentine; Obasi, Lawrence Nnamdi; Elzagheid, Mohamed I.; Rhyman, Lydia; Lutter, Michael; Jurkschat, Klaus; Dege, Necmi; Ramasami, Ponnadurai

2018-01-01

The Schiff base 3-{(E)-[(2-hydroxyphenyl)imino]methyl}benzene-1,2-diol was synthesized by the condensation of 2,3-dihydroxybenzaldehyde and 2-aminophenol in water at room temperature. The crystal was grown using two solvents (dry methanol and 60% methanol). The compound was characterized using elemental microanalysis, IR, NMR, UV spectroscopies and single-crystal X-ray diffraction crystallography. The X-ray structure reveals that the Schiff base crystallizes as a methanol solvate in dry methanol with triclinic crystal system, space group P-1 and Z = 2 in the unit cell and as a non-methanol solvate in 60% methanol with triclinic crystal system, space group P-1 and Z = 4 in the unit cell. The compound showed absorption bands at 272, 389, 473 and 602 nm in DMSO. These bands were assigned as π → π ∗, n → π∗ and n-σ∗ transitions. The 473 and 602 nm bands in DMSO reveal that the compound exists in tautomeric forms. The presence of N-H, C-O and Cdbnd N stretching vibrations in the IR spectrum indicates that the compound is zwitterionic in the solid state. This study was supplemented using density functional theory method.

Synthesis, crystal structure, characterizations and magnetic study of a novel two-dimensional iron fluoride

NASA Astrophysics Data System (ADS)

Bouketaya, Sabrine; Smida, Mouna; Abdelbaky, Mohammed S. M.; Dammak, Mohamed; García-Granda, Santiago

2018-06-01

A new hybrid compound formulated as [Fe3F8(H2O)2](Am2TAZ)2 (Am2TAZ= 3,5-diamino-1,2,4-triazole) was prepared under hydrothermal conditions. The crystal structure was solved by single-crystal X-ray diffraction and the bulk was characterized by thermal analyses (TG-MS), vibrational spectroscopy (FTIR, Raman), Ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM-EDX). It crystallizes in the triclinic system space group P 1 ̅ with unit cell parameters a= 7.100(2) Å, b= 7.658(2) Å, c= 8.321(2) Å, α = 107.330(20)°, β = 111.842(18)°, γ = 93.049(17)°, Z = 1 and V= 394.01(17) Å3. The studied X-ray crystal structure shows the two oxidation states for iron atoms (Fe2+, Fe3+) and generates a 2D inorganic network, built up of inorganic layers constructed from infinite inorganic chains running along a axis. In fact, these chains are connected via (Fe3+(3)F6) octahedral. OW-H…F and N-H…F hydrogen bonds, making up the whole 3D network, are strongly linked in the layers. Magnetization measurements were performed, exhibiting the paramagnetic feature of the studied compound above 150 K.

New asymmetric and symmetric 2-((pyridin-4-yl)methylenamino)-3 aminomaleo nitrile and 2,3-bis((pyridin-4-yl)methylenamino)maleonitrile Schiff bases: Synthesis, experimental characterization along with theoretical studies

NASA Astrophysics Data System (ADS)

Zare, Nahid; Zabardasti, Abedien; Dusek, Michal; Eigner, Vaclav

2018-07-01

Two novel Schiff bases 2-((pyridin-4-yl)methelenamino)-3-aminomaleonitrile (L1) and 2,3-bis((pyridin-yl)methylenamino)maleonitrile (L2) were synthesized by the condensation of 2,3-diaminomaleonitrile and 4-pyridine carboxaldehyde using the reflux in absolute methanol. The light yellow crystalline precipitates of L1 were used for single-crystal X-ray crystallography. Two ligans L1 and L2 were characterized by UV-Vis, FT-IR and 1H/13C NMR spectroscopy. Also the FT-IR, 1H NMR and 13C NMR spectra of the compounds were calculated at the B3LYP/6-31 + G(d) level of theory. The Schiff base L1 with unit cell parameters: a = 19.8380(9), b = 4.7221(2), c = 12.9703(6) Å, V = 1215.02(9) Å3, Z = 4 crystallizes in the orthorhombic crystal system with space group Pna21. The crystal structure was solved by charge flipping using single crystal X-ray diffraction data collected at 120 K. For both ligands, the experimentally obtained NMR and IR spectra were a good agreement with their calculated counterparts.

Structural, crystal structure, Hirshfeld surface analysis and physicochemical studies of a new chlorocadmate template by 1-(2-hydroxyethyl)piperazine

NASA Astrophysics Data System (ADS)

Soudani, S.; Jeanneau, E.; Jelsch, C.; Lefebvre, F.; Ben Nasr, C.

2016-11-01

The synthesis, crystal structure and spectroscopic characterization of a new chlorocadmate template by the 1-(2-hydroxyethyl)piperazine ligand are reported. In the atomic arrangement, the CdCl5O entities are deployed in corrugated rows along the a-axis at y = 1/4 and y = 3/4 to form layers parallel to the (a,b) plane. In these crystals, piperazinediium cations are in a chair conformation and are inserted between these layers through Nsbnd H⋯Cl, Csbnd H⋯Cl, Osbnd H⋯Cl and Nsbnd H⋯O hydrogen bonds to form infinite three-dimensional network. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that H⋯Cl and Csbnd H⋯Hsbnd C intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The crystal contacts enrichments reveals that, the Cd++ … Cl- salt bridges, the Cd⋯O complexation and Osbnd H⋯Cl- and Nsbnd H⋯Cl-strong H-bonds are the driving forces in the packing formation. The presence of twelve independent chloride anions and four organic cation in the asymmetric unit allowed comparing their contact propensities. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. Additional characterization of this compound has also been performed by IR spectroscopy.

Magnetic zeolite NaA: synthesis, characterization based on metakaolin and its application for the removal of Cu2+, Pb2+.

PubMed

Liu, Haibo; Peng, Shuchuan; Shu, Lin; Chen, Tianhu; Bao, Teng; Frost, Ray L

2013-06-01

The optimum parameters for synthesis of zeolite NaA based on metakaolin were investigated according to results of cation exchange capacity and static water adsorption of all synthesis products and selected X-ray diffraction (XRD). Magnetic zeolite NaA was synthesized by adding Fe3O4 in the precursor of zeolite. Zeolite NaA and magnetic zeolite NaA were characterized with scanning electron microscopy (SEM) and XRD. Magnetic zeolite NaA with different Fe3O4 loadings was prepared and used for removal of heavy metals (Cu(2+), Pb(2+)). The results show the optimum parameters for synthesis zeolite NaA are SiO2/Al2O3=2.3, Na2O/SiO2=1.4, H2O/Na2O=50, crystallization time 8h, crystallization temperature 95 °C. The addition of Fe3O4 makes the NaA zeolite with good magnetic susceptibility and good magnetic stability regardless of the Fe3O4 loading, confirming the considerable separation efficiency. Additionally, Fe3O4 loading had a little effect on removal of heavy metal by magnetic zeolite, however, the adsorption capacity still reaches 2.3 mmol g(-1) for Cu(2+), Pb(2+) with a removal efficiency of over 95% in spite of 4.7% Fe3O4 loading. This indicates magnetic zeolite can be used to remove metal heavy at least Cu(2+), Pb(2+) from water with metallic contaminants and can be separated easily after a magnetic process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis and structural characterization of Co2+ ions doped ZnO nanopowders by solid state reaction through sonication

NASA Astrophysics Data System (ADS)

Babu, B.; Rama Krishna, Ch.; Venkata Reddy, Ch.; Pushpa Manjari, V.; Ravikumar, R. V. S. S. N.

2013-05-01

Cobalt ions doped zinc oxide nanopowder was prepared at room temperature by a novel and simple one step solid-state reaction method through sonication in the presence of a suitable surfactant Sodium Lauryl Sulphate (SLS). The prepared powder was characterized by various spectroscopic techniques. Powder XRD data revealed that the crystal structure belongs to hexagonal and its average crystallite size was evaluated. From optical absorption data, crystal fields (Dq), inter-electronic repulsion parameters (B, C) were evaluated. By correlating optical and EPR spectral data, the site symmetry of Co2+ ion in the host lattice was determined as octahedral. Photoluminescence spectra exhibited the emission bands in ultraviolet and blue regions. The CIE chromaticity coordinates are also evaluated from the emission spectrum. FT-IR spectra showed the characteristic vibrational bands of Znsbnd O.

Synthesis, characterization of (3E)-1-(6-chloro-2-methyl-4-phenyl quinolin-3-Yl)-3-aryl prop-2-en-1-ones through IR, NMR, single crystal X-ray diffraction and insights into their electronic structure using DFT calculations

NASA Astrophysics Data System (ADS)

Sarveswari, S.; Srikanth, A.; Arul Murugan, N.; Vijayakumar, V.; Jasinski, Jerry P.; Beauchesne, Hanna C.; Jarvis, Ethan E.

2015-02-01

3E-1-(6-Chloro-2-methyl-4-phenylquinolin-3-yl)-3-arylprop-2-en-1-ones were synthesized and characterized by FTIR, 1H NMR, 13C NMR, HSQC, DEPT-135. In addition the compound 3E-1-(6-chloro-2-methyl-4-phenylquinolin-3-yl)-3-(2,5-dimethoxyphenyl)prop-2-en-1-one was subjected to the single crystal X-ray diffraction studies. Density functional theory calculations were carried out for this chalcone and its derivatives to investigate into their electronic structure, chemical reactivity, linear and non-linear optical properties. The structure predicted from DFT for chalcone is in good agreement with the structure from XRD measurement.

Synthesis, structural characterization and DFT calculation on a square-planar Ni(II) complex of a compartmental Schiff base ligand

NASA Astrophysics Data System (ADS)

Biswas, Surajit; Dolai, Malay; Dutta, Arpan; Ali, Mahammad

2016-12-01

Reaction of a symmetric compartmental Schiff-base ligand, (H2L) with nickel(II) perchlorate hexahydrate in 1:1 M ratio in methanol gives rise to a mononuclear nickel(II) compound, NiL (1). The compound has been characterized by C, H, N microanalyses and UV-Vis spectra. The single crystal X-ray diffraction studies reveal a square planar geometry around the Ni(II) center. The compound crystallizes in monoclinic system with space group C2/c with a = 21.6425(6), b = 9.9481(3), c = 13.1958(4) Å, β = 107.728(2)°, V = 2706.16(14) Å3 and Z = 4. Ground state DFT optimization and TDDFT calculations on the ligand and complex were performed to get their UV-Vis spectral pattern.

Synthesis, spectroscopic characterization and structural investigations of new adduct compound of carbazole with picric acid: DNA binding and antimicrobial studies.

PubMed

Saravanabhavan, Munusamy; Sathya, Krishnan; Puranik, Vedavati G; Sekar, Marimuthu

2014-01-24

Carbazole picrate (CP), a new organic compound has been synthesized, characterized by various analytical and spectroscopic technique such as FT-IR, UV-Vis, (1)H and (13)C NMR spectroscopy. An orthorhombic geometry was proposed based on single crystal XRD study. The thermal stability of the crystal was studied by using thermo-gravimetric and differential thermal analyses and found that it was stable up to 170°C. Further, the newly synthesized title compound was tested for its in vitro antibacterial and antifungal activity against various bacterial and fungal species. Also, the compound was tested for its binding activity with Calf thymus (CT) DNA and the results show a considerable interaction between CP and CT-DNA. Copyright © 2013 Elsevier B.V. All rights reserved.

A novel mixed-metal borate with large [B12O18(OH)6]6- motif: Synthesis, structure and property

NASA Astrophysics Data System (ADS)

Wei, Li; Pan, Jie; Xue, Zhen-Zhen; Wang, Guo-Ming; Wang, Ying-Xia

2018-01-01

A new mixed-metal polyborate, Na5Li[B12O18(OH)6]·2H2O (1), has been synthesized using solvothermal method and characterized by IR spectroscopy, thermogravimetric analysis, UV-Vis spectroscopy, powder and single-crystal X-ray diffraction, respectively. It crystallizes in the trigonal space group R-3c (No. 167) with unit cell parameters of a = b = 9.6767(6) Å, c = 36.358(5) Å, and Z = 6. Its structure features unprecedented 3D framework constructed from novel honeycomb-shaped inorganic Na-O sheets with unique 12-MR sodium rings and supramolecular polyborate 2D layers of lithium-centered [B12O18(OH)6]6-. UV-Vis spectral characterization indicates that compound 1 is a wide-band-gap semiconductor.

Synthesis, crystal structures, spectral, thermal and antimicrobial properties of new Zn(II) 5-iodo- and 5-bromosalicylates

NASA Astrophysics Data System (ADS)

Košická, Petra; Győryová, Katarína; Smolko, Lukáš; Gyepes, Róbert; Hudecová, Daniela

2018-03-01

Two new analogous zinc(II) complexes containing 5-iodo- and 5-bromosalicylate ligands, respectively, were prepared in single-crystal form and characterized by IR spectroscopy, thermal analysis and elemental analysis. The solid-state structures of prepared complexes were determined by single crystal X-ray crystallography. Both complexes are isostructural and their crystal structures composed of neutral molecules [Zn(5-Xsal)2(H2O)2] (where X = Br, I, sal = salicylato). Central Zn(II) atom is in both complexes coordinated by six oxygen atoms, four of which are from two chelate bonded 5-halosalicylates and remaining two from coordinated water molecules. The found chelate binding mode is in line with the Δ values calculated from IR spectral data. Antimicrobial activity of prepared complexes was studied against selected bacteria, yeast and filamentous fungi. Obtained results indicate that 5-iodosalicylate complex is more antimicrobially active than its 5-bromo substituted analogue.

Investigation of Y/SBA Composite Molecular Sieves Morphology Control and Catalytic Performance for n-Pentane Aromatization

PubMed Central

Shi, Chun-Wei; Wu, Wen-Yuan; Li, Shuai; Bian, Xue; Zhao, Shan-lin; Pei, Ming-Yuan

2016-01-01

Using Y molecular sieve as the core, Y/SBA-15 composite molecular sieves were prepared by different crystallization methods in the paper. The growth process and morphologies of the composite molecular sieves were controlled by adjusting the synthesis factors. The structures and acidity of two kinds of composite molecular sieves were characterized by X-ray diffraction (XRD), N2 adsorption/desorption, transmission electron microscopy (TEM), and NH3-TPD. The catalysis performances of the composite molecular sieves were investigated in the aromatization reaction of n-pentane. The results indicated that the desired core-shell composite molecular sieves were obtained when the crystallization conditions were 36 hours, 100 °C and secondary crystallization. The aromatization results showed that core-shell composite molecular sieves had better selectivity for producing high application value xylenes compared to mixed-crystal composite molecular sieves. PMID:27029526

Synthesis, crystal structure and electronic structure of the binary phase Rh2Cd5

NASA Astrophysics Data System (ADS)

Koley, Biplab; Chatterjee, S.; Jana, Partha P.

2017-02-01

A new phase in the Rh-Cd binary system - Rh2Cd5 has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh2Cd5 crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh2Cd5 can be described as a defect form of the In3Pd5 structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (35) (37)- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh2Cd5.

Synthesis and characterization of 3-acetoxy-2-methyl-N-(phenyl)benzamide and 3-acetoxy-2-methyl-N-(4- methylphenyl)benzamide

NASA Astrophysics Data System (ADS)

Kırca, Başak Koşar; Çakmak, Şükriye; Kütük, Halil; Odabaşoğlu, Mustafa; Büyükgüngör, Orhan

2018-01-01

This study treats about two successfully synthesized secondary amide compounds 3-Acetoxy-2-methyl-N-(phenyl)benzamide, I and 3-Acetoxy-2-methyl-N-(4-methylphenyl)benzamide, II. Compounds were characterized by FTIR, 1H NMR, 13C NMR and X-ray single crystal diffraction analysis techniques. Single crystal X-ray diffraction analyses show that while I crystallized in the orthorhombic system with space group Pbca, II crystallized in the triclinic system with space group P-1 and the asymmetric unit of II consists of two crystallographically independent molecules. Lattice constants are a = 7.9713 (3) Å, b = 9.5059 (3) Å, c = 37.1762 (2) Å, Z = 8 for I and a = 7.5579 (8) Å, b = 8.8601 (8) Å, c = 23.363 (3) Å, α = 97.011 (9) °, β = 96.932 (9)°, γ = 90.051 (8)°, Z = 4 for II. Crystallographic studies also show that the supramolecular structures were stabilized by intramolecular, intermolecular hydrogen bonds and Csbnd H … π interactions for both compounds. Characteristic amide bonds were observed in IR and NMR spectra.

Novel thiourea derivative and its complexes: Synthesis, characterization, DFT computations, thermal and electrochemical behavior, antioxidant and antitumor activities

NASA Astrophysics Data System (ADS)

Yeşilkaynak, Tuncay; Muslu, Harun; Özpınar, Celal; Emen, Fatih Mehmet; Demirdöğen, Ruken Esra; Külcü, Nevzat

2017-08-01

A novel thiourea derivative, N-((2-chloropyridin-3-yl)carbamothioyl) thiophene-2-carboxamide,C11H8ClN3OS2 (HL) and its Co(II), Ni(II) and Cu(II) complexes (ML2 type) were prepared and characterized by elemental analysis, FT-IR,1H NMR and HR-MS methods. The crystal structure of HL was also investigated by single crystal X-ray diffraction study. The HL crystallizes in the orthorhombic crystal system with P 21 21 21 space group, Z = 4, a = 3.8875(3) Å, b = 14.6442(13) Å, c = 21.8950(19) Å. The [ML2] complex structures were optimized by using B97D/TZVP level. Molecular orbitals of HL ligand were calculated at the same level. Thermal and electrochemical behaviors of the complexes were investigated. Anticancer and antioxidant activities of the complexes were also investigated. Antioxidant activities were determined by using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2‧-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) assays. Anticancer activities were studied via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in MCF-7 (Michigan Cancer Foundation-7) breast cancer cells.

Synthesis, characterization, crystal structure and theoretical study of a compound with benzodiazole ring: antimicrobial activity and DNA binding.

PubMed

Latha, P; Kodisundaram, P; Sundararajan, M L; Jeyakumar, T

2014-08-14

2-(Thiophen-2-yl)-1-((thiophen-2-yl)methyl)-1H-1,3-benzodiazole (HL) is synthesized and characterized by elemental analysis, UV-Vis, FT-IR, (1)H, (13)C NMR, mass spectra, scanning electron microscope (SEM) and single crystal X-ray diffraction. The crystal structure is stabilized by intermolecular CH⋯N and CH⋯π interactions. The molecular structure is also optimized at the B3LYP/6-31G level using density functional theory (DFT). The structural parameters from the theory are nearer to those of crystal, the calculated total energy of coordination is -1522.814a.u. The energy of HOMO-LUMO and the energy gap are -0.20718, -0.04314, 0.16404a.u, respectively. All data obtained from the spectral studies support the structural properties of the compound HL. The benzimidazole ring is essentially planar. The in vitro biological screening effects of the synthesized compound is tested against four bacterial and four fungal strains by well diffusion method. Antioxidant property and DNA binding behaviour of the compound has been investigated using spectrophotometric method. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, characterization, crystal structure, DNA/BSA binding ability and antibacterial activity of asymmetric europium complex based on 1,10- phenanthroline

NASA Astrophysics Data System (ADS)

Alfi, Nafiseh; Khorasani-Motlagh, Mozhgan; Rezvani, Ali Reza; Noroozifar, Meissam; Molčanov, Krešimir

2017-06-01

A heteroleptic europium coordination compound formulated as [Eu(phen)2(OH2)2(Cl)2](Cl)(H2O) (phen = 1,10-phenanthroline), has been synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffractometer. Crystal structure analysis reveals the complex is crystallized in orthorhombic system with Pca21 space group. Electronic absorption and various emission methods for investigation of the binding system of europium(III) complex to Fish Salmon deoxyribonucleic acid (FS-DNA) and Bovamin Serum Albumin (BSA) have been explored. Furthermore, the binding constants, binding sites and the corresponding thermodynamic parameters of the interaction system based on the van't Hoff equation for FS-DNA and BSA were calculated. The thermodynamic parameters reflect the exothermic nature of emission process (ΔH°<0 and ΔS°<0). The experimental results seem to indicate that the [Eu(phen)2(OH2)2(Cl)2](Cl)(H2O) bound to FS-DNA by non-intercalative mode which the groove binding is preferable mode. Also, the complex exhibits a brilliant antimicrobial activity in vitro against standard bacterial strains.

Crystal structures and infrared spectra of two Fe-bearing hydrous magnesium silicates synthesized at high temperature and pressure

NASA Technical Reports Server (NTRS)

Yang, H.; Prewitt, C. T.; Liu, Z.

2002-01-01

The synthesis and characterization of Fe-bearing phase E and phase E' demonstrate that the phase E-type structures can be rather compliant and complex, and that as we further explore the temperature-pressure-composition space, other types of structures that are similar to or related to the structure of phase E may be discovered.

Synthesis and Characterization of Zeolite Na-Y and Its Conversion to the Solid Acid Zeolite H-Y

ERIC Educational Resources Information Center

Warner, Terence E.; Klokker, Mads Galsgaard; Nielsen, Ulla Gro

2017-01-01

Zeolite Y has an iconic crystal structure, but more importantly, the hydrogen modification zeolite H-Y is the classic example of a solid acid which is used extensively as a catalyst in the oil industry. This metastable compound cannot be synthesized directly, which creates an opportunity to discuss various preparative strategies with the students,…

Synthesis and Characterization of Functional Mesostructures Using Colloidal Crystal Templating

DTIC Science & Technology

2004-01-01

fluorescent probes in aqueous polymer solutions . Khoury and co-workers measured the diffusion coefficient of several fluorescein-labeled proteins in...diffraction naq refractive index of the aqueous solution phase xvii ni refractive index of component i ngel refractive index of the hydrogel...phase Tg glass transition temperature α angle of diffraction φaq volume fraction of the aqueous solution phase φi volume fraction of

Synthesis and Characterization of Polyether Adducts of Barium and Strontium Carboxylates and Their Use in the Formation of MTiO(3) Films.

PubMed

Wojtczak, William A.; Atanassova, Paolina; Hampden-Smith, Mark J.; Duesler, Eileen

1996-11-20

The synthesis, characterization, and reactivity of new polyether adducts of strontium and barium carboxylates of general composition M(O(2)CCF(3))(n)()(L) (M = Ba, L = 15-crown-5, (1); M = Ba (2), Sr (3), respectively, with L = tetraglyme are reported. The compounds were synthesized by reaction of BaCO(3) or MH(2) (M = Sr or Ba) with organic acids in the presence of the polyether ligands. These compounds have been characterized by IR and (13)C and (1)H NMR spectroscopies, elemental analyses, and thermogravimetric analysis. The species Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) and [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2), were also characterized by single-crystal X-ray diffraction. Ba(2)(O(2)CCF(3))(4)(15-crown-5)(2) (1) crystallizes in the orthorhombic space group Cccm with cell dimensions of a = 13.949(1) Å, b = 19.376(2) Å, c = 16.029(1) Å, and Z = 8. [Ba(2)(O(2)CCF(3))(4)(tetraglyme)](infinity) (2) crystallizes in the monoclinic space group C2/c with cell dimensions of a = 12.8673(12) Å, b = 16.6981(13) Å, c = 15.1191(12) Å, beta = 99.049(8) degrees, and Z = 4. Compounds 1-3 thermally decompose at high temperatures in the solid state to give MF(2). However, solutions of compounds 1-3 dissolved in ethanol with Ti(O-i-Pr)(4) give crystalline perovskite phase MTiO(3) films, or in the case of mixtures of 2 and 3, Ba(1)(-)(x)()Sr(x)()TiO(3) films below 600 degrees C when spin coated onto silicon substrates and thermally treated. The crystallinity, purity, and elemental composition of the films was determined by glancing angle X-ray diffraction and Auger electron spectroscopy.

Hydrothermal synthesis and crystal structure of alkaline earth metal (Mg, Ca) based on 2,5-Dimethylbenzene-1,4-diylbis(methylene) diphosphonic acid

NASA Astrophysics Data System (ADS)

Xie, Y. C.; Cheng, Q. R.; Pan, Z. Q.

2018-02-01

New magnesium phosphonates Mg(H2L)31 (H4L = 2,5-dimethylbenzene-1,4 -diylbis(methylene)diphosphonic acid) and Ca(H2L)·2H2O 2 have been hydrothermally synthesized from H4L and the corresponding metal salts. Complex 1 and 2 have been characterized by IR, powder and single-crystal X-ray diffraction methods. Complex 1 crystallizes in trigonal space group R-3c and complex 2 belongs to the triclinic space group. The complexes both form two-dimensional (2D) network structure and show three-dimensional (3D) network through hydrogen bonds. Thermal stability of complex 1 and 2 have also been investigated. CCDC: 1534599 for 1; 1536423 for 2.

Synthesis, spectral, thermal, X-ray single crystal of new RuCl₂(dppb)diamine complexes and their application in hydrogenation of Cinnamic aldehyde.

PubMed

Warad, Ismail; Al-Hussain, Hanan; Al-Far, Rawhi; Mahfouz, Refaat; Hammouti, Belkheir; Hadda, Taibi Ben

2012-09-01

The preparation of new three trans-[RuCl(2)(dppb)(N-N)] with mixed diamine (N-N) and 1,4-bis-(diphenylphosphino)butane (dppb) ligands, starting from RuCl(2)(PPh(3))(3) as precursor is presented. The complexes are characterized on the basis of elemental analysis, IR, (1)H, (13)C and (31)P{(1)H}NMR, FAB-MS, TG/DTA and single crystal X-ray diffraction studies. Complex (2L(1)) crystallizes in the monoclinic unit cells with the space group P2(1). The catalysts are evaluated for their Cinnamic aldehyde hydrogenation. The catalysts show excellent activity and selectivity for the unsaturated carbonyl compound under mild conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis, characterization and cholinesterase enzymes inhibitory activity of 1-[3-methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-4,5-dihydro-pyrazol-1-yl]-ethanone

NASA Astrophysics Data System (ADS)

Mehdi, Sayed Hasan; Ghalib, Raza Murad; Hashim, Rokiah; da Silva, M. Fátima C. Guedes; Sulaiman, Othman; Murugaiyah, Vikneswaran; Marimuthu, Mani Maran; Naqvi, Mehnaz

2013-10-01

The crystal structure of the title compound, 1-[3-methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-4,5-dihydro-pyrazol-1-yl]-ethanone has been determined by single crystal X-ray diffraction. It crystallizes in the orthorhombic space group P212121. The FTIR as well as the 1H and 13C NMR spectra of the compound were also recorded and briefly discussed. Compound 1 demonstrated good inhibitory activity against butyrylcholinesterase (BChE; IC50 = 46.42 μM) comparable to physostigmine. However it showed moderate inhibitory activity against acetylcholinesterase (AChE; IC50 = 157.31 μM). It showed moderate inhibitory activity against acetylcholinesterase and selective inhibitory activity towards butyrylcholinesterase enzyme.

Time Dependent Structural Evolution of Porous Organic Cage CC3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lucero, Jolie; Elsaidi, Sameh; Anderson, Ryther

Porous organic cage compounds are emerged with remarkable structural diversity and functionality that have applications in gas separation, catalysis and energy storage. Fundamental understanding of nucleation and growth of such materials have significant implications for understanding molecularly directed self-assembly phenomena. Herein we followed the structural evolution of a prototypical type of porous organic cage, CC3 as a function of synthesis time. Three distinctive crystal formation stages were identified: at short synthesis times, a rapid crystal growth stage in which amorphous agglomerates transformed into larger irregular particles was observed. At intermediate synthesis times, a decrease in crystal size over time wasmore » observed presumably due to crystal fragmentation, redissolution and/or homogeneous nucleation led. Finally, at longer synthesis times, a regrowth process was observed in which particles coalesced through Ostwald ripening leading to a continuous increase in crystal size. Molecular simulation studies, based on the construction of in silico CC3 models and simulation of XRD patterns and nitrogen isotherms, confirm the samples at different synthesis times to be a mixture of CC3α and CC3 amorphous phases. The CC3α phase is found to contract at different synthesis times, and the amorphous phase is found to essentially disappear at the longest synthesis time. Nitrogen and carbon dioxide adsorption properties of these CC3 phases were evaluated, and were highly dependent on synthesis time.« less

Bis (3-methoxy-4-hydroxybenzaldehyde-2,4,6-trinitrophenol) organic cocrystal: Synthesis and physico-chemical properties

NASA Astrophysics Data System (ADS)

Sudharsana, N.; Krishnakumar, V.; Nagalakshmi, R.

2016-10-01

A 3-methoxy-4-hydroxybenzaldehyde-2,4,6-trinitrophenol (mhba-tnp) cocrystal was grown by the slow evaporation solution growth technique using ethanol as a solvent. As-grown crystals were characterized by single crystal X-ray diffraction (XRD) study and crystallized with a centrosymmetric space group. Optical properties of the grown crystal have been studied by Ultraviolet-Visible (UV-Vis) absorption spectra in the range from 200 to 800nm and the band gap energy of the crystal was obtained as 2.8eV. Fourier transform infrared (FTIR) and micro Raman spectral analyses have been carried out to confirm the functional groups present in the title compound. Differential scanning calorimetry (DSC) and polarized light thermomicroscopy (PLTM) analyses were carried out to find the melting point. In addition, the optimized geometric parameters and the molecular orbitals were calculated using density functional theory (DFT) with the help of the Gaussian 03W software.

Synthesis, crystal structure analysis, molecular docking studies and density functional theory predictions of the local reactive properties and degradation properties of a novel halochalcone

NASA Astrophysics Data System (ADS)

Arshad, Suhana; Pillai, Renjith Raveendran; Zainuri, Dian Alwani; Khalib, Nuridayanti Che; Razak, Ibrahim Abdul; Armaković, Stevan; Armaković, Sanja J.

2017-09-01

In the present study, single crystals of E)-3-(3,5-dichlorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one, were prepared and structurally characterized by single crystal X-ray diffraction analysis. The molecular structure crystallized in monoclinic crystal system with P21/c space group. Sensitivity of the title molecule towards electrophilic attacks has been examined by calculations of average localized ionization energies (ALIE) and their mapping to electron density surface. Further determination of atoms that could be important reactive centres has been performed by calculations of Fukui functions. Sensitivity of title molecule towards autoxidation and hydrolysis mechanisms has been assessed by calculations of bond dissociation energies and radial distribution functions (RDF), respectively. Also, in order to explore possible binding mode of the title compound towards Dihydrofolate reductase enzyme, we have utilized in silico molecular docking to explore possible binding modes of the title compound with the DHFR enzyme.

Synthesis and physicochemical characterizations and antimicrobial activity of ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Bhumika K.; Patel, Kinjal; Roy, Debesh R.

2018-05-01

Nanoparticles exhibit very interesting and useful physicochemical properties when they interact with substrates and goes through some physicochemical and/or biological processes. ZnO is known to be a highly demanding nanomaterial due to its discreet properties, shapes and sizes. A detail experimental study on the synthesis, characterization and antibacterial activity of ZnO nanoparticles (NPs) is performed. ZnO NPs are synthesized using chemical precipitation method. The understanding of crystal structure, morphology and elemental compositions are explained using Powder X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM) respectively. Fourier transform infrared spectroscopy (FTIR) is performed to achieve the information on the presence of various functional groups. The antibacterial activity of these ZnO NPs is investigated in terms of Zone of Inhibition (ZOI) against Escherichia coli (Gram negative) microorganisms.

Synthesis and characterization of a novel inorganic-organic hybrid material based on polyoxometalates and dicyclohexylcarbodiimide

NASA Astrophysics Data System (ADS)

Huang, Bo; Hu, Xiaokang; Hu, Xunliang; Wang, Nan; Yang, Kang; Xiao, Zicheng; Wu, Pingfan

2017-12-01

Towards design and synthesis of bulky molecules and molecular machines, we reported a new inorganic-organic hybrid material based on polyoxometalates and 1, 3-dicyclohexylcarbodiimide (DCC): (Bu4N)2[V6O13{(OCH2)3CCH2OOCCH2CH2CON(C6H11)CONHC6H11}2]. The hybrid was characterized by FT-IR, 1H NMR, UV-Vis, ESI-MS, and the structure of the compound was determined through single-crystal X-ray diffraction. There was an interesting supramolecular assembly in the hybrid material through intermolecular hydrogen bonding, and each cyclohexyl in the polymer looks like one of blades in the propeller. Furthermore, the thermal stability of the hybrid was tested by TGA analyses, and the electrochemical property has also been studied by cyclic voltammogram.

RBAP, a rhodamine B-based derivative: synthesis, crystal structure analysis, molecular simulation, and its application as a selective fluorescent chemical sensor for Sn2+.

PubMed

Bao, Xiaofeng; Cao, Xiaowei; Nie, Xuemei; Jin, Yanyan; Zhou, Baojing

2014-06-11

A new fluorescent chemosensor based on a Rhodamine B and a benzyl 3-aminopropanoate conjugate (RBAP) was designed, synthesized, and structurally characterized. Its single crystal structure was obtained and analyzed by X-ray analysis. In a MeOH/H2O (2:3, v/v, pH 5.95) solution RBAP exhibits a high selectivity and excellent sensitivity for Sn2+ ions in the presence of many other metal cations. The binding analysis using the Job's plot suggested the RBAP formed a 1:1 complex with Sn2+.

1-Formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline: Synthesis, characterization, antimicrobial activity and DFT studies

NASA Astrophysics Data System (ADS)

Sid, Assia; Messai, Amel; Parlak, Cemal; Kazancı, Nadide; Luneau, Dominique; Keşan, Gürkan; Rhyman, Lydia; Alswaidan, Ibrahim A.; Ramasami, Ponnadurai

2016-10-01

The structure of 1-formyl-3-phenyl-5-(4-isopropylphenyl)-2-pyrazoline synthesized as single crystal was investigated by FTIR, NMR, XRD. Experimental data were complemented by quantum mechanical calculations. XRD data show that the compound crystallizes in the triclinic system (P-1) via trans isomer (a = 6.4267(4) Å, b = 10.9259(12) Å, c = 12.4628(9) Å and α = 102.894(8)°, β = 102.535(6)°, γ = 101.633(7)°). Anti-microbial screening results indicate that the compound shows promising activity. The theoretically predicted and experimentally obtained parameters reveal further insight into pyrazoline systems.

Low-temperature solvothermal synthesis of EuS hollow microspheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Yong; Wang, Hong; Li, Peng

2014-09-15

Graphical abstract: Synthesis of EuS hollow microspheres at low-temperature via solvothermal method for the first time. - Highlights: • We adopt an improved method to synthesise the (Phen)Eu(Et{sub 2}CNS{sub 2}){sub 3} in deionized water. • We have successfully synthesised the EuS hollow microsphere at 230 °C in acetonitrile. • The price of acetonitrile is more inexpensive, so the price of preparation was reduced. - Abstract: EuS crystals are synthesized by low-temperature solvothermal decomposition of the single source precursor complex (Phen)Eu(Et{sub 2}CNS{sub 2}){sub 3} in acetonitrile. X-ray powder diffraction, scanning electron microscopy, granulocyte diameter statistical analysis, surface energy-dispersive X-ray spectroscopy analysis,more » and UV–vis absorption spectroscopy are used to characterize the structure and properties of the obtained EuS crystals. The results show that the formed EuS crystals are uniform hollow microspheres with a typical cubic phase structure of rock salt and the average particle size of 2.01 μm. The mechanisms for the thermal decomposition of the precursor complex and the formation of the EuS hollow microspheres are postulated based on the experimental observations and previous reports.« less

Synthesis, crystal structure, catecholase and phenoxazinone synthase activities of a mononuclear cobalt(III) complex containing in situ formed tridentate N-donor Schiff base

NASA Astrophysics Data System (ADS)

Maji, Ashis Kumar; Chatterjee, Arnab; Khan, Sumitava; Ghosh, Barindra Kumar; Ghosh, Rajarshi

2017-10-01

Synthesis and structural characterization of a mononuclear cobalt(III) Schiff base complex is reported. It crystallizes with monoclinic crystal system with P21/n space group with a = 9.9793(4) Å, b = 28.2907(12) Å and c = 13.1233(6) Å, and β = 97.532(3)°. The compound is active to catecholase and phenoxazinone synthase activities in MeOH, and MeOH and MeCN solvents, respectively at room temperature. Each of the reactions was found to be of first order with reaction rate 8.08 × 10-3 min-1 (MeOH) for the catecholase activity and 1.05 × 10-3 min-1 (MeOH) and 3.82 × 10-3 min-1 (MeCN) for the phenoxazinone synthase activity. The turn over numbers for the catecholase activity is 5.02 × 103 h-1 (MeOH) and for the phenoxazinone synthase activity is 4.59 × 103 h-1 (MeOH) and 5.12 × 103 h-1 (MeCN). Substrate-catalyst adduct was tried to be trapped in each case using mass spectrometry.

Synthesis, Characterization and Decomposition Studies of Tris(N,N-dibenzyldithiocarbamato) Indium(III): Chemical Spray Deposition of Polycrystalline CuInS2 on Copper Films

NASA Technical Reports Server (NTRS)

Hehemann, David G.; Lau, J. Eva; Harris, Jerry D.; Hoops, Michael D.; Duffy, Norman V.; Fanwick, Philip E.; Khan, Osman; Jin, Michael H.-C.; Hepp, Aloysius F.

2005-01-01

Tris(bis(phenylmethyl)carbamodithioato-S,S ), commonly referred to as tris(N,Ndibenzyldithiocarbamato) indium(III), In(S2CNBz2)3, was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P1 bar with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry and Fourier-Transform infrared spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS2 and benzyl moieties in to the gas phase, resulting in bulk In2S3. Preliminary spray CVD experiments indicate that In(S2CNBz2)3 decomposed on a Cu substrate reacts to produce stoichiometric CuInS2 films.

Synthesis and Physical Properties of Liquid Crystals: An Interdisciplinary Experiment

ERIC Educational Resources Information Center

Van Hecke, Gerald R.; Karukstis, Kerry K.; Hanhan Li; Hendargo, Hansford C.; Cosand, Andrew J.; Fox, Marja M.

2005-01-01

A study involves multiple chemistry and physics concepts applied to a state of matter that has biological relevance. An experiment involving the synthesis and physical properties of liquid crystals illustrates the interdisciplinary nature of liquid crystal research and the practical devices derived from such research.

Synthesis, growth and characterization of L-Phenylalaninium methanesulfonate nonlinear optical single crystal

NASA Astrophysics Data System (ADS)

Mangaiyarkarasi, K.; Ravichandran, A. T.; Anitha, K.; Manivel, A.

2018-03-01

The titled compound, L-Phenylalaninium methanesulfonate (LPA-MS) was synthesized and grown into single crystals by slow solvent evaporation solution growth technique in aqueous solution containing equimolar concentrations of L-phenylalanine and methanesulfonic acid at room temperature. The grown crystals were subjected to single crystal X-ray diffraction studies. It crystallizes in the monoclinic crystal structure with P21 space group and the unit cell parameters are a = 5.312 (10) Å, b = 8.883 (2) Å and c = 25.830 (7) Å. The functional groups of the LPA-MS crystal were confirmed with FT-IR and FT-Raman analysis. The carbon-hydrogen skeleton was confirmed with 1H NMR and 13C NMR analysis. TG-DTG and DSC studies were carried out to determine the thermal stability of the crystals. The optical transparency ranges were studied through UV-vis-spectroscopy and the crystal was found to be transparent in the visible region. The second Harmonic generation (SHG) efficiency of the grown LPA-MS crystal was measured by the Kurtz-Perry powder technique. The dipolar nature of the L-phenylalaninium methanesulfonate and the presence of the intermolecular hydrogen bonding between the molecules are the vital factors responsible for the existence of SHG activity in the crystal.

Effect of solvent on the synthesis of SnO{sub 2} nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Virender; Singh, Karamjit; Singh, Kulwinder

Tin oxide (SnO{sub 2}) nanoparticles have been synthesized by co-precipitation method. The synthesized nanoparticles have been characterized by X-ray diffraction (XRD) and Ultraviolet-Visible spectroscopy (UV-VIS). XRD analysis confirmed the formation of single phase of SnO{sub 2} nanoparticles. It has been found that solvents played important role in controlling the crystallite size of SnO{sub 2} nanoparticles. The XRD analysis showed well crystallized tetragonal SnO{sub 2} nanoparticles. The crystallite size of SnO{sub 2} nanoparticles varies with the solvent. Tauc plot showed that optical band gap was also tailored by controlling the solvent during synthesis.

Synthesis, crystal growth and characterization of bioactive material: 2- Amino-1H-benzimidazolium pyridine-3-carboxylate single crystal- a proton transfer molecular complex

NASA Astrophysics Data System (ADS)

Fathima, K. Saiadali; Kavitha, P.; Anitha, K.

2017-09-01

The 1:1 molecular adducts 2- Amino-1H-benzimidazolium pyridine-3-carboxylate (2ABPC) was synthesized and grown as single crystal where 2-aminobenzimidazole (ABI) acts as a donor and nicotinic acid (NA) acts as an acceptor. The presence of proton and carbon were predicted using 1H and 13C NMR spectral analysis. The molecular structure of the crystal was elucidated by subjecting the grown crystals to the single crystal x-ray diffraction analysis and was refined by full matrix least-squares method to R = 0.038 for 2469 reflections. The vibrational modes of functional group have been studied using FTIR and Raman spectroscopic analysis. The UV-Vis spectrum exhibited a visible band at 246 nm for 2ABPC due to the nicotinate anion of the molecule. Further, the antimicrobial activity of 2ABPC complex against B. subtilis, klebsiella pneumonia, Pseudomonas eruginos and E. coli pathogens was investigated. Minimum Inhibitory Concentration (MIC) for this crystal was obtained using UV spectrometer against MRSA pathogen. It was found that the benzimidazole with aminogroup at position 2 increases the general antimicrobial activities of 2ABPC crystal.

Silver nanoplates with ground or metastable structures obtained from template-free two-phase aqueous/organic synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhelev, Doncho V., E-mail: dontcho.jelev@nih.gov; Zheleva, Tsvetanka S.

2014-01-28

Silver has unique electrical, catalytic, and plasmonic characteristics and has been widely sought for fabrication of nanostructures. The properties of silver nanostructures are intimately coupled to the structure of silver crystals. Two crystal structures are known for silver: the stable (ground) state cubic face centered 3C-Ag structure and the metastable hexagonal 4H-Ag structure. Recently, Chackraborty et al. [J. Phys.: Condens. Matter 23, 325401 (2011)] discovered a low density, highly reactive metastable hexagonal 2H-Ag structure accessible during electrodeposition of silver nanowires in porous anodic alumina templates. This 2H-Ag structure has enhanced electrical and catalytic characteristics. In the present work we reportmore » template-free synthesis of silver nanoplates with the metastable 2H-Ag crystal structure, which appears together with the ground 3C-Ag and the metastable 4H-Ag structures in a two-phase solution synthesis with citric acid as the capping agent. The capacity of citric acid to stabilize both the stable and the metastable structures is explained by its preferential binding to the close packed facets of Ag crystals, which are the (111) planes for 3C-Ag and the (0001) planes for 4H-Ag and 2H-Ag. Nanoplate morphology and structure are characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The synthesized nanoplates have thickness from 15 to 17 nm and edge length from 1 to 10 μm. Transmission electron microscopy selected area electron diffraction is used to uniquely identify and distinguish between nanoplates with 2H-Ag or 4H-Ag or 3C-Ag structures.« less

Synthesis and characterization of silver nanoparticles using crystal compound of sodium para-hydroxybenzoate tetrahydrate isolated from Vitex negundo. L leaves and its apoptotic effect on human colon cancer cell lines.

PubMed

Durai, Prabhu; Chinnasamy, Arulvasu; Gajendran, Babu; Ramar, Manikandan; Pappu, Srinivasan; Kasivelu, Govindaraju; Thirunavukkarasu, Ashokkumar

2014-09-12

Metallic nanoparticles are major concern, particularly silver nanoparticles (AgNPs) are used in various applications. In the present investigation, we report a novel strategy with biological approach for synthesis of AgNPs using sodium para-hydroxybenzoate tetrahydrate (SPHT) isolated from Vitex negundo leaves. The synthesized SPHT-AgNPs were characterized by UV-vis spectroscopy, high resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED) pattern, field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDX), zeta potential and Fourier transform infrared spectroscopy (FT-IR) analysis. The various pH and temperature were evaluated to find their stability effects on SPHT-AgNPs synthesis peak at 430 nm. The size of SPHT-AgNPs were ranging from 26 to 39 nm and were spherical in shape. The hydroxyl and carboxylic functional groups from bio-reducing mediators of SPHT have a stronger ability towards synthesis of AgNPs, which was confirmed using FT-IR spectrum. In addition, anticancer activity were determined by MTT assay, Annexin V-FITC/PI and cell cycle analysis. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Ca(BH 4) 2 as a simple tool for the preparation of thorium and uranium metallocene borohydride complexes: First synthesis and crystal structure of (C 5Me 5) 2Th(η 3-H 3BH) 2

DOE PAGES

Erickson, Karla A.; Scott, Brian Lindley; Kiplinger, Jaqueline Loetsch

2017-01-18

Here, calcium borohydride allows for the high-yielding synthesis of (C 5Me 5)2An(η 3-H 3BH) 2 (An = Th, U) by reaction with (C 5Me 5) 2AnCl 2 (An = Th, U). While a preparative synthesis of (C 5Me 5) 2U(η 3-H 3BH) 2 has been previously reported in the literature using K(C 5Me 5) and U(BH 4) 4, the use of Ca(BH 4) 2 is higher yielding and mild. Full characterization of the novel compound (C 5Me 5) 2Th(η 3-H 3BH) 2 is presented.

Ca(BH 4) 2 as a simple tool for the preparation of thorium and uranium metallocene borohydride complexes: First synthesis and crystal structure of (C 5Me 5) 2Th(η 3-H 3BH) 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, Karla A.; Scott, Brian Lindley; Kiplinger, Jaqueline Loetsch

Here, calcium borohydride allows for the high-yielding synthesis of (C 5Me 5)2An(η 3-H 3BH) 2 (An = Th, U) by reaction with (C 5Me 5) 2AnCl 2 (An = Th, U). While a preparative synthesis of (C 5Me 5) 2U(η 3-H 3BH) 2 has been previously reported in the literature using K(C 5Me 5) and U(BH 4) 4, the use of Ca(BH 4) 2 is higher yielding and mild. Full characterization of the novel compound (C 5Me 5) 2Th(η 3-H 3BH) 2 is presented.

Synthesis and characterization of tetra phenoxy-substituted halogen-rich metallophthalocyanine derivatives: A study on their LCD color filter requirements

NASA Astrophysics Data System (ADS)

Muthukumar, Palanisamy; Kim, Hak-Soo; Jeong, Jong Woo; Son, Young-A.

2016-09-01

This study addresses the synthesis and characterization of new tetra phenoxy-substituted halogen-rich metallophthalocyanine derivatives (MPcs) 4-7 (M = Co, Ni, Cu and Zn). The synthesized new compounds were characterized using UV-Vis, FT-IR, MALDI-TOF, 1H NMR and elemental analyses. In addition, the basic requirements such as aggregation behavior, thermal stability, transmittance and solubility in propylene glycol monomethyl ether acetate (PGMEA) of MPcs 4-7 were investigated for their usage as a green color filter in Liquid Crystal Displays (LCDs). All of the MPcs showed thermal stability and sufficient solubility in PGMEA. However, the addition of binder into PGMEA solution of MPcs 5 and 6 leads to precipitation. Among the four MPcs, zinc phthalocyanine (7) showed higher transmittance. The higher transmittance of zinc phthalocyanine (7) along with its thermal stability and sufficient solubility in PGMEA are promising for its application as a green color filter in LCDs.

On-Surface Synthesis and Characterization of Honeycombene Oligophenylene Macrocycles.

PubMed

Chen, Min; Shang, Jian; Wang, Yongfeng; Wu, Kai; Kuttner, Julian; Hilt, Gerhard; Hieringer, Wolfgang; Gottfried, J Michael

2017-01-24

We report the on-surface formation and characterization of [30]-honeycombene, a cyclotriacontaphenylene, which consists of 30 phenyl rings (C 180 H 120 ) and has a diameter of 4.0 nm. This shape-persistent, conjugated, and unsubstituted hexagonal hydrocarbon macrocycle was obtained by solvent-free synthesis on a silver (111) single-crystal surface, making solubility-enhancing alkyl side groups unnecessary. Side products include strained macrocycles with square, pentagonal, and heptagonal shape. The molecules were characterized by scanning tunneling microscopy and density functional theory (DFT) calculations. On the Ag(111) surface, the macrocycles act as molecular quantum corrals and lead to the confinement of surface-state electrons inside the central cavity. The energy of the confined surface state correlates with the size of the macrocycle and is well described by a particle-in-the-box model. Tunneling spectroscopy suggests conjugation within the planar rings and reveals influences of self-assembly on the electronic structure. While the adsorbed molecules appear to be approximately planar, the free molecules have nonplanar conformation, according to DFT.

Synthesis, characterization and theoretical study in gaseous and solid phases of the imine 4-Acetyl-N-(4-methoxybenzylidene)aniline

NASA Astrophysics Data System (ADS)

Batista, J. F. N.; Cruz, J. W.; Doriguetto, A. C.; Torres, C.; de Almeida, E. T.; Camps, I.

2017-11-01

In the present paper we describe the synthesis and characterization of the Schiff's base or imine 4-Acetyl-N-(4-methoxybenzylidene)aniline (1), which provided experimental support for the theoretical calculations. The imine was characterized by infrared spectroscopy and single crystal XRD techniques. The computational studies were performed using the density functional theory (DFT) for the gaseous and solid phases. As similar compounds already shown biological activity, the pharmacokinetic properties of (1) were evaluated. Our results shown that (1), in its gaseous form, it is electronically stable and has pharmacological drug like properties. Due to its structural similarity with commercial drugs, it is a promise candidate to act as a nonsteroidal anti-inflammatory and to treat dementia, sleep disorders, alcohol dependence, and psychosis. From the solid state calculations we obtain that (1) is a low gap semiconductor and can act as an absorber for electromagnetic radiations with energy greater that ∼ 0.9eV .

Synthesis, structural and spectral characterization of a novel NLO crystal N,N‧-diphenylguanidinium picrate: diacetone solvate

NASA Astrophysics Data System (ADS)

Shanmugavadivu, T.; Dhandapani, M.; Naveen, S.; Lokanath, N. K.

2017-09-01

An organic NLO active material N,N‧-diphenylguanidinium picrate: diacetone solvate (C13H14N3+. C6H2N3O7-. 2C3H6O) (DPGPD) was synthesized and single crystals were grown by slow evaporation-solution growth technique at room temperature. DPGPD crystallizes in monoclinic crystal system with noncentrosymmetric space group, Cc confirmed by single crystal X-ray diffraction analysis. The presence of various functional groups was identified from FT-IR spectral analysis and the proton transfer during the formation of compound was confirmed by NMR spectroscopic techniques. The thermal stability was investigated by TG/DTA analyses. Optical transmittance was measured by UV-Vis-NIR spectroscopy and band gap energy was calculated. Photoluminescence spectrum was used to explore its applicability towards laser diodes. Dielectric property of the material was ascertained at different temperatures and it is found that the grown crystal has higher dielectric constant in low frequencies. Photoconductivity study revealed that DPGPD exhibits positive photoconductivity. SHG property was found to be 0.6 times higher than that of KDP.

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

NASA Astrophysics Data System (ADS)

He, Dan; Xiao, Xiufeng; Liu, Fang; Liu, Rongfang

2008-11-01

By Ca(NO 3) 2·4H 2O and (NH 4) 3PO 4·3H 2O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration (≥0.5 wt.%) of ChS as a template.

Synthesis of zeolite NaA membrane from fused fly ash extract.

PubMed

Ameh, Alechine E; Musyoka, Nicholas M; Fatoba, Ojo O; Syrtsova, Daria A; Teplyakov, Vladimir V; Petrik, Leslie F

2016-01-01

Zeolite-NaA membranes were synthesized from an extract of fused South African fly ash on a porous titanium support by a secondary growth method. The influence of the synthesis molar regime on the formation of zeolite NaA membrane layer was investigated. Two synthesis mixtures were generated by adding either aluminium hydroxide or sodium aluminate to the fused fly ash extract. The feedstock material and the synthesized membranes were characterized by X-diffraction (XRD), scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). It was found by XRD and SEM that the cubic crystals of a typical zeolite NaA with a dense intergrown layer was formed on the porous Ti support. The study shows that the source of Al used had an effect on the membrane integrity as sodium aluminate provided the appropriate amount of Na(+) to form a coherent membrane of zeolite NaA, whereas aluminium hydroxide did not. Morphological, the single hydrothermal stage seeded support formed an interlocked array of zeolite NaA particles with neighbouring crystals. Also, a robust, continuous and well-intergrown zeolite NaA membrane was formed with neighbouring crystals of zeolite fused to each other after the multiple stage synthesis. The synthesized membrane was permeable to He (6.0 × 10(6) L m(-2)h(-1) atm(-1)) and CO2 (5.6 × 10(6) L m(-2)h(-1) atm(-1)), which indicate that the layer of the membrane was firmly attached to the porous Ti support. Membrane selectivity was maintained showing membrane integrity with permselectivity of 1.1, showing that a waste feedstock, fly ash, could be utilized for preparing robust zeolite NaA membranes on Ti support.

Self-assembled 3D zinc borate florets via surfactant assisted synthesis under moderate pressures: Process temperature dependent morphology study

NASA Astrophysics Data System (ADS)

Mahajan, Dhiraj S.; Deshpande, Tushar; Bari, Mahendra L.; Patil, Ujwal D.; Narkhede, Jitendra S.

2018-04-01

In the present study, we prepared zinc borates using aqueous phase synthesis under moderate pressures (MP) (<150 psi) with ethanol as a co-solvent in the presence of a quaternary ammonium surfactant-Cetyltrimethylammonium bromide (CTAB). 3D morphologies of self-assembled zinc borate (Zn(H2O)B2O4 · 0.12 H2O, Zn3B6O12 · 3.5H2O, ZnB2O4) resembling flower-like structures were obtained by varying temperature under moderate pressure conditions. Synthesized zinc borates’ florets were morphologically characterized by Field Emission Scanning Electron Microscopy. The x-ray diffractions of borate species reveal rhombohydra, monoclinic and cubic phases of zinc borate crystals as a function of process temperature. Additionally, thermal analysis confirms excellent dehydration/degradation behavior for the zinc borate crystals synthesized at moderate pressures and elevated temperatures and could be utilized as potential flame retardant fillers in the polymer matrices.

Two sodium and lanthanide(III) MOFs based on oxalate and V-shaped 4,4‧-oxybis(benzoate) ligands: Hydrothermal synthesis, crystal structure, and luminescence properties

NASA Astrophysics Data System (ADS)

Wang, Chongchen; Guo, Guangliang; Wang, Peng

2013-01-01

Two lanthanide based metal-organic frameworks, [NaLn(oba)(ox)(H2O)] (Lndbnd6 Eu(1) and Sm(2)) were obtained from 4,4'-oxybisbenzoic acid, sodium oxalate and corresponding lanthanide salts by hydrothermal synthesis. They were characterized by single-crystal X-ray diffraction, IR spectra, and photoluminescent spectra. The crystallographic data reveals that complexes 1 and 2 are isomorphous and isostructural, composed of three-dimensional framework built up of distorted tricapped trigonal EuO9 units, distorted octahedron NaO6 units, 4,4'-oxybis(benzoate) and oxalate. The carboxylate oxygen atoms of the 4,4'-oxybis(benzoate) and oxalate ligand are coordinated to lanthanide ions and sodium ions, resulting into two-dimensional inorganic sheets, which are further linked into three-dimensional network by organic ligands. Thermogravimetric analyses of 1-2 display a considerable thermal stability. Photoluminescent measurements indicated that europium complex 1 displayed strong red emission.

The Effect of an Ultrasound Radiation on the Synthesis of 4A Zeolite from Fly Ash

NASA Astrophysics Data System (ADS)

Susanto, H.; Imani, N. A. C.; Aslamiyah, N. R.; Istirokhatun, T.; Robbani, M. H.

2018-05-01

The use of coal as a fuel source generates a lot of solid waste fly ash. Thus, efforts to reduce or utilize the amount of fly ash are urgently needed. This paper presents zeolite synthesis from fly ash. The fly ash was activated by using NaOH solution prior to fusing process with a weight ratio of 1:2 and mixing with distilled water at a weight ratio of 1:5. Thereafter, the addition of alumina with a concentration of 0.71 %, 1.42 %, 2.12 %, and 2.8 % w/v was performed. The effects of heating and ultrasound radiation on the characteristic of zeolite products were investigated. The results showed that the addition of alumina 2.8 % w/v resulted in the Si/Al ratio of zeolite 4A is ∼1. SEM images demonstrated that the presence of ultrasound wave resulted in crystals structure morphology as also supported by XRD characterization. The average crystal size for the ultrasonic treatment was 42.46 nm.

Synthesis of highly-monodisperse spherical titania particles with diameters in the submicron range.

PubMed

Tanaka, Shunsuke; Nogami, Daisuke; Tsuda, Natsuki; Miyake, Yoshikazu

2009-06-15

Monodisperse titania spheres with particle diameters in the range 380-960 nm were successfully synthesized by hydrolysis and condensation of titanium tetraisopropoxide. The preparation was performed using ammonia or dodecylamine (DDA) as a catalyst in methanol/acetonitrile co-solvent at room temperature. The samples were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and nitrogen sorption measurement. The use of DDA was effective for the synthesis of monodisperse titania spheres with low coefficient of variation. When the titania spherical particles with coefficient of variation less than 4% were obtained, the colloidal crystallization easily occurred simply by centrifugation. The monodispersity was maintained even after crystallization of the particles by high temperature annealing. The titania particles prepared using DDA had mesopores near the surface of the spheres, providing high pore accessibility to the sphere from the surface-air interface. The particle size uniformity and photocatalytic reactivity of the titania prepared using DDA were higher than those of the titania prepared using ammonia.

Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

PubMed

Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

2016-11-23

An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

Spectroscopic characterization of zinc oxide nanorods synthesized by solid-state reaction

NASA Astrophysics Data System (ADS)

Prasad, Virendra; D'Souza, Charlene; Yadav, Deepti; Shaikh, A. J.; Vigneshwaran, Nadanathangam

2006-09-01

Well-crystallized zinc oxide nanorods have been fabricated by single step solid-state reaction using zinc acetate and sodium hydroxide, at room temperature. The sodium lauryl sulfate (SLS) stabilized zinc oxide nanorods were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and photoluminescence spectroscopy. The X-ray diffraction revealed the wurtzite structure of zinc oxide. The size estimation by XRD and TEM confirmed that the ZnO nanorods are made of single crystals. The growth of zinc oxide crystals into rod shape was found to be closely related to its hexagonal nature. The mass ratio of SLS:ZnO in the nanorods was found to be 1:10 based on the thermogravimetric analysis. Blue shift of photoluminescence emission was noticed in the ZnO nanorods when compared to that of ZnO bulk. FT-IR analysis confirmed the binding of SLS with ZnO nanorods. Apart from ease of preparation, this method has the advantage of eco-friendliness since the solvent and other harmful chemicals were eliminated in the synthesis protocol.

Synthesis, spectral characterization, thermal behaviour, antibacterial activity and DFT calculation on N‧-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide and N‧-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester

NASA Astrophysics Data System (ADS)

Bharty, M. K.; Dani, R. K.; Kushawaha, S. K.; Prakash, Om; Singh, Ranjan K.; Sharma, V. K.; Kharwar, R. N.; Singh, N. K.

2015-06-01

Two new compounds N‧-[bis(methylsulfanyl) methylene]-2-hydroxybenzohydrazide {Hbmshb (1)} and N‧-(4-methoxy benzoyl)-hydrazinecarbodithioic acid ethyl ester {H2mbhce (2)} have been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray diffraction data. Compounds 1 and 2 crystallize in orthorhombic and monoclinic systems with space group Pna21 and P21/n, respectively. Inter and intra molecular hydrogen bonding link two molecules and provide linear chain structure. In addition to this, compound 2 is stabilized by CH⋯π and NH⋯π interactions. Molecular geometry from X-ray analysis, geometry optimization, charge distribution, bond analysis, frontier molecular orbital (FMO) analysis and non-linear optical (NLO) effects have been performed using the density functional theory (DFT) with the B3LYP functional. The bioefficacy of compounds has been examined against the growth of bacteria to evaluate their anti-microbial potential. Compounds 1 and 2 are thermally stable and show NLO behaviour better than the urea crystal.

Materials for high-temperature thermoelectric conversion

NASA Technical Reports Server (NTRS)

Feigelson, R. S.; Elwell, D.; Auld, B. A.

1984-01-01

The development of materials for high temperature thermoelectric energy conversion devices was investigated. The development of new criteria for the selection of materials which is based on understanding of the fundamental principles governing the behavior of high temperature thermoelectric materials is discussed. The synthesis and characterization of promising new materials and the growth of single crystals to eliminate possible problems associated with grain boundaries and other defects in polycrystalline materials are outlined.

Synthesis, spectroscopy and computational studies of some biologically important hydroxyhaloquinolines and their novel derivatives

NASA Astrophysics Data System (ADS)

Malecki, Grzegorz; Nycz, Jacek E.; Ryrych, Ewa; Ponikiewski, Lukasz; Nowak, Maria; Kusz, Joachim; Pikies, Jerzy

2010-04-01

A series crystalline compounds of methyl and phosphinyl derivatives of 2-methylquinolin-8-ol ( 1a) and related 5,7-dichloro-2-methylquinolin-8-ol ( 1b) were quantitatively prepared and characterized by microanalysis, IR, UV-vis and multinuclear NMR spectroscopy. Five of them have been characterized by single crystal X-ray diffraction method. The known compounds, 8-methoxy-2-methylquinoline ( 2a) and 8-methoxyquinoline ( 2d), were synthesised by a new route. NMR solution spectra at ambient temperature, showed readily diagnostic H-1 and C-13 signals from methyl groups. The geometries of the studied compounds were optimized in singlet states using the density functional theory (DFT) method with B3LYP functional. In general, the predicted bond lengths and angles are in a good agreement with the values based on the X-ray crystal structure data. Electronic spectra were calculated by TDDFT method.

A novel salt of antidiabetic drug metformin resulting from a proton transfer reaction: Synthesis, characterization, crystal structure and solution studies

NASA Astrophysics Data System (ADS)

Ghasemi, Fatemeh; Ghasemi, Khaled; Rezvani, Ali Reza; Shokrollahi, Ardeshir; Refahi, Masoud; García-Granda, Santiago; Mendoza-Meroño, Rafael

2017-03-01

Reaction between N,N-dimethylebiguanidine, Met = Metformin, and 4-hydroxy-2,6-pyridinedicarboxylic acid, HO-dipicH2, results in the formation of a novel proton transfer compound, [MetH2][HO-dipicH]2·H2O, 1. The characterization was performed using FTIR, UV-Vis, 1H and 13C NMR spectroscopy and X-ray crystallography. The crystal system is triclinic with space group P 1 bar and two molecules per unit cell. The protonation constants of O-dipic and Met, in all of probability protonated forms, and the equilibrium constants for the O-dipic-Met proton transfer system were investigated by the potentiometric pH titration method using the Hyperquad2008 program. The stoichiometry of the proton transfer species in solution were in agreement with the solid state result.

Synthesis, characterizations and catalytic studies of a new two-dimensional metal-organic framework based on Co-carboxylate secondary building units

NASA Astrophysics Data System (ADS)

Bagherzadeh, Mojtaba; Ashouri, Fatemeh; Đaković, Marijana

2015-03-01

A metal-organic framework [Co3(BDC)3(DMF)2(H2O)2] was synthesized and structurally characterized. X-ray single crystal analysis revealed that the framework contains a 2D polymeric chain through coordination of 1,4-benzenedicarboxylic acid linker ligand to cobalt centers. The polymer crystallize in monoclinic P21/n space group with a=13.989(3) Å, b=9.6728(17) Å, c=16.707(3) Å, and Z=2. The polymer features a framework based on the perfect octahedral Co-O6 secondary building units. The catalytic activities of [Co3(BDC)3(DMF)2(H2O)2]n for olefins oxidation was conducted. The heterogeneous catalyst could be facilely separated from the reaction mixture, and reused three times without significant degradation in catalytic activity. Furthermore, no contribution from homogeneous catalysis of active species leaching into reaction solution was detected.

Synthesis, characterization, AIM and NBO analysis of HMX/DMI cocrystal explosive

NASA Astrophysics Data System (ADS)

Lin, He; Zhu, Shun-Guan; Li, Hong-Zhen; Peng, Xin-Hua

2013-09-01

1,3,5,7-Tetranitro-1,3,5,7-tetrazacyclooctane (HMX)/1,3-dimethyl-2-imidazolidinone (DMI) cocrystal explosive was synthesized and characterized by using X-ray single crystal diffraction. HMX/DMI cocrystal crystallizes in the monoclinic system (space group Cm), with cell parameters a = 7.231(2)Å, b = 14.739(2)Å, c = 7.552(1)Å, β = 96.66°. In addition, density functional theory, involving binding energy, natural bond orbital (NBO) analysis, atoms in molecule (AIM) analysis, band structure, and density of states, was adopted to investigate intermolecular interactions for the formation of HMX/DMI cocrystal. The results show that hydrogen bondings between methylene groups of HMX molecules and O atoms of DMI molecules are the main intermolecular interactions. This research provides the basis for further design of cocrystal explosives, which are composed of HMX and energetic materials.

Synthesis, spectral characterization and catalytic activity of Co(II) complexes of drugs: crystal structure of Co(II)-trimethoprim complex.

PubMed

Madhupriya, Selvaraj; Elango, Kuppanagounder P

2014-01-24

New Co(II) complexes with drugs such as trimethoprim (TMP), cimetidine (CTD), niacinamide (NAM) and ofloxacin (OFL) as ligands were synthesized. The complexes were characterized by analytical analysis, various spectral techniques such as FT-IR, UV-Vis, magnetic measurements and molar conductivity. The magnetic susceptibility results coupled with the electronic spectra suggested a tetrahedral geometry for the complexes. The coordination mode of trimethoprim ligand and geometry of the complex were confirmed by single crystal X-ray studies. In this complex the metal ion possesses a tetrahedral geometry with two nitrogen atom from two TMP ligands and two chloride ions coordinated to it. The catalytic activity of the complexes in aryl-aryl coupling reaction was screened and the results indicated that among the four complexes [Co(OFL)Cl(H2O)] exhibited excellent catalytic activity. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis, characterization, photoluminescence, and electrochemical studies of novel mononuclear Cu(II) and Zn(II) complexes with the 1-benzylimidazolium ligand

NASA Astrophysics Data System (ADS)

Bibi, Sherino; Mohammad, Sharifah; Manan, Ninie Suhana Abdul; Ahmad, Jimmy; Kamboh, Muhammad Afzal; Khor, Sook Mei; Yamin, Bohari M.; Abdul Halim, Siti Nadiah

2017-08-01

Two new mononuclear coordination complexes [Cu(bim)4Cl2]ṡ2H2O (1) and [Zn(bim)2Cl2] (2) containing the 1-benzylimidazole (bim) ligand were successfully synthesized. Both complexes were characterized by IR, UV-vis, and fluorescence spectroscopies, single crystal and powder X-ray diffraction measurements, and thermogravimetric analysis. Self-assembly during the recrystallization process resulted in the formation of octahedral and tetrahedral Cu(II) and Zn(II) complexes, respectively. The single crystals obtained are representative of the bulk material, as shown by the powder X-ray diffraction patterns. Cyclic voltammetry measurements showed that complex 1 undergoes a quasi-reversible redox reaction, while complex 2 undergoes reduction alone, and no oxidation peak was observed; this is due to the stability of the reduced form of complex 2.

Homo- and Heterometallic Bis(Pentafluorobenzoyl)Methanide Complexes of Copper(II) and Cobalt(II)

NASA Astrophysics Data System (ADS)

Crowder, Janell M.

beta-Diketones are well known to form metal complexes with practically every known metal and metalloid. Metal complexes of fluorinated beta-diketones generally exhibit increased volatility and thermal stability compared to the non-fluorinated analogues, and thus are used extensively in various chemical vapor deposition (CVD) processes for the deposition of metal, simple or mixed metal oxides, and fluorine-doped metal oxide thin films. Furthermore, the electron-withdrawing nature of the fluorinated ligand enhances the Lewis acidity of a coordinatively unsaturated metal center which facilitates additional coordination reactions. The physical and structural properties of fluorinated beta-diketonate complexes are discussed in Chapter 1 and a few key application examples are given. The focus of this work is the synthesis and single crystal X-ray structural characterization of unsolvated and coordinatively unsaturated metal complexes of bis(pentafluorobenzoyl)- methanide (L, C6F5COCHCOC 6F5-). In Chapter 2, we present the preparation and isolation of the unsolvated complex [Cu(L)2] in pure crystalline form for the first time. We subsequently investigated the reaction of unsolvated [Cu(L)2] with sodium hexafluoroacetylacetonate [Na(hfac)] in a solvent-free environment. This reaction allowed the isolation of the first heterometallic Na-Cu diketonate [Na2Cu2(L) 4(hfac)2] structurally characterized by single crystal X-ray crystallography. Thermal decomposition of [Na2Cu2(L) 4(hfac)2] was investigated for its potential application in MOCVD processes. In the final chapter, we present the first exploration of the anhydrous synthesis of Co(II) complexed with bis(pentafluorobenzoyl)methanide in order to produce a complex without ligated water. Single crystal X-ray crystallographic investigations revealed the isolation of the ethanol adduct, [Co2(L)4(C2H5OH)2], and following the removal of ethanol, a 1,4-dioxane adduct, [{Co 2(L)4}2(C4H8O2)]. In this work, we have provided the first investigation of the synthesis, isolation and single crystal X-ray structural characterization of unsolvated and coordinatively unsaturated Cu(II) and Co(II) complexes of bis(pentafluorobenzoyl)methanide ligand. These studies demonstrate how the electrophilicity of a coordinatively unsaturated metal complexed to highly-fluorinated â-diketone ligands can be utilized for the formation of new adducts or new and interesting heterometallic complexes. This body of work provides a basis upon which future research into unsolvated and unligated bis(pentafluorobenzoyl)methanide metal complexes can expand.

Multicomponent hydrogen-bonding organic solids constructed from 6-hydroxy-2-naphthoic acid and N-heterocycles: Synthesis, structural characterization and synthon discussion

NASA Astrophysics Data System (ADS)

Zong, Yingxia; Shao, Hui; Pang, Yanyan; Wang, Debao; Liu, Kang; Wang, Lei

2016-07-01

Seven novel multicomponent crystals involving various substituted organic amine molecules and 6-hydroxy-2-naphthoic acid were prepared and characterized by using single crystal X-ray diffraction, infrared and thermogravimetric analyses (TGA). Crystal structures with 1,4-bis(imidazol) butane (L1) 1, 1,4-bis(imidazol-1-ylmethyl)benzene (L2) 2, 1-phenyl piperazine 3, 2-amino-4-hydroxy-6-methyl pyrimidine 4, 4,4'-bipyridine 5, 5,5'-dimethyl-2,2'-dipyridine 6, 2-amino-4,6-dimethyl pyrimidine 7 were determined. Among the seven molecular complexes, total proton transfer from 6-hydroxy-2-naphthoic acid to coformer has occurred in crystals 1-4, while the remaining were cocrystals. X-ray single-crystal structures of these complexes reveal that strong hydrogen bonding O-H···O/N-H···O/O-H···N and weak C-H···O/C-H···π/π···π intermolecular interactions direct the packing modes of molecular crystals together. The analysis of supramolecular synthons in the present structures shows that some classical supramolecular synthons like pyridine-carboxylic acid heterosynthon R22 (7) and aminopyridine-carboxylic acid heterosynthon R22 (8), are again observed in constructing the hydrogen-bonding networks in this paper. Besides, we noticed that water molecules act as a significant hydrogen-bonding connector in constructing supramolecular architectures of 3, 4, 6, and 7.

Six new complexes constructed from silver(I) and 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ): Synthesis, crystal structure and properties

NASA Astrophysics Data System (ADS)

Feng, Zhicun; Zhang, Hang; Xu, Kangzhen; Song, Jirong; Zhao, Fengqi

2018-04-01

Six different energetic silver complexes of 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ), Ag(DNDZ) (1), [Ag2(H2O)(DNDZ)]n (2), Ag(NH3)DNDZ (3), Ag(CH3NH2)(DNDZ) (4), Ag(C2H5NH2)(DNDZ) (5) and Ag(C3H7NH2)(DNDZ) (6), were first synthesized and structurally characterized. Complexes 2, 3, 5 and 6 were characterized by the single crystal X-ray diffraction analysis. Complexes 2, 5 and 6 crystallize in the monoclinic crystal system with space group P21/n containing four molecules per unit cell, but the crystal of complex 3 is triclinic with space group P-1 containing two molecules in each unit cell. Complexes 2 and 3 possess Ag⋯Ag interaction and corresponding central symmetric structure, but complexes 5 and 6 do not. Thermal behaviors of complexes 1-6 were determined and analyzed. The order of thermal stability for the six complexes is 4 > 3 >1 > 2 >5 > 6. Impact sensitivities for complexes 1-6 are >12 J, > 4 J, > 13 J, > 16 J, > 8 J and >7 J respectively, which corresponds well to the results of thermal stability for the six complexes except for complex 2. Moreover, natural bond orbital (NBO) analysis was used to investigate the bonding and hybridization of complex 3.

Structural characterization of cevimeline and its trans-impurity by single crystal XRD.

PubMed

Stepanovs, Dmitrijs; Tetere, Zenta; Rāviņa, Irisa; Kumpiņš, Viktors; Zicāne, Daina; Bizdēna, Ērika; Bogans, Jānis; Novosjolova, Irina; Grigaloviča, Agnese; Meri, Remo Merijs; Fotins, Juris; Čerkasovs, Maksims; Mishnev, Anatoly; Turks, Māris

2016-01-25

Cevimeline is muscarinic receptor agonist which increases secretion of exocrine glands. Cevimeline base is a liquid (m.p. 20-25 °C) at ambient conditions, therefore its pharmaceutical formulation as a solid hydrochloride hemihydrate has been developed. The synthesis of cevimeline yields its cis- and trans-isomers and only the cis-isomer is recognized as the API and used in the finished formulation. In this study structural and physicochemical investigations of hydrochloride hemihydrates of cis- and trans-cevimelines have been performed. Single crystal X-ray analyses of both cis- and trans-isomers of cevimeline are reported here for the first time. It was found that the cis-isomer, the API, has less dense crystal packing, lower melting point and higher solubility in comparison to the trans-isomer. Copyright © 2015 Elsevier B.V. All rights reserved.

A new cadmium(II) complex with bridging dithiolate ligand: Synthesis, crystal structure and antifungal activity study

NASA Astrophysics Data System (ADS)

Singh, Mahesh Kumar; Sutradhar, Sanjit; Paul, Bijaya; Adhikari, Suman; Laskar, Folguni; Butcher, Raymond J.; Acharya, Sandeep; Das, Arijit

2017-07-01

A new polymeric complex of Cd(II) with 1,1-dicyanoethylene- 2,2-dithiolate [ i-MNT2- = {S2C:C(CN)2}2- ] as a bridging ligand has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single crystal X-ray diffraction analysis reveals that the Cadmium (II) complex is six coordinated 1D polymeric in nature. Biological screening effects in vitro of the synthesized polymeric complex has been tested against five fungi Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans(ATCC10231), Trichophyton mentagrophytes by the disc diffusion method. In vitro antifungal screening indicates that the complex exhibits fungistatic and fungicidal antifungal activity whereas K2i-MNT.H2O became silent on Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), Trichophyton mentagrophytes.

Synthesis, crystal structure, vibrational spectra and theoretical calculations of quantum chemistry of a potential antimicrobial Meldrum's acid derivative

NASA Astrophysics Data System (ADS)

Campelo, M. J. M.; Freire, P. T. C.; Mendes Filho, J.; de Toledo, T. A.; Teixeira, A. M. R.; da Silva, L. E.; Bento, R. R. F.; Faria, J. L. B.; Pizani, P. S.; Gusmão, G. O. M.; Coutinho, H. D. M.; Oliveira, M. T. A.

2017-10-01

A new derivative of Meldrum's acid 5-((5-chloropyridin-2-ylamino)methylene)-2,2-dimethyl-1,3-dioxane-4,6-dione (CYMM) of molecular formula C12H11ClN2O4 was synthesized and structurally characterized using single crystal X-ray diffraction technique. The vibrational properties of the crystal were studied by Fourier Transform infrared (FT-IR), Fourier Transform Raman (FT-Raman) techniques and theoretical calculations of quantum chemistry using Density functional theory (DFT) and Density functional perturbation theory (DFPT). A comparison with experimental spectra allowed the assignment of all the normal modes. The descriptions of the normal modes were carried by means of potential energy distribution (PED). Additionally, analysis of the antimicrobial activity and antibiotic resistance modulatory activity was carried out to evaluate the antibacterial potential of the CYMM.

Aqueous Combustion Synthesis and Characterization of Nanosized Tetragonal Zirconia Single Crystals

NASA Astrophysics Data System (ADS)

Reddy, B. S. B.; Mal, Indrajit; Tewari, Shanideep; Das, Karabi; Das, Siddhartha

2007-08-01

Nanocrystalline zirconia powder has been synthesized by an aqueous combustion synthesis route using glycine as fuel and nitrate as oxidizer. The powders have been prepared by using different glycine to zirconyl nitrate molar ratios (G/N). The powders produced with different G/N ratios have been characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) to determine the parameters resulting from powder with attractive properties. The theoretical combustion temperature (T ad ) has been calculated for different G/N ratios, and it is correlated with powder characteristics. An attempt is also made to explain the stability of tetragonal zirconia on the basis of extrinsic factors such as the morphology of nanocrystallites. Nanocrystalline metastable tetragonal zirconia (˜25 nm) powder (TZ) with disc-shaped morphology has been produced with a weak agglomeration in fuel deficient mixtures.

Development and characterization of Mn{sup 2+}-doped MgO nanoparticles by solution combustion synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basha, Md. Hussain; Gopal, N. O., E-mail: nogopal@yahoo.com; Rao, J. L.

2015-06-24

Mn doped MgO Nanoparticles have been prepared by Solution Combustion Synthesis. The synthesized sample is characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). The prepared MgO:Mn (1 mol%) nano crystals appear to be of simple cubic crystalline phase with lattice parameters a = 4.218(2) Å and cell volume = 74.98 (7) Å{sup 3}. SEM micrograph of powders show highly porous, many agglomerates with irregular morphology, large voids, cracks and pores. EPR spectrum of the sample at room temperature exhibit an isotropic sextet hyperfine pattern, centered at g=1.99, characteristic if Mn{sup 2+} ions with S=I=5/2.The observedmore » g value and the hyperfine value reveal the ionic bonding between Mn{sup 2+} and its surroundings.« less

Chemistry of electronic ceramic materials. Proceedings of the International Conference on the Chemistry of Electronic Ceramic Materials

NASA Technical Reports Server (NTRS)

Davies, P. K.; Roth, R. S.

1991-01-01

The conference was held at Jackson Hole, Wyoming from August 17 to 22, 1990, and in an attempt to maximize the development of this rapidly moving, multidisciplinary field, this conference brought together major national and international researchers to bridge the gap between those primarily interested in the pure chemistry of inorganic solids and those interested in the physical and electronic properties of ceramics. With the many major discoveries that have occurred over the last decade, one of the goals of this meeting was to evaluate the current understanding of the chemistry of electronic ceramic materials, and to assess the state of a field that has become one of the most important areas of advanced materials research. The topics covered include: crystal chemistry; dielectric ceramics; low temperature synthesis and characterization; solid state synthesis and characterization; surface chemistry; superconductors; theory and modeling.

Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [clln(sch2(co)o)2]2-[(4-mepyh)2]2+

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K.; Duraj, Stan A.; Fanwick, Philip E.; Hepp, Aloysius F.; Martock, Robert A.

2004-01-01

The synthesis and structural characterization of a novel In(III) complex is described. The reaction between InCl3 with sodium mercapto-acetic acid, (NaSCH2(CO)OH) in 4-methylpyridine, (CH3(C5H5N), (4-Mepy)) at 25 C affords [ClIn(SCH2(CO)O)2]2- [(4-MepyH)2]2+. X-ray diffraction studies show it to have a distorted square pyramidal geometry, with the [(-SCH2(CO)CO-)] ligands in a trans conformation. The compound crystallizes in the P(raised dash) 1 (No. 2) space group with a = 7.8624 Angstrom, b = 9.950 Angstrom, c = 13.793 Angstrom, alpha = 107.60 degrees, beta= 90.336 degrees, gamma = 98.983 degrees, V = 1014.3 Angstroms (sup 3), R(F(raised circle)) = 0.037, and R(sub w) = 0.048.

Synthesis, stability range and characterization of Pr2Cu2O5

NASA Astrophysics Data System (ADS)

Fernández-Sanjulián, Javier; Morán, Emilio; Ángel Alario-Franco, Miguel

2010-03-01

A novel Pr2Cu2O5 phase has been prepared under high-pressure and high-temperature conditions (P ∼6 GPa and T ∼1673 K) in a Belt-type apparatus and characterized by X-ray diffraction and electron microscopy. The crystal structure appears to be an orthorhombic "oxygen-deficient perovskite" (M.T. Anderson, J.T. Vaughey, and K.R. Poeppelmeier, Structural similarities among oxygen-deficient perovskites, Chem. Mater. 5 (1993), pp. 151-165) isostructural with La2Cu2O5 (J.F. Bringley, B.A. Scott, S.J. La Placa, R.F. Boheme, T.M. Shaw, M.W. McElfresh, S.S. Trail, and D.E. Cox, Synthesis of the defect perovskite series LaCuO 3-δ with copper valence varying from 2+to 3+, Nature 347 (1990), pp. 263-265) and Nd2Cu2O5 (B.-H. Chen, D. Walker, E. Suard, B.A. Scott, B. Mercey, M. Hervieu, and B. Raveau, High pressure synthesis of NdCuO3-δ perovskites (0≤δ≤0.5). Inorg. Chem. 34 (1995), pp. 2077-2083).

Mesoporous CdS via Network of Self-Assembled Nanocrystals: Synthesis, Characterization and Enhanced Photoconducting Property.

PubMed

Patra, Astam K; Banerjee, Biplab; Bhaumik, Asim

2018-01-01

Semiconduction nanoparticles are intensively studied due to their huge potential in optoelctronic applications. Here we report an efficient chemical route for hydrothermal synthesis of aggregated mesoporous cadmium sulfide (CdS) nanoparticles using supramolecular-assembly of ionic and water soluble sodium salicylate as the capping agent. The nanostructure, mesophase, optical property and photoconductivity of these mesoporous CdS materials have been characterized by using small and wide angle powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2-sorption, Raman analysis, Fourier transformed infrared (FT-IR), UV-Visible DSR spectroscopy, and photoconductivity measurement. Wide angle XRD pattern and high resolution TEM image analysis suggested that the particle size of the materials is within 10 nm and the nanoparticles are in well-crystallized cubic phase. Mesoporous CdS nanoparticles showed drastically enhanced photoelectrochemical response under visible light irradiation on entrapping a photosensitizer (dye) molecule in the interparticle spaces. Efficient synthesis strategy and the enhanced photo response in the mesoporous CdS material could facilitate the designing of other porous semiconductor oxide/sulfide and their applications in photon-to-electron conversion processes.

Copper nanoparticles mediated by chitosan: synthesis and characterization via chemical methods.

PubMed

Usman, Muhammad Sani; Ibrahim, Nor Azowa; Shameli, Kamyar; Zainuddin, Norhazlin; Yunus, Wan Md Zin Wan

2012-12-14

Herein we report a synthesis of copper nanoparticles (Cu-NPs) in chitosan (Cts) media via a chemical reaction method. The nanoparticles were synthesized in an aqueous solution in the presence of Cts as stabilizer and CuSO(4)·5H(2)O precursor. The synthesis proceeded with addition of NaOH as pH moderator, ascorbic acid as antioxidant and hydrazine( )as the reducing agent. The characterization of the prepared NPs was done using ultraviolet-visible spectroscopy, which showed a 593 nm copper band. The Field Emission Scanning Electron Microscope (FESEM) images were also observed, and found to be in agreement with the UV-Vis result, confirming the formation of metallic Cu-NPs. The mean size of the Cu-NPs was estimated to be in the range of 35-75 nm using X-ray diffraction. XRD was also used in analysis of the crystal structure of the NPs. The interaction between the chitosan and the synthesized NPs was studied using Fourier transform infrared (FT-IR) spectroscopy, which showed the capping of the NPs by Cts.

Facile Route to Rare Heterobimetallic Aluminum-Copper and Aluminum-Zinc Selenide Clusters.

PubMed

Li, Bin; Li, Jiancheng; Liu, Rui; Zhu, Hongping; Roesky, Herbert W

2017-03-20

Heterobimetallic aluminum-copper and aluminum-zinc clusters were prepared from the reaction of LAl(SeH) 2 [1; L = HC(CMeNAr) 2 and Ar = 2,6-iPr 2 C 6 H 3 ] with (MesCu) 4 and ZnEt 2 , respectively. The resulting clusters with the core structures of Al 2 Se 4 Cu 4 and Al 2 Se 4 Zn 3 exhibit unique metal-organic frameworks. This is a novel pathway for the synthesis of aluminum-copper and aluminum-zinc selenides. The products have been characterized by spectroscopic methods and single-crystal X-ray structural characterization.

Metal-organic coordination architectures of tetrazole heterocycle ligands bearing acetate groups: Synthesis, characterization and magnetic properties

NASA Astrophysics Data System (ADS)

Hu, Bo-Wen; Zheng, Xiang-Yu; Ding, Cheng

2015-12-01

Two new coordination complexes with tetrazole heterocycle ligands bearing acetate groups, [Co(L)2]n (1) and [Co3(L)4(N3)2·2MeOH]n (2) (L=tetrazole-1-acetate) have been synthesized and structurally characterized. Single crystal structure analysis shows that the cobalt-complex 1 has the 3D 3,6-connected (42.6)2(44.62.88.10)-ant topology. By introducing azide in this system, complex 2 forms the 2D network containing the [Co3] units. And the magnetic properties of 1 and 2 have been studied.

Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine

PubMed Central

Kljun, Jakob; Petriček, Saša; Žigon, Dušan; Hudej, Rosana; Miklavčič, Damijan; Turel, Iztok

2010-01-01

Novel ruthenium(III) complexes with histamine [RuCl4(dmso-S)(histamineH)] · H2O (1a) and [RuCl4(dmso-S)(histamineH)] (1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound 1b combined with electroporation were performed to determine its potential for future medical applications in cancer treatment. PMID:20631838

Synthesis, crystal structure, spectroscopic characterization and nonlinear optical properties of manganese (II) complex of picolinate: A combined experimental and computational study

NASA Astrophysics Data System (ADS)

Tamer, Ömer; Avcı, Davut; Atalay, Yusuf; Çoşut, Bünyemin; Zorlu, Yunus; Erkovan, Mustafa; Yerli, Yusuf

2016-02-01

A novel manganese (II) complex with picolinic acid (pyridine 2-carboxylic acid, Hpic), namely, [Mn(pic)2(H2O)2] was prepared and its crystal structure was fully characterized by using single crystal X-ray diffraction. Picolinate (pic) ligands were coordinated to the central manganese(II) ion as bidentate N,O-donors through the nitrogen atoms of pyridine rings and the oxygen atoms of carboxylate groups forming five-membered chelate rings. The spectroscopic characterization of Mn(II) complex was performed by the applications of FT-IR, Raman, UV-vis and EPR techniques. In order to support these studies, density functional theory (DFT) calculations were carried out by using B3LYP level. IR and Raman spectra were simulated at B3LYP level, and obtained results indicated that DFT calculations generally give compatible results to the experimental ones. The electronic structure of the Mn(II) complex was predicted using time dependent DFT (TD-DFT) method with polarizable continuum model (PCM). Molecular stability, hyperconjugative interactions, intramolecular charge transfer (ICT) and bond strength were investigated by applying natural bond orbital (NBO) analysis. Nonlinear optical properties of Mn(II) complex were investigated by the determining of molecular polarizability (α) and hyperpolarizability (β) parameters.

Synthesis, spectral characterization and structural studies of a novel O, N, O donor semicarbazone and its binuclear copper complex with hydrogen bond stabilized lattice

NASA Astrophysics Data System (ADS)

Layana, S. R.; Saritha, S. R.; Anitha, L.; Sithambaresan, M.; Sudarsanakumar, M. R.; Suma, S.

2018-04-01

A novel O,N,O donor salicylaldehyde-N4-phenylsemicarbazone, (H2L) has been synthesized and physicochemically characterized. Detailed structural studies of H2L using single crystal X-ray diffraction technique reveals the existence of intra and inter molecular hydrogen bonding interactions, which provide extra stability to the molecule. We have successfully synthesized a binuclear copper(II) complex, [Cu2(HL)2(NO3)(H2O)2]NO3 with phenoxy bridging between the two copper centers. The complex was characterized by elemental analysis, magnetic susceptibility and conductivity measurements, FT-IR, UV-Visible, mass and EPR spectral methods. The grown crystals of the copper complex were employed for the single crystal X-ray diffraction studies. The complex possesses geometrically different metal centers, in which the ligand coordinates through ketoamide oxygen, azomethine nitrogen and deprotonated phenoxy oxygen. The extensive intermolecular hydrogen bonding interactions of the coordinated and the lattice nitrate groups interconnect the complex units to form a 2D supramolecular assembly. The ESI mass spectrum substantiates the existence of 1:1 complex. The g values obtained from the EPR spectrum in frozen DMF suggest dx2 -y2 ground state for the unpaired electron.

Synthesis, characterization, crystal structure and theoretical studies of 4-[(E)-(3-chloro-4-hydroxyphenyl) diazenyl]-1, 5-dimethyl-2-phenyl-1, 2-dihydro-3H-pyrazol-3-one

NASA Astrophysics Data System (ADS)

Athira, L. S.; Lakshmi, C. S. Nair; Balachandran, S.; Arul Dhas, D.; Hubert Joe, I.

2017-11-01

Crystals of new heterocyclic azo compound of 4-aminoantipyrine, 4-[(E)-(3-chloro-4-hydroxyphenyl)diazenyl]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one have been grown by slow evaporation method at room temperature and its structural characterization was performed by X- ray diffraction method. The spectroscopic characterization was also performed by FT-IR, UV-Vis, 13C and 1H NMR techniques. The compound crystallizes in the monoclinic CC space group with cell dimensions a = 12.4842 (13), b = 16.4492 (16), c = 8.3389 (8) and β = 102.698 (3)°. The phenyl ring attached to the pyrazolone moiety is disordered over two positions with an occupancy ratio 52:48. The components of the disorder were refined. DFT calculations have been performed by using B3LYP/6-311G (d,p) level basis set. The calculated vibrational frequency showed a red shift for Cdbnd O and OH stretching. The natural bond orbital analysis of monomer, dimer and trimer structures reveals the absence of intramolecular hydrogen bonding; however intermolecular hydrogen bonding is observed. The cationic and anionic reactive sites of compound have been visualized on MEP surface.

Influence of the substituents on the electronic and electrochemical properties of a new square-planar nickel-bis(quinoxaline-6,7-dithiolate) system: synthesis, spectroscopy, electrochemistry, crystallography, and theoretical investigation.

PubMed

Bolligarla, Ramababu; Reddy, Samala Nagaprasad; Durgaprasad, Gummadi; Sreenivasulu, Vudagandla; Das, Samar K

2013-01-07

We describe the synthesis, crystal structures, electronic absorption spectra, and electrochemistry of a series of square-planar nickel-bis(quinoxaline-6,7-dithiolate) complexes with the general formula [Bu(4)N](2)[Ni(X(2)6,7-qdt)(2)], where X = H (1a), Ph (2a), Cl (3), and Me (4). The solution and solid-state electronic absorption spectral behavior and electrochemical properties of these compounds are strongly dependent on the electron donating/accepting nature of the substituent X, attached to the quinoxaline-6,7-dithiolate ring in the system [Bu(4)N](2)[Ni(X(2)6,7-qdt)(2)]. Particularly, the charge transfer (CT) transition bands observed in the visible region are greatly affected by the electronic nature of the substituent. A possible explanation for this influence of the substituents on electronic absorption and electrochemistry is described based on highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) gaps, which is further supported by ground-state electronic structure calculations. In addition to this, the observed CT bands in all the complexes are sensitive to the solvent polarity. Interestingly, compounds 1a, 2a, 3, and 4 undergo reversible oxidation at very low oxidation potentials appearing at E(1/2) = +0.12 V, 0.033 V, 0.18 V, and 0.044 V vs Ag/AgCl, respectively, in MeOH solutions, corresponding to the respective couples [Ni(X(2)6,7-qdt)(2)](-)/[Ni(X(2)6,7-qdt)(2)](2-). Compounds 1a, 3, and 4 have been characterized unambiguously by single crystal X-ray structural analysis; compound 2a could not be characterized by single crystal X-ray structure determination because of the poor quality of the concerned crystals. Thus, we have synthesized the tetraphenyl phosphonium salt of the complex anion of 2a, [PPh(4)](2)[Ni(Ph(2)6,7-qdt)(2)]·3DMF (2b) for its structural characterization.

Synthesis of parallel and antiparallel core-shell triangular nanoparticles

NASA Astrophysics Data System (ADS)

Bhattacharjee, Gourab; Satpati, Biswarup

2018-04-01

Core-shell triangular nanoparticles were synthesized by seed mediated growth. Using triangular gold (Au) nanoparticle as template, we have grown silver (Ag) shellto get core-shell nanoparticle. Here by changing the chemistry we have grown two types of core-shell structures where core and shell is having same symmetry and also having opposite symmetry. Both core and core-shell nanoparticles were characterized using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) to know the crystal structure and composition of these synthesized core-shell nanoparticles. From diffraction pattern analysis and energy filtered TEM (EFTEM) we have confirmed the crystal facet in core is responsible for such two dimensional growth of core-shell nanostructures.

Synthesis, crystal structure investigation, spectroscopic characterizations and DFT computations on a novel 1-(2-chloro-4-phenylquinolin-3-yl)ethanone

NASA Astrophysics Data System (ADS)

Murugavel, S.; Stephen, C. S. Jacob Prasanna; Subashini, R.; Reddy, H. Raveendranatha; AnanthaKrishnan, Dhanabalan

2016-10-01

The title compound 1-(2-chloro-4-phenylquinolin-3-yl)ethanone (CPQE) was synthesised effectively by chlorination of 3-acetyl-4-phenylquinolin-2(1H)-one (APQ) using POCl3 reagent. Structural and vibrational spectroscopic studies were performed by utilizing single crystal X-ray diffraction, FTIR and NMR spectral analysis along with DFT method utilizing GAUSSIAN‧ 03 software. Veda program has been employed to perform a detailed interpretation of vibrational spectra. Mulliken population analyses on atomic charges, MEP, HOMO-LUMO, NBO, Global chemical reactivity descriptors and thermodynamic properties have been examined by (DFT/B3LYP) method with the 6-311G(d,p) basis set level.

Sulfonamide-containing PTP 1B inhibitors: Docking studies, synthesis and model validation

NASA Astrophysics Data System (ADS)

Niu, Enli; Gan, Qiang; Chen, Xi; Feng, Changgen

2017-01-01

PTP 1B plays an important role in regulating insulin signaling pathway and is regarded as a valid target for curing diabetes and obesity. In this paper, two novel sulfonamide-containing PTP 1B inhibitors were designed, synthesized in mild condition, and characterized by FT-IR, 1H NMR, 13C NMR and elemental analysis. The single crystal of compounds 7 and 8 were obtained and their structures were determined by X-ray single crystal diffraction analysis. In addition, their inhibitory activity were predicted by genetic algorithm, and carried on in vitro enzyme activity test. Of which compound 8 showed good inhibitory activity, in consistent with docking studies.

Synthesis, crystal structures, molecular docking and urease inhibition studies of Ni(II) and Cu(II) Schiff base complexes

NASA Astrophysics Data System (ADS)

Sangeeta, S.; Ahmad, K.; Noorussabah, N.; Bharti, S.; Mishra, M. K.; Sharma, S. R.; Choudhary, M.

2018-03-01

[Ni(L)2] 1 and [Cu(L)2] 2 [HL = 2-((E)-(2-methoxyphenylimino)methyl)-4,6-dichlorophenol] Schiff base complexes have been successfully synthesized and were characterized by FT-IR, UV-Vis, fluorescence spectroscopy and thermogravimetric analysis. The crystal structures of the two complexes were determined through X-ray crystallography. Its inhibitory activity against Helicobacter pylori urease was evaluated in vitro and showed strong inhibitory activity against H. pylori urease compared with acetohydroxamic acid (IC50 = 42.12 μmolL-1), which is a positive reference. A docking analysis using the AutoDock 4.0 program could explain the inhibitory activity of the complex against urease.

A dataset for preparing pristine graphene-palladium nanocomposites using swollen liquid crystal templates

NASA Astrophysics Data System (ADS)

Vats, Tripti; Siril, Prem Felix

2017-12-01

Pristine graphene (G) has not received much attention as a catalyst support, presumably due to its relative inertness as compared to reduced graphene oxide (RGO). In the present work, we used swollen liquid crystals (SLCs) as nano-reactors for graphene-palladium nanocomposites synthesis. The 'soft' confinement of SLCs directs the growth of palladium (Pd) nanoparticles over the G sheets. In this dataset we include all the parameters and details of different techniques used for the characterization of G, SLCs and synthesized G-Pd nanocomposites. The synthesized G-palladium nanocomposites (Pd-G) exhibited improved catalytic activity compared with Pd-RGO and Pd nanoparticles, in the hydrogenation of nitrophenols and C-C coupling reactions.

Synthesis, characterization, single crystal X-ray and DFT analysis of disubstituted phosphorodithioates

NASA Astrophysics Data System (ADS)

Kour, Mandeep; Kumar, Sandeep; Feddag, Ahmed; Andotra, Savit; Chouaih, Abdelkader; Gupta, Vivek K.; Kant, Rajni; Pandey, Sushil K.

2018-04-01

Disubstituted phosphorodithioates of the type [{(2,5-CH3)2C6H3O}2PS2HNEt3] (1) and [{(3,5-CH3)2C6H3O)2(PS2)}2] (2) were synthesized and characterized by IR and NMR (1H,13C and 31P) spectroscopic studies and as single crystal X-ray analysis. The compound 1 crystallizes in monoclinic space group P21/c whereas compound 2 crystallizes in triclinic space group Pbar1. The X-ray analysis reveals that in compound 1 phosphorus atom is coordinated to the two S and two O atoms to form tetrahedral geometry. The structure is stabilized by cation-anion Nsbnd H⋯S hydrogen bonded interactions. In compound 2, the two phosphorus atoms have a distorted tetrahedral geometry coordinated to two (3,5-CH3)2C6H3O groups. The molecule possesses a crystallographic center of symmetry and consists of zig-zag array of Sdbnd Psbnd Ssbnd Ssbnd Pdbnd S linkages with two diphenyldithiophosphate moieties in the trans configuration. Molecular geometries, HOMO-LUMO analysis and molecular electrostatic potential of compounds 1 and 2 are investigated by theoretical calculations using B3LYP functional with the 6-311G basis combination set in the ground state and compared with the experimental values.

Synthesis, characterization, crystal structure and DFT study of two new polymorphs of a Schiff base (E)-2-((2,6-dichlorobenzylidene)amino)benzonitrile

NASA Astrophysics Data System (ADS)

Benarous, N.; Cherouana, A.; Aubert, Emmanuel; Durand, Pierrick; Dahaoui, S.

2016-02-01

Two new polymorphs of Schiff base, (E)-2-((2,6-dichlorobenzylidene)amino)benzonitrile, were prepared from the condensation of 4-amino-benzonitrile and 2,6-dichlorobenzaldehyde. The two polymorphs crystallize in two different space groups: P21/c for polymorph (I) with volume 1264.23(2) Å3 and Pbca for polymorph (II) with volume 2469.3(2) Å3. The two polymorphs have been characterized by FT-IR and UV-VIS spectroscopy. The crystal structures of both compounds were determined by single X-ray analysis. The difference between the two polymorphs was observed at the angle between the two phenyl rings which is 4.81° for the first one and 82.27° for the second one. Both crystal structures are built on the basis of moderate and weak hydrogen bonds. Theoretical calculations on isolated molecules at the MP2 cc-pVDZ level show that the two polymorphs correspond to two molecular conformations that are within less than 1 kJ mol-1 and DFT periodic calculations indicate that (II) is more stable than (I) by 4.1 kJ mol-1 of formula unit. Additionally, we performed TD-DFT calculation for free ligands to support the experimental data.

2006 Global Demilitarization Symposium Volume 1 Presentations

DTIC Science & Technology

2006-05-04

produce inorganic crystals in continuous-reaction mode: Continuous synthesis of CdSe–ZnS composite nanoparticles in a microfluidic reactor, Hongzhi...crystallize lead azide nanoparticles , and to grow them into dextrinated microparticles; Point of Application Microfluidic Synthesis of Sensitive...National Laboratory Point of Application Synthesis of Sensitive Explosive Mr. Karl Wally, Sandia National Laboratories Session III- A Session

Crystal structures and optical properties of new quaternary strontium europium aluminate luminescent nanoribbons

DOE PAGES

Li, Xufan; Budai, John D.; Liu, Feng; ...

2014-11-12

We report the synthesis and characterizations of three series of quaternary strontium europium aluminate (Sr-Eu-Al-O; SEAO) luminescent nanoribbons that show blue, green, and yellow luminescence from localized Eu2+ luminescent centers. These three series of SEAO nanoribbons are: blue luminescent, tetragonal Sr1-xEuxAl6O10 (01-xEu xAl 2O 4 (01-xEu xAl 2O 4 (0

Synthesis and Crystal Structures of Benzimidazole-2-thione Derivatives by Alkylation Reactions.

PubMed

El Ashry, El Sayed H; El Kilany, Yeldez; Nahas, Nariman M; Barakat, Assem; Al-Qurashi, Nadia; Ghabbour, Hazem A; Fun, Hoong-Kun

2015-12-22

Alkylated, benzylated and bromoalkylated benzimidazole-thione that intramolecularly heterocyclized to 3,4-dihydro-2H-[1,3]thiazino[3,2-a]benzimidazole were synthesized. The chemical structure of the synthesized product was characterized by Infra Red, ¹H-NMR, (13)C-NMR, and Mass spectroscopy. Furthermore, the molecular structures of 8 and 9 were confirmed by X-ray single crystallography in different space groups, Pbca and P2₁/c, respectively.

Opto-EM and Devices Investigation

DTIC Science & Technology

1989-06-01

value of bandwidth is used the signal to noise ratio of the UAM system becomes ( SNP )u z exp ’cr. 2P,\\ 3 .V N._ W/ 3.3 GAUSSIAN SHAPED MESSAGE SPECTRA...Unclassified N/A 2a. SECURITY CLASSIFICATION AUTHORITY 3 . DISTRIBUTION/AVAILABILITY OF REPORT N/A Approved for public release; 2b. DECLASSIFICATION...Synthesis, Single Crystal Growth, Purification and Characterization of Indium Phosphide 2. Deposition of Select Silicides Under High Vacuum Conditions 3 . Use

Potassium Benzoate for Pyrotechnic Whistling Compositions: Its Synthesis and Characterization as an Anhydrous Salt,

DTIC Science & Technology

1983-02-01

subsequently established that potassium benzoate crystallizes from water at 293 - 298 K (20-25*C) and also precipitates from aqueous alcohol as colourless...benzoic acid and potassium bicarbonate or benzoic acid and potassium hydroxide, recrystallizes from water and also precipitates from aqueous alcohol...and a copious white precipitate was formed. The mixture was taken to dryness under reduced pressure and water (100 ml) added to the mixture, which

Low temperature synthesis and characterization of Na–M–(O)–F phases with M=Ti, V

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nava-Avendaño, Jessica; Ayllón, José A.; Frontera, Carlos

2015-03-15

Na{sub 5}Ti{sub 3}O{sub 3}F{sub 11} was prepared by the microwave assisted method, and presents a chiolite related structure with cell parameters a=10.5016(5), b=10.4025(5), and c=10.2911(5) Å and Cmca (no. 64) space group. From solvothermal synthesis at 100 °C the cryolite Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} was prepared, which crystallizes in the monoclinic system with a=5.5403(2), b=5.6804(2), c=7.9523(2) Å, β=90.032(7)° cell parameters and P2{sub 1}/n (no. 14) space group. Under similar synthesis conditions but with higher HF concentration the chiolite-type phase Na{sub 5−δ}V{sub 3}F{sub 14} was achieved, which exhibits a=10.5482(2), b=10.4887(1) and c=10.3243(1) Å cell parameters and Cmc2{sub 1} (no. 36) spacemore » group. A single crystal also having the chiolite structure was synthesized at 200 °C which exhibits tetragonal symmetry (a=7.380(3) and c=10.381(11) Å and space group P4{sub 2}2{sub 1}2 (no. 94)). Bond valence sum indicates that it contains V{sup 4+} and therefore can be formulated as Na{sub 5}V{sub 3}O{sub 3}F{sub 11}. - Graphical abstract: Na{sub 5}M{sub 3}(O,F){sub 14} with M=Ti and V having chiolite structure and Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} cryolite were prepared by means of microwave-assisted and solvothermal synthesis. - Highlights: • Na{sub 5}Ti{sub 3}O{sub 3}F{sub 11} chiolite was prepared by a microwave assisted method and characterized. • Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} and Na{sub 5−δ}V{sub 3}F{sub 14} were prepared by solvothermal synthesis. • The compounds were structurally characterized by diffraction techniques. • O/F distribution was estimated by applying Pauling’s second rule.« less

Synthesis and reactions of C-phosphanylated thiazol-2-thiones.

PubMed

Begum, I; Schnakenburg, G; Streubel, R

2016-02-21

The facile regioselective synthesis of the P(iii) substituted thiazol-2-thione 2 is presented. Reaction of 2 with hydrogenperoxide-urea, elemental sulfur and selenium resulted in P(v) chalcogenide thiazol-2-thiones 3-5. All compounds were characterized using (31)P, (1)H, (13)C NMR, IR and elemental analyses and, additionally, by the single-crystal X-ray diffraction technique. Oxidative desulfurization of the 5-phosphinoylated thiazol-2-thione 3 using hydrogenperoxide led to the first C-phosphanoyl substituted thiazolium salt (6). Deprotonation of 6 and in situ reaction with the cyclooctadiene rhodium(i) chloride dimer yielded thiazol-2-ylidene rhodium(i) complex 7 which was confirmed by NMR spectroscopy and ESI-MS spectrometry.

Rare earth indates (RE: La-Yb): influence of the synthesis route and heat treatment on the crystal structure.

PubMed

Shukla, Rakesh; Grover, Vinita; Srinivasu, Kancharlapalli; Paul, Barnita; Roy, Anushree; Gupta, Ruma; Tyagi, Avesh Kumar

2018-05-15

Rare earth indates are an interesting class of compounds with rich crystallography. The present study explores the crystallographic phases observed in REInO3 (RE: La-Yb) systems and their dependence on synthesis routes and annealing temperature. All REInO3 compositions were synthesized by a solid state route as well as gel-combustion synthesis (GC) followed by annealing at different temperatures. The systems were well characterized by powder XRD studies and were analysed by Rietveld refinement for the structural parameters. The cell parameters were observed to decrease in accordance with the trend in ionic radii on proceeding from lighter to heavier rare earth ions. Interestingly, the synthesis route and the annealing temperature had a profound bearing on the phase relationships observed in the REInO3 series. The solid state synthesized samples depicted an orthorhombic phase (Pbnm) field for LaInO3 to SmInO3, followed by a hexagonal-type phase (P63cm) for GdInO3 to DyInO3. However, the phase field distribution was greatly influenced upon employing gel-combustion (GC) wherein both single-phasic hexagonal and orthorhombic phase fields were found to shrink. Annealing the GC-synthesized compositions to still higher temperatures (1250 °C) further evolved the phase boundaries. An important outcome of the study is observance of polymorphism in SmInO3 which crystallized in the hexagonal phase when synthesized by GC and orthorhombic phase by solid state synthesis. This reveals the all-important role played by synthesis conditions. The existence and energetics of the two polymorphs have been elucidated and discussed with the aid of theoretical studies.

Synthesis, characterization and biological activities of semicarbazones and their copper complexes.

PubMed

Venkatachalam, Taracad K; Bernhardt, Paul V; Noble, Chris J; Fletcher, Nicholas; Pierens, Gregory K; Thurecht, Kris J; Reutens, David C

2016-09-01

Substituted semicarbazones/thiosemicarbazones and their copper complexes have been prepared and several single crystal structures examined. The copper complexes of these semicarbazone/thiosemicarbazones were prepared and several crystal structures examined. The single crystal X-ray structure of the pyridyl-substituted semicarbazone showed two types of copper complexes, a monomer and a dimer. We also found that the p-nitrophenyl semicarbazone formed a conventional 'magic lantern' acetate-bridged dimer. Electron Paramagnetic Resonance (EPR) of several of the copper complexes was consistent with the results of single crystal X-ray crystallography. The EPR spectra of the p-nitrophenyl semicarbazone copper complex in dimethylsulfoxide (DMSO) showed the presence of two species, confirming the structural information. Since thiosemicarbazones and semicarbazones have been reported to exhibit anticancer activity, we examined the anticancer activity of several of the derivatives reported in the present study and interestingly only the thiosemicarbazone showed activity while the semicarbazones were not active indicating that introduction of sulphur atom alters the biological profile of these thiosemicarbazones. Copyright © 2016 Elsevier Inc. All rights reserved.

Cross-linked lysozyme crystal templated synthesis of Au nanoparticles as high-performance recyclable catalysts.

PubMed

Liang, Miao; Wang, Libing; Liu, Xia; Qi, Wei; Su, Rongxin; Huang, Renliang; Yu, Yanjun; He, Zhimin

2013-06-21

Bio-nanomaterials fabricated using a bioinspired templating technique represent a novel class of composite materials with diverse applications in biomedical, electronic devices, drug delivery, and catalysis. In this study, Au nanoparticles (NPs) are synthesized within the solvent channels of cross-linked lysozyme crystals (CLLCs) in situ without the introduction of extra chemical reagents or physical treatments. The as-prepared AuNPs-in-protein crystal hybrid materials are characterized by light microscopy, transmission electron microscopy, x-ray diffraction, and Fourier-transform infrared spectroscopy analyses. Small AuNPs with narrow size distribution reveal the restriction effects of the porous structure in the lysozyme crystals. These composite materials are proven to be active heterogeneous catalysts for the reduction of 4-nitrophenol to 4-aminophenol. These catalysts can be easily recovered and reused at least 20 times because of the physical stability and macro-dimension of CLLCs. This work is the first to use CLLCs as a solid biotemplate for the preparation of recyclable high-performance catalysts.

The first 3-D LaIII-SrII heterometallic complex: Synthesis, structure and luminescent properties

NASA Astrophysics Data System (ADS)

Hong, Zhiwei; Ran, Jingwen; Li, Tao; Chen, Yanmei

2016-10-01

The first 3-D LaIII-SrII heterometallic complex, namely [La2Sr(pda)4(H2O)4]n·6nH2O (1, H2pda = pyridine-2,6-dicarboxylic acid), has been successfully synthesized under solvothermal conditions. Single crystal X-ray diffraction analysis reveals that complex 1 features a 3-D porous framework and displays a new topology. The crystal structure can be simplified to a 4,6-connected 3-D network with Schläfli symbol of {34·42·88·9}2{34·42}. The crystals also have been characterized by X-ray powder diffraction, elemental analysis, thermal analysis, and IR spectroscopy. The infrared spectral analysis indicates that complex 1 is a carboxylate coordinated compound, several water molecules exist in the compound. The thermal study shows that there are ten water molecules in the crystal structure. The luminescent property has also been investigated. It shows a blue-purple fluorescence emission.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricagno, Stéfano; Coutard, Bruno; Grisel, Sacha

Crystals of Nsp15 from the aetiological agent of SARS have been grown at room temperature. Crystals have cubic symmetry and diffract to a maximum resolution of 2.7 Å. The non-structural protein Nsp15 from the aetiological agent of SARS (severe acute respiratory syndrome) has recently been characterized as a uridine-specific endoribonuclease. This enzyme plays an essential role in viral replication and transcription since a mutation in the related H229E human coronavirus nsp15 gene can abolish viral RNA synthesis. SARS full-length Nsp15 (346 amino acids) has been cloned and expressed in Escherichia coli with an N-terminal hexahistidine tag and has been purifiedmore » to homogeneity. The protein was subsequently crystallized using PEG 8000 or 10 000 as precipitants. Small cubic crystals of the apoenzyme were obtained from 100 nl nanodrops. They belong to space group P4{sub 1}32 or P4{sub 3}32, with unit-cell parameters a = b = c = 166.8 Å. Diffraction data were collected to a maximum resolution of 2.7 Å.« less

Synthesis and crystal structures of three new benzotriazolylpropanamides

PubMed Central

Amenta, Donna S.; Liebing, Phil; Biero, Julia E.; Sherman, Robert J.; Gilje, John W.

2017-01-01

The base-catalyzed Michael addition of 2-methyl­acryl­amide to benzotriazole afforded 3-(1H-benzotriazol-1-yl)-2-methyl­propanamide, C10H12N4O (1), in 32% yield in addition to small amounts of isomeric 3-(2H-benzotriazol-2-yl)-2-methyl­propanamide, C10H12N4O (2). In a similar manner, 3-(1H-benzotriazol-1-yl)-N,N-di­methyl­propanamide, C11H14N4O (3), was prepared from benzotriazole and N,N-di­methyl­acryl­amide. All three products have been structurally characterized by single-crystal X-ray diffraction. The crystal structures of 1 and 2 comprise infinite arrays formed by N—H⋯O and N—H⋯N bridges, as well as π–π inter­actions, while the mol­ecules of 3 are aggregated to simple π-dimers in the crystal. PMID:28638650

Cross-linked lysozyme crystal templated synthesis of Au nanoparticles as high-performance recyclable catalysts

NASA Astrophysics Data System (ADS)

Liang, Miao; Wang, Libing; Liu, Xia; Qi, Wei; Su, Rongxin; Huang, Renliang; Yu, Yanjun; He, Zhimin

2013-06-01

Bio-nanomaterials fabricated using a bioinspired templating technique represent a novel class of composite materials with diverse applications in biomedical, electronic devices, drug delivery, and catalysis. In this study, Au nanoparticles (NPs) are synthesized within the solvent channels of cross-linked lysozyme crystals (CLLCs) in situ without the introduction of extra chemical reagents or physical treatments. The as-prepared AuNPs-in-protein crystal hybrid materials are characterized by light microscopy, transmission electron microscopy, x-ray diffraction, and Fourier-transform infrared spectroscopy analyses. Small AuNPs with narrow size distribution reveal the restriction effects of the porous structure in the lysozyme crystals. These composite materials are proven to be active heterogeneous catalysts for the reduction of 4-nitrophenol to 4-aminophenol. These catalysts can be easily recovered and reused at least 20 times because of the physical stability and macro-dimension of CLLCs. This work is the first to use CLLCs as a solid biotemplate for the preparation of recyclable high-performance catalysts.

Synthesis, characterization and solubility of a new anthelmintic salt: Mebendazole nitrate

NASA Astrophysics Data System (ADS)

Gutiérrez, Eduardo L.; Souza, Matheus S.; Diniz, Luan F.; Ellena, Javier

2018-06-01

Salt formation approach was taken to improve Mebendazole (MBZ) solubility. MBZ polymorph A was easily recrystallized as a 1:1 nitrate salt (MBZ N) in methanol. Single crystal X-ray diffraction data show that MBZ N crystallizes in the P 1 bar space group. By strong intermolecular H-bonding interactions, MBZ is associated with a nitrate anion forming a supramolecular R22(8) synthon. Crystal packing is stabilized by these H-bonds, through which each nitrate connects two molecules of MBZ forming chains along the b axis. The vibrational behavior studied by micro FT-Raman and FT-IR spectroscopy is consistent with the crystal structure. Thermal analysis of the salt indicates that the compound is stable up to 150 °C, when an almost simultaneous elimination of HNO3 and CO2 occurs. MBZ N equilibrium solubility was evaluated in hydrochloric acid 0.1 M solution and compared with those of MBZ A and C. An improvement in a factor of 5 and 1.22 was found respectively.

Synthesis, crystal structure and electrical properties of N,N-dimethylanilinium trichloridostannate (II): (C8H12N)SnCl3

NASA Astrophysics Data System (ADS)

Chouaib, H.; Kamoun, S.; Costa, L. C.; Graça, M. P. F.

2015-12-01

A new (C8H12N)SnCl3 crystal of the general formula AMX3 was grown by soft chemistry method. X-ray study shows that the crystal crystallized in a monoclinic system with the space group P21/a. The structure was solved by Patterson method and refined to a final value of R = 0.0304 for 1157 independent observed reflections. The cohesion and the stability of the atomic arrangement result from the N-H … Cl hydrogen bonds between (C8H12N)+ cations and isolated (SnCl3)- anions. At high temperature this compound exhibits a structural phase transition at 340 K. This transition has been characterized by differential scanning calorimetric and impedance spectroscopy. The impedance data were well fitted to an Rp//CPE equivalent electrical circuit model. The close values of activation energies, obtained from the thermal behavior of the conductivity and the relaxation time confirm the presence of a hopping transport mechanism.

Nanoscale zero-valent metals: a review of synthesis, characterization, and applications to environmental remediation.

PubMed

Li, Lingyun; Hu, Jiwei; Shi, Xuedan; Fan, Mingyi; Luo, Jin; Wei, Xionghui

2016-09-01

Engineered nanoscale zero-valent metals (NZVMs) representing the forefront of technologies have been considered as promising materials for environmental remediation and antimicrobial effect, due to their high reducibility and strong adsorption capability. This review is focused on the methodology for synthesis of bare NZVMs, supported NZVMs, modified NZVMs, and bimetallic systems with both traditional and green methods. Recent studies have demonstrated that self-assembly methods can play an important role for obtaining ordered, controllable, and tunable NZVMs. In addition to common characterization methods, the state-of-the-art methods have been developed to obtain the properties of NZVMs (e.g., granularity, size distribution, specific surface area, shape, crystal form, and chemical bond) with the resolution down to subnanometer scale. These methods include spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), electron energy-loss spectroscopy (EELS), and near edge X-ray absorption fine structure (NEXAFS). A growing body of experimental data has proven that nanoscale zero-valent iron (NZVI) is highly effective and versatile. This article discusses the applications of NZVMs to treatment of heavy metals, halogenated organic compounds, polycyclic aromatic hydrocarbons, nutrients, radioelements, and microorganisms, using both ex situ and in situ methods. Furthermore, this paper briefly describes the ecotoxicological effects for NZVMs and the research prospects related to their synthesis, modification, characterization, and applications.

Synthesis of three new thiophene condensed pyrene derivatives, crystal structure and evaluation of their photophysical properties

NASA Astrophysics Data System (ADS)

Moriguchi, Tetsuji; Yakeya, Daisuke; Tsuge, Akihiko; Jalli, Venkataprasad

2018-04-01

Three new thiophene condensed fluorescent pyrene derivatives have been synthesized by a two-step process, via. Wittig reaction followed by iodine promoted photocyclization. These molecules have been characterized by 1H NMR and EI-MS. Further, the molecular structures of 4a, 4b and 4c has been confirmed by single crystal X-ray diffraction analysis. The protons located in the fjord and cove-regions of molecules 4b and 4c showed downfield shifts of the protons. Molecule 4a crystallized under monoclinic system with space group P21/c, molecule 4b crystallized under monoclinic system with space group C2/c and the molecule 4c crystalized under triclinic system with space group P-1. Molecules 4a, 4b and 4c showed strong absorption maxima wavelengths at 305, 358 and 330 nm, respectively. The molar extinctinction coefficients (ε) of the compounds 4a, 4b and 4c indicated molecule 4c has better ability to absorb UV light, molecule 4b has better fluorescence intensity than molecule 4a and 4c.

Monodisperse colloidal gallium nanoparticles: synthesis, low temperature crystallization, surface plasmon resonance and Li-ion storage.

PubMed

Yarema, Maksym; Wörle, Michael; Rossell, Marta D; Erni, Rolf; Caputo, Riccarda; Protesescu, Loredana; Kravchyk, Kostiantyn V; Dirin, Dmitry N; Lienau, Karla; von Rohr, Fabian; Schilling, Andreas; Nachtegaal, Maarten; Kovalenko, Maksym V

2014-09-03

We report a facile colloidal synthesis of gallium (Ga) nanoparticles with the mean size tunable in the range of 12-46 nm and with excellent size distribution as small as 7-8%. When stored under ambient conditions, Ga nanoparticles remain stable for months due to the formation of native and passivating Ga-oxide layer (2-3 nm). The mechanism of Ga nanoparticles formation is elucidated using nuclear magnetic resonance spectroscopy and with molecular dynamics simulations. Size-dependent crystallization and melting of Ga nanoparticles in the temperature range of 98-298 K are studied with X-ray powder diffraction, specific heat measurements, transmission electron microscopy, and X-ray absorption spectroscopy. The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively. We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions. We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.

Monodisperse Colloidal Gallium Nanoparticles: Synthesis, Low Temperature Crystallization, Surface Plasmon Resonance and Li-Ion Storage

PubMed Central

2015-01-01

We report a facile colloidal synthesis of gallium (Ga) nanoparticles with the mean size tunable in the range of 12–46 nm and with excellent size distribution as small as 7–8%. When stored under ambient conditions, Ga nanoparticles remain stable for months due to the formation of native and passivating Ga-oxide layer (2–3 nm). The mechanism of Ga nanoparticles formation is elucidated using nuclear magnetic resonance spectroscopy and with molecular dynamics simulations. Size-dependent crystallization and melting of Ga nanoparticles in the temperature range of 98–298 K are studied with X-ray powder diffraction, specific heat measurements, transmission electron microscopy, and X-ray absorption spectroscopy. The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140–145 and 240–250 K, respectively. We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions. We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g–1, 50% higher than those achieved for bulk Ga under identical testing conditions. PMID:25133552

High-pressure synthesis of mesoporous stishovite: potential applications in mineral physics

NASA Astrophysics Data System (ADS)

Stagno, Vincenzo; Mandal, Manik; Landskron, Kai; Fei, Yingwei

2015-06-01

Recently, we have described a successful synthesis route to obtain mesoporous quartz and its high-pressure polymorph coesite by nanocasting at high pressure using periodic mesostructured precursors, such as SBA-16 and FDU-12/carbon composite as starting materials. Periodic mesoporous high-pressure silica polymorphs are of particular interest as they combine transport properties and physical properties such as hardness that potentially enable the industrial use of these materials. In addition, synthesis of mesoporous crystalline silica phases can allow more detailed geology-related studies such as water/mineral interaction, dissolution/crystallization rate and the surface contribution to the associated thermodynamic stability (free energy and enthalpy) of the various polymorphs and their crossover. Here, we present results of synthesis of mesoporous stishovite from cubic large-pore periodic mesoporous silica LP-FDU-12/C composite as precursor with an fcc lattice. We describe the synthesis procedure using multi-anvil apparatus at 9 GPa (about 90,000 atm) and temperature of 500 °C. The synthetic mesoporous stishovite is, then, characterized by wide and small-angle X-ray diffraction, scanning/transmission electron microscopy and gas adsorption. Results show that this new material is characterized by accessible mesopores with wide pore size distribution, surface area of ~45 m2/g and volume of pores of ~0.15 cm3/g. Results from gas adsorption indicate that both porosity and permeability are retained at the high pressures of synthesis but with weak periodic order of the pores.

Fundamental Studies of Crystal Growth of Microporous Materials

NASA Technical Reports Server (NTRS)

Singh, Ramsharan; Doolittle, John, Jr.; Payra, Pramatha; Dutta, Prabir K.; George, Michael A.; Ramachandran, Narayanan; Schoeman, Brian J.

2003-01-01

Microporous materials are framework structures with well-defined porosity, often of molecular dimensions. Zeolites contain aluminum and silicon atoms in their framework and are the most extensively studied amongst all microporous materials. Framework structures with P, Ga, Fe, Co, Zn, B, Ti and a host of other elements have also been made. Typical synthesis of microporous materials involve mixing the framework elements (or compounds, thereof) in a basic solution, followed by aging in some cases and then heating at elevated temperatures. This process is termed hydrothermal synthesis, and involves complex chemical and physical changes. Because of a limited understanding of this process, most synthesis advancements happen by a trial and error approach. There is considerable interest in understanding the synthesis process at a molecular level with the expectation that eventually new framework structures will be built by design. The basic issues in the microporous materials crystallization process include: (a) Nature of the molecular units responsible for the crystal nuclei formation; (b) Nature of the nuclei and nucleation process; (c) Growth process of the nuclei into crystal; (d) Morphological control and size of the resulting crystal; (e) Surface structure of the resulting crystals; and (f) Transformation of frameworks into other frameworks or condensed structures.

Solution-mediated growth of NBA-ZSM-5 crystals retarded by gel entrapment

NASA Astrophysics Data System (ADS)

Aguilar-Mamani, Wilson; Akhtar, Farid; Hedlund, Jonas; Mouzon, Johanne

2018-04-01

The synthesis of flat tablet-shaped ZSM-5 crystals from a gel using metakaolin as aluminosilicate source and n-butyl amine as structure directing agent was investigated. The evolution inside the solid phase was characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry and mass spectrometry. A kinetic study indicated that the nucleation of the majority crystals occurred concurrently with the formation of the gel upon heating the starting liquid suspension. Microstructural evidences undeniably showed that the gel precipitated on ZSM-5 crystals and mineral impurities originating from kaolin. As a result, crystal growth was retarded by gel entrapment, as indicated by the configuration and morphology of the embedded crystals. The results presented herein are harmonized with a solution-mediated nucleation and growth mechanism. Our observations differ from the autocatalytic model that suggests that the nuclei rest inside the gel until released when the gel is consumed. Our results show instead that it is crystals that formed in an early stage before entrapment inside the gel that rest inside the gel until exposed at the gel surface. These results illustrate the limitation of the classical method used in the field to determine nucleation profiles when the crystals become trapped inside the gel.

Synthesis and modification of nano-sized TiO{sub 2} for photo-degradation process under visible light irradiation; a Placket–Burman experimental design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izadyar, Soheila; Fatemi, Shohreh, E-mail: shfatemi@ut.ac.ir; Mousavand, Tahereh

2013-09-01

Graphical abstract: - Highlights: • Nanosized TiO{sub 2} doped with nitrogen and iron was produced by sol-gel method. • Linear models were derived to relate the phase and particle size to synthesis factors. • High photocatalytic activity was observed for acetaldehyde degradation. - Abstract: In this research, nitrogen and iron (III) co-doped nano TiO{sub 2} (N-Fe-TiO{sub 2}) was prepared by sol-gel method using ammonium chloride and iron chloride solutions as nitrogen and iron sources, respectively. The effect of synthesis parameters (weight ratios of N/TiO{sub 2} and Fe/TiO{sub 2}, synthesis temperature, calcination time and temperature) was simultaneously investigated on the qualitymore » of the N-Fe-TiO{sub 2} product by a two-level Placket–Burman experimental design. The synthesized powders were characterized by XRD, XPS and UV–Vis spectroscopy techniques. The mean crystal size and anatase content were determined and evaluated as the linear functions of so-called synthesis parameters by the statistical analysis and regression. The 2%N-1%Fe-TiO{sub 2} product by 11 nm mean crystal size and 78% anatase content, synthesized at 35 °C and calcined at 500 °C during 2 h, exhibited the most significant activity during the photo-degradation of acetaldehyde under visible light irradiation and its efficiency was obtained about four times more than photocatalytic activity of Degussa TiO{sub 2}-P25.« less

Band gap and composition engineering on a nanocrystal (BCEN) in solution.

PubMed

Peng, Xiaogang

2010-11-16

Colloidal nanocrystals with "artificial" composition and electron band structure promise to expand the fields of nanomaterials and inorganic chemistry. Despite their promise as functional materials, the fundamental science associated with the synthesis, characterization, and properties of colloidal nanocrystals is still in its infancy and deserves systematic study. Furthermore, such studies are important for our basic understanding of crystallization, surface science, and solid state chemistry. "Band gap and composition engineering on a nanocrystal" (BCEN) refers to the synthesis of a colloidal nanocrystal with composition and/or electron energy band structure that are not found in natural bulk crystals. The BCEN nanostructure shown in the Figure includes a magnetic domain for the separation and recycling of the complex nanostructure, a photoactivated catalytic center, and an additional chemical catalytic center. A thin but porous film (such as a silicate) might be coated onto the nanocrystal, both to provide chemical stability and to isolate the reaction processes from the bulk solution. This example is a catalytic complex analogous to an enzyme that facilitates two sequential reactions in a microenvironment different from bulk solution. The synthesis of colloidal nanocrystals has advanced by a quantum leap in the past two decades. The field now seems ready to extend colloidal nanocrystal synthesis into the BCEN regime. Although BCEN is a very new branch of synthetic chemistry, this Account describes advances in related synthetic and characterization techniques that can serve as a useful starting point for this new area of investigation. To put these ideas into context, this Account compares this new field with organic synthesis, the most developed branch in synthetic chemistry. The structural and functional diversity of organic compounds results from extending design and synthesis beyond the construction of natural organic compounds. If this idea also holds true for inorganic nanocrystals, "artificial" BCEN nanocrystals will most likely outperform the inorganic nanocrystals with naturally occurring structure and composition. If the importance of artificial molecules is a positive lesson from organic synthesis, the practical disadvantage of organic chemistry is that purification can prove much more time consuming than the reaction itself. To get around this problem, colloidal nanocrystal chemists can attempt to avoid these potential purification challenges in the early stages of synthetic method development.

In-situ nano-crystal-to-crystal transformation synthesis of energetic materials based on three 5,5′-azotetrazolate Cr(III) salts

PubMed Central

Miao, Yu; Qiu, Yanxuan; Cai, Jiawei; Wang, Zizhou; Yu, Xinwei; Dong, Wen

2016-01-01

The in-situ nano-crystal-to-crystal transformation (SCCT) synthesis provides a powerful approach for tailoring controllable feature shapes and sizes of nano crystals. In this work, three nitrogen-rich energetic nano-crystals based on 5,5′-azotetrazolate(AZT2−) Cr(III) salts were synthesized by means of SCCT methodology. SEM and TEM analyses show that the energetic nano-crystals feature a composition- and structure-dependent together with size-dependent thermal stability. Moreover, nano-scale decomposition products can be obtained above 500 °C, providing a new method for preparing metallic oxide nano materials. PMID:27869221

Synthesis, purification and bulk crystal growth of radiation detector materials using melt growth technique

NASA Astrophysics Data System (ADS)

Surabhi, Raja Rahul Reddy

In the past decade, there has been new and increased usage of radiation-detection technologies for applications in homeland security, non-proliferation, and national defense. Most of these applications require a portable device with high gamma-ray energy resolution and detection efficiency, compact size, room-temperature operation, and low cost. Consequently, there is a renewed understanding of the material limitations for these technologies and a great demand to develop next-generation radiation-detection materials that can operate at room temperature. Mercuric iodide (HgI2), Lead iodide (PbI2), and CdZnTe (CZT) are the current leading candidates for radiation detector applications. This is because of their high atomic number and large band gap that makes them particularly well suited for fabrication of high resolution and high efficiency compact devices. PbI2 is a promising material for room temperature nuclear radiation detectors, characterized by its wide band gap (EG=2.32eV) and high-density (rho=6.2g/cm3). It has been reported that PbI2 crystal detectors are able to detect gamma-ray in the range of 1KeV-1MeV, with good energy resolution. However, PbI 2 detectors have not been studied in detail because of non-availability of high quality single crystals. This study presents the synthesis, purification, growth and characterization of PbI2 single crystals grown. In this research, solid-state synthesis technique has been utilized for obtaining PbI2 as a starting material. For the first time, a unique low-temperature purification technique has been developed to obtain high-purity starting material. The crystals were grown using 2-zone Bridgman-Stockbarger (B.S) technique wherein growth rate and temperature gradient at the solid-liquid interface were optimized. Single crystals of PbI2 were successfully grown in quartz glass ampoule under different growth conditions. Material purity was determined by measuring the elemental concentration using the Inductively coupled plasma-optical emission spectroscopy (ICP-OES). ICP-OES is utilized for estimating impurities present in the low-temperature purified material, zone refined material and melt grown PbI2 crystals. The zone-refined material contains no traceable amounts of impurities, whereas the low-temperature purified material and melt grown PbI2 crystals show very low concentration of K (potassium) and Na (sodium) impurities. Crystal characterization has been performed for determining optical properties by UV-VIS spectroscopy. The energy band gap (EG) is an important parameter for materials used for room temperature gamma-ray detector applications. The absorption peak at 530nm is a characteristic of PbI2 and corresponds to the onset of the transitions from the valence band to the exciton level. From this absorption spectrum the calculated indirect band gap of PbI 2 was 2.33+/-0.025 eV at room temperature. For measuring the electrical properties (Dielectric and I-V characteristics) of the crystal, Ag (silver) contacts are applied to both sides of the sample. Dielectric analysis on melt grown PbI2 showed that space charge polarization was dominant at lower frequencies but stabilizes at higher frequencies over different operating temperatures. On the other hand, dielectric analysis for zone-refined material space charge polarization was constant over the operating range resulting in fewer lattice defects. Therefore the low temperature purified material followed by zone-refined purification provides detector grade material with fewer lattice defects. The measured electrical resistivity for melt grown PbI2 and zone-refined material are 3.185 x 10 10 O-cm and 0.754 x 109 O-cm at room temperature along (001) plane respectively.

Raw material variability of an active pharmaceutical ingredient and its relevance for processability in secondary continuous pharmaceutical manufacturing.

PubMed

Stauffer, F; Vanhoorne, V; Pilcer, G; Chavez, P-F; Rome, S; Schubert, M A; Aerts, L; De Beer, T

2018-06-01

Active Pharmaceutical Ingredients (API) raw material variability is not always thoroughly considered during pharmaceutical process development, mainly due to low quantities of drug substance available. However, synthesis, crystallization routes and production sites evolve during product development and product life cycle leading to changes in physical material attributes which can potentially affect their processability. Recent literature highlights the need for a global approach to understand the link between material synthesis, material variability, process and product quality. The study described in this article aims at explaining the raw material variability of an API using extensive material characterization on a restricted number of representative batches using multivariate data analysis. It is part of a larger investigation trying to link the API drug substance manufacturing process, the resulting physical API raw material attributes and the drug product continuous manufacturing process. Eight API batches produced using different synthetic routes, crystallization, drying, delumping processes and processing equipment were characterized, extensively. Seventeen properties from seven characterization techniques were retained for further analysis using Principal Component Analysis (PCA). Three principal components (PCs) were sufficient to explain 92.9% of the API raw material variability. The first PC was related to crystal length, agglomerate size and fraction, flowability and electrostatic charging. The second PC was driven by the span of the particle size distribution and the agglomerates strength. The third PC was related to surface energy. Additionally, the PCA allowed to summarize the API batch-to-batch variability in only three PCs which can be used in future drug product development studies to quantitatively evaluate the impact of the API raw material variability upon the drug product process. The approach described in this article could be applied to any other compound which is prone to batch-to-batch variability. Copyright © 2018 Elsevier B.V. All rights reserved.

Synthesis and characterization of Gd-doped magnetite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Honghu; Iowa State Univ., Ames, IA; Malik, Vikash

There has been rising interest in the synthesis of magnetite nanoparticles due to their importance in biomedical and technological applications. Tunable magnetic properties of magnetite nanoparticles to meet specific requirements will greatly expand the spectrum of applications. Tremendous efforts have been devoted to studying and controlling the size, shape and magnetic properties of magnetite nanoparticles. We investigate gadolinium (Gd) doping to influence the growth process as well as magnetic properties of magnetite nanocrystals via a simple co-precipitation method under mild conditions in aqueous media. Gd doping was found to affect the growth process leading to synthesis of controllable particle sizesmore » under the conditions tested (0–10 at% Gd 3+). Typically, undoped and 5 at% Gd-doped magnetite nanoparticles were found to have crystal sizes of about 18 and 44 nm, respectively, supported by X-ray diffraction and transmission electron microscopy. These results showed that Gd-doped nanoparticles retained the magnetite crystal structure, with Gd 3+ randomly incorporated in the crystal lattice, probably in the octahedral sites. The composition of 5 at% Gd-doped magnetite was Fe (3-x)Gd xO 4 (x=0.085±0.002), as determined by inductively coupled plasma mass spectrometry. 5 at% Gd-doped nanoparticles exhibited ferrimagnetic properties with small coercivity (~65 Oe) and slightly decreased magnetization at 260 K in contrast to the undoped, superparamagnetic magnetite nanoparticles. Templation by the bacterial biomineralization protein Mms6 did not appear to affect the growth of the Gd-doped magnetite particles synthesized by this method.« less

Synthesis of t-butyl 2-(4-hydroxy-3-methoxybenzylidene)hydrazine carboxylate: Experimental and theoretical investigations of its properties

NASA Astrophysics Data System (ADS)

Bhat, Muzzaffar A.; Lone, Shabir H.; Mir, Muzzaffar A.; Majid, Sheikh A.; Bhat, Haroon Mohi-ud-din; Butcher, Raymond J.; Srivastava, Sanjay K.

2018-07-01

A convenient and facile synthesis of t-butyl-2-(4-hydroxy-3-methoxybenzylidene)hydrazine carboxylate (1) was accomplished by refluxing t-butyl carbazate with an appropriate aldehyde in ethanol. The resulting compound was characterized using spectral data analysis augmented by X-ray. Single crystal analysis depicted that compound 1 crystallizes in a monoclinic crystal system with P 21/c space group having trans-geometry at the Cdbnd N bond. The structural and electronic properties of the title compound have been calculated using DFT/B3LYP/6-311G (d,p) level of theory. Theoretically obtained parameters were well compared to the experimentally obtained results which depicted excellent agreement. Molecular electrostatic potential surface, frontier orbital analysis and vibrational analysis were also carried out. HOMO-LUMO energy gap was calculated which allowed the calculation of relative reactivity descriptors like chemical hardness, chemical inertness, chemical potential, nucleophilicity and electrophilicity index of the synthesized product. Pass prediction was carried out which revealed that compound 1 can be highly active against Mcl-1 enzyme, with Pa of 0.544. Based on Pass, molecular docking of compound 1 was carried out against Mcl-1 protein. Compound 1 displayed a binding free energy of -5.22 kcal/mol and inhibition constant of 149.06 μM and 1 depicted only alkyl hydrophobic and mixed pi/alkyl hydrophobic interactions with Mcl-1 enzyme. In short, this study reveals the synthesis of a new schiff base, and unravels the structural, electronic and biological properties of the title compound, paving way for further research in the field of drug development.

Synthesis and characterization of Gd-doped magnetite nanoparticles

DOE PAGES

Zhang, Honghu; Iowa State Univ., Ames, IA; Malik, Vikash; ...

2016-10-04

There has been rising interest in the synthesis of magnetite nanoparticles due to their importance in biomedical and technological applications. Tunable magnetic properties of magnetite nanoparticles to meet specific requirements will greatly expand the spectrum of applications. Tremendous efforts have been devoted to studying and controlling the size, shape and magnetic properties of magnetite nanoparticles. We investigate gadolinium (Gd) doping to influence the growth process as well as magnetic properties of magnetite nanocrystals via a simple co-precipitation method under mild conditions in aqueous media. Gd doping was found to affect the growth process leading to synthesis of controllable particle sizesmore » under the conditions tested (0–10 at% Gd 3+). Typically, undoped and 5 at% Gd-doped magnetite nanoparticles were found to have crystal sizes of about 18 and 44 nm, respectively, supported by X-ray diffraction and transmission electron microscopy. These results showed that Gd-doped nanoparticles retained the magnetite crystal structure, with Gd 3+ randomly incorporated in the crystal lattice, probably in the octahedral sites. The composition of 5 at% Gd-doped magnetite was Fe (3-x)Gd xO 4 (x=0.085±0.002), as determined by inductively coupled plasma mass spectrometry. 5 at% Gd-doped nanoparticles exhibited ferrimagnetic properties with small coercivity (~65 Oe) and slightly decreased magnetization at 260 K in contrast to the undoped, superparamagnetic magnetite nanoparticles. Templation by the bacterial biomineralization protein Mms6 did not appear to affect the growth of the Gd-doped magnetite particles synthesized by this method.« less

Biomolecular crystals for material applications and a mechanistic study of an iron oxide nanoparticle synthesis

NASA Astrophysics Data System (ADS)

Falkner, Joshua Charles

The three projects within this work address the difficulties of controlling biomolecular crystal formats (i.e. size and shape), producing 3-D ordered composite materials from biomolecular crystal templates, and understanding the mechanism of a practical iron oxide synthesis. The unifying thread consistent throughout these three topics is the development of methods to manipulate nanomaterials using a bottom-up approach. Biomolecular crystals are nanometer to millimeter sized crystals that have well ordered mesoporous solvent channels. The overall physical dimensions of these crystals are highly dependent on crystallization conditions. The controlled growth of micro- and nanoprotein crystals was studied to provide new pathways for creating smaller crystalline protein materials. This method produced tetragonal hen egg-white lysozyme crystals (250--100,000 nm) with near monodisperse size distributions (<15%). With this degree of control, existing protein crystal applications such as drug delivery and analytical sensors can reach their full potential. Applications for larger crystals with inherently ubiquitous pore structures could extend to materials used for membranes or templates. In this work, the porous structure of larger cowpea mosaic virus crystals was used to template metal nanoparticle growth within the body centered cubic crystalline network. The final composite material was found to have long range ordering of palladium and platinum nonocrystal aggregates (10nm) with symmetry consistent to the virus template. Nanoparticle synthesis itself is an immense field of study with an array of diverse applications. The final piece of this work investigates the mechanism behind a previously developed iron oxide synthesis to gain more understanding and direction to future synthesis strategies. The particle growth mechanism was found to proceed by the formation of a solvated iron(III)oleate complex followed by a reduction of iron (III) to iron (II). This unstable iron(II) nucleates to form a wustite (FeO) core which serves as an epitaxial surface for the magnetite (Fe3O4) shell growth. This method produces spherical particles (6-60nm) with relative size distributions of less than 15%.

Advances in containment methods and plutonium recovery strategies that led to the structural characterization of plutonium(IV) tetrachloride tris-diphenylsulfoxide, PuCl 4(OSPh 2) 3

DOE PAGES

Schrell, Samantha K.; Boland, Kevin Sean; Cross, Justin Neil; ...

2017-01-18

In an attempt to further advance the understanding of plutonium coordination chemistry, we report a robust method for recycling and obtaining plutonium aqueous stock solutions that can be used as a convenient starting material in plutonium synthesis. This approach was used to prepare and characterize plutonium(IV) tetrachloride tris-diphenylsulfoxide, PuCl 4(OSPh 2) 3, by single crystal X-ray diffraction. The PuCl 4(OSPh 2) 3 compound represents a rare example of a 7-coordinate plutonium(IV) complex. Structural characterization of PuCl 4(OSPh 2) 3 by X-ray diffraction utilized a new containment method for radioactive crystals. The procedure makes use of epoxy, polyimide loops, and amore » polyester sheath to provide a robust method for safely containing and easily handling radioactive samples. Lastly, the described procedure is more user friendly than traditional containment methods that employ fragile quartz capillary tubes. Additionally, moving to polyester, instead of quartz, lowers the background scattering from the heavier silicon atoms.« less

From computational discovery to experimental characterization of a high hole mobility organic crystal

PubMed Central

Sokolov, Anatoliy N.; Atahan-Evrenk, Sule; Mondal, Rajib; Akkerman, Hylke B.; Sánchez-Carrera, Roel S.; Granados-Focil, Sergio; Schrier, Joshua; Mannsfeld, Stefan C.B.; Zoombelt, Arjan P.; Bao, Zhenan; Aspuru-Guzik, Alán

2011-01-01

For organic semiconductors to find ubiquitous electronics applications, the development of new materials with high mobility and air stability is critical. Despite the versatility of carbon, exploratory chemical synthesis in the vast chemical space can be hindered by synthetic and characterization difficulties. Here we show that in silico screening of novel derivatives of the dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene semiconductor with high hole mobility and air stability can lead to the discovery of a new high-performance semiconductor. On the basis of estimates from the Marcus theory of charge transfer rates, we identified a novel compound expected to demonstrate a theoretic twofold improvement in mobility over the parent molecule. Synthetic and electrical characterization of the compound is reported with single-crystal field-effect transistors, showing a remarkable saturation and linear mobility of 12.3 and 16 cm2 V−1 s−1, respectively. This is one of the very few organic semiconductors with mobility greater than 10 cm2 V−1 s−1 reported to date. PMID:21847111

A Zero-Dimensional Organic Seesaw-Shaped Tin Bromide with Highly Efficient Strongly Stokes-Shifted Deep-Red Emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chenkun; Lin, Haoran; Shi, Hongliang

The synthesis and characterization is reported of (C 9NH 20) 2SnBr 4, a novel organic metal halide hybrid with a zero-dimensional (0D) structure, in which individual seesaw-shaped tin (II) bromide anions (SnBr 4 2-) are co-crystallized with 1-butyl-1-methylpyrrolidinium cations (C 9NH 20 +). Upon photoexcitation, the bulk crystals exhibit a highly efficient broadband deep-red emission peaked at 695 nm, with a large Stokes shift of 332 nm and a high quantum efficiency of around 46 %. Furthermore, the unique photophysical properties of this hybrid material are attributed to two major factors: 1) the 0D structure allowing the bulk crystals tomore » exhibit the intrinsic properties of individual SnBr 4 2- species, and 2) the seesaw structure then enables a pronounced excited state structural deformation as confirmed by density functional theory (DFT) calculations.« less

An unexpected Schiff base-type Ni(II) complex: Synthesis, crystal structures, fluorescence, electrochemical property and SOD-like activities

NASA Astrophysics Data System (ADS)

Chai, Lan-Qin; Zhang, Hong-Song; Huang, Jiao-Jiao; Zhang, Yu-Li

2015-02-01

An unexpected Schiff base-type Ni(II) complex, [Ni(L2)2]ṡCH3OH (HL2 = 1-(2-{[(E)-3, 5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Ni(II) acetate tetrahydrate with HL1 (2-(3,5-dibromo-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide) originally. HL1 and its corresponding Ni(II) complex were characterized by IR, 1H NMR spectra, as well as by elemental analysis, UV-Vis and emission spectroscopy, respectively. Crystal structures of the ligand and complex have been determined by single-crystal X-ray diffraction. Each complex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonding interactions. Moreover, the electrochemical property of the nickle complex was studied by cyclic voltammetry. In addition, SOD-like activities of HL1 and Ni(II) complex were also investigated.

A 1:1 pharmaceutical cocrystal of myricetin in combination with uncommon piracetam conformer: X-ray single crystal analysis and mechanochemical synthesis

NASA Astrophysics Data System (ADS)

Sowa, Michał; Ślepokura, Katarzyna; Matczak-Jon, Ewa

2014-01-01

Combination of two Active Pharmaceutical Ingredients, myricetin and piracetam, yields a 1:1 cocrystal characterized by X-ray single-crystal and powder diffraction, Raman spectroscopy, 1H NMR, thermal analysis (DSC and TG-DTA) methods. Constituents of the cocrystalline phase were also investigated in terms of Hirshfeld surfaces. Compounds in their neutral forms cocrystallize in the Pna21 space group of orthorhombic system. Notably, piracetam adopts an uncommon conformation, not encountered in its cocrystals previously described. In the crystal lattice, a three-dimensional hydrogen-bonded network is observed, including formation of a 2D molecular scaffolding motif. A scale-up procedure is readily available with use of solvent-drop grinding method, in which application of a variety of common solvents leads to formation of the cocrystal, as confirmed by XRPD and Raman spectroscopy.

Synthesis, crystal structure and antitumor activities of water soluble protonated salt of 20(S)-camptothecin

NASA Astrophysics Data System (ADS)

Lu, Wen; Wang, Yong; Wang, Luna; Zhao, Fengyi; Yang, Shilong; Xi, Chengjie; Yang, Yu; Xu, Li; Chi, Xingwei

2018-03-01

A water soluble camptothecin protonated salt has been synthesized; single crystals were grown by slow evaporation solution growth technique at room temperature and characterized by single crystal X-ray diffraction, FT-IR and 1H NMR. The CPT was protonated as (CPT+H+) cations, the cationic protonation occurred on the N position at pyridine group, which fromed a cation-anion compound with perchlorate ion that determined by X-Ray diffraction. Its activities against Hela (cervix), MCF-7 (breast), A549 (lung), HepG2 (liver) and HUVEC (umbilical vein, normal cell) were investigated. The toxicity of the protonated salt was slightly lower than camptothecin. IC50 values of 7.01 μM against HepG-2 cell, 8.61 μM against A549 cell, 17.82 μM against McF-7 cell, all of them are lower than the IC50 values of CPT against these cells except Hela cell.

Synthesis and Characterization of a New Modification of the Quasi-Low-Dimensional Compound KMo 4O 6

NASA Astrophysics Data System (ADS)

Ramanujachary, K. V.; Greenblatt, D. M.; Jones, E. B.; McCarroll, W. H.

1993-01-01

Prismatic single crystals, up to 3 mm in length, of a third modification of KMo4O6 have been prepared by electrolysis of a melt with a high ratio of K2MoO4 to MoO3. Single-crystal X-ray diffraction analysis shows that the structure conforms more closely than the other two modifications to that reported originally for NaMo4O6. When current is passed parallel to the tetragonal c axis (i.e., parallel to the trans-edge-sharing chains of Mo6 octahedra) the compound displays metallic conductivity down to 100 K, where a broad transition to semiconducting behavior occurs. If the current is passed perpendicular to the c axis the conductivity is approximately a factor of 5 lower. Magnetic susceptibility measurements on a randomly oriented collection of crystals showed Pauli paramagnetic behavior with a small Curie tail at low temperatures.

One-step synthesis of van der Waals heterostructures of graphene and two-dimensional superconducting α -M o2C

NASA Astrophysics Data System (ADS)

Qiao, Jia-Bin; Gong, Yue; Zuo, Wei-Jie; Wei, Yi-Cong; Ma, Dong-Lin; Yang, Hong; Yang, Ning; Qiao, Kai-Yao; Shi, Jin-An; Gu, Lin; He, Lin

2017-05-01

Assembling different two-dimensional (2D) crystals, covering a very broad range of properties, into van der Waals (vdW) heterostructures enables unprecedented possibilities for combining the best of different ingredients in one objective material. So far, metallic, semiconducting, and insulating 2D crystals have been used successfully in making functional vdW heterostructures with properties by design. Here, we expand 2D superconducting crystals as a building block of vdW hererostructures. One-step growth of large-scale high-quality vdW heterostructures of graphene and 2D superconducting α -M o2C by using chemical vapor deposition is reported. The superconductivity and its 2D nature of the heterostructures are characterized by our scanning tunneling microscopy measurements. This adds 2D superconductivity, the most attractive property of condensed matter physics, to vdW heterostructures.

A new series of lanthanide coordination polymers with 2,2‧-bipyridine and glutaric acid: Synthesis, crystal structures and properties of [Ln(bipy)(glut)(NO3)

NASA Astrophysics Data System (ADS)

Wang, Chunguang; Xing, Yongheng; Li, Zhangpeng; Li, Jing; Zeng, Xiaoqing; Ge, Maofa; Niu, Shuyun

2009-08-01

A series of new lanthanide coordination polymers, with the formula [Ln(bipy)(glut)(NO 3)] (Ln = Eu ( 1), Tb ( 2), Sm ( 3), Pr ( 4); bipy = 2,2'-bipyridine; H 2glut = glutaric acid), have been synthesized under the hydrothermal condition and characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, and single-crystal X-ray diffraction. Structural analyses reveal that all four complexes are isostructural and crystallized in monoclinic system, P2 1/ c space group. For these complexes, the Ln 3+ are all linked through glutaric acid ligands to form 1D chain-like polymeric structures, and bipy and NO3- are coordinated on two sides of the chains. The thermogravimetric analysis of 1 and photoluminescent properties of 1 and 2 are discussed in detail.

Synthesis, stereochemistry, crystal structure, docking study and biological evaluation of some new N-benzylpiperidin-4-ones

NASA Astrophysics Data System (ADS)

Ponnuswamy, S.; Kayalvizhi, R.; Sethuvasan, S.; Sugumar, P.; Ponnuswamy, M. N.

2018-03-01

Two new N-benzylpiperidin-4-ones 3 and 4 have been synthesized and characterized using IR, 1D and 2D NMR spectral studies. The NMR data of N-benzylpiperidin-4-ones 3 and 4 reveal that the compounds prefer to exist in chair conformation with equatorial orientation of the bulky substituents and the single crystal X-ray structure of compound 4 also reveals a similar conformation in solid state. Furthermore, the antimicrobial studies carried out for the compounds 1-4 indicate moderate activities with the selected strains. The antioxidant potency of 3 is superior whereas 4 exhibits moderate activity when compared to that of standard drug. The results of molecular docking studies with the AmpC β-lactamase enzyme indicate that compound 3 shows better docking score and binding energy than the co-crystal ligand.

Structural and optical properties of silicon layers with InSb and InAs nanocrystals formed by ion-beam synthesis

NASA Astrophysics Data System (ADS)

Komarov, F.; Vlasukova, L.; Greben, M.; Milchanin, O.; Zuk, J.; Wesch, W.; Wendler, E.; Togambaeva, A.

2013-07-01

We have studied the formation of InSb and InAs precipitates with sizes of several nanometers in Si and SiO2/Si by means of implantation of (Sb + In) or (As + In) ions with energies from 170 to 350 keV and fluencies from 2.8 to 3.5 × 1016 cm-2 at 500 °C and subsequent annealing at 1050-1100 °C for 3-30 min. RBS, TEM/TED, RS and PL techniques were employed to characterize the implanted layers. A broad band in the region of 1.2-1.6 μm has been registered in the low-temperature PL spectra of both (Sb + In) and (As + In) implanted and annealed silicon crystals. It was shown that structural and optical properties of oxidized silicon crystals strongly depend on type of implanted species in silicon crystals.

Synthesis and characterization of natural and modified antifreeze glycopeptides: glycosylated foldamers.

PubMed

Nagel, Lilly; Plattner, Carolin; Budke, Carsten; Majer, Zsuzsanna; DeVries, Arthur L; Berkemeier, Thomas; Koop, Thomas; Sewald, Norbert

2011-08-01

In Arctic and Antarctic marine regions, where the temperature declines below the colligative freezing point of physiological fluids, efficient biological antifreeze agents are crucial for the survival of polar fish. One group of such agents is classified as antifreeze glycoproteins (AFGP) that usually consist of a varying number (n = 4-55) of [AAT]( n )-repeating units. The threonine side chain of each unit is glycosidically linked to β-D: -galactosyl-(1 → 3)-α-N-acetyl-D: -galactosamine. These biopolymers can be considered as biological antifreeze foldamers. A preparative route for stepwise synthesis of AFGP allows for efficient synthesis. The diglycosylated threonine building block was introduced into the peptide using microwave-enhanced solid phase synthesis. By this versatile solid phase approach, glycosylated peptides of varying sequences and lengths could be obtained. Conformational studies of the synthetic AFGP analogs were performed by circular dichroism experiments (CD). Furthermore, the foldamers were analysed microphysically according to their inhibiting effect on ice recrystallization and influence on the crystal habit.

Synthesis and structural study of N-isopropenylbenzimidazolone

NASA Astrophysics Data System (ADS)

Mondieig, D.; Negrier, Ph.; Leger, J. M.; Lakhrissi, L.; El Assyry, A.; Lakhrissi, B.; Essassi, E. M.; Benali, B.; Boucetta, A.

2015-05-01

The synthesis and the crystal structure of the N-isopropenylbenzimidazolone (C10H10N2O) are presented. The synthesis was performed by Meth-Cohen method by reaction of o-phenylenediamine with ethyl acetoacetate in refluxed xylene. The single crystal structure was determined at room temperature by means of X-rays diffraction. The crystal system is monoclinic, with space group C2/c and eight molecules per unit cell. The unit cell dimensions are: a = 15.978(1) Å, b = 6.100(2) Å, c = 18.222(2) Å, β = 90.16(1)° and V = 1776.0(6) Å3.

Synthesis and characterization of LTA nanozeolite using barley husk silica: Mercury removal from standard and real solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azizi, Seyed Naser, E-mail: azizi@umz.ac.ir; Dehnavi, Ahmad Roozbehani, E-mail: Roozbehanisulfur@yahoo.com; Joorabdoozha, Amir

2013-05-15

Highlights: ► Silica extraction from barley husk with high purity for the synthesis of A nanozeolite. ► Free template A nanozeolite synthesized via new source of silica at low temperature. ► Optimization of SiO{sub 2}/Al{sub 2}O{sub 3}, Na{sub 2}O/SiO{sub 2} ratios, temperature and time of the synthesis. ► Utilizing of synthesized A nanozeolite for mercury removal from aqueous solutions. ► Mercury removal at optimized pH, contact time and adsorbent dose from real solution. - Abstract: In this study, synthesized Lined Type A (LTA) nanozeolite from barley husk silica (BHS) was used for mercury removal from standard and real aqueous solutions.more » The BHS in amorphous phase with 80% purity was extracted from barley husk ash (BHA), and used effectively as a new source of silica for the synthesis of NaA nanozeolite. The NaA nanocrystal in pure phase has been synthesized at low temperature, without adding any organic additives. The effects of heating time, reaction temperature, SiO{sub 2}/Al{sub 2}O{sub 3}, and Na{sub 2}O/SiO{sub 2} mole ratios on the crystallization of NaA nanozeolite were studied. The adsorption capacity of mercury (II) was studied as a function of pH, contact time, and amount of adsorbent. The crystallization of NaA nanozeolite from BHS was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET), and FTIR techniques. Moreover, concentration of Hg{sup 2+} ions in the aqueous solutions was analyzed by hydride generation atomic absorption spectroscopy method (HG-AAS). The standard and real samples analysis showed that NaA nanozeolite is capable of Hg{sup 2+} ions removal from the aqueous solutions. Efficiency of mercury (II) adsorption from real solutions onto the nano-sized NaA zeolite was 98%.« less

Mimicking the properties of antifreeze glycoproteins: synthesis and characterization of a model system for ice nucleation and antifreeze studies.

PubMed

Hederos, Markus; Konradsson, Peter; Borgh, Annika; Liedberg, Bo

2005-08-25

Synthesis of beta-D-Gal-(1 --> 3)-beta-D-GalNAc coupled to HOC2H4NHCOC15H30SH is described. This compound was coadsorbed at various proportions with C2H5OC2H4NHCOC15H30SH to form statistically mixed self-assembled monolayers (SAMs) on gold in an attempt to mimic the properties of the active domain in antifreeze glycoproteins (AFGPs). The monolayers were characterized by null ellipsometry, contact angle goniometry, X-ray photoelectron spectroscopy, and infrared reflection-absorption spectroscopy. The disaccharide compound adsorbed preferentially, and SAMs prepared at a solution molar ratio >0.3 displayed total wetting. The mixed SAMs showed well-organized alkyl chains up to a disaccharide surface fraction of 0.8. The amount of gauche conformers in the alkyls increased rapidly above this point, and the monolayers became disordered and less densely packed. Furthermore, the generated mixed SAMs were subjected to water vapor at constant relative humidity and the subsequent ice crystallization on a cooled substrate was monitored via an optical microscope. Interestingly, rapid crystallization occurred within a narrow range of temperatures on mixed SAMs with a high disaccharide content, surface fraction >0.3. The reported crystallization temperatures and the ice layer topography were compared with results obtained for a much simpler reference system composed of -OH/-CH3 terminated n-alkanethiols in order to account for changes in topography of the water/ice layer with surface energy. Although preliminary, the obtained results can be useful in the search for the molecular mechanism behind the antifreeze activity of AFGPs.

Pentamethylcyclopentadienyl-rhodium and iridium complexes containing (N^N and N^O) bound chloroquine analogue ligands: synthesis, characterization and antimalarial properties.

PubMed

Ekengard, Erik; Kumar, Kamlesh; Fogeron, Thibault; de Kock, Carmen; Smith, Peter J; Haukka, Matti; Monari, Magda; Nordlander, Ebbe

2016-03-07

The synthesis and characterization of twenty new pentamethylcyclopentadienyl-rhodium and iridium complexes containing N^N and N^O-chelating chloroquine analogue ligands are described. The in vitro antimalarial activity of the new ligands as well as the complexes was evaluated against the chloroquine sensitive (CQS) NF54 and the chloroquine resistant (CQR) Dd2 strains of Plasmodium falciparum. The antimalarial activity was found to be good to moderate; although all complexes are less active than artesunate, some of the ligands and complexes showed better activity than chloroquine (CQ). In particular, rhodium complexes were found to be considerably more active than iridium complexes against the CQS NF54 strain. Salicylaldimine Schiff base ligands having electron-withdrawing groups (F, Cl, Br, I and NO2) in para position of the salicyl moiety and their rhodium complexes showed good antiplasmodial activity against both the CQS-NF54 and the CQR-Dd2 strains. The crystal structures of (η(5)-pentamethylcyclopentadienyl){N(1)-(7-chloroquinolin-4-yl)-N(2)-(pyridin-2-ylmethyl)ethane-1,2-diamine)} chlororhodium(III) chloride and (η(5)-pentamethylcyclopentadienyl){(4-chloro-2-(((2-((7-chloroquinolin-4-yl)amino)ethyl)imino)methyl)phenolate)}chlororhodium(III) chloride are reported. The crystallization of the amino-pyridyl complex (η(5)-pentamethylcyclopentadienyl){(N(1)-(7-chloroquinolin-4-yl)-N(2)-(pyridin-2-ylmethyl)ethane-1,2-diamine)}chloroiridium(III) chloride in acetone resulted in the formation of the imino-pyridyl derivative (η(5)-pentamethylcyclopentadienyl){(N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethylene)ethane-1,2-diamine)}chloroiridium(III) chloride, the crystal structure of which is also reported.

Synthesis, spectral characterization, molecular structure and pharmacological studies of N'-(1, 4-naphtho-quinone-2yl) isonicotinohyWdrazide

NASA Astrophysics Data System (ADS)

Kavitha Rani, P. R.; Fernandez, Annette; George, Annie; Remadevi, V. K.; Sudarsanakumar, M. R.; Laila, Shiny P.; Arif, Muhammed

2015-01-01

A simple and efficient procedure was employed for the synthesis of N'-(1,4-naphtho-quinone-2-yl) isonicotinohydrazide (NIH) by the reaction of 2-hydroxy-1,4-naphthaquinone (lawsone) and isonicotinoyl hydrazine in methanol using ultrasonic irradiation. Lawsone is the principal dye, isolated from the leaves of henna (Lawsonia inermis). Structural modification was done on the molecule aiming to get a more active derivative. The structure of the parent compound and the derivative was characterized by elemental analyses, infrared, electronic, 1H, 13C NMR and GC-MS spectra. The fluorescence spectral investigation of the compound was studied in DMSO and ethanol. Single crystal X-ray diffraction studies reveal that NIH crystallizes in monoclinic space group. The DNA cleavage study was monitored by gel electrophoresis method. The synthesized compound was found to have significant antioxidant activity against DPPH radical (IC50 = 58 μM). The in vitro cytotoxic studies of the derivative against two human cancer cell lines MCF-7 (human breast cancer) and HCT-15 (human colon carcinoma cells) using MTT assay revealed that the compound exhibited higher cytotoxic activity with a lower IC50 value indicating its efficiency in killing the cancer cells even at low concentrations. These results suggest that the structural modifications performed on lawsone could be considered a good strategy to obtain a more active drug.

Identification, isolation, and synthesis of seven novel impurities of anti-diabetic drug Repaglinide.

PubMed

Kancherla, Prasad; Keesari, Srinivas; Alegete, Pallavi; Khagga, Mukkanti; Das, Parthasarathi

2018-01-01

Seven unknown impurities in Repaglinide bulk drug batches at below 0.1% (ranging from 0.05 to 0.10%) were detected by an ultra-performance liquid chromatographic (UPLC) method. These impurities were isolated from the crude sample of Repaglinide using preparative high performance liquid chromatography (prep-HPLC). Based on liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI/MS) study, the chemical structures of seven new impurities (8, 9, 10, 11, 13, 14, and 16) were presumed and characterized as 4-(cyanomethyl)-2-ethoxybenzoic acid (8), 4-(cyanomethyl)-2-ethoxy-N-(3-methyl-1-(2-(piperidin-1-yl)phenyl)butyl)benzamide (9), 4-(2-amino-2-oxoethyl)-2-ethoxy-N-(3-methyl-1-(2-(piperidin-1-yl)phenyl)butyl) benzamide (10) and 2-(3-ethoxy-4-((3-methyl-1-(2-(piperidin-1-yl)phenyl)butyl) carbamoyl) phenyl) acetic acid (11) and 4-(cyanomethyl)-N-cyclohexyl-2-ethoxybenzamide (13), 2-(4-(cyclohexylcarbamoyl)-3-ethoxyphenyl) acetic acid (14) and N-cyclohexyl-4-(2-(cyclohexylamino)-2-oxoethyl)-2-ethoxybenzamide (16). The complete spectral analysis, proton nuclear magnetic resonance ( 1 H NMR), 13 C NMR, MS, and infrared (IR) confirmed the proposed chemical structures of impurities. Identification, structural characterization, formation, and their synthesis was first reported in this study. The impurity 11 was crystallized and structure was solved by single crystal X-ray diffraction. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Tuned apatitic materials: Synthesis, characterization and potential antimicrobial applications

NASA Astrophysics Data System (ADS)

Fierascu, Irina; Fierascu, Radu Claudiu; Somoghi, Raluca; Ion, Rodica Mariana; Moanta, Adriana; Avramescu, Sorin Marius; Damian, Celina Maria; Ditu, Lia Mara

2018-04-01

Inorganic antimicrobial materials can be viable for multiple applications (related to its use for new buildings with special requirements related to microbiological loading, such as hospital buildings and for consolidation of cultural heritage constructions); also the use of substituted hydroxyapatites for protection of stone artefacts against environmental factors (acidic rain) and biodeterioration it's an option to no longer use of toxic substances. This paper presents methods of synthesis and characterization of the material from the point of view of the obtained structures and final applications. The materials were characterized in terms of composition and morphology (using X-ray Diffraction, X-ray Fluorescence, Inductively coupled plasma-atomic emission spectrometry, Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy, Surface area and pore size determination). Antimicrobial activity was tested against filamentous fungi strains and pathogenic bacteria strains, using both spot on lawn qualitative method (on agar medium) and serial microdilution quantitative method (in broth medium). Further, it was evaluated the anti-biofilm activity of the tested samples toward the most important microbial strains implicated in biofilm development, using crystal violet stained biofilms microtiter assay, followed by spectrophotometric quantitative evaluation.

An alternative gas sensor material: Synthesis and electrical characterization of SmCoO{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michel, Carlos Rafael; Delgado, Emilio; Santillan, Gloria

2007-01-18

Single-phase perovskite SmCoO{sub 3} was prepared by a wet-chemical synthesis technique using metal-nitrates and citric acid; after its characterization by thermal analyses and X-ray diffraction, sintering at 900 deg. C in air, gave single phase and well crystallized powders. The powders were mixed with an organic solvent to prepare a slurry, which was deposited on alumina substrates as thick films, using the screen-printing technique. Electrical and gas sensing properties of sintered SmCoO{sub 3} films were investigated in air, O{sub 2} and CO{sub 2}, the results show that sensitivity reached a maximum value at 420 deg. C, for both gases. Dynamicmore » tests revealed a better behavior of SmCoO{sub 3} in CO{sub 2} than O{sub 2}, due to a fast response and a larger electrical resistance change to this gas. X-ray diffraction made on powders after electrical characterization in gases, showed that perovskite-type structure was preserved.« less

Low-Temperature Growth of Two-Dimensional Layered Chalcogenide Crystals on Liquid.

PubMed

Zhou, Yubing; Deng, Bing; Zhou, Yu; Ren, Xibiao; Yin, Jianbo; Jin, Chuanhong; Liu, Zhongfan; Peng, Hailin

2016-03-09

The growth of high-quality two-dimensional (2D) layered chalcogenide crystals is highly important for practical applications in future electronics, optoelectronics, and photonics. Current route for the synthesis of 2D chalcogenide crystals by vapor deposition method mainly involves an energy intensive high-temperature growth process on solid substrates, often suffering from inhomogeneous nucleation density and grain size distribution. Here, we first demonstrate a facile vapor-phase synthesis of large-area high-quality 2D layered chalcogenide crystals on liquid metal surface with relatively low surface energy at a growth temperature as low as ∼100 °C. Uniform and large-domain-sized 2D crystals of GaSe and GaxIn1-xSe were grown on liquid metal surface even supported on a polyimide film. As-grown 2D GaSe crystals have been fabricated to flexible photodetectors, showing high photoresponse and excellent flexibility. Our strategy of energy-sustainable low-temperature growth on liquid metal surface may open a route to the synthesis of high-quality 2D crystals of Ga-, In-, Bi-, Hg-, Pb-, or Sn-based chalcogenides and halides.

Bio-inspired routes for synthesizing efficient nanoscale platinum electrocatalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cha, Jennifer N.; Wang, Joseph

2014-08-31

The overall objective of the proposed research is to use fundamental advances in bionanotechnology to design powerful platinum nanocrystal electrocatalysts for fuel cell applications. The new economically-viable, environmentally-friendly, bottom-up biochemical synthetic strategy will produce platinum nanocrystals with tailored size, shape and crystal orientation, hence leading to a maximum electrochemical reactivity. There are five specific aims to the proposed bio-inspired strategy for synthesizing efficient electrocatalytic platinum nanocrystals: (1) isolate peptides that both selectively bind particular crystal faces of platinum and promote the nucleation and growth of particular nanocrystal morphologies, (2) pattern nanoscale 2-dimensional arrays of platinum nucleating peptides from DNA scaffolds,more » (3) investigate the combined use of substrate patterned peptides and soluble peptides on nanocrystal morphology and growth (4) synthesize platinum crystals on planar and large-area carbon electrode supports, and (5) perform detailed characterization of the electrocatalytic behavior as a function of catalyst size, shape and morphology. Project Description and Impact: This bio-inspired collaborative research effort will address key challenges in designing powerful electrocatalysts for fuel cell applications by employing nucleic acid scaffolds in combination with peptides to perform specific, environmentally-friendly, simultaneous bottom-up biochemical synthesis and patterned assembly of highly uniform and efficient platinum nanocrystal catalysts. Bulk synthesis of nanoparticles usually produces a range of sizes, accessible catalytic sites, crystal morphologies, and orientations, all of which lead to inconsistent catalytic activities. In contrast, biological systems routinely demonstrate exquisite control over inorganic syntheses at neutral pH and ambient temperature and pressures. Because the orientation and arrangement of the templating biomolecules can be precisely controlled, the nanocrystals boast a defined shape, morphology, orientation and size and are synthesized at benign reaction conditions. Adapting the methods of biomineralization towards the synthesis of platinum nanocrystals will allow effective control at a molecular level of the synthesis of highly active metal electrocatalysts, with readily tailored properties, through tuning of the biochemical inputs. The proposed research will incorporate many facets of biomineralization by: (1) isolating peptides that selectively bind particular crystal faces of platinum (2) isolating peptides that promote the nucleation and growth of particular nanocrystal morphologies (3) using two-dimensional DNA scaffolds to control the spatial orientation and density of the platinum nucleating peptides, and (4) combining bio-templating and soluble peptides to control crystal nucleation, orientation, and morphology. The resulting platinum nanocrystals will be evaluated for their electrocatalytic behavior (on common carbon supports) to determine their optimal size, morphology and crystal structure. We expect that such rational biochemical design will lead to highly uniform and efficient platinum nanocrystal catalysts for fuel cell applications.« less

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Yan; Ding Shaohua; Zheng Xuefang

2007-07-15

Two new lanthanum sulfates DySO{sub 4}(OH) 1 and Eu{sub 2}(SO{sub 4}){sub 3}(H{sub 2}O){sub 8} 2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) A, b=10.945(5) A, c=8.164(4) A, {alpha}=90{sup o}, {beta}=93.619(6){sup o}, {gamma}=90{sup o}, V=713.0(5) A{sup 3}, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) A, b=6.7676(8) A, c=18.318(2) A, {alpha}=90{sup o}, {beta}=102.265(2){sup o}, {gamma}=90{supmore » o}, V=1642.7 (4) A{sup 3}, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner. - Graphical abstract: Two new lanthanum sulfates DySO{sub 4}(OH) 1 and Eu{sub 2} (SO{sub 4}){sub 3} (H{sub 2}O){sub 8} 2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. It displays a three dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains.« less

Synthesis, spectral characterization, crystal structure and molecular docking study of 2,7-diaryl-1,4-diazepan-5-ones

NASA Astrophysics Data System (ADS)

Sethuvasan, S.; Sugumar, P.; Maheshwaran, V.; Ponnuswamy, M. N.; Ponnuswamy, S.

2016-07-01

In this study, a series of variously substituted r-2,c-7-diaryl-1,4-diazepan-5-ones 9-16 have been synthesized using Schmidt rearrangement and are characterized by IR, mass and 1D & 2D NMR spectral data. The proton NMR coupling constant and estimated dihedral angles reveal that the compounds 9-16 prefer a chair conformation with equatorial orientation of alkyl and aryl groups. Single crystal X-ray structure has been solved for compounds 9 and 11 which also indicates the preference for distorted chair conformation with equatorial orientation of substituents. The compounds 9-16 have been docked with the structure of Methicillin-resistant Staphylococcus aureus (MRSA) and the results demonstrate that compound 10 is having better docking score and glide energy than others and it is comparable to co-crystal ligand. Furthermore, all the compounds have been evaluated for their antibacterial and antioxidant activities. All the compounds show moderate antibacterial activity and only 11 exhibits better activity against S. aures and Escherichia coli. The compounds 11, 13 and 14 exhibit half of the antioxidant power when compared to the BHT and the remaining compounds show moderate activity.

Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands

NASA Astrophysics Data System (ADS)

Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S. Ahmad

2015-04-01

A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s-1 scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction.

Thermolysis synthesis of pure phase NiO from novel sonochemical synthesized Ni(II) nano metal-organic supramolecular architecture.

PubMed

Hanifehpour, Younes; Morsali, Ali; Mirtamizdoust, Babak; Joo, Sang Woo; Soltani, Behzad

2017-07-01

Nano-structures of a new supramolecular coordination compound of divalent nickel with the pyrazol (pzH) containing the terminal azide anions, [Ni(pzH) 2 (N 3 ) 2 ] (1), with discrete molecular architecture (DMA) in solid state was synthesized via sonochemical method. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, IR, and elemental analysis. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal X-ray data shows that the coordination number of Ni (II) ions is six, (NiN 6 ), with four N-donor atoms from neutral "pzH" ligands and two N-donors from two terminal azide anions. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The structure of the title complex was optimized by density functional theory calculations. Calculated structural parameters and IR spectra for the title complex are consistent with the crystal structure. The NiO nanoparticles were obtained by thermolysis of 1 at 180°C with oleic acid as a surfactant. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and characterization of the heavy-fermion compound CePtAl 4Ge 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shin, Soohyeon; Rosa, Priscila Ferrari Silveira; Ronning, Filip

Here, we report the synthesis of the Ce-based quaternary compound CePtAl 4Ge 2 that crystallizes in the trigonal structure (space group R 3¯m, 166) with unit cell parameters, a = 4.1995(5) Å, c = 31.851(7) Å, and γ = 120°. Powder X-ray diffraction and energy dispersive X-ray spectroscopy show that CePtAl 4Ge 2 (LaPtAl 4Ge 2) is in a single, homogeneous phase. Magnetic susceptibility, electrical resistivity, and heat capacity measurements of CePtAl 4Ge 2 show that it exhibits antiferromagnetic behavior below 2.3 K. The magnetic susceptibility for the magnetic field applied perpendicular (χ ab) and parallel (χ c) to themore » crystalline c-axis is very anisotropic, and the susceptibility ratio (χ ab/χ c) reaches a maximum value of 10, indicating that the spin easy axis is within the Ce plane. The entropy recovered at T N is consistent with the doublet ground state of the crystal field split J = 5/2 multiplet of Ce 3+ ions.« less

Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3-δ perovskite nanoparticles fabricated by modified polymer precursor method

NASA Astrophysics Data System (ADS)

Miruszewski, T.; Gdaniec, P.; Karczewski, J.; Bochentyn, B.; Szaniawska, K.; Kupracz, P.; Prześniak-Welenc, M.; Kusz, B.

2016-09-01

The yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low-temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15-70 nm). The results of thermal analysis indicate that the crystallization of precursor takes place at different stages. The product after heat treatment at 600 °C for 3 h in air was also characterized by X-Ray diffraction method (XRD) and Fourier transform - infrared spectroscopy (FT-IR). After the crystallization and the impurity removal process, a single-phase material was obtained in case of all analyzed samples. The morphology of obtained nano-powders was also studied by a scanning electron microscopy (SEM). It can be concluded, that this method allows obtaining a perovskite phase of a metal doped SrTiO3 with nanometric particles.

Synthesis and characterization of the heavy-fermion compound CePtAl 4Ge 2

DOE PAGES

Shin, Soohyeon; Rosa, Priscila Ferrari Silveira; Ronning, Filip; ...

2017-12-18

Here, we report the synthesis of the Ce-based quaternary compound CePtAl 4Ge 2 that crystallizes in the trigonal structure (space group R 3¯m, 166) with unit cell parameters, a = 4.1995(5) Å, c = 31.851(7) Å, and γ = 120°. Powder X-ray diffraction and energy dispersive X-ray spectroscopy show that CePtAl 4Ge 2 (LaPtAl 4Ge 2) is in a single, homogeneous phase. Magnetic susceptibility, electrical resistivity, and heat capacity measurements of CePtAl 4Ge 2 show that it exhibits antiferromagnetic behavior below 2.3 K. The magnetic susceptibility for the magnetic field applied perpendicular (χ ab) and parallel (χ c) to themore » crystalline c-axis is very anisotropic, and the susceptibility ratio (χ ab/χ c) reaches a maximum value of 10, indicating that the spin easy axis is within the Ce plane. The entropy recovered at T N is consistent with the doublet ground state of the crystal field split J = 5/2 multiplet of Ce 3+ ions.« less

Studies on the synthesis, spectral, optical and thermal properties of l-Valine Zinc Sulphate: an organic inorganic hybrid nonlinear optical crystal.

PubMed

Puhal Raj, A; Ramachandra Raja, C

2012-11-01

Nonlinear optical (NLO) organic inorganic hybrid l-Valine Zinc Sulphate (LVZS) was synthesized and single crystals were obtained from saturated aqueous solution by slow evaporation method at 36°C using a constant temperature bath (CTB) with an accuracy of ±0.01°C. This crystal is reported with its characterization by single crystal and powder XRD, FTIR, UV-Vis-NIR, TG/DTA analysis and SHG test. Single crystal XRD study reveals that LVZS crystallizes in monoclinic system with the lattice constants a=9.969(3) Å, b=7.238(3) Å, c=24.334(9) Å and cell volume is 1736.00Å(3). Sharp peaks observed in powder X-ray diffraction studies confirm the high degree of crystallinity of grown crystal. The incorporation of sulphate ion with l-valine is confirmed by FTIR spectrum in LVZS crystal(.) A remarkable increase in optical transparency has been observed in LVZS when compared to l-valine and zinc sulphate heptahydrate Thermal properties of LVZS have been reported by using TG/DTA analysis. Kurtz powder second harmonic generation (SHG) test confirms NLO property of the crystal and SHG efficiency of LVZS was found to be 1.34 times more than pure l-valine. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of alkali ions (Na+, K+, Cs+) on reaction mechanism of CZTS nano-particles synthesis

NASA Astrophysics Data System (ADS)

Kumar, Suresh; Altosaar, Mare; Grossberg, Maarja; Mikli, Valdek

2018-04-01

The control of morphology, elemental composition and phase composition of Cu2ZnSnS4 (CZTS) nano-crystals depends on the control of complex formation and surface stabilization of nano-particles in solution-based synthesis in oleylamine. At temperatures ≥280 °C, the control of nano-crystal's morphology and homogenous growth is difficult because of fast poly-nuclear growth occurring at higher temperatures. In the present work the effect of oleylamine complex formation with different alkali ions (Na+, K+ and Cs+) on nano-crystals growth at synthesis temperature of 280 °C was studied. It was found that nano-powders synthesized in the presence of Na+ and K+ ions showed the formation of crystals of different sizes - small nano-particles (18 nm-30 nm), large aggregated crystals (few nm to 1 μm) and large single crystals (1 μm - 4 μm). The presence of Cs+ ions in the nano-powder synthesis in oleylamine-metal precursor-CsOH solution promoted growth of nano-crystals of homogenous size. It is proposed that the formed oleylamine-Cs complexes a) enhance the formation and stabilization of oleylamine-metal (Cu, Zn and Sn) complexes before the injection of sulphur precursor into the oleylamine-metal precursor solution and b) after addition of sulphur stabilize the fast nucleated nano-particles and promote diffusion limited growth.

Synthesis and characterization of Ni(II) complex with 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-7,14-dienium bromide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yusoff, Latifah M.; Yusoff, Siti Fairus M.; Ismail, Wafiuddin

Nickel(II) complex have been synthesized by treating a 14-membered ring tetraaza macrocyclic compound, 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-7,14-dienium, bromide (Me{sub 6}N{sub 4}H{sub 4})Br{sub 2} with nickel acetate in metanol. The complex was characterized using elemental analysis, Fourier Transform Infrared (FTIR), Ultraviolet-Visible (UV-Vis), and single crystal diffraction (X-ray). The nickel atom coordinates through four nitrogen atoms in the ligand. Square planar geometry has been proposed for this complex.

A series of 2, 4, 5-trisubstituted oxazole: Synthesis, characterization and DFT modelling

NASA Astrophysics Data System (ADS)

Kadam, Vinay S.; Shaikh, Saminaparwin G.; Patel, Arun L.

2016-06-01

A new series of 2,4,5-trisubstituted oxazole were synthesized with good yields using simple methodology. All the compounds were thoroughly characterized by IR, NMR (1H and 13C) and mass spectrometry and structures of 2-(4-butyloxyphenyl)-4,5-dimethyloxazole (5b) and 4,5-dimethyl-2-(4-(octyloxy)phenyl)oxazole(5e) were unambiguously determined by X-ray crystallography. Evidently, the crystal structures of these compounds showed C-H⋯N and C-H⋯O intermolecular interactions. The electronic structures of these compounds were also studied by DFT at B3LYP/6-311G ++ level of theory.

Synthesis and excellent field emission properties of three-dimensional branched GaN nanowire homostructures

NASA Astrophysics Data System (ADS)

Li, Enling; Sun, Lihe; Cui, Zhen; Ma, Deming; Shi, Wei; Wang, Xiaolin

2016-10-01

Three-dimensional branched GaN nanowire homostructures have been synthesized on the Si substrate via a two-step approach by chemical vapor deposition. Structural characterization reveals that the single crystal GaN nanowire trunks have hexagonal wurtzite characteristics and grow along the [0001] direction, while the homoepitaxial single crystal branches grow in a radial direction from the six-sided surfaces of the trunks. The field emission measurements demonstrate that the branched GaN nanowire homostructures have excellent field emission properties, with low turn-on field at 2.35 V/μm, a high field enhancement factor of 2938, and long emission current stability. This indicates that the present branched GaN nanowire homostructures will become valuable for practical field emission applications.

Two rhodamine 6G derivative compounds: a structural and fluorescence single-crystal study.

PubMed

Di Paolo, Matias; Bossi, Mariano L; Baggio, Ricardo; Suarez, Sebastián A

2016-10-01

The synthesis, characterization, structural analysis and fluorescence properties of two rhodamine 6G derivatives are described, namely a propargylamine derivative, 3',6'-bis(ethylamino)-2',7'-dimethyl-2-(methylcyanide)spiro[isoindole-1,9'-xanthen]-3(2H)-one (I), and a γ-aminobutyric acid (GABA) derivative, 3',6'-bis(ethylamino)-2',7'-dimethyl-3-oxospiro[isoindole-1,9'-xanthen]-2(3H)-yl)butyricacid (II). Both structures are compared with four similar ones from the Cambridge Structural Database (CSD), and the interactions involved in the stabilization are analyzed using the atoms in molecules (AIM) theory. Finally, a single-crystal in-situ reaction study is presented, carried out by fluorescence methods, which enabled the `opening' of the spirolactam ring in the solid phase.

Aqueous phase synthesis, crystal structure and biological study of isoxazole extensions of pyrazole-4-carbaldehyde derivatives

NASA Astrophysics Data System (ADS)

Wazalwar, Sachin S.; Banpurkar, Anita R.; Perdih, Franc

2017-12-01

A series of novel isoxazol derivatives was synthesized by green route in aqueous phase at room temperature by the reaction of 3-methyl-4H-isoxazol-5-one with 3-(substituted phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde by one-pot Knoevenagel condensation method using sodium benzoate as a catalyst. Compounds were characterized on the basis of IR, 1H NMR, mass spectroscopy and melting point determination. Crystal structures of five compounds were determined by X-ray diffraction. The compounds formed were screened for antibacterial and antifungal activity. Some compounds showed activity close to ampicillin against E. coli, S. aureus, and S. pyogenus. Two compounds showed antifungal activity against C. albicans close to standard greseofulvin.

Fundamental Studies of Crystal Growth of Microporous Materials

NASA Technical Reports Server (NTRS)

Dutta, P.; George, M.; Ramachandran, N.; Schoeman, B.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Microporous materials are framework structures with well-defined porosity, often of molecular dimensions. Zeolites contain aluminum and silicon atoms in their framework and are the most extensively studied amongst all microporous materials. Framework structures with P, Ga, Fe, Co, Zn, B, Ti and a host of other elements have also been made. Typical synthesis of microporous materials involve mixing the framework elements (or compounds, thereof) in a basic solution, followed by aging in some cases and then heating at elevated temperatures. This process is termed hydrothermal synthesis, and involves complex chemical and physical changes. Because of a limited understanding of this process, most synthesis advancements happen by a trial and error approach. There is considerable interest in understanding the synthesis process at a molecular level with the expectation that eventually new framework structures will be built by design. The basic issues in the microporous materials crystallization process include: (1) Nature of the molecular units responsible for the crystal nuclei formation; (2) Nature of the nuclei and nucleation process; (3) Growth process of the nuclei into crystal; (4) Morphological control and size of the resulting crystal; (5) Surface structure of the resulting crystals; (6) Transformation of frameworks into other frameworks or condensed structures. The NASA-funded research described in this report focuses to varying degrees on all of the above issues and has been described in several publications. Following is the presentation of the highlights of our current research program. The report is divided into five sections: (1) Fundamental aspects of the crystal growth process; (2) Morphological and Surface properties of crystals; (3) Crystal dissolution and transformations; (4) Modeling of Crystal Growth; (5) Relevant Microgravity Experiments.

Synthesis, structure and luminescence of novel co-crystals based on bispyridyl-substituted α,β-unsaturated ketones with coformers

NASA Astrophysics Data System (ADS)

Li, Hong-Juan; Wang, Lei; Zhao, Juan-Juan; Sun, Ju-Feng; Sun, Ji-Liang; Wang, Chun-Hua; Hou, Gui-Ge

2015-01-01

Based on 2,6-bis((pyridin-4-yl)methylene)cyclohexanone (A) and N-methyl-3,5-bis((pyridin-4-yl)methylene)-4-piperidone (B) with coformers, three novel macrocyclic co-crystals, (A)ṡ(resorcinol) (1), (A)ṡ(1,3,5-benzenetriol) (2), (B)2ṡ(1,3,5-benzenetriol)2 (3) and three chain co-crystals, (A)ṡ(hydroquinone) (4), (A)ṡ(isophthalic acid) (5), (B)ṡ(isophthalic acid) (6) have been synthesized and structurally characterized by IR, 1H NMR and X-ray crystal structure analysis. Structural analysis indicates that four-component macrocycles in 1-3 are generated from "clip-like" resorcinol templates and building blocks, while 4-6 show infinite H-bonding chains. In addition, the luminescent properties of A, B and 1-6 are investigated primarily in the solid state. Compared with free building blocks, 1-6 are blue-shifted 55-60 nm with decreasing emission intensities in spite of the enhancement in 6. The change of luminescent properties might be caused mainly by incorporation of coformers into co-crystals, including H-bonds, molecular conformations, arranging dispositions and π-π characteristics. It might have potential applications for crystal engineering to construct patentable crystals with interesting luminescent properties.

Generation of mariner-based transposon insertion mutant library of Bacillus sphaericus 2297 and investigation of genes involved in sporulation and mosquito-larvicidal crystal protein synthesis.

PubMed

Wu, Yiming; Hu, Xiaomin; Ge, Yong; Zheng, Dasheng; Yuan, Zhiming

2012-05-01

Bacillus sphaericus has been used with great success in mosquito control programs worldwide. Under conditions of nutrient limitation, it undergoes sporulation via a series of well defined morphological stages. However, only a small number of genes involved in sporulation have been identified. To identify genes associated with sporulation, and to understand the relationship between sporulation and crystal protein synthesis, a random mariner-based transposon insertion mutant library of B. sphaericus strain 2297 was constructed and seven sporulation-defective mutants were selected. Sequencing of the DNA flanking of the transposon insertion identified several genes involved in sporulation. The morphologies of mutants were determined by electron microscopy and synthesis of crystal proteins was analyzed by SDS-PAGE and Western blot. Four mutants blocked at early stages of sporulation failed to produce crystal proteins and had lower larvicidal activity. However, the other three mutants were blocked at later stages and were able to form crystal proteins, and the larvicidal activity was similar to wild type. These results indicated that crystal protein synthesis in B. sphaericus is dependent on sporulation initiation. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Synthesis, characterization and thermal decomposition of tetramethylammonium rare earth double selenates

NASA Astrophysics Data System (ADS)

Divekar, Sandesh K.; Achary, S. Nagabhusan; Ajgaonkar, Vishnu R.

2018-06-01

A series of double selenates, as (CH3)4NLn(SeO4)2rad 4H2O (Ln = Rare earth ion like La, Pr, Nd, Sm, Gd, Tb, Dy) was crystallized from mixed solution and characterized in detail for their structure, vibrational and optical properties as well as thermal stabilities. The crystal structure of the praseodymium compound was obtained by single crystal X-ray diffraction (XRD) and revealed a monoclinic (C2/c) lattice with chains formed by PrO8 and SeO4 units. The chains with compositions [Pr(SeO4)4(H2O)4]- are stacked in three dimensions and the (CH3)4N+ ions located in between them provide charge neutrality to the structure. The characterization of other compounds were carried out from powder XRD data and revealed that they all are isostructural to Pr-compound. All the functional groups were identified by Raman and IR spectroscopic studies. Solid state 77Se NMR revealed noticeable changes in selenium environment in these compounds. The optical absorption studies on the compounds show strong band edge absorptions in UV region. Thermal stabilities of the compounds, as investigated by simultaneous TG-DTA techniques indicate their sequential decompositions due to loss of H2O, (CH3)4N+ group, SeO2 and finally leaving their corresponding rare earth oxides.

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti-proliferative properties against HeLa cell line.

PubMed

Srivastava, Pallavee; Braganca, Judith M; Kowshik, Meenal

2014-01-01

Nanoparticles synthesis by bacteria and yeasts has been widely reported, however, synthesis using halophilic archaea is still in a nascent stage. This study aimed at the intracellular synthesis of selenium nanoparticles (SeNPs) by the haloarchaeon Halococcus salifodinae BK18 when grown in the presence of sodium selenite. Crystallographic characterization of SeNPs by X-ray diffraction, Selected area electron diffraction, and transmission electron microscopy exhibited rod shaped nanoparticles with hexagonal crystal lattice, a crystallite domain size of 28 nm and an aspect ratio (length:diameter) of 13:1. Energy disruptive analysis of X-ray analysis confirmed the presence of selenium in the nano-preparation. The nitrate reductase enzyme assay and the inhibitor studies indicated the involvement of NADH-dependent nitrate reductase in SeNPs synthesis and metal tolerance. The SeNPs exhibited good anti-proliferative properties against HeLa cell lines while being non-cytotoxic to normal cell line model HaCat, suggesting the use of these SeNPs as cancer chemotherapeutic agent. This is the first study on selenium nanoparticles synthesis by haloarchaea. © 2014 American Institute of Chemical Engineers.

A review on the synthesis, crystal growth, structure and physical properties of rare earth based quaternary intermetallic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumbaraddi, Dundappa; Sarkar, Sumanta; Peter, Sebastian C., E-mail: sebastiancp@jncasr.ac.in

2016-04-15

This review highlights the synthesis and crystal growth of quaternary intermetallic compounds based on rare earth metals. In the first part of this review, we highlight briefly about intermetallics and their versatile properties in comparison to the constituent elements. In the next part, we have discussed about various synthesis techniques with more focus on the metal flux technique towards the well shaped crystal growth of novel compounds. In the subsequent parts, several disordered quaternary compounds have been reviewed and then outlined most known ordered quaternary compounds with their complex structure. A special attention has been given to the ordered compoundsmore » with structural description and relation to the parent binary and ternary compounds. The importance of electronic and structural feature is highlighted as the key roles in designing these materials for emerging applications. - Graphical abstract: Rare earth based quaternary intermetallic compounds crystallize in complex novel crystal structures. The diversity in the crystal structure may induce unique properties and can be considered them as future materials. - Highlights: • Crystal growth and crystal structure of quaternary rare earth based intermetallics. • Structural complexity of quaternary compounds in comparison to the parent compounds. • Novel quaternary compounds display unique crystal structure.« less

Synthesis and structure determination of the novel aluminophosphate TL-1: A new layered compound with corner-sharing AlX{sub 6} chains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pastero, Linda; Interdepartmental Centre “Nanostructured Interfaces and Surfaces-NIS”, Via Quarello 15A, 10135 Torino; CrisDi – Interdepartmental Center for Crystallography, Università di Torino, Via Pietro Giuria 7, I-10125 Torino

2016-10-15

A novel layered aluminophosphate (TL-1) has been synthesized. Crystals grow as pseudo-hexagonal thin platelets and their whole morphology depends on the synthesis conditions. The structure was solved by single-crystal X-ray diffraction using charge flipping methods. The synthesized layered material, with composition [AlPO{sub 4}F(H{sub 2}O)]-(H{sub 10}C{sub 4}ON){sub 4}, crystallizes in the monoclinic space group P2{sub 1}/a with a=9.2282(5) Å, b=6.9152(4) Å, c=14.4615(9) Å, β=101.57(1)°. The novel compound has corner sharing AlO{sub 3}F{sub 2}(H{sub 2}O) octahedral chains running along [010], where fluorine atoms are at the shared apices, three oxygen atoms are shared with PO{sub 4} tetrahedra while the sixth oxygen pertainmore » to an H{sub 2}O molecule. The stability field of the novel material is enclosed in the HF/Al{sub 2}O{sub 3} ratio ranging between 1 and 4 and the HF/morpholine ratio lower than 3. At temperature lower than 190 °C, the synthesis results is a pure aluminophosphate sample (low alumina/morpholine ratio). A treatment with H{sub 2}CO{sub 3} leads to a complete morpholine removal, as shown by in situ Raman spectroscopy. Powder X-ray diffraction reveals that, after morpholine extraction, the material collapses. The collapse is irreversible. - Highlights: • A new layered aluminophosphate was obtained and characterized. • The crystal structure is a sequence of aluminophosphate and organic layers. • The stability field of the new phase was defined by changing chemistry and T. • The templating agent can be removed by using a CO{sub 2} aqueous solution. • The decomposition of the morpholine induce a collapse in the structure.« less

Solid State Division progress report for period ending September 30, 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, P.H.; Hinton, L.W.

1994-08-01

This report covers research progress in the Solid State Division from April 1, 1992, to September 30, 1993. During this period, the division conducted a broad, interdisciplinary materials research program with emphasis on theoretical solid state physics, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. This research effort was enhanced by new capabilities in atomic-scale materials characterization, new emphasis on the synthesis and processing of materials, and increased partnering with industry and universities. The theoretical effort included a broad range of analytical studies, as well as a new emphasismore » on numerical simulation stimulated by advances in high-performance computing and by strong interest in related division experimental programs. Superconductivity research continued to advance on a broad front from fundamental mechanisms of high-temperature superconductivity to the development of new materials and processing techniques. The Neutron Scattering Program was characterized by a strong scientific user program and growing diversity represented by new initiatives in complex fluids and residual stress. The national emphasis on materials synthesis and processing was mirrored in division research programs in thin-film processing, surface modification, and crystal growth. Research on advanced processing techniques such as laser ablation, ion implantation, and plasma processing was complemented by strong programs in the characterization of materials and surfaces including ultrahigh resolution scanning transmission electron microscopy, atomic-resolution chemical analysis, synchrotron x-ray research, and scanning tunneling microscopy.« less

Glycine and metformin as new counter ions for mono and dinuclear vanadium(V)-dipicolinic acid complexes based on the insulin-enhancing anions: Synthesis, spectroscopic characterization and crystal structure

NASA Astrophysics Data System (ADS)

Ghasemi, Fatemeh; Rezvani, Ali Reza; Ghasemi, Khaled; Graiff, Claudia

2018-02-01

Complexes [VO(dipic) (H2O)2]·2H2O (1), [H2Met][V2O4(dipic)2] (2) and [HGly][VO2(dipic)] (3), where H2dipic = 2,6-pyridinedicarboxylic acid, Met = Metformin (N,N-dimethylbiguanide) and Gly = glycine, were synthesized. The three complexes were characterized by elemental analysis, FTIR, 1H and 13C NMR, and UV-Vis spectroscopy. Solid-state structures of (2) and (3) were determined by single-crystal X-ray diffraction analysis. The coordination geometry around the vanadium atoms in 2 is octahedral, while the coordination geometry in 3 is between trigonal bipyramidal and squared pyramidal. In the binuclear complex 2 and mononuclear complex 3, metformin and glycine are diprotonated and monoprotonated respectively, and act as a counter ion. The redox behavior of the complexes was also investigated by cyclic voltammetry.

Synthesis, crystal structure, characterization and antifungal activity of pyrazolo[1,5-a]pyrimidines derivatives

NASA Astrophysics Data System (ADS)

Zhang, Jin; Peng, Ju-Fang; Wang, Tao; Wang, Ping; Zhang, Zun-Ting

2016-09-01

Under microwave radiation, isomers 2-(pyrazolo[1,5-a]pyrimidin-5-yl)phenols (3) and 2-(pyrazolo[1,5-a]pyrimidin-7-yl)phenols (4) were simultaneously obtained by the condensation of chromones and 3-aminopyrazoles. These two isomers were fully characterized by IR, 1H NMR, 13C NMR and HRMS. In addition, a representative product 5-chloro-2-(2-methyl-pyrazolo[1,5-a] pyrimidin-5-yl)phenol (3e) was further conformed by the single crystal X-ray diffraction. The antifungal abilities of the obtained products 3 and 4 were evaluated against five phytopathogenic fungi (Cytospora sp., Colletotrichum gloeosporioides, Botrytis cinerea, Alternaria solani and Fusarium solani). The results revealed that 2-(pyrazolo[1,5-a]pyrimidin-5-yl)phenol (3a) and 4-chloro-2-(2-methylpyrazolo[1,5-a]pyrimidin-7-yl)phenol (4e) exhibited good antifungal abilities against Colletotrichum gloeosporioides with the IC50 values of 24.90 and 28.28 μg/mL, respectively.

Atomic Layer Deposition of Pd Nanoparticles on TiO₂ Nanotubes for Ethanol Electrooxidation: Synthesis and Electrochemical Properties.

PubMed

Assaud, Loïc; Brazeau, Nicolas; Barr, Maïssa K S; Hanbücken, Margrit; Ntais, Spyridon; Baranova, Elena A; Santinacci, Lionel

2015-11-11

Palladium nanoparticles are grown on TiO2 nanotubes by atomic layer deposition (ALD), and the resulting three-dimensional nanostructured catalysts are studied for ethanol electrooxidation in alkaline media. The morphology, the crystal structure, and the chemical composition of the Pd particles are fully characterized using scanning and transmission electron microscopies, X-ray diffraction, and X-ray photoelectron spectroscopy. The characterization revealed that the deposition proceeds onto the entire surface of the TiO2 nanotubes leading to the formation of well-defined and highly dispersed Pd nanoparticles. The electrooxidation of ethanol on Pd clusters deposited on TiO2 nanotubes shows not only a direct correlation between the catalytic activity and the particle size but also a steep increase of the response due to the enhancement of the metal-support interaction when the crystal structure of the TiO2 nanotubes is modified by annealing at 450 °C in air.

Solvothermal synthesis and structure of 3D frameworks of Nd(III) and Y(III) with thiophene-2,5-dicarboxylate and N,N‧-diethylformamide

NASA Astrophysics Data System (ADS)

Sharma, Swati; Yawer, Mohd; Kariem, Mukaddus; Sheikh, Haq Nawaz

2016-08-01

Two new 3D MOFs [Nd2(TDA)3(DEF)2(H2O)]n (1) and [Y4(TDA)6(DEF)4]n (2) [Thiophene-2,5-dicarboxylic acid (H2TDA) and N,N‧-diethylformamide (DEF)] were synthesized by solvothermal method. They were characterized by elemental analyses, infrared spectroscopy and single crystal X-ray diffraction studies. The two MOFs (1) and (2) belong to the monoclinic system with space group P21/n and C 2 respectively. Structural characterizations by single-crystal X-ray crystallography reveal that 1 and 2 adopt three-dimensional frameworks constructed by cross-linking of rod shaped infinite chain secondary building unit (SBU) by thiophene-2,5-dicarboxylates as linker. These frameworks feature rhomboidal channels, inside which coordinated DEF/H2O solvent molecules are located. DEF plays pivotal role in reaction and design of MOFs. Thermogravimetric analysis shows that both MOFs are thermally robust.

Solvothermal synthesis and structural characterization of a three-dimensional metal organic polymer [NaZn(1,2,4-BTC)] (1,2,4-BTC=1,2,4-benzenetricarboxylate)

NASA Astrophysics Data System (ADS)

Wang, Lei; Shi, Zhan; Li, Guanghua; Fan, Yong; Fu, Wensheng; Feng, Shouhua

2004-01-01

A new three-dimensional metal-organic polymer, [NaZn(1,2,4-BTC)] (where 1,2,4-BTC=1,2,4-benzenetricarboxylate), has been prepared under solvothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2 1/ c, with cell parameters: a=9.7706(4) Å, b=12.3549(5) Å, c=6.8897(3) Å, β=91.640(2)°, V=831.35(6) Å 3 and Z=4. In the three-dimensional structure of the compound, each Zn atom is five-coordinated in distorted trigonal bipyramidal geometry, while the sixfold coordination of Na corresponds to a slightly distorted triangular prism. The organic ligand, 1,2,4-BTC, shows a novel and unprecedented coordination mode: 11 bonds to 10 metals with each carboxylate function exhibiting different linkages. It remains stable when desolvated and when heated up to 410 °C.

Solution-Based Synthesis of Crystalline Silicon from Liquid Silane through Laser and Chemical Annealing

DOE PAGES

Iyer, Ganjigunte R. S.; Hobbie, Erik K.; Guruvenket, Srinivasan; ...

2012-05-23

We report a solution process for the synthesis of crystalline silicon from the liquid silane precursor cyclohexasilane (Si 6H 12). Polysilane films were crystallized through thermal and laser annealing, with plasma hydrogenation at atmospheric pressure generating further structural changes in the films. The evolution from amorphous to microcrystalline is characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy and impedance spectroscopy. A four-decade enhancement in the electrical conductivity is attributed to a disorder-order transition in a bonded Si network. Lastly, our results demonstrate a potentially attractive approach that employs a solution process coupled with ambient post-processing tomore » produce crystalline silicon thin films.« less

Influence of Synthesis Temperature on the Growth and Surface Morphology of Co₃O₄ Nanocubes for Supercapacitor Applications.

PubMed

Samal, Rashmirekha; Dash, Barsha; Sarangi, Chinmaya Kumar; Sanjay, Kali; Subbaiah, Tondepu; Senanayake, Gamini; Minakshi, Manickam

2017-10-31

A facile hydrothermal route to control the crystal growth on the synthesis of Co₃O₄ nanostructures with cube-like morphologies has been reported and tested its suitability for supercapacitor applications. The chemical composition and morphologies of the as-prepared Co₃O₄ nanoparticles were extensively characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Varying the temperature caused considerable changes in the morphology, the electrochemical performance increased with rising temperature, and the redox reactions become more reversible. The results showed that the Co₃O₄ synthesized at a higher temperature (180 °C) demonstrated a high specific capacitance of 833 F/g. This is attributed to the optimal temperature and the controlled growth of nanocubes.

Synthesis and characterization of poly(3-sulfopropylmethacrylate) brushes for potential antibacterial applications.

PubMed

Ramstedt, Madeleine; Cheng, Nan; Azzaroni, Omar; Mossialos, Dimitris; Mathieu, Hans Jörg; Huck, Wilhelm T S

2007-03-13

This article describes the aqueous atom transfer radical polymerization synthesis of poly(3-sulfopropylmethacrylate) brushes onto gold and Si/SiO2 surfaces in a controlled manner. The effect of Cu(I)/Cu(II) ratio was examined, and a quartz crystal microbalance was used to study the kinetics of the brush synthesis. The synthesized brushes displayed a thickness from a few nanometers to several hundred nanometers and were characterized using atomic force microscopy, ellipsometry, Fourier transform infrared spectroscopy (FTIR), contact angle measurements, and X-ray photoelectron spectroscopy (XPS). The as-synthesized sulfonate brushes had very good ion-exchange properties for the ions tested in this study, i.e., Na+, K+, Cu2+, and Ag+. FTIR and XPS show that the metal ions are coordinating to sulfonate moieties inside the brushes. The brushes were easily loaded with silver ions, and the effect of silver ion concentration on silver loading of the brush was examined. The silver-loaded brushes were shown to be antibacterial toward both gram negative and gram positive bacteria. The silver leaching was studied through leaching experiments into water, NaNO3, and NaCl (physiological medium). The results from these leaching experiments are compared and discussed in the article.

Synthesis, structural characterization, Hirshfeld surface analysis and spectroscopic studies of cadmium (II) chloride complex with 4-hydroxy-1-methylpiperidine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soudani, S.; Ferretti, V.; Jelsch, C.

The chemical preparation, crystal structure, Hirshfeld surface analysis and spectroscopic characterization of the novel cadmium (II) 4-hydroxy-1-methylpiperidine complex, Cd{sub 4}Cl{sub 10}(C{sub 6}H{sub 14}NO){sub 2}·2H{sub 2}O, have been reported. The atomic arrangement can be described as built up by an anionic framework, formed by edge sharing CdCl{sub 6} and CdCl{sub 5}O octahedral linear chains spreading along the a-axis. These chains are interconnected by water molecules via O–H⋯Cl and O–H⋯O hydrogen bonds to form layers parallel to (011) plane. The organic cations are inserted between layers through C–H⋯Cl hydrogen bonds. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis revealsmore » that the H{sub C}⋯Cl and H{sub C}⋯H{sub C} intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The statistical analysis of crystal contacts reveals the driving forces in the packing formation. The {sup 13}C and {sup 15}N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.« less

Structural variability in neptunium(V) oxalate compounds: synthesis and structural characterization of Na2NpO2(C2O4)OH.H2O.

PubMed

Bean, Amanda C; Garcia, Eduardo; Scott, Brian L; Runde, Wolfgang

2004-10-04

Reaction of a (237)Np(V) stock solution in the presence of oxalic acid, calcium chloride, and sodium hydroxide under hydrothermal conditions produces single crystals of a neptunium(V) oxalate, Na(2)NpO(2)(C(2)O(4))OH.H(2)O. The structure consists of one-dimensional chains running down the a axis and is the first example of a neptunium(V) oxalate compound containing hydroxide anions.

Sonochemical synthesis and structural characterization of a new Zn(II) nanoplate metal-organic framework with removal efficiency of Sudan red and Congo red.

PubMed

Abdollahi, Nasrin; Masoomi, Mohammad Yaser; Morsali, Ali; Junk, Peter C; Wang, Jun

2018-07-01

A 3-D Zn(II) based metal-organic framework (MOF) of [Zn 4 (oba) 3 (DMF) 2 ] was synthesized using the nonlinear dicarboxylate ligand, 4,4'-oxybis(benzoic acid) (H 2 oba) via sonochemical and solvothermal routes. IR spectroscopy, single-crystal X-ray crystallography, scanning electron microscopy, and X-ray powder diffraction were used to characterize these MOF samples. The effect of different times of irradiation and various concentrations of primary reagents were experimented for obtaining monotonous morphology. The results show that uniform nanoplates can be achieved by increasing the time of irradiation and decreasing the concentration. N 2 adsorption was applied to examine the effect of synthesis method on porosity of the framework. Also Congo red and Sudan red dyes were employed to explore the efficiency of this MOF in removal of the dye pollutants. Copyright © 2018 Elsevier B.V. All rights reserved.

Preparation and characterization of carbon nanofluid by a plasma arc nanoparticles synthesis system

PubMed Central

2011-01-01

Heat dissipation from electrical appliances is a significant issue with contemporary electrical devices. One factor in the improvement of heat dissipation is the heat transfer performance of the working fluid. In this study, we used plasma arc technology to produce a nanofluid of carbon nanoparticles dispersed in distilled water. In a one-step synthesis, carbon was simultaneously heated and vaporized in the chamber, the carbon vapor and particles were then carried to a collector, where cooling furnished the desired carbon/water nanofluid. The particle size and shape were determined using the light-scattering size analyzer, SEM, and TEM. Crystal morphology was examined by XRD. Finally, the characterization include thermal conductivity, viscosity, density and electric conductivity were evaluated by suitable instruments under different temperatures. The thermal conductivity of carbon/water nanofluid increased by about 25% at 50°C compared to distilled water. The experimental results demonstrated excellent thermal conductivity and feasibility for manufacturing of carbon/water nanofluids. PMID:21711828

Synthesis and spectral studies on Cd(II) dithiocarbamate complexes and their use as precursors for CdS nanoparticles

NASA Astrophysics Data System (ADS)

Sathiyaraj, Ethiraj; Padmavathy, Krishnaraj; Kumar, Chandran Udhaya; Krishnan, Kannan Gokula; Ramalingan, Chennan

2017-11-01

Bis(N-cyclopropyl-N-4-chlorobenzyldithiocarbamato-S,S‧)cadmium(II) (1) and (2,2‧-bipyridine) bis(N-cyclopropyl-N-4-chlorobenzyldithiocarbamato-S,S‧)cadmium(II) (2) have been synthesized and characterized by FT-IR, 1HNMR and 13C NMR analyses. For the complex 2, single crystal X-ray diffraction analysis and computational studies (optimized geometry, HOMO-LUMO and MEP) have been executed employing DFT/B3LYP method with LANL 2DZ basic set. The optimized bond lengths and bond angles agree well with the experimental results. The complexes 1 and 2 have been used as single source precursors for the synthesis of ethyleneglycol capped CdS1 and CdS2 nanoparticles, respectively. CdS1 and CdS2 nanoparticles have been synthesized by solvothermal method. PXRD, SEM, Elemental colour mapping, EDAX, TEM and UV-Vis spectroscopy have been used to characterize the as-prepared CdS nanoparticles. The X-ray diffraction pattern confirms both their hexagonal structures.

Synthesis, growth, structural, optical, spectral, thermal and mechanical studies of 4-methoxy 4-nitrostilbene (MONS): a new organic nonlinear optical single crystal.

PubMed

Dinakaran, Paul M; Bhagavannarayana, G; Kalainathan, S

2012-11-01

4-Methoxy 4-nitrostilbene (MONS), a new organic nonlinear optical material has been synthesized. Based on the solubility data good quality single crystal with dimensions up to 38×11×3 mm(3) has been grown by slow evaporation method using ethyl methyl ketone (MEK) as a solvent. Powder XRD confirms the crystalline property and also the diffraction planes have been indexed. The lattice parameters for the grown MONS crystals were determined by using single crystal X-ray diffraction analysis and it reveals that the crystal lattice system is triclinic. The crystalline perfection of the grown crystals has been analysed by high resolution X-ray diffraction (HRXRD) rocking curve measurements. Fourier transform infrared (FTIR) spectrum for powdered MONS sample confirms the functional groups present in the grown crystal. The UV-vis absorption spectrum has been recorded in the range of 190-1100 nm and the cut off wavelength 499 nm has been determined. The optical constants of MONS have been determined through UV-vis-NIR spectroscopy. The MONS crystals were further subjected to other characterizations. i.e., (1)H NMR, TG/DTA, photoluminescence and microhardness test. The Kurtz and Perry powder technique confirms the NLO property of the grown crystal and the SHG efficiency of MONS was found to be 1.55× greater than that of KDP crystal. Copyright © 2012 Elsevier B.V. All rights reserved.

Silver nanostructures from Ag(CN) 2 - reduction by citrate ions in the presence of dodecyl sulfate and Cu2+ ions. Synthesis and characterization

NASA Astrophysics Data System (ADS)

López-Miranda, A.; Viramontes-Gamboa, G.; López-Valdivieso, A.

2014-02-01

The synthesis of silver nanoparticles has been investigated using Ag(CN) 2 - species as precursor, citrate ions as reducing agent, and dodecyl sulfate ions as stabilizer, at pH 11 and 97 °C, in a batch stirred glass reactor. The role of Cu2+ ions in the synthesis was also studied. Bird- of- paradise flower-type nanostructures composed of AgCN nanowires having inside Ag and AgCN nanoparticles were produced in the absence of Cu2+ ions. The nanostructures slowly grew and transformed to AgCN nanowires with embedded Ag and AgCN nanoparticles, having a mean size of 9.7 ± 3.6 nm. The presence of Cu2+ ions in the synthesis significantly enhanced the production of the nanostructures. Nanowires having a thickness of 63 ± 33 nm and length of up to 20 μm were produced. Cu2+ ions also simultaneously lead to the synthesis of ordinary free Ag nanoparticles with a bimodal size distribution (mean sizes of 9.9 ± 3.9 and 65.5 ± 27 nm) and a low experimental formation kinetic rate constant of 1.22 × 10-4 s-1. Feasible mechanisms are presented for the origin of the AgCN nanowires, Ag and AgCN nanoparticles inside the nanowires, and for the free Ag nanoparticles. UV/Vis spectrometry was used to measure the surface plasmon resonance of the nanoparticles and the synthesis kinetic rate constant of the free Ag nanoparticles. ATR-FTIR spectroscopy, EDS-SEM, EDS-TEM, and HRTEM were used to characterize the size, crystal structure, texture, and chemical composition of the synthesis products.

The effect of B{sub 2}O{sub 3} flux on growth NLBCO superconductor by solid state reaction and wet-mixing methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suharta, W. G., E-mail: wgsuharta@gmail.com; Wendri, N.; Ratini, N.

The synthesis of B{sub 2}O{sub 3} flux substituted NLBCO superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} has been done using solid state reaction and wet-mixing methods in order to obtain homogeneous crystals and single phase. From DTA/TGA characteritations showed the synthesis process by wet-mixing requires a lower temperature than the solid state reaction in growing the superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂}. Therefore, in this research NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} sample calcinated at 650°C for wet-mixing method and 820°C for solid state reaction methods. The all samples was sintered at 950°C for ten hours. Crystallinity of the sample was confirmedmore » using X-ray techniques and generally obtained sharp peaks that indicates the sample already well crystallized. Search match analyses for diffraction data gave weight fractions of impurity phase of the solid state reaction method higher than wet-mixing method. In this research showed decreasing the price of the lattice parameter about 1% with the addition of B{sub 2}O{sub 3} flux for the both synthesis process and 2% of wet mixing process for all samples. Characterization using scanning electron microscopy (SEM) showed the distribution of crystal zise for wet-mixing method more homogeneous than solid state reaction method, with he grain size of samples is around 150–250 nm. The results of vibrating sample magnetometer (VSM) showed the paramagnetic properties for all samples.« less

Enhanced oxidation stability of quasi core-shell alloyed CdSeS quantum dots prepared through aqueous microwave synthesis technique.

PubMed

Zhan, Hong-Ju; Zhou, Pei-Jiang; Ma, Rong; Liu, Xi-Jing; He, Yu-Ning; Zhou, Chuan-Yun

2014-01-01

Quasi core shell alloyed CdSeS quantum dots (QDs) have been prepared through a facile aqueous-phase route employing microwave irradiation technique. The optical spectroscopy and structure characterization evidenced the quasi core shell alloyed structures of CdSeS QDs. The X-ray diffraction patterns of the obtained CdSeS QDs displayed peak positions very close to those of bulk cubic CdS crystal structures and the result of X-ray photoelectron spectroscopy data re-confirmed the thick CdS shell on the CdSe core. The TEM images and HRTEM images of the CdSeS QDs ascertained the well-defined spherical particles and a relatively narrow size distribution. On the basis, the stability of the obtained QDs in an oxidative environment was also discussed using etching reaction by H2O2. The experiments result showed the as-prepared QDs present high tolerance towards H2O2, obviously superior to the commonly used CdTe QDs and core-shell CdTe/CdS QDs, which was attributed to the unique quasi core-shell CdSeS crystal structure and the small lattice mismatch between CdSe and CdS semiconductor materials. This assay provided insight to obtain high stable crystal structured semiconductor nanocrystals in the design and synthesis process.

Large-scale preparation of shape controlled SnO and improved capacitance for supercapacitors: from nanoclusters to square microplates

NASA Astrophysics Data System (ADS)

Wang, Lu; Ji, Hongmei; Zhu, Feng; Chen, Zhi; Yang, Yang; Jiang, Xuefan; Pinto, João; Yang, Gang

2013-07-01

Here, we first provide a facile ultrasonic-assisted synthesis of SnO using SnCl2 and the organic solvent of ethanolamine (ETA). The moderate alkalinity of ETA and ultrasound play very important roles in the synthesis of SnO. After the hydrolysis of the intermediate of ETA-Sn(ii), the as-synthesized SnO nanoclusters undergo assembly, amalgamation, and preferential growth to microplates in hydrothermal treatment. The as-synthesized SnO was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray diffraction (XRD). To explore its potential applications in energy storage, SnO was fabricated into a supercapacitor electrode and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The as-synthesized SnO exhibits remarkable pseudocapacitive activity including high specific capacitance (208.9 F g-1 at 0.1 A g-1), good rate capability (65.8 F g-1 at 40 A g-1), and excellent cycling stability (retention 119.3% after 10 000 cycles) for application in supercapacitors. The capacitive behavior of SnO with various crystal morphologies was observed by fitted EIS using an equivalent circuit. The novel synthetic route for SnO is a convenient and potential way to large-scale production of microplates which is expected to be applicable in the synthesis of other metal oxide nanoparticles.Here, we first provide a facile ultrasonic-assisted synthesis of SnO using SnCl2 and the organic solvent of ethanolamine (ETA). The moderate alkalinity of ETA and ultrasound play very important roles in the synthesis of SnO. After the hydrolysis of the intermediate of ETA-Sn(ii), the as-synthesized SnO nanoclusters undergo assembly, amalgamation, and preferential growth to microplates in hydrothermal treatment. The as-synthesized SnO was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray diffraction (XRD). To explore its potential applications in energy storage, SnO was fabricated into a supercapacitor electrode and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The as-synthesized SnO exhibits remarkable pseudocapacitive activity including high specific capacitance (208.9 F g-1 at 0.1 A g-1), good rate capability (65.8 F g-1 at 40 A g-1), and excellent cycling stability (retention 119.3% after 10 000 cycles) for application in supercapacitors. The capacitive behavior of SnO with various crystal morphologies was observed by fitted EIS using an equivalent circuit. The novel synthetic route for SnO is a convenient and potential way to large-scale production of microplates which is expected to be applicable in the synthesis of other metal oxide nanoparticles. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00951c

One dimensional coordination polymers: Synthesis, crystal structures and spectroscopic properties

NASA Astrophysics Data System (ADS)

Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla; Şenyel, Mustafa; Şahin, Onur

2016-11-01

Two new one dimensional (1D) cyanide complexes, namely [M(4-aepy)2(H2O)2][Pt(CN)4], (4-aepy = 4-(2-aminoethyl)pyridine M = Cu(II) (1) or Zn(II) (2)), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. The crystallographic analyses reveal that 1 and 2 are isomorphous and isostructural, and crystallize in the monoclinic system and C2 space group. The Pt(II) ions are coordinated by four cyanide-carbon atoms in the square-planar geometry and the [Pt(CN)4]2- ions act as a counter ion. The M(II) ions display an N4O2 coordination sphere with a distorted octahedral geometry, the nitrogen donors belonging to four molecules of the organic 4-aepy that act as unidentate ligands and two oxygen atoms from aqua ligands. The crystal structures of 1 and 2 are similar each other and linked via intermolecular hydrogen bonding, Pt⋯π interactions to form 3D supramolecular network. Vibration assignments of all the observed bands are given and the spectral features also supported to the crystal structures of the complexes.

Crystal growth methods dedicated to low solubility actinide oxalates

NASA Astrophysics Data System (ADS)

Tamain, C.; Arab-Chapelet, B.; Rivenet, M.; Grandjean, S.; Abraham, F.

2016-04-01

Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am2(C2O4)3(H2O)3·xH2O, Th(C2O4)2·6H2O, M2+x[PuIV2-xPuIIIx(C2O4)5]·nH2O and M1-x[PuIII1-xPuIVx(C2O4)2·H2O]·nH2O. It is the first time that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV-visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds.

Synthesis, crystal structure, Hirshfeld surfaces analysis and anti-ischemic activity of cinnamide derivatives

NASA Astrophysics Data System (ADS)

Zhong, Jian-gang; Han, Jia-pei; Li, Xiao-feng; Xu, Yi; Zhong, Yan; Wu, Bin

2018-02-01

Two cinnamide derivatives, namely, (E)-1-(4-(bis(4-methylphenyl)- methyl)piperazin-1-yl)-3-(3,4-diethoxyphenyl)prop-2-en-1-one (5) and (E)-1-(4-(bis- (4-fluorophenyl)methyl)piperazin-1-yl)-3-(4-methoxyphenyl)prop-2-en-1-one (6), have been synthesized and characterized by IR spectra, High resolution mass spectra, 1H NMR spectra, 13C NMR spectra. The compound 5 is a novel compound and has never been reported in the literature. Their crystal structures were studied by single-crystal X-ray diffraction. They all crystallize in the monoclinic system. The single-crystal X-ray revealed that compound 5 has infinite X-shaped 1-D polymeric chains structure and compound 6 has a layered 3-D structure by intermolecular interactions. Hirshfeld surface analysis demonstrated the presence of H⋯H, O⋯H, C⋯H, F⋯H, Csbnd H⋯π and π⋯π intermolecular interactions. In addition, the MTT assay results indicated that the compounds 5 and 6 display effective activities against neurotoxicity which is induced by glutamine in PC12 cells. The in vivo experiment indicated that the compound 6 has a good protective effect on cerebral infarction.

Synthesis, properties and crystal structure of (Gly) 2H 4SiW 12O 40·5.5H 2O

NASA Astrophysics Data System (ADS)

Lihua, Bi; Qizhuang, He; Qiong, Jia; Enbo, Wang

2001-10-01

A novel polyoxometalate containing Glycine (Gly), (Gly)2H4SiW12O40·5.5H2O (I), has been synthesized and characterized by single-crystal X-ray diffraction, elemental analyzes, IR spectrum, cyclic voltammograms and thermogravimetric analysis. The compound crystallizes in the monoclinic space group C2/C with a=40.362 (8) Å, b=12.478 (3) Å, c=19.879 (4) Å, β=96.22 (3)°, V=9953 (4) Å3, Z=8 and R1 (wR2)=0.0699 (0.1609). The crystal structure consists of [SiW12O40]4- units linked together with Gly molecules through hydrogen bonding. The electrochemical properties of I showed that the electrode reaction is surface-controlled. The compound has photosensitivity under irradiation of sunlight to result in charge transfer by oxidation of Gly and the reduction of SiW12O404-. We also found that the compound exhibited effectiveness in preventing cucumber mosaic virus (CMV).

A Deuterium NMR Study of Bent-Core Liquid Crystals. 1; Synthesis and Characterization of Deuterium-Labeled Oxadiazole-Containing Liquid Crystals

NASA Technical Reports Server (NTRS)

Dingemans, Theo J.; Madsen, Louis A.; Samulski, Edward T.; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

We have synthesized two deuterated boomerang-shaped liquid crystals based on 2,5-bis(4-hydroxyphenyl)-1,3,4-oxadiazole (ODBP). Deuterium was introduced in the rigid 2,5-diphenyl-1,3,4-oxadiazole core and in the aromatic ring of the terminal 4-dodecyloxyphenyl moiety using standard acid catalyzed deuterium exchange conditions. Both compounds, ([4,4'(1,3,4-oxadiazole-2,5-diyl-d4)] di-4-dodecyloxybenzoate: ODBP-d4-Ph-O-C12) and ([4,4'(1,3,4-oxadiazole-2,5-diyl)] di-4-dodecyloxy-benzoate-d4; ODBP-Ph-d4-O-C12) were investigated by nuclear magnetic resonance, optical microscopy and differential scanning calorimetry. The optical textures and thermal behavior of both compounds were found to be identical to the non-deuterated analog [4,4(1,3,4-oxadiazole-2,5-diyl)] di-4-dodecyloxybenzoate (ODBP-Ph-O-C12) which we reported earlier. These compounds exhibit behavior indicative of a biaxial nematic liquid crystal phase, which we hope to confirm using deuterium NMR spectroscopy in the next phase of this study.

Synthesis, structural characterization, and DFT calculations of 3-buthyl-4-(3-methyl-3-mesitylcyclobut-1-yl)-1,3-thiazole-2(3H)-thione

DOE Office of Scientific and Technical Information (OSTI.GOV)

Şen, B.; Barim, E.; Kirilmis, C.

2016-03-15

The title compound, C{sub 21}H{sub 29}NS{sub 2}, has been synthesized and its crystal structure has been determined from single crystal X-ray diffraction data. Crystals are monoclinic, a = 11.4923(8), b = 13.1842(7), c = 14.6583(8) Å, β = 109.983(6)°, sp. gr. P2{sub 1}/c, Z = 4. Mesityl and thiazole groups are in cis positions with respect to the cyclobutane ring. The cyclobutane ring is puckered, with a dihedral angle of 26.6(2)° between the two three-atom planes. The crystal structure involves one weak intermolecular C–H···S hydrogen-bond. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d,more » p) basis set in ground state. Geometric parameters (bond lengths, bond angles and torsion angles) and vibrational assignments have been calculated theoretically and compared with the experimental data.« less

Synthesis and crystal structure of imidazole containing amide as a turn on fluorescent probe for nickel ion in aqueous media. An experimental and theoretical investigation

NASA Astrophysics Data System (ADS)

Annaraj, B.; Mitu, L.; Neelakantan, M. A.

2016-01-01

Imidazole containing amide fluorescence probe (PAIC) for Ni2+ was designed and successfully synthesized in good yield by reaction between 1-methyl-1H-imidazole-2-carboxylic acid and L-phenylalanine methyl ester. The probe was characterized by FTIR, 1H NMR, ESI-MS, UV-vis and fluorescence spectroscopy. Single crystal XRD analysis reveals that PAIC crystallizes in a monoclinic crystal lattice system with the space group of P21/n. Chemosensor property of PAIC was tested against different metal ions by UV-vis and fluorescent techniques in aqueous medium. Test results show that PAIC has high selectivity for Ni2+ compared to other metal ions (Na+, K+, Ca2+, Ag+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Zn2+ and Pb2+). Time-dependent density functional theory (TD-DFT) and configuration interaction singles (CIS) calculations were carried out to understand the sensing mechanism. The practical applicability of PAIC was tested in real water samples.

Synthesis, antityrosinase activity of curcumin analogues, and crystal structure of (1 E,4 E)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one

NASA Astrophysics Data System (ADS)

Chantrapromma, S.; Ruanwas, P.; Boonnak, N.; Chantrapromma, K.; Fun, H.-K.

2016-12-01

Five derivatives of curcumin analogue ( R = OCH2CH3 ( 1), R = N(CH3)2 ( 2), R = 2,4,5-OCH3 ( 3), R = 2,4,6-OCH3 ( 4), and R = 3,4,5-OCH3 ( 5)) were synthesized and characterized by 1H NMR, FT-IR and UV-Vis spectroscopy. The synthesized derivatives were screened for antityrosinase activity, and found that 4 and 5 possess such activity. The crystal structure of 1 was determined by single crystal X-ray diffraction: monoclinic, sp. gr. P21/ c, a = 17.5728(15) Å, b = 5.9121(5) Å, c = 19.8269(13) Å, β = 121.155(5)°, Z = 4. The molecule 1 is twisted with the dihedral angle between two phenyl rings being 15.68(10)°. In the crystal packing, the molecules 1 are linked into chains by C-H···π interactions and further stacked by π···π interactions with the centroid-centroid distance of 3.9311(13) Å.

Reticular synthesis of porous molecular 1D nanotubes and 3D networks.

PubMed

Slater, A G; Little, M A; Pulido, A; Chong, S Y; Holden, D; Chen, L; Morgan, C; Wu, X; Cheng, G; Clowes, R; Briggs, M E; Hasell, T; Jelfs, K E; Day, G M; Cooper, A I

2017-01-01

Synthetic control over pore size and pore connectivity is the crowning achievement for porous metal-organic frameworks (MOFs). The same level of control has not been achieved for molecular crystals, which are not defined by strong, directional intermolecular coordination bonds. Hence, molecular crystallization is inherently less controllable than framework crystallization, and there are fewer examples of 'reticular synthesis', in which multiple building blocks can be assembled according to a common assembly motif. Here we apply a chiral recognition strategy to a new family of tubular covalent cages to create both 1D porous nanotubes and 3D diamondoid pillared porous networks. The diamondoid networks are analogous to MOFs prepared from tetrahedral metal nodes and linear ditopic organic linkers. The crystal structures can be rationalized by computational lattice-energy searches, which provide an in silico screening method to evaluate candidate molecular building blocks. These results are a blueprint for applying the 'node and strut' principles of reticular synthesis to molecular crystals.

Reticular synthesis of porous molecular 1D nanotubes and 3D networks

NASA Astrophysics Data System (ADS)

Slater, A. G.; Little, M. A.; Pulido, A.; Chong, S. Y.; Holden, D.; Chen, L.; Morgan, C.; Wu, X.; Cheng, G.; Clowes, R.; Briggs, M. E.; Hasell, T.; Jelfs, K. E.; Day, G. M.; Cooper, A. I.

2017-01-01

Synthetic control over pore size and pore connectivity is the crowning achievement for porous metal-organic frameworks (MOFs). The same level of control has not been achieved for molecular crystals, which are not defined by strong, directional intermolecular coordination bonds. Hence, molecular crystallization is inherently less controllable than framework crystallization, and there are fewer examples of 'reticular synthesis', in which multiple building blocks can be assembled according to a common assembly motif. Here we apply a chiral recognition strategy to a new family of tubular covalent cages to create both 1D porous nanotubes and 3D diamondoid pillared porous networks. The diamondoid networks are analogous to MOFs prepared from tetrahedral metal nodes and linear ditopic organic linkers. The crystal structures can be rationalized by computational lattice-energy searches, which provide an in silico screening method to evaluate candidate molecular building blocks. These results are a blueprint for applying the 'node and strut' principles of reticular synthesis to molecular crystals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Shuguang, E-mail: hustcsg@sohu.com; Zeng Kai; Li Haibin

Dispersed rhombohedral NiS rods with high aspect ratios and rhombic dodecahedron-like cubic NiS{sub 2} crystals were prepared by solvothermal routes using NiCl{sub 2}.6H{sub 2}O and Na{sub 2}S{sub 2}O{sub 3}.5H{sub 2}O as reagents and ethylenediamine as a solvent, and 3D blossoming flower-like rhombohedral NiS microstructures were synthesized using different sulfur sources of thiourea. The products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersion spectrometry and selected area electronic diffraction. All the products were pure and had good single crystalline nature. The synthesis parameters were of great importance on the purity and morphology of themore » products. The possible growth mechanisms have been discussed based on the analyses of the effects of sulfur sources and solvent on the crystal structures and detailed configurations of the products. The present work is likely to help the phase-controlled synthesis of other metal chalcogenides. - Graphical abstract: Rhombohedral NiS dispersed rods and 3D flower-like microstructures are evolved from dispersed nucleus and aggregate of nucleus, respectively, and the cross-sections of such rods are in equilateral triangle-like shape. Highlights: > 3D blossoming flower-like r-NiS microstructures are obtained. > Equilateral triangle-like cross-sections of r-NiS rods are observed. > Approach based on XRD analysis to phase-controlled synthesis is presented.« less

Cationic metal complex, carbonatobis(1,10-phenanthroline)cobalt(III) as anion receptor: Synthesis, characterization, single crystal X-ray structure and packing analysis of [Co(phen) 2CO 3](3,5-dinitrobenzoate)·5H 2O

NASA Astrophysics Data System (ADS)

Sharma, Raj Pal; Singh, Ajnesh; Brandão, Paula; Felix, Vitor; Venugopalan, Paloth

2009-03-01

To explore the potential of [Co(phen) 2CO 3] + as anion receptor, red coloured single crystals of [Co(phen) 2CO 3](dnb)·5H 2O (dnb = 3,5-dinitrobenzoate) were obtained by recrystallizing the red microcrystalline product synthesised by the reaction of carbonatobis (1,10-phenanthroline)cobalt(III)chloride with sodium salt of 3,5-dinitrobenzoic acid in aqueous medium (1:1 molar ratio). The newly synthesized complex salt has been characterized by elemental analysis, spectroscopic studies (IR, UV/visible, 1H and 13C NMR), solubility and conductance measurements. The complex salt crystallizes in the triclinic crystal system with space group P1¯, having the cell dimensions a = 10.3140(8), b = 12.2885(11), c = 12.8747(13), α = 82.095(4), β = 85.617(4), γ = 79.221(4)°, V = 1585.6(2) Å 3, Z = 2. Single crystal X-ray structure determination revealed ionic structure consisting of cationic carbonatobis(1,10-phenanthroline)cobalt(III), dnb anion and five lattice water molecule. In the complex cation [Co(phen) 2CO 3] +, the cobalt(III) is bonded to four nitrogen atoms, originating from two phenanthroline ligands and two oxygen atoms from the bidentate carbonato group showing an octahedral geometry around cobalt(III) center. Supramolecular networks between ionic groups [ CHphen+⋯Xanion-] by second sphere coordination i.e. C sbnd H⋯O (benzoate), C sbnd H⋯O (nitro), C sbnd H⋯O (water) besides electrostatic forces of attraction alongwith π-π interactions stabilize the crystal lattice.

Ultrasonic-assisted synthesis of monodisperse single-crystalline silver nanoplates and gold nanorings.

PubMed

Jiang, Li-Ping; Xu, Shu; Zhu, Jian-Min; Zhang, Jian-Rong; Zhu, Jun-Jie; Chen, Hong-Yuan

2004-09-20

A simple sonochemical route was developed for the crystal growth of uniform silver nanoplates and ringlike gold nanocrystals in a N,N-dimethylformamide solution. The platelike structures were generated from the selective growth on different crystal planes in the presence of poly(vinylpyrrolidone) and the ultrasonic-assisted Ostwald ripening processes. The silver nanoplates in solution served as the templates for the synthesis of ringlike gold crystals via a displacement reaction. Both the silver nanoplates and gold nanorings were highly oriented single crystals with (111) planes as the basal planes. Copyright 2004 American Chemical Society

Racemic & quasi-racemic protein crystallography enabled by chemical protein synthesis.

PubMed

Kent, Stephen Bh

2018-04-04

A racemic protein mixture can be used to form centrosymmetric crystals for structure determination by X-ray diffraction. Both the unnatural d-protein and the corresponding natural l-protein are made by total chemical synthesis based on native chemical ligation-chemoselective condensation of unprotected synthetic peptide segments. Racemic protein crystallography is important for structure determination of the many natural protein molecules that are refractory to crystallization. Racemic mixtures facilitate the crystallization of recalcitrant proteins, and give diffraction-quality crystals. Quasi-racemic crystallization, using a single d-protein molecule, can facilitate the determination of the structures of a series of l-protein analog molecules. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis, spectral characterization, and single crystal structure studies of (2-nitro-ethene-1,1-diyl)-bis-((4-isopropyl-benzyl)sulfane)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakthikumar, L., E-mail: lsakthisbk@gmail.com; Mahalakshmy, R.; Bhargavi, G.

2015-12-15

The title compound (2-nitro-ethene-1,1-diyl)-bis-(4-isopropylbenzyl)sulfane) (5), was synthesised using a two step process. The structure of the product (5) was established by UV, FT-IR, {sup 1}H NMR, {sup 13}C NMR, C,H,N analysis, LC-MS and single crystal X-ray diffraction analysis. The single crystal of the title compound (5) was crystallized in Monoclinic with the space group of P21/c. The crystal exhibit the following unit cell parameters a = 12.8165(18), b = 6.1878(6), c = 27.082(4) Å, β = 90.705(17)°, V = 2147.6(5) A{sup 3}, Z = 4, D{sub x} = 1.242 Mg/m{sup 3} and the molecular formula of C{sub 22}H{sub 27}N{sub 1}O{submore » 2}S{sub 2} was found. The final R value was 0.0776. The crystal structure is stabilized by an interesting intramolecular push and pull five membered electrocyclic interaction between the O1–N1–C2–C1–S1- and via the intermolecular H-bonding interaction between C2–H2···O2.« less

Precursor routes to quaternary intermetallics: Synthesis, crystal structure, and physical properties of clathrate-II Cs8Na16Al24Si112

NASA Astrophysics Data System (ADS)

Wei, Kaya; Dong, Yongkwan; Nolas, George S.

2016-05-01

A new quaternary clathrate-II composition, Cs8Na16Al24Si112, was synthesized by kinetically controlled thermal decomposition (KCTD) employing both NaSi and NaAlSi as the precursors and CsCl as a reactive flux. The crystal structure and composition of Cs8Na16Al24Si112 were investigated using both Rietveld refinement and elemental analysis, and the temperature dependent transport properties were investigated. Our results indicate that KCTD with multiple precursors is an effective method for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques.

Synthesis and characterization of high surface area TiO 2/SiO 2 mesostructured nanocomposite

NASA Astrophysics Data System (ADS)

Bonne, Magali; Pronier, Stéphane; Can, Fabien; Courtois, Xavier; Valange, Sabine; Tatibouët, Jean-Michel; Royer, Sébastien; Marécot, Patrice; Duprez, Daniel

2010-06-01

Recently titania synthesis was reported using various structuration procedures, leading to the production of solid presenting high surface area but exhibiting moderate thermal stability. The study presents the synthesis of TiO 2/SiO 2 nanocomposites, a solid that can advantageously replace bulk titania samples as catalyst support. The silica host support used for the synthesis of the nanocomposite is a SBA-15 type silica, having a well-defined 2D hexagonal pore structure and a large pore size. The control of the impregnation media is important to obtain dispersed titania crystals into the porosity, the best results have been obtained using an impregnation in an excess of solvent. After calcination at low temperature (400 °C), nanocomposites having titania nanodomains (˜2-3 nm) located inside the pores and no external aggregates visible are obtained. This nanocomposite exhibits high specific surface area (close to that of the silica host support, even with a titania loading of 55 wt.%) and a narrow pore size distribution. Surprisingly, the increase in calcination temperature up to 800 °C does not allow to detect the anatase to rutile transition. Even at 800 °C, the hexagonal mesoporous structure of the silica support is maintained, and the anatase crystal domain size is evaluated at ˜10 nm, a size close to that of the silica host support porosity (8.4 nm). Comparison of their physical properties with the results presented in literature for bulk samples evidenced that these TiO 2/SiO 2 solids are promising in term of thermal stability.

Synthesis and crystal structure of a novel Mn(II) coordination polymer with 3-(4-(1H-benzo[d]imidazol-1-yl)-4-methoxyphenyl)-1-phenylprop-2-en-1-one ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G.-F., E-mail: wgf1979@126.com; Zhang, X., E-mail: zhangx@hit.edu.cn; Sun, S.-W., E-mail: s-shuwen@163.com

3-(4-(1H-Benzo[d]imidazol-1-yl)-4-methoxyphenyl)-1-phenylprop-2-en-1-one (L{sup 1}, 1) and its Mn(II) complex, [Mn(L{sup 1}){sub 2}(SCN){sub 2}]{sub ∞} (2), were synthesized and characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. The Mn(II) ion in 2 is six-coordinated to four nitrogen atoms of two L{sup 1} ligands, two SCN-ligands, and two oxygen atoms of other two L{sup 1} ligands to form a distorted octahedral geometry. Therefore, each L{sup 1} links Mn ions through the O and N atoms to generate 2D sheet structure.

Synthesis and characterization of high-quality cobalt vanadate crystals and their applications in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Bhuiyan, Md. Tofajjol Hossen; Rahman, Md. Afjalur; Rahman, Md. Atikur; Sultana, Rajia; Mostafa, Md. Rakib; Tania, Asmaul Husna; Sarker, Md. Abdur Razzaque

2016-12-01

High-quality cobalt vanadate crystals have been synthesized by solid-state reaction route. Structure and morphology of the synthesized powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. The XRD patterns revealed that the as prepared materials are of high crystallinity and high quality. The SEM images showed that the crystalline CoV2O6 material is very uniform and well separated, with particle (of) area 252 μm. The electronic and optical properties were investigated by impedance analyzer and UV-visible spectrophotometer. Temperature-dependent electrical resistivity was measured using four-probe technique. The crystalline CoV2O6 material is a semiconductor and its activation energy is 0.05 eV.

Crystal Orientation Controlled Photovoltaic Properties of Multilayer GaAs Nanowire Arrays.

PubMed

Han, Ning; Yang, Zai-Xing; Wang, Fengyun; Yip, SenPo; Li, Dapan; Hung, Tak Fu; Chen, Yunfa; Ho, Johnny C

2016-06-28

In recent years, despite significant progress in the synthesis, characterization, and integration of various nanowire (NW) material systems, crystal orientation controlled NW growth as well as real-time assessment of their growth-structure-property relationships still presents one of the major challenges in deploying NWs for practical large-scale applications. In this study, we propose, design, and develop a multilayer NW printing scheme for the determination of crystal orientation controlled photovoltaic properties of parallel GaAs NW arrays. By tuning the catalyst thickness and nucleation and growth temperatures in the two-step chemical vapor deposition, crystalline GaAs NWs with uniform, pure ⟨110⟩ and ⟨111⟩ orientations and other mixture ratios can be successfully prepared. Employing lift-off resists, three-layer NW parallel arrays can be easily attained for X-ray diffraction in order to evaluate their growth orientation along with the fabrication of NW parallel array based Schottky photovoltaic devices for the subsequent performance assessment. Notably, the open-circuit voltage of purely ⟨111⟩-oriented NW arrayed cells is far higher than that of ⟨110⟩-oriented NW arrayed counterparts, which can be interpreted by the different surface Fermi level pinning that exists on various NW crystal surface planes due to the different As dangling bond densities. All this indicates the profound effect of NW crystal orientation on physical and chemical properties of GaAs NWs, suggesting the careful NW design considerations for achieving optimal photovoltaic performances. The approach presented here could also serve as a versatile and powerful platform for in situ characterization of other NW materials.

Synthesis, crystal structure and catalytic effect on thermal decomposition of RDX and AP: An energetic coordination polymer [Pb{sub 2}(C{sub 5}H{sub 3}N{sub 5}O{sub 5}){sub 2}(NMP)·NMP]{sub n}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jin-jian; Yancheng Teachers College, Yancheng 224002; Liu, Zu-Liang, E-mail: liuzl@mail.njust.edu.cn

2013-04-15

An energetic lead(II) coordination polymer based on the ligand ANPyO has been synthesized and its crystal structure has been got. The polymer was characterized by FT-IR spectroscopy, elemental analysis, DSC and TG-DTG technologies. Thermal analysis shows that there are one endothermic process and two exothermic decomposition stages in the temperature range of 50–600 °C with final residues 57.09%. The non-isothermal kinetic has also been studied on the main exothermic decomposition using the Kissinger's and Ozawa–Doyle's methods, the apparent activation energy is calculated as 195.2 KJ/mol. Furthermore, DSC measurements show that the polymer has significant catalytic effect on the thermal decompositionmore » of ammonium perchlorate. - Graphical abstract: An energetic lead(II) coordination polymer of ANPyO has been synthesized, structurally characterized and properties tested. Highlights: ► We have synthesized and characterized an energetic lead(II) coordination polymer. ► We have measured its molecular structure and thermal decomposition. ► It has significant catalytic effect on thermal decomposition of AP.« less

Synthesis and Characterization of Potassium Aryl- and Alkyl-Substituted Silylchalcogenolate Salts

DOE PAGES

Brown, Jessica Lynn; Montgomery, Ashley C.; Samaan, Christopher A.; ...

2016-02-23

Treatment of either triphenyl(chloro)silane or tert-butyldiphenyl(chloro)silane with potassium metal in THF, followed by addition of 18-crown-6, affords [K(18-crown-6)][SiPh 3] (1) and [K(18-crown-6)][SiPh 2 tBu] (2), respectively, as the reaction products in high yield. Compounds 1 and 2 were fully characterized including by multi-nuclear NMR and IR spectroscopies. Addition of elemental chalcogen to either 1 or 2, results in facile chalcogen insertion into the potassium-silicon bond to afford the silylchalcogenolates, [K(18-crown-6)][E– SiPh2R] (E = S, R = Ph (3); Se, R = Ph (4); E = Te, R = Ph (5); E = S, R = tBu (6); E = Se,more » R = tBu (7); E = Te, R = tBu (8)), in moderate to good yield. The silylchalcogenolates reported herein were characterized by multi-nuclear NMR and IR spectroscopies, and their solid-state molecular structures were determined by single-crystal X-ray crystallography. Importantly, the reported compounds crystallize as discrete monomers in the solid-state, a structural feature not previously observed in silylchalcogenolates, providing well-defined access routes into systematic metal complexation studies.« less

Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material.

PubMed

Dinakaran, Paul M; Kalainathan, S

2013-07-01

4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6×2×3 mm(3)) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and (1)H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV). Copyright © 2013 Elsevier B.V. All rights reserved.

Ethyl 7-hydroxycoumarin-3-carboxylate derivatives: Synthesis, characterization and effect of liquid crystal properties

NASA Astrophysics Data System (ADS)

Srinivasa, H. T.; Palakshamurthy, B. S.; Mohammad, AbdulKarim-Talaq

2018-03-01

Two sets of new ethyl 7-hydroxycoumarin-3-carboxylate derivatives were synthesized and characterized to study the liquid crystalline properties. Chemical structures were confirmed by IR, NMR, CHN analysis techniques. Mesomarphic properties were accomplished by DSC, POM and X-ray studies. Density functional theory calculations and photophysical studies also performed. In the first set, smaller homologues of alkoxybenzoic acid derivatives exhibit monotropic smectic A (SmA) and higher homologous exhibit enantiotropic smectic A mesophase. The second set alkyl biphenyl derivatives exhibit stable SmA and nematic (N) mesophases. The well defined focal conic texture for SmA and threaded texture for nematic mesophases have been observed.

Characterization of diacetone diperoxide (DADP)

NASA Astrophysics Data System (ADS)

Bowden, Patrick R.; Tappan, Bryce C.; Manner, Virginia W.; Preston, Daniel N.; Scott, Brian L.

2017-01-01

To date, diacetone diperoxide (DADP) has been significantly less studied than its well-known counterpart, triacetone triperoxide (TATP). Much of this disparity in the literature is due to the harsher conditions/multi-step syntheses required to obtain DADP leading to much lower evidence of frequency of use. Because of this, DADP is often misrepresented as being more dangerous (i.e. more sensitive and less stable) than TATP. This paper discusses the synthesis and characterization (sensitivity, thermal stability, etc.) of DADP with comparisons to other energetic organic peroxides (TATP, HMTD and MEKP) and differences in polymorphism, crystal habit and effects of aging and processing differences are discussed. Additionally, the deflagration-to-detonation transition (DDT) behavior of DADP is discussed with comparison to TATP.

Characterization of α-Fe-Free Heteroepitaxial NdFe12- x Ti x Thin-Film Materials with a Novel Cubic Laves Fe2Ti Phase

NASA Astrophysics Data System (ADS)

Hadorn, Jason Paul; Hirayama, Yusuke; Ohkubo, Tadakatsu

2018-01-01

Thin films with compositions of NdFe12 and NdFe11Ti1 were fabricated on W-buffered MgO(001) substrates of varying roughness. In this study, X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the films microstructurally, chemically, and crystallographically. This study revealed successful heteroepitaxial synthesis of the tetragonal NdFe12 and NdFe12- x Ti x phases in the Ti-free and Ti-containing films, respectively, both with surface-normal c-axis orientation. It also revealed the presence of other phases within the magnetic layer. The NdFe12 films contained many α-Fe particles, which preferentially precipitated at locally rough regions of the W-buffer interface. The NdFe11Ti1 film showed the ubiquitous presence of an Fe2Ti phase, which covered most of the buffer thereby preventing the formation of α-Fe. This phase was determined to have a novel Cu2Mg-type cubic Laves ( C15) crystal structure with fourfold interfacial symmetry, good coherency, and a low mismatch with the W-buffer, thus rendering itself as being an ideal interface for the heteroepitaxial synthesis of NdFe12- x Ti x crystals. It is proposed that successful application of a cubic Fe2Ti underlayer on W can contribute to the development of a fabrication strategy for NdFe12 thin films without the presence of soft magnetic α-Fe.

Synthesis, characterization and crystal structure of a 1D thiocyanato bridged [Cu(en)2Zn(NCS)4]ṡH2O. Comparison of the three structures with the same [Cu(en)2Zn(NCS)4] unit - different in structural terms

NASA Astrophysics Data System (ADS)

Wrzeszcz, Grzegorz; Muzioł, Tadeusz M.; Tereba, Natalia

2015-03-01

In this paper we report the synthesis method and the structure of a one-dimensional thiocyanato bridged heterometallic compound, [Cu(en)2Zn(NCS)4]ṡH2O (1). Moreover, we compare the structure of (1) with the previously described structures of [Cu(en)2Zn(NCS)4]ṡ0.5H2O (2) and [Cu(en)2Zn(NCS)4]ṡCH3CN (3) Pryma et al. (2003) [7]. The compound (1) has been characterized by thermal decomposition, IR, Vis and EPR spectra, and magnetic studies. Structure has been determined by X-ray analysis. Described coordination polymer crystallizes in the orthorhombic Cmcm space group with a = 12.414(2), b = 10.3276(14), c = 14.967(2) Å, α = β = γ = 90°, V = 1918.8(5) Å3 and Z = 4. Each distorted tetrahedral zinc(II) centre (with N-bonded NCS-) links two tetragonally distorted octahedral copper(II) centres by two end-to-end thiocyanato bridges and vice versa forming a zigzag type of CuZn chain. The structures of (1), (2) and (3) differ in crystallographic system, space group and/or CuZn chain type as well as in details. Variable temperature magnetic susceptibility measurements show very weak antiferromagnetic interactions between the paramagnetic copper(II) ions for compound (1).

Technical Report: Understanding Functional Lyotropic Liquid Crystal Network Phase Self-Assembly and the Properties of Nanoconfined Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahanthappa, Mahesh K; Yethiraj, Arun

Through the synergistic interplay of molecular dynamics (MD) simulations, chemical synthesis, and materials characterization by X-ray and neutron scattering techniques, this project investigated the phase behaviors of new classes of aqueous lyotropic liquid crystals (LLCs) and the properties of water nanoconfined within their pores. A portion of our studies focused on the synthesis of new classes of alkylsulfonic acid and alkylphosphonate amphiphiles, which were shown to undergo water-induced self-assembly to form a wide variety of nanostructured morphologies with unusually high degrees of long-range translational order observed by small- angle X-ray scattering (SAXS). Sample LLC morphologies that were observed include themore » lamellar (L!), tricontinuous double gyroid (G), hexagonally-packed cylinders (H), and low symmetry discontinuous micellar (I) Frank-Kasper phases. Since the G and H phases are the most promising for the development of selective ion transporting membranes for energy applications, we sought the characterize the structure and dynamics of water confined within the sub-3 nm pores of these LLCs using wide-angle neutron diffraction (WAND) and quasielastic neutron scattering (QENS) experiments performed at the Spallation Neutron Source at Oak Ridge National Laboratory. Using molecular dynamics (MD) simulations, we validated models for analyzing this QENS data to obtain water self-diffusion coefficients in LLC G and H phases of carboxylate and sulfonate surfactant LLCs as a function of the identities of their charge compensating counterions.« less

Synthesis, characterization, antimicrobial activity and carbonic anhydrase enzyme inhibitor effects of salicilaldehyde-N-methyl p-toluenesulfonylhydrazone and its Palladium(II), Cobalt(II) complexes

NASA Astrophysics Data System (ADS)

Alyar, Saliha; Adem, Şevki

2014-10-01

We report the synthesis of the ligand, salicilaldehyde-N-methyl p-toluenesulfonylhydrazone (salptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Pd(II) and Co(II) metal complexes were synthesized for the first time. The structure of the ligand and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, NMR and LC-MS) measurements. Salptsmh has also been characterized by single crystal X-ray diffraction. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The complexes were found to have general composition [ML2]. The results of elemental analysis showed 1:2 (metal/ligand) stoichiometry for all the complex. Magnetic and spectral data indicate a square planar geometry for Pd(II) complex and a distorted tetrahedral geometry for Co(II) complexes. The ligand and its metal chelates have been screened for their antimicrobial activities using the disk diffusion method against the selected Gram positive bacteria: Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Gram negative bacteria: Eschericha coli, Pseudomonas aeruginosa, Klebsiella pneumonia. The inhibition activities of these compounds on carbonic anhydrase II (CA II) and carbonic anhydrase I (CA I) have been investigated by comparing IC50 and Ki values and it has been found that Pd(II) complex have more enzyme inhibition efficiency than salptsmh and Co(II) complex.

Hydroxide precursors to produce nanometric YCrO{sub 3}: Characterization and conductivity analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durán, A., E-mail: dural@cnyn.unam.mx; Meza F, C.; Arizaga, Gregorio Guadalupe Carbajal, E-mail: gregoriocarbajal@yahoo.com.mx

2012-06-15

Highlights: ► Y/Cr mixed hydroxide was precipitated with gaseous ammonia. ► The hydroxide treated at 1373 K formed YCrO{sub 3} crystals with 20 nm diameter. ► Electrical properties were different than those found in other methods of synthesis. ► E{sub act} suggests small-polarons as conduction mechanisms. -- Abstract: A precursor to produce perovskite-type YCrO{sub 3} was precipitated by bubbling gaseous ammonia into an yttrium/chromium salts solution. X-ray diffraction showed that the as-prepared powders were amorphous. Thermal treatment between 1273 and 1373 K, leads to formation of polycrystalline YCrO{sub 3} with crystal sizes around 20 nm. High resolution X-ray photoelectron spectramore » showed uniform chemical environment for yttrium and chromium in the amorphous hydroxide and crystalline YCrO{sub 3}. Shifts between Y 3d{sub 5/2} and Cr 2p{sub 3/2} binding energy suggest redistribution or charge transfer between yttrium and chromium ions in the YCrO{sub 3} structure. The electrical properties of YCrO{sub 3}, whose precursors were precipitated with gaseous ammonia are different than those prepared by combustion synthesis. Electrical conductivity presents a sudden increase at ∼473 K, which is associated to the grain size and morphology of the crystallites. The redistribution of charge between Y(III) and Cr(III) is thermally activated by the hopping of small-polarons, which are characterized by the Arrhenius law as the conductive mechanism.« less

Flux free single crystal growth and characterization of FeTe1-xSx (x=0.00 and 0.10) crystals

NASA Astrophysics Data System (ADS)

Maheshwari, P. K.; Awana, V. P. S.

2018-05-01

We report synthesis of S doped FeTe1-xSx (x = 0.00 and 0.10) single crystals using flux free method via solid state reaction. Single crystal XRD patterns of FeTe1-xSx (x = 0.00 and 0.10) confirm the single crystalline property, as the crystals are grown in (00l) plane only. Powder XRD result of FeTe1-xSx (x = 0.00 and 0.10) crystals show that crystalline in tetragonal structure having P4/nmm space group. Rietveld refinement results show that both a and c lattice parameters decreases with S doping of 10% at Te site in FeTe1-xSx. Detailed scanning electron microscopy (SEM) image of FeTe0.90S0.10 shows that the growth of crystal is in slab-like morphology. Electrical resistivity measurement results onset confirm the superconductivity in S doped 10% sample at Te site and superconducting transition Tconset occurs at 9.5K and Tcoffset(ρ=0) occurs at 6.5K. ρ-T measurement has been performed under various magnetic field up to 12 Tesla down to 2K. Upper critical field Hc2(0), for x=0.10, which comes around 70Tesla, 60Tesla and 45Tesla of normal resistivity criterion ρn = 90%, 50% and 10% criterion respectively.

Gd-DTPA Adsorption on Chitosan/Magnetite Nanocomposites

NASA Astrophysics Data System (ADS)

Pylypchuk, Ie. V.; Kołodyńska, D.; Kozioł, M.; Gorbyk, P. P.

2016-03-01

The synthesis of the chitosan/magnetite nanocomposites is presented. Composites were prepared by co-precipitation of iron(II) and iron(III) salts by aqueous ammonia in the 0.1 % chitosan solution. It was shown that magnetite synthesis in the chitosan medium does not affect the magnetite crystal structure. The thermal analysis data showed 4.6 % of mass concentration of chitosan in the hybrid chitosan/magnetite composite. In the concentration range of initial Gd-DTPA solution up to 0.4 mmol/L, addition of chitosan to magnetite increases the adsorption capacity and affinity to Gd-DTPA complex. The Langmuir and Freundlich adsorption models were applied to describe adsorption processes. Nanocomposites were characterized by scanning electron microscopy (SEM), differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and specific surface area determination (ASAP) methods.

Influence of Synthesis Temperature on the Growth and Surface Morphology of Co3O4 Nanocubes for Supercapacitor Applications

PubMed Central

Samal, Rashmirekha; Dash, Barsha; Sarangi, Chinmaya Kumar; Subbaiah, Tondepu; Senanayake, Gamini; Minakshi, Manickam

2017-01-01

A facile hydrothermal route to control the crystal growth on the synthesis of Co3O4 nanostructures with cube-like morphologies has been reported and tested its suitability for supercapacitor applications. The chemical composition and morphologies of the as-prepared Co3O4 nanoparticles were extensively characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Varying the temperature caused considerable changes in the morphology, the electrochemical performance increased with rising temperature, and the redox reactions become more reversible. The results showed that the Co3O4 synthesized at a higher temperature (180 °C) demonstrated a high specific capacitance of 833 F/g. This is attributed to the optimal temperature and the controlled growth of nanocubes. PMID:29088061

Salt-assistant combustion synthesis of nanocrystalline Nd{sub 2}(Zr{sub 1-x}Sn{sub x}){sub 2}O{sub 7} (0 {<=} x {<=} 1) solid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tong Yuping, E-mail: huabeitong@yahoo.cn; Wang Yanping

2009-11-15

Nanocrystalline Nd{sub 2}(Zr{sub 1-x}Sn{sub x}){sub 2}O{sub 7} series solid solutions were prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy and high-resolution transmission electron microscopy. The results showed the Zr ion can be partially replaced by Sn ion. The partial substituted products were still single-phase solid solutions and the crystal form remained unchanged. TEM images reveal that the products are composed of well-dispersed square-shaped nanocrystals. The method provides a convenient and low-cost route for the synthesis of nanostructures of oxide materials.

Biomimetic composite microspheres of collagen/chitosan/nano-hydroxyapatite: In-situ synthesis and characterization.

PubMed

Teng, Shu-Hua; Liang, Mian-Hui; Wang, Peng; Luo, Yong

2016-01-01

The collagen/chitosan/hydroxyapatite (COL/CS/HA) composite microspheres with a good spherical form and a high dispersity were successfully obtained using an in-situ synthesis method. The FT-IR and XRD results revealed that the inorganic phase in the microspheres was crystalline HA containing carbonate ions. The morphology of the composite microspheres was dependent on the HA content, and a more desirable morphology was achieved when 20 wt.% HA was contained. The composite microspheres exhibited a narrow particle distribution, most of which ranged from 5 to 10 μm. In addition, the needle-like HA nano-particles were uniformly distributed in the composite microspheres, and their crystallinity and crystal size decreased with the HA content. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis, crystal structure, and biological evaluation of a series of phloretin derivatives.

PubMed

Wang, Li; Li, Zheng-Wei; Zhang, Wei; Xu, Rui; Gao, Fei; Liu, Yang-Feng; Li, Ya-Jun

2014-10-13

A one-step synthesis of phloretin derivatives 2-11 from phloretin in good to excellent yields is reported. Their structures were characterized by 1H-NMR, 13C-NMR and MS, and the structures of 8 and 11 were determined by X-ray diffraction analysis. A mechanism for the formation of 9-11 is proposed. Compared with the anticancer drug docetaxel, phloretin, phloretin derivatives and phlorizin exhibited moderate cytotoxicity toward the MDA-MB-231, SPC-A1, A549, MCF-7 and EC109 cell lines. Among all of the tested compounds, 7 exhibited the strongest cytotoxicity toward the five cell lines and was more active than docetaxel in MDA-MB-231 cells. Our findings suggest that these derivatives hold great promise for further development as anticancer agents.

Review on Material Synthesis and Characterization of Sodium (Na) Super-Ionic Conductor (NASICON)

NASA Astrophysics Data System (ADS)

Kimpa, M. I.; Mayzan, M. Z. H.; Yabagi, J. A.; Nmaya, M. M.; Isah, K. U.; Agam, M. A.

2018-04-01

Sodium (Na) Super Ionic Conductor (NASICON) has general formula Na1+ x Zr2P3- xSi x O12 (0 ≤x ≤ 3) derived from its parent compound, sodium zirconium phosphate NaZr2(PO4)3 (NZP) which belong to a rhombohedral crystal structure. This material consists of three-dimensional structure with interesting features such as low thermal expansion coefficient, thermal stability, gas sensor and nuclear waste immobilization that make it viable for industrial applications. Current study presents comprehensive studies on the synthesis and essential characteristics required to understand the theory behind the mechanism that justifies the study of NASICON structure and its application such as lithium ion rechargeable battery, gas sensor, and nuclear waste immobilization and so on.

Synthesis and Structural Characterization of Tris(dimethyldithiocarbamate)Indium(III), In[S2CN(CH3)2]3

NASA Technical Reports Server (NTRS)

Clark, Eric B.; Breen, Marc L.; Fanwick, Phillip E.; Hepp, Aloysius F.; Duraj, Stan A.

1998-01-01

The synthesis and structure of the indium dithiocarbamate, In[SCN(CH3)2]3*1/2 4-mepy (4-mepy = 4-methylpyridine), is described. Indium metal was oxidized by tetramethylthiuramdisulfide in 4-methylpyridine at 25C to form a new, homoleptic indium(HI) dithiocarbamate in yields exceeding 60%. In[S2CN(CH3)213 exists as a discrete molecule with a distorted-octahedral geometry. The compound crystallizes in the P 1-bar (No. 2) space group with a = 9.282(l)A, b = 10.081(1)A, c = 12.502 A, alpha= 73.91 (1) degrees, beta = 70.21(1) degrees, gamma = 85.84(1) degrees, Z = 2,v(A(exp 3)) =1057.3(3), R = 0.046, and R(sub w) = 0.061.

Influence of the solvent in the synthesis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals at room temperature.

PubMed

Bustamante, Eugenia L; Fernández, José L; Zamaro, Juan M

2014-06-15

The effect of the solvent on the synthesis process and on the nanocrystal characteristics of the zeolitic imidazolate framework-8 (ZIF-8) was investigated. A synthesis protocol at room temperature employing a series of aliphatic alcohols, water, dimethylformamide and acetone was employed. The results show that the solvent modifies the evolution of the reaction, altering the crystallization rates and nanocrystal sizes. Its hydrogen bond donation ability is the main factor that governs this effect. More precisely, the solvent modulates the formation of ZIF-8 nanocrystals with sizes in the range between 15 and 42 nm. When synthesized in alcohol and acetone, these nanocrystals form globular aggregates with sizes between 130 and 420 nm. In contrast, under the same synthesis conditions, when using water or dimethylformamide the ZIF phase is not developed. In alcohols other than methanol, the crystals develop pill-shaped morphologies with poorly defined facets. Moreover, a markedly fast growing kinetics is verified in these alcohols, leading to an ultra-fast crystallization of ZIF-8 in about 60s. These findings provide new information about the role of the solvent in the synthesis process of nanoZIF-8, which can be useful for controlling the crystallization rates and nanocrystal sizes of this material. Copyright © 2014 Elsevier Inc. All rights reserved.

Synthesis, structural analysis, Hirshfeld surface, spectroscopic characterization and, in vitro, antioxidant activity of a novel organic cyclohexaphosphate

NASA Astrophysics Data System (ADS)

Fezai, Ramzi; Mezni, Ali; Rzaigui, Mohamed

2018-02-01

The new hybrid [4-Cl-2-(CH3)C6H3NH3]6P6O18·2H2O was synthesized under normal conditions of temperature and pressure. Single crystal X-ray diffraction study was used to identify its structure. It revealed that this organic cyclohexaphosphate crystallized in the P 1 bar triclinic space group with a = 10.41 (10) Å b = 10.94 (7) Å, c = 15.45 (10) Å, α = 77.37 (8), β = 89.75 (8)°, γ = 61.69 (7)°, V = 1501 (2) Å3 and Z = 1. In the crystal framework, the assembling of the three dimensional (3D) structure is formed by intermolecular hydrogen bonds and Van Der Waals interactions. A spectroscopic characterization was carried out to elucidate the structure (UV-Vis, FTIR, 31P MAS-NMR and fluorescent properties). The thermal stability was studied by TG-DTA diagrams under argon atmosphere. Furthermore, 3-D Hirshfeld surfaces in combination with 2-D fingerprint plots were carried out. This compound was also evaluated for its antioxidant activity; four tests were done, in vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl scavenging ability (OH•), ferric reducing power (FRP) and ferrous ion chelating (FIC) ability, using ascorbic acid as a control.

Synthesis, crystal structures, and characterization of double complex salts [Au(en)2][Rh(NO2)6]·2H2O and [Au(en)2][Rh(NO2)6

NASA Astrophysics Data System (ADS)

Plyusnin, Pavel E.; Makotchenko, Evgenia V.; Shubin, Yury V.; Baidina, Iraida A.; Korolkov, Ilya V.; Sheludyakova, Liliya A.; Korenev, Sergey V.

2015-11-01

Double complex salts of rhodium(III) and gold(III) of the composition [Au(en)2][Rh(NO2)6]·2H2O (1) and [Au(en)2][Rh(NO2)6] (2) have been prepared. Crystal structures of the compounds have been determined by single crystal X-ray diffraction. The compounds have been characterized by PXRD, IR, far-IR, CHN and DTA. The complexes have a layered structures. The presence of water in 1 makes the structure of the hydrated DCS less dense as compared to the anhydrous one. The environment of the cation and the anion in the two structures is the same, oxygen atoms of the nitro groups are involved in hydrogen bonds N-H⋯O, N⋯O distances being approximately the same. The structures of 1 and 2 are notable in having shortened contacts between the gold atoms and the oxygen atoms of the nitro groups of the neighboring complex anions. The thermal behavior of the complexes in a hydrogen atmosphere was investigated. The final product of thermolysis prepared at the temperature 600°C is a two-phase mixture of pure metallic gold and the solid solution Rh0.93Au0.07.

Synthesis, characterization and dissolution of three pharmaceutical cocrystals based on deferiprone

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Tian, Yuyang; Jia, Jiangtao; Zhang, Tingting; Zhu, Guangshan

2016-03-01

In this paper we present three new cocrystals based on deferiprone which is the first oral medicine as iron chelator. Solitary deferiprone possesses some known problems due to its good solubility and frequent dosing side effects. For these three novel co crystals, deferiprone is the active pharmaceutical ingredient (API), p-hydroxybenzoic acid (1, C7H9NO2·C7H6O3), 2, 5-dihydroxybenzoic acid (2, C7H9NO2·C7H6O4) and maleic acid (3, C7H9NO2·C4H4O4) are used as cocrystal formers (CCFs), respectively. Their structures were characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) analysis, thermogravimetric analyses (TGA), differential thermal analysis (DTA), elemental analysis (EA) and infrared spectral analysis (IR). Single crystal X-ray diffraction demonstrates that all three cocrystals (1-3) possess strong hydrogen-bondings assembled through hydroxyl of API and carboxylic acids of CCFs. The PXRD results indicate their high purity of as-synthesized samples. TGA, DTA, EA, IR and dissolution study of API and cocrystals were also measured and discussed, respectively. The results suggest that the cocrystals exhibit low dissolution rates comparing with solitary deferiprone, which is very advantageous for the oral medicine with frequent dosing side effects.

Synthesis and characterization of a series of transition metal complexes with a new symmetrical polyoxaaza macroacyclic Schiff base ligand: X-ray crystal structure of cobalt(II) and nickel(II) complexes and their antibacterial properties

NASA Astrophysics Data System (ADS)

Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Valencia, Laura

2013-01-01

A new symmetrical [N4O2] hexadentate Schiff base ligand, (E)-N-(pyridin-2-ylmethylene)-2-(3-(2-((E)-pyridin-2-lmethyleneamino)phenoxy)naphthalen-2-yloxy)benzenamine, abbreviated to L, and its complexes of Ni(II), Cu(II), Zn(II), Co(II), Cd(II) and Mn(II) have been synthesized in the presence of metal ions. The complexes were structurally characterized by elemental analyses, IR, UV-Vis, NMR and molar conductivity. The crystal structures of two complexes, [NiL(ONO2)2]·2H2O and [CoLCl2]CH3OH·0.5H2O, have been determined by a single crystal X-ray diffraction study. In these complexes, the ligand is coordinated in a neutral form via pyridine and azomethine nitrogen atoms. The metal ions complete their six coordination with two coordinated nitrate or chloride ions, forming a distorted octahedral geometry. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Enterococcus faecalis, Bacillus cereus and Staphylococcus epid and also against the three Gram-negative bacteria: Citrobacter freundii, Enterobacter aerogenes and Salmonella typhi. The activity data show that the complexes are more potent antibacterials than the parent Schiff base.

Synthesis, characterization and computational study of the newly synthetized sulfonamide molecule

NASA Astrophysics Data System (ADS)

Murthy, P. Krishna; Suneetha, V.; Armaković, Stevan; Armaković, Sanja J.; Suchetan, P. A.; Giri, L.; Rao, R. Sreenivasa

2018-02-01

A new compound N-(2,5-dimethyl-4-nitrophenyl)-4-methylbenzenesulfonamide (NDMPMBS) has been derived from 2,5-dimethyl-4-nitroaniline and 4-methylbenzene-1-sulfonyl chloride. Structure was characterized by SCXRD studies and spectroscopic tools. Compound crystallized in the monoclinic crystal system with P21/c space group a = 10.0549, b = 18.967, c = 8.3087, β = 103.18 and Z = 4. Type and nature of intermolecular interaction in crystal state investigated by 3D-Hirshfeld surface and 2D-finger print plots revealed that title compound stabilized by several interactions. The structural and electronic properties of title compound have been calculated at DFT/B3LYP/6-311G++(d,p) level of theory. Computationally obtained spectral data was compared with experimental results, showing excellent mutual agreement. Assignment of each vibrational wave number was done on the basis of potential energy distribution (PED). Investigation of local reactivity descriptors encompassed visualization of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) surfaces, visualization of Fukui functions, natural bond order (NBO) analysis, bond dissociation energies for hydrogen abstraction (H-BDE) and radial distribution functions (RDF) after molecular dynamics (MD) simulations. MD simulations were also used in order to investigate interaction of NDMPMBS molecule with 1WKR and 3ETT proteins protein.

BiSr3(YO)3(BO3)4: a new gaudefroyite-type rare-earth borate with moderate SHG response.

PubMed

Gao, Jianhua; Li, Shuai

2012-01-02

The synthesis, crystal structure, crystal growth, and characterization of a new noncentrosymmetric rare-earth borate BiSr(3)(YO)(3)(BO(3))(4) are reported. BiSr(3)(YO)(3)(BO(3))(4) belongs to gaudefroyite type of structure and crystallizes in the polar hexagonal space group P6(3) (no. 173) with a = 10.6975(16) Å and c = 6.7222(12) Å. In the structure, the YO(7) polyhedra share edges to form an one-dimensional chain along the [001] direction. These chains are interconnected by the BO(3) group to construct a three-dimensional framework, leaving two kinds of channels for Bi atoms and Sr atoms together with BO(3) groups, respectively. On the basis of the powder second-harmonic generation (SHG) measurement, BiSr(3)(YO)(3)(BO(3))(4) belongs to the phase-matchable class with a SHG response of about 3 × KDP.

Synthesis, crystal structure and valence tautomerism of a 4,4‧-bipyridine-bridged one-dimensional chiral cobalt complex

NASA Astrophysics Data System (ADS)

Cheng, Wei-Qin; Li, Guo-Ling; Zhang, Ran; Ni, Zhong-Hai; Wang, Wen-Feng; Sato, Osamu

2015-05-01

A linear-chain cobalt coordination polymer, [Co(2,3-LH2)2(4,4‧-bipy)]ṡ2H2Oṡ4,4‧-bipy]n (1) (2,3-LH2 = 2,3-tetrahydroxy-9,10-dimethyl-9,10-dihydro- 9,10-ethanoanthracene, 4,4‧-bipy = 4,4‧-bipyridine), has been synthesized and structurally characterized. Single-crystal X-ray analysis reveals that complex 1 is a chiral polymer assemblied from achiral components. The complex 1 crystallizes in the chiral space group P3221 and the central Co ion has a slightly distorted octahedral coordination environment. The temperature dependence of magnetic susceptibility indicates that the complex 1 undergoes valence tautomeric interconversion between low-spin ls-[CoIII(2,3-LH2Cat)(2,3-LH2SQ)] and high-spin hs-[CoII(2,3-LH2SQ)2] (2,3-LH2Cat = 2,3-LH2catecholate, 2,3-LH2SQ = 2,3-LH2semiquinone).

Size- and morphology-controllable synthesis of MIL-96 (Al) by hydrolysis and coordination modulation of dual aluminium source and ligand systems.

PubMed

Liu, Dandan; Liu, Yunqi; Dai, Fangna; Zhao, Jinchong; Yang, Kang; Liu, Chenguang

2015-10-07

In this paper, an efficient method to fabricate Al-based metal organic framework (Al-MOF) MIL-96 crystals with controllable size and morphology, by mixing other forms of reactants to replace the coordination modulators or capping agents, is presented. The size and morphology of the MIL-96 crystals can be selectively varied by simply altering the ratio of dual reactants via their hydrolysis reaction. All the samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and nitrogen sorption. Then based on the BFDH theory, a mechanism for the impact of hydrolysis of reactants on the crystal size and morphology is presented and discussed. We also evaluated the performance of these MOFs as sorbents for capturing CO2, and they all show enhanced adsorption properties compared with the bulk material, displaying high adsorption capacities on CO2 at atmospheric pressure and ambient temperature.

New mixed valence defect dicubane cobalt(II)/cobalt(III) complex: Synthesis, crystal structure, photoluminescence and magnetic properties

NASA Astrophysics Data System (ADS)

Coban, Mustafa Burak; Gungor, Elif; Kara, Hulya; Baisch, Ulrich; Acar, Yasemin

2018-02-01

A new defect dicubane cobalt(II)/cobalt(III), [(CoII2CoIII2L42(H2O)(CH3COO)(CH3COOH]. 4H2O complex (1) where H2L = [1-(3-hydroxypropyliminomethyl)naphthalene-2-ol], has been synthesized and characterized by element analysis, FT-IR, solid UV-Vis spectroscopy and single crystal X-ray diffraction. The crystal structure determination shows a cationic tetrameric arrangement consisting of a defect dicubane core with two missing vertexes. Each cobalt ion has a distorted octahedral geometry with six coordinate ordered CoII and CoIII ions. The solid state photoluminescence properties of complex (1) and its ligand H2L have been investigated under UV light at 349 nm in the visible region. H2L exhibits blue emission while complex (1) shows red emission at room temperature. Variable-temperature magnetic susceptibility measurements on the complex (1) in the range 2-300 K indicate an antiferromagnetic interaction.

Novel Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine): Synthesis, crystal structure and magnetic properties

NASA Astrophysics Data System (ADS)

Smolko, Lukáš; Černák, Juraj; Kuchár, Juraj; Miklovič, Jozef; Boča, Roman

2016-09-01

Green crystals of Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine) were isolated from the aqueous system CoBr2 - bapen - HBr, crystallographically studied and characterized by elemental analysis and IR spectroscopy. Its ionic crystal structure is built up of [Co(bapen)Br2]+ cations and [CoBr4]2- anions. The Co(III) central atoms within the complex cations are hexacoordinated (donor set trans-N4Br2) with bromido ligands placed in the axial positions. The Co(II) atoms exhibit distorted tetrahedral coordination. Beside ionic forces weak Nsbnd H⋯Br intermolecular hydrogen bonding interactions contribute to the stability of the structure. Temperature variable magnetic measurements confirm the S = 3/2 behavior with the zero-field splitting of an intermediate strength: D/hc = 8.7 cm-1.

Synthesis of barium and strontium carbonate crystals with unusual morphologies using an organic additive

NASA Astrophysics Data System (ADS)

Chen, Long; Jiang, Jizhong; Bao, Zuben; Pan, Jian; Xu, Weibing; Zhou, Lili; Wu, Zhigang; Chen, Xu

2013-12-01

In this paper, strontium carbonate (SrCO3) and barium carbonate (BaCO3) crystals were synthesized in the presence of an organic additive-hexamethylenetetramine (HMT) using two CO2 sources. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the products. The results showed that the morphologies of orthorhombic strontianite SrCO3 transformed from branch-like to flower-like, and to capsicum-like at last, while the morphologies of BaCO3 change from fiber-like to branchlike, and to rod-like finally with an increase of the molar ratio HMT/Sr2+ and HMT/Ba2+ from 0.2 to 10 using ammonium carbonate as CO2 source. When using diethyl carbonate instead of ammonium carbonate as CO2 source, SrCO3 flowers aggregated by rods and BaCO3 shuttles were formed. The possible formation mechanisms of SrCO3 and BaCO3 crystals obtained in different conditions were also discussed.

Synthesis and characterization of tetraacetonitrilolithiumhexafluorophosphate crystal

NASA Astrophysics Data System (ADS)

Li, Xuecong; Li, Xuanli; Zhang, Zhiye; Yang, Lin; Zhong, Benhe; Wang, Xinlong

2015-08-01

Tetraacetonitrilolithiumhexafluorophosphate (Li(CH3CN)4PF6) crystal is an important intermediate in the preparation of high purity lithium hexafluorophosphate electrolyte via a simple transformation method. In this study, the crystal parameters were determined by X-ray powder diffraction analysis, which showed that it belongs to the triclinic system with space group P1. FTIR spectral studies identified the characteristic absorption bands of Ctbnd N and PF6- in the synthesized complex. Chemical analysis, gas chromatography, and ICP-AES results showed that the elementary ratio of Li:P:F: CH3CN in the complex is approximately: 1:1:6:4. Furthermore, the geometric optimization structure of Li(CH3CN)4PF6 was obtained using GAUSSIAN 09 program on a B3LYP/6-31+G(d, p) level. In this structure, two acetonitrile ligands bind strongly with the Li+ ion, whereas the other two are weakly-coordinated with lithium. The results of solid-state 13C-, 31P-, and 19F-NMR spectra confirmed that this configuration is reasonable.

Synthesis, crystal structure, spectroscopic characterization and optical properties of bis(4-acetylanilinium) tetrachlorocobalt (II)

NASA Astrophysics Data System (ADS)

Abkari, A.; Chaabane, I.; Guidara, K.

2017-02-01

The chemical preparation, crystal structure, spectroscopic investigations and optical features are given for a novel organic-inorganic hybrid material [C8H10NO]2CoCl4.The compound is crystallized in the orthorhombic space group Cmca, with the following unit cell parameters: a=19.461(2) Å, b=15.523(2) Å, c=13.7436(15) Å, and Z=8. The atomic arrangement shows an alternation of organic and inorganic layers along the b-axis. The cohesion between these entities is performed by N-H…Cl and N-H…O hydrogen bonds and π-π stacking interactions. Infrared and Raman spectra at room temperature are recorded in the 4000-400 and 4000-0 cm-1 frequency regions, respectively and analyzed on the basis of literature data. This study confirms the presence of the organic cation [C8H10NO]+ and of the [CoCl4]2- anion. UV-vis spectroscopy results showed the indirect transition with band gap energy 2.98 eV.

Interlaced crystals having a perfect Bravais lattice and complex chemical order revealed by real-space crystallography

DOE PAGES

Shen, Xiao; Hernandez-Pagan, Emil; Zhou, Wu; ...

2014-11-14

The search for optimal thermoelectric materials aims for structures in which the crystalline order is disrupted to lower the thermal conductivity without degradation of the electron conductivity. Here we report the synthesis and characterization of ternary nanoparticles (two cations and one anion) that exhibit a new form of crystal-line order: an uninterrupted, perfect, global Bravais lattice, in which the two cations exhibit a wide array of distinct ordering patterns within the cation sublattice, form-ing interlaced domains and phases. Partitioning into domains and phases is not unique; the corresponding boundaries have no structural defects or strain and entail no energy cost.more » We call this form of crystalline order “interlaced crystals” and present the example of hexagonal-CuInS 2. Interlacing is possible in multi-cation tetrahedral-ly-bonded compound with an average of two electrons per bond. Interlacing has min-imal effect on electronic properties, but should strongly reduce phonon transport, making interlaced crystals attractive for thermoelectric applications.« less

Synthesis, growth, spectral, electrical, mechanical and thermal characterization of a potential optical material: γ-glycine single crystal

NASA Astrophysics Data System (ADS)

Sivakumar, N.; Jayavel, R.; Anbalagan, G.; Yadav, R. R.

2018-06-01

Gamma glycine, an organic material was grown by slow solvent evaporation method. Conventional polythermal method was employed in the temperature range, 30-50 °C to obtain the solubility and the metastable zonewidth. The crystal and molecular structures were analyzed by X-ray powder diffraction, FT-IR and FT-Raman spectral studies. Optical refractive index was determined by prism coupling technique and was found to be 1.4488. Electrical properties such as ac conductivity and activation energy were studied for different temperatures in the frequency range from 40 Hz to 6 MHz. The dc electrical conductivity was estimated from the Cole-Cole plot and the values were found to be 2.19 × 10-6 Sm-1 at 353K and 1.46 × 10-6 Sm-1 at 373K respectively. Mechanical studies on the grown crystal revealed that the material belongs to soft materials category. Thermal conductivity and specific heat capacities were estimated by Hot Disk Thermal Constants Analyzer.

Synthesis, spectral, structural prediction and computational studies of octylcarbazole ornamented 3-phenothiazinal

NASA Astrophysics Data System (ADS)

Karuppasamy, Ayyanar; Udhaya kumar, Chandran; Karthikeyan, Subramanian; Velayutham Pillai, Muthiah Pillai; Ramalingan, Chennan

2017-11-01

A novel conjugated octylcarbazole ornamented 3-phenothiazinal, 10-(9-octyl-9H-carbazol-3-yl)-10H-phenothiazine-3-carbaldehyde (OCPTC) was synthesized and fully characterized by 1H-NMR, 13C-NMR, elemental and single crystal XRD analyses. The optimized geometrical structure, vibrational frequencies and NMR have been computed with M06-2X method using 6-31+G(d,p) basis set. Total electronic energies and HOMO-LUMO energy gaps in gas phase are discussed. The geometrical parameters of the title compound obtained from single crystal XRD studies have been found in accord with the calculated (DFT) values. The experimental and theoretical FT-IR and NMR results of the title molecule have been investigated. The experimentally observed vibrational frequencies have been compared with the calculated ones, which are in good agreement with each other. Single crystal X-ray structural analysis of OCPTC, evidences the ''butterfly conformation'' of phenothiazine ring with nearly perpendicular orientation of the carbazole structural motif to the phenothiazine moiety.

Insight into Evolution, Processing and Performance of Multi-length-scale Structures in Planar Heterojunction Perovskite Solar Cells.

PubMed

Huang, Yu-Ching; Tsao, Cheng-Si; Cho, Yi-Ju; Chen, Kuan-Chen; Chiang, Kai-Ming; Hsiao, Sheng-Yi; Chen, Chang-Wen; Su, Chun-Jen; Jeng, U-Ser; Lin, Hao-Wu

2015-09-04

The structural characterization correlated to the processing control of hierarchical structure of planar heterojunction perovskite layer is still incomplete due to the limitations of conventional microscopy and X-ray diffraction. This present study performed the simultaneously grazing-incidence small-angle scattering and wide-angle scattering (GISAXS/GIWAXS) techniques to quantitatively probe the hierarchical structure of the planar heterojunction perovskite solar cells. The result is complementary to the currently microscopic study. Correlation between the crystallization behavior, crystal orientation, nano- and meso-scale internal structure and surface morphology of perovskite film as functions of various processing control parameters is reported for the first time. The structural transition from the fractal pore network to the surface fractal can be tuned by the chloride percentage. The GISAXS/GIWAXS measurement provides the comprehensive understanding of concurrent evolution of the film morphology and crystallization correlated to the high performance. The result can provide the insight into formation mechanism and rational synthesis design.

Insight into Evolution, Processing and Performance of Multi-length-scale Structures in Planar Heterojunction Perovskite Solar Cells

NASA Astrophysics Data System (ADS)

Huang, Yu-Ching; Tsao, Cheng-Si; Cho, Yi-Ju; Chen, Kuan-Chen; Chiang, Kai-Ming; Hsiao, Sheng-Yi; Chen, Chang-Wen; Su, Chun-Jen; Jeng, U.-Ser; Lin, Hao-Wu

2015-09-01

The structural characterization correlated to the processing control of hierarchical structure of planar heterojunction perovskite layer is still incomplete due to the limitations of conventional microscopy and X-ray diffraction. This present study performed the simultaneously grazing-incidence small-angle scattering and wide-angle scattering (GISAXS/GIWAXS) techniques to quantitatively probe the hierarchical structure of the planar heterojunction perovskite solar cells. The result is complementary to the currently microscopic study. Correlation between the crystallization behavior, crystal orientation, nano- and meso-scale internal structure and surface morphology of perovskite film as functions of various processing control parameters is reported for the first time. The structural transition from the fractal pore network to the surface fractal can be tuned by the chloride percentage. The GISAXS/GIWAXS measurement provides the comprehensive understanding of concurrent evolution of the film morphology and crystallization correlated to the high performance. The result can provide the insight into formation mechanism and rational synthesis design.

Eu(III) and Tb(III) complexes with the nonsteroidal anti-inflammatory drug carprofen: synthesis, crystal structure, and photophysical properties.

PubMed

Zhou, Xianju; Zhao, Xiaoqi; Wang, Yongjie; Wu, Bing; Shen, Jun; Li, Li; Li, Qingxu

2014-12-01

Two new lanthanide complexes with general formula [Ln2(carprofen)6(DMF)2] (Ln = Eu (1), Tb (2), DMF = N,N-dimethylformamide, carprofen = 6-chloro-α-methylcarbazole-2-acetic acid) have been synthesized by a hydrothermal method. Complex 1 was characterized by single-crystal X-ray diffraction (XRD), and it was found to crystallize in the monoclinic space group C2/c. The coordination of the ligand to the lanthanide ion has been investigated by Fourier-transform infrared (FTIR) spectra and ultraviolet-visible (UV-vis) absorption spectra. Complex 1 emits red light, but the antenna effect of the ligand is not effective, whereas complex 2 presents intense green emission with effective energy transfer from the ligand. The different performance of the two complexes is related to the energy matching between the excited states of the lanthanide ion and the triplet state of the ligand. The intramolecular energy transfer mechanisms are also discussed.

Synthesis, crystal structure, antimicrobial activity and DNA-binding of hydrogen-bonded proton-transfer complex of 2,6-diaminopyridine with picric acid.

PubMed

Khan, Ishaat M; Ahmad, Afaq; Ullah, M F

2011-04-04

A proton-transfer (charge transfer) complex formed on the reaction between 2,6-diaminopyridine (donor) and picric acid (acceptor) was synthesized and characterized by FTIR, (1)H NMR, thermal and elemental analysis. The crystal structure determined by single-crystal X-ray diffraction indicates that cation and anion are joined together by strong N(+)-H- -O(-) type hydrogen bonds. The hydrogen-bonded charge transfer (HBCT) complex was screened for its pharmacology such as antimicrobial activity against various fungal and bacterial strains and Calf thymus DNA-binding. The results showed that HBCT complex (100μg/ml) exhibited good antibacterial antifungal activity as that of standard antibiotics Tetracycline and Nystatin. A molecular frame work through H-bonding interactions between neighboring moieties is found to be responsible for high melting point of resulting complex. This has been attributed to the formation of 1:1 HBCT complex. Copyright © 2011 Elsevier B.V. All rights reserved.

Synthesis, crystal, and biological activity of a novel carbene silver(I) complex with imidazole derivative

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiu-Fu, Lu, E-mail: jiufulu@163.com; Hong-Guang, Ge; Juan, Shi

2015-12-15

Reaction of 2-(1-methyl-1,2-dihydroimidazol-3-yl)acetonitrile tetrafluoroborate with silver oxide in dichloromethane readily yields [Ag(DIM){sub 2}]BF{sub 4}, where DIM is 2-(1-methyl-1, 2-dihydroimidazol-3-yl)acetonitrile, representing a carbene organic ligand. The title compound was characterized by elemental analysis, IR, MS and single crystal X-ray diffraction. The crystal is of monoclinic system, space group C2/c with a = 14.010(18), b = 8.303(11), c = 14.936(20) Å, β = 93.910(4)°, V = 1639(4) Å{sup 3}, Z = 4, D{sub x} = 1.771 g/cm{sup 3}, F (000) = 864, µ(MoK{sub α}) = 1.278 mm{sup –1}. The final R{sup 1} = 0.0711 and wR{sup 2} = 0.1903 for reflections withmore » I > 2σ(I). In addition, the preliminary biological test showed that the title compound had anti-fungus yeast activity.« less

New copper complexes with bipyrazolic ligands: Synthesis, characterization and evaluation of the antibacterial and catalytic properties

NASA Astrophysics Data System (ADS)

Harit, Tarik; Abouloifa, Houssam; Tillard, Monique; Eddike, Driss; Asehraou, Abdeslam; Malek, Fouad

2018-07-01

The synthesis of new bipyrazolic ligands functionalized by carboxyl groups, namely 3-Bis(3‧-carboxyl-5‧-methyl-l'-pyrazolyl) propan-2-ol (L1) and 1,3-Bis(3‧-carboxyl-5‧-methyl-l '-pyrazolyl),2-methyl propane (L2) is reported. Their corresponding [C13H15CuN4O5] (CuL1) and [C14H16CuN4O4] (CuL2) copper (II) complexes are also elaborated and characterized by elemental analysis, FTIR an UV-visible spectroscopy. The crystal structure of the CuL1 complex confirms that copper atom is 4-coordinated, in a distorted square planar geometry within the molecule, and achieves its coordination through weak intermolecular interactions leading to two dimensional slabs. This geometry is in agreement with UV-visible results which also evidence that structure of complexes are affected in DMSO in contrast to methanol. No antibacterial activity against all the tested bacterial strains has been found for the Cu (II) complexes. By contrast, CuL1 is characterized with good catalytic properties in the air-oxidation of catechol substrate to quinone.

Hafnium(IV) chloride complexes with chelating β-ketiminate ligands: Synthesis, spectroscopic characterization and volatility study

NASA Astrophysics Data System (ADS)

Patil, Siddappa A.; Medina, Phillip A.; Antic, Aleks; Ziller, Joseph W.; Vohs, Jason K.; Fahlman, Bradley D.

2015-09-01

The synthesis and characterization of four new β-ketiminate hafnium(IV) chloride complexes dichloro-bis[4-(phenylamido)pent-3-en-2-one]-hafnium (4a), dichloro-bis[4-(4-methylphenylamido)pent-3-en-2-one]-hafnium (4b), dichloro-bis[4-(4-methoxyphenylamido)pent-3-en-2-one]-hafnium (4c), and dichloro-bis[4-(4-chlorophenylamido)pent-3-en-2-one]-hafnium (4d) are reported. All the complexes (4a-d) were characterized by spectroscopic methods (1H NMR, 13C NMR, IR), and elemental analysis while the compound 4c was further examined by single-crystal X-ray diffraction, revealing that the complex is monomer with the hafnium center in octahedral coordination environment and oxygens of the chelating N-O ligands are trans to each other and the chloride ligands are in a cis arrangement. Volatile trends are established for four new β-ketiminate hafnium(IV) chloride complexes (4a-d). Sublimation enthalpies (ΔHsub) were calculated from thermogravimetric analysis (TGA) data, which show that, the dependence of ΔHsub on the molecular weight (4a-c) and inductive effects from chlorine (4d).

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates.

PubMed

Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

2015-04-05

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis, spectroscopic characterization, biological screenings, DNA binding study and POM analyses of transition metal carboxylates

NASA Astrophysics Data System (ADS)

Uddin, Noor; Sirajuddin, Muhammad; Uddin, Nizam; Tariq, Muhammad; Ullah, Hameed; Ali, Saqib; Tirmizi, Syed Ahmed; Khan, Abdur Rehman

2015-04-01

This article contains the synthesis of a novel carboxylic acid derivative, its transition metal complexes and evaluation of biological applications. Six carboxylate complexes of transition metals, Zn(II) and Hg(II), have been successfully synthesized and characterized by FT-IR and NMR (1H, 13C). The ligand, HL, (4-[(2,6-Diethylphenyl)amino]-4-oxobutanoic acid) was also characterized by single crystal X-ray analysis. The complexation occurs via oxygen atoms of the carboxylate moiety. FT-IR date show the bidentate nature of the carboxylate moiety of the ligand as the Δν value in all complexes is less than that of the free ligand. The ligand and its complexes were screened for antifungal and antileishmanial activities. The results showed that the ligand and its complexes are active with few exceptions. UV-visible spectroscopy and viscometry results reveal that the ligand and its complexes interact with the DNA via intercalative mode of interaction. A new and efficient strategy to identify the pharmacophores and anti-pharmacophores sites in carboxylate derivatives for the antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out.

RNA Crystallization

NASA Technical Reports Server (NTRS)

Golden, Barbara L.; Kundrot, Craig E.

2003-01-01

RNA molecules may be crystallized using variations of the methods developed for protein crystallography. As the technology has become available to syntheisize and purify RNA molecules in the quantities and with the quality that is required for crystallography, the field of RNA structure has exploded. The first consideration when crystallizing an RNA is the sequence, which may be varied in a rational way to enhance crystallizability or prevent formation of alternate structures. Once a sequence has been designed, the RNA may be synthesized chemically by solid-state synthesis, or it may be produced enzymatically using RNA polymerase and an appropriate DNA template. Purification of milligram quantities of RNA can be accomplished by HPLC or gel electrophoresis. As with proteins, crystallization of RNA is usually accomplished by vapor diffusion techniques. There are several considerations that are either unique to RNA crystallization or more important for RNA crystallization. Techniques for design, synthesis, purification, and crystallization of RNAs will be reviewed here.

Synthesis and structural study of 4-(2-chlorophenyl)-2-ethoxy-5,6,7,8,9,10-hexahydrocycloocta[B]pyridine-3-carbonitrile

NASA Astrophysics Data System (ADS)

Fathima, K. Saiadali; Vasumathi, M.; Anitha, K.

2016-05-01

The novel organic material C20H21ClN2O was synthesized by One-Pot synthesis method and the single crystals were grown by slow evaporation solution growth technique. The crystal structure was elucidated by subjecting the grown crystals to the single crystal x-ray diffraction analysis and was refined by full matrix least-squares method to R=0.039 for 2746 reflections. Crystal system of the grown crystal was found to be monoclinic with the space group P21/a and a=9.196(4) Å, b=13.449(4) Å, c=14.818(4) Å, β= 101.542(3)°, V=1795.6(11) Å3 and Z=4. In this crystal structure, cyclooctanone prefers to reside in a chair-boat conformation. The structure is stabilized by attractive molecular force such as CH/π interaction called hydrophobic interaction.

Insights into Metal Oxide and Zero-Valent Metal Nanocrystal Formation on Multiwalled Carbon Nanotube Surfaces during Sol-Gel Process.

PubMed

Das, Dipesh; Sabaraya, Indu V; Sabo-Attwood, Tara; Saleh, Navid B

2018-06-05

Carbon nanotubes are hybridized with metal crystals to impart multifunctionality into the nanohybrids (NHs). Simple but effective synthesis techniques are desired to form both zero-valent and oxides of different metal species on carbon nanotube surfaces. Sol-gel technique brings in significant advantages and is a viable technique for such synthesis. This study probes the efficacy of sol-gel process and aims to identify underlying mechanisms of crystal formation. Standard electron potential (SEP) is used as a guiding parameter to choose the metal species; i.e., highly negative SEP (e.g., Zn) with oxide crystal tendency, highly positive SEP (e.g., Ag) with zero-valent crystal-tendency, and intermediate range SEP (e.g., Cu) to probe the oxidation tendency in crystal formation are chosen. Transmission electron microscopy and X-ray diffraction are used to evaluate the synthesized NHs. Results indicate that SEP can be a reliable guide for the resulting crystalline phase of a certain metal species, particularly when the magnitude of this parameter is relatively high. However, for intermediate range SEP-metals, mix phase crystals can be expected. For example, Cu will form Cu₂O and zero-valent Cu crystals, unless the synthesis is performed in a reducing environment.

Divalent europium doped and un-doped calcium iodide scintillators: Scintillator characterization and single crystal growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boatner, L. A.; Ramey, J. O.; Kolopus, J. A.

2015-02-21

Initially, the alkaline-earth scintillator, CaI 2:Eu 2+, was discovered around 1964 by Hofstadter, Odell, and Schmidt. Serious practical problems quickly arose, however, that were associated with the growth of large monolithic single crystals of this material due to its lamellar, mica-like structure. As a result of its theoretically higher light yield, CaI 2:Eu 2+ has the potential to exceed the excellent scintillation performance of SrI 2:Eu 2+. In fact, theoretical predictions for the light yield of CaI2:Eu 2+ scintillators suggested that an energy resolution approaching 2% at 662 keV could be achievable. Like the early SrI 2:Eu 2+ scintillator, themore » performance of CaI 2:Eu 2+ scintillators has traditionally suffered due, at least in part, to outdated materials synthesis, component stoichiometry/purity, and single-crystal-growth techniques. Based on our recent work on SrI 2:Eu 2+ scintillators in single-crystal form, we have developed new techniques that are applied here to CaI 2:Eu 2+ and pure CaI 2 with the goal of growing large un-cracked crystals and, potentially, realizing the theoretically predicted performance of the CaI 2:Eu 2+ form of this material. Calcium iodide does not adhere to modern glassy carbon Bridgman crucibles - so there should be no differential thermal-contraction-induced crystal/crucible stresses on cooling that would result in crystal cracking of the lamellar structure of CaI 2. Here we apply glassy carbon crucible Bridgman growth, high-purity growth-charge compounds, our molten salt processing/filtration technique, and extended vacuum-melt-pumping methods to the growth of both CaI 2:Eu 2+ and un-doped CaI 2. Moreover, large scintillating single crystals were obtained, and detailed characterization studies of the scintillation properties of CaI 2:Eu 2+ and pure CaI 2 single crystals are presented that include studies of the effects of plastic deformation of the crystals on the scintillator performance.« less

One-Step Hydrothermal Synthesis of Zeolite X Powder from Natural Low-Grade Diatomite.

PubMed

Yao, Guangyuan; Lei, Jingjing; Zhang, Xiaoyu; Sun, Zhiming; Zheng, Shuilin

2018-05-28

Zeolite X powder was synthesized using natural low-grade diatomite as the main source of Si but only as a partial source of Al via a simple and green hydrothermal method. The microstructure and surface properties of the obtained samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), wavelength dispersive X-ray fluorescence (XRF), calcium ion exchange capacity (CEC), thermogravimetric-differential thermal (TG-DTA) analysis, and N₂ adsorption-desorption technique. The influence of various synthesis factors, including aging time and temperature, crystallization time and temperature, Na₂O/SiO₂ and H₂O/Na₂O ratio on the CEC of zeolite, were systematically investigated. The as-synthesized zeolite X with binary meso-microporous structure possessed remarkable thermal stability, high calcium ion exchange capacity of 248 mg/g and large surface area of 453 m²/g. In addition, the calcium ion exchange capacity of zeolite X was found to be mainly determined by the crystallization degree. In conclusion, the synthesized zeolite X using diatomite as a cost-effective raw material in this study has great potential for industrial application such as catalyst support and adsorbent.

Temperature-dependent Raman spectroscopy studies of the interface coupling effect of monolayer ReSe2 single crystals on Au foils

NASA Astrophysics Data System (ADS)

Jiang, Shaolong; Zhao, Liyun; Shi, Yuping; Xie, Chunyu; Zhang, Na; Zhang, Zhepeng; Huan, Yahuan; Yang, Pengfei; Hong, Min; Zhou, Xiebo; Shi, Jianping; Zhang, Qing; Zhang, Yanfeng

2018-05-01

Rhenium diselenide (ReSe2), which bears in-plane anisotropic optical and electrical properties, is of considerable interest for its excellent applications in novel devices, such as polarization-sensitive photodetectors and integrated polarization-controllers. However, great challenges to date in the controllable synthesis of high-quality ReSe2 have hindered its in-depth investigations and practical applications. Herein, we report a feasible synthesis of monolayer single-crystal ReSe2 flakes on the Au foil substrate by using a chemical vapor deposition route. Particularly, we focus on the temperature-dependent Raman spectroscopy investigations of monolayer ReSe2 grown on Au foils, which present concurrent red shifts of Eg-like and Ag-like modes with increasing measurement temperature from 77–290 K. Linear temperature dependences of both modes are revealed and explained from the anharmonic vibration of the ReSe2 lattice. More importantly, the strong interaction of ReSe2 with Au, with respect to that with SiO2/Si, is further confirmed by temperature-dependent Raman characterization. This work is thus proposed to shed light on the optical and thermal properties of such anisotropic two-dimensional three-atom-thick materials.

Effective removal of hydrogen sulfide using 4A molecular sieve zeolite synthesized from attapulgite.

PubMed

Liu, Xinpeng; Wang, Rui

2017-03-15

In this work, 4A molecular sieve zeolite was synthesized from attapulgite (ATP) in different conditions and was applied initially for H 2 S removal. The sorbent was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectra and N 2 adsorption/desorption. The effects of the synthesis condition and adsorption temperature were studied by dynamic adsorption experiment. The optimal adsorption temperature is 50°C. The H 2 S adsorption results have showed that the optimal synthesis conditions are as follows: the ratio of silicon to aluminum and ratio of sodium to silicon are both 1.5, the ratio of water to sodium is 30, crystallization temperature and crystallization time is 90°C, 4h, respectively. The breakthrough and saturation sulfur sorption capacities of zeolite synthesized under optimum conditions are up to nearly 10 and 15mg/g-sorbent, respectively, and the H 2 S removal rate is nearly 100%. The adsorption kinetics nonlinear fitting results show that the adsorption system follows Bingham model. These results indicate that 4A molecular sieve zeolite synthesized from attapulgite can be used for H 2 S removal promisingly. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis of calcium carbonate using extract components of croaker gill as morphology and polymorph adjust control agent.

PubMed

Chen, Hao; Qing, Chengsong; Zheng, Jiaoling; Liu, Yuxi; Wu, Gang

2016-06-01

Biomimetic synthesis of calcium carbonate with various polymorphs, sizes and morphologies by using organic substrates has become an interesting topic for the last years. Calcium carbonate has been synthesized by the reaction of Na2CO3 and CaCl2 in the presence of extract components of croaker gill. The products were characterized by powder X-ray diffraction (PXRD) and Fourier transform infrared (FT-IR) spectrum, and particle morphologies were observed by scanning electron microscope (SEM). The results show that at lower concentration yellow croaker gill extract has no effect on calcium carbonate crystal polymorph. Calcite was obtained only. But the morphologies of calcite particle change with the increase of the concentration. The corners of the particle change from angular to curved. However, with the further increase of the concentration of yellow croaker gill extract, the calcium carbonate obtained is a mixture of calcite and vaterite. The vaterite component in the mixture rises with increasing concentration of extract solution, indicating that the proteins from the yellow croaker gill during growth play a crucial role in stabilizing and directing the crystal growth. Copyright © 2016 Elsevier B.V. All rights reserved.

One-pot pseudomorphic crystallization of mesoporous porous silica to hierarchical porous zeolites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xing, Jun-Ling; Jiang, Shu-Hua; Pang, Jun-Ling

2015-09-15

Hierarchically porous silica with mesopore and zeolitic micropore was synthesized via pseudomorphic crystallization under high-temperature hydrothermal treatment in the presence of cetyltrimethylammonium tosylate and tetrapropylammonium ions. A combined characterization using small-angle X-ray diffraction (XRD), nitrogen adsorption, high-resolution transmission electron microscopy (TEM), thermogravimetric analysis (TG), and elemental analysis showed that dual templates, CTA{sup +} and TPA{sup +} molecules, can work in a cooperative manner to synthesize mesoporous zeolite in a one-pot system by precisely tuning the reaction conditions, such as reaction time and temperature, and type and amount of heterometal atoms. It is found that the presence of Ti precursor ismore » critical to the successful synthesis of such nanostructure. It not only retards the nucleation and growth of crystalline MFI domains, but also acts as nano-binder or nano-glue to favor the assembly of zeolite nanoblocks. - Graphical abstract: Display Omitted - Highlights: • A facile method to synthesize mesoporous zeolites with hierarchical porosity was presented. • It gives a new insight into keeping the balance between mesoscopic and molecular ordering in hierarchical porous materials. • A new understanding on the solid–solid transformation mechanism for the synthesis of titanosilicate zeolites was proposed.« less

Direct synthesis of antimicrobial coatings based on tailored bi-elemental nanoparticles

NASA Astrophysics Data System (ADS)

Benetti, Giulio; Cavaliere, Emanuele; Canteri, Adalberto; Landini, Giulia; Rossolini, Gian Maria; Pallecchi, Lucia; Chiodi, Mirco; Van Bael, Margriet J.; Winckelmans, Naomi; Bals, Sara; Gavioli, Luca

2017-03-01

Ultrathin coatings based on bi-elemental nanoparticles (NPs) are very promising to limit the surface-related spread of bacterial pathogens, particularly in nosocomial environments. However, tailoring the synthesis, composition, adhesion to substrate, and antimicrobial spectrum of the coating is an open challenge. Herein, we report on a radically new nanostructured coating, obtained by a one-step gas-phase deposition technique, and composed of bi-elemental Janus type Ag/Ti NPs. The NPs are characterized by a cluster-in-cluster mixing phase with metallic Ag nano-crystals embedded in amorphous TiO2 and present a promising antimicrobial activity including also multidrug resistant strains. We demonstrate the flexibility of the method to tune the embedded Ag nano-crystals dimension, the total relative composition of the coating, and the substrate type, opening the possibility of tailoring the dimension, composition, antimicrobial spectrum, and other physical/chemical properties of such multi-elemental systems. This work is expected to significantly spread the range of applications of NPs coatings, not only as an effective tool in the prevention of healthcare-associated infections but also in other technologically relevant fields like sensors or nano-/micro joining.

One pot synthesis, X-ray crystal structure of 2-(2‧-hydroxyphenyl)oxazolo[4,5-b]pyridine derivatives and studies of their optical properties

NASA Astrophysics Data System (ADS)

Briseño-Ortega, Horacio; Juárez-Guerra, Lizbeth; Rojas-Lima, Susana; Mendoza-Huizar, Luis Humberto; Vázquez-García, Rosa A.; Farfán, Norberto; Arcos-Ramos, Rafael; Santillan, Rosa; López-Ruiz, Heralio

2018-04-01

A series of five 2-(2-hydroxyphenyl)oxazolo [4,5-b]pyridines (HPOP) (3a-e), where four are novel, were synthesized by a mild, one pot, phenylboronic acid-NaCN catalyzed reaction. Spectroscopic characterization and photophysical properties of these compounds are reported. Absorption and excitation spectra of the compounds were dependent on the substituents in the phenyl ring. Fluorescence quantum yields (0.009-0.538) were associated with the donor strength and the position of the substituents. Also, DFT analysis allowed us to determine the contribution of diethylamino and methoxy moieties to the π-system, which is in agreement with the experimental data analyzed in solution and by cyclic voltammetry. The results obtained in the solid state by single-crystal X-ray diffraction experiments indicate that, the quasi-planarity envisioned for the explored compounds is present, supporting the hypothesis that both the H-bonding of a hydroxyl group to the Cdbnd N moiety and a donor groups such as diethylamino and methoxy moieties favor an electronic communication. Due to the facile synthesis and their photophysical properties, the novel HPOP 3a-e have potential application as organic semiconductors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boppana, Venkata Bharat Ram; Hould, Nathan D.; Lobo, Raul F., E-mail: lobo@udel.ed

We report the first instance of a hydrothermal synthesis of zinc germanate (Zn{sub 2}GeO{sub 4}) nano-materials having a variety of morphologies and photochemical properties in surfactant, template and catalyst-free conditions. A systematic variation of synthesis conditions and detailed characterization using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, Raman spectroscopy, electron microscopy, X-ray photoelectron spectroscopy and small angle X-ray scattering led to a better understanding of the growth of these particles from solution. At 140 {sup o}C, the zinc germanate particle morphology changes with pH from flower-shaped at pH 6.0, to poly-disperse nano-rods at pH 10 when the Zn to Ge ratiomore » in the synthesis solution is 2. When the Zn to Ge ratio is reduced to 1.25, mono-disperse nano-rods could be prepared at pH 7.5. Nanorod formation is also independent of the addition of cetyltrimethylammonium bromide (CTAB), in contrast to previous reports. Photocatalytic tests show that Zn{sub 2}GeO{sub 4} nano-rods (by weight) and flower shaped (by surface area) are the most active for methylene blue dye degradation among the synthesized zinc germanate materials. -- Graphical abstract: Zinc germanate materials were synthesized possessing unique morphologies dependent on the hydrothermal synthesis conditions in the absence of surfactant, catalyst or template. These novel materials are characterized and evaluated for their photocatalytic activities. Display Omitted highlights: > Zinc germanate synthesized hydrothermally (surfactant free) with unique morphologies. > Flower-shaped, nano-rods, globular particles obtained dependent on synthesis pH. > At 140 {sup o}C, they possess the rhombohedral crystal irrespective of synthesis conditions. > They are photocatalytically active for the degradation of methylene blue. > Potential applications could be photocatalytic water splitting and CO{sub 2} reduction.« less

Excitons in Cuprous Oxide: Photoionization and Other Multiphoton Processes

NASA Astrophysics Data System (ADS)

Frazer, Nicholas Laszlo

In cuprous oxide (Cu2O), momentum from the absorption of two infrared photons to make an orthoexciton is conserved and detected through the photon component of a resulting mixed exciton/photon (quadrupole exciton polariton) state. I demonstrated that this process, which actually makes the photon momentum more precisely defined, is disrupted by photoionization of excitons. Some processes are known to affect exciton propagation in both the pump and exciton stages, such as phonon emission, exciton-exciton (Auger) scattering, and third harmonic generation. These processes alone were not able to explain all observed losses of excitons or all detected scattering products, which lead me to design an optical pump-probe experiment to measure the exciton photoionization cross section, which is (3.9+/-0.2) x 10-22 m2. This dissertation describes the synthesis of cuprous oxide crystals using oxidation of copper, crystallization from melt with the optical floating zone method, and annealing. The cuprous oxide crystals were characterized using time and space resolved luminescence, leading to the discovery of new defect properties. Selection rules and overall efficiency of third harmonic generation in these crystals were characterized. Exciton photoionization was demonstrated through the depletion of polariton luminescence by an optical probe, the production of phonon linked luminescence as a scattering product, temporal delay of the probe, and time resolved luminescence. The results are integrated with the traditional dynamical model of exciton densities. An additional investigation of copper/cuprous oxide/gold photovoltaic devices is appended.

The Impact of Chemical Substitutions on Interfacial Properties of REE Orthophosphates (Monazite, Xenotime)

NASA Astrophysics Data System (ADS)

Gamage McEvoy, J.; Thibault, Y.

2016-12-01

Mineral surface properties strongly influence liquid-solid interface behaviour in the presence of various ligands, and can significantly affect processes of natural (ex. fluids, melts) and industrial (ex. oil recovery) relevance. Many Rare Earth Element (REE)-bearing minerals display extensive solid solutions resulting in significant chemical variations which influence their crystal and surface properties and, can consequently impact the interfacial features of their interaction with substances such as organic molecules (i.e. reactivity and sorption). For example, the surface charge properties of some REE orthophosphates show an uncharacteristically wide variation in reported values, where large differences in literature are commonly attributed to compositional differences between samples. However the impact of these chemical substitutions remains largely unknown. As such, the aim of this research was to systematically investigate the influence of mineralogical variation within the compositional space of the REE orthophosphates on their surface chemistry and resulting interaction with organic molecules. To better isolate the chemical, structural, and morphological variables, the synthesis of REE orthophosphate crystals along a number of defined substitutions was conducted, and their surface chemistry characteristics benchmarked against well-characterized natural monazite and xenotime from various localities. The interaction of these crystal surfaces with model organic molecules (long chain carboxylic acids and alkyl hydroxamic acids, respectively) was then studied and characterized via surface (X-ray photoelectron) and near-surface (vibrational) spectroscopic techniques. The implications of crystal surface-organic molecule interactions to mineral processing through flotation were also experimentally investigated.

Synthesis, crystal structure, Hirshfeld surface analysis, spectroscopic characterization, reactivity study by DFT and MD approaches and molecular docking study of a novel chalcone derivative

NASA Astrophysics Data System (ADS)

Arshad, Suhana; Pillai, Renjith Raveendran; Zainuri, Dian Alwani; Khalib, Nuridayanti Che; Razak, Ibrahim Abdul; Armaković, Stevan; Armaković, Sanja J.; Panicker, C. Yohannan; Van Alsenoy, C.

2017-05-01

In the present study, the title compound named as (E)-1-(4-bromophenyl)-3-(4-(trifluoromethyl)phenyl)prop-2-en-1-one was synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in monoclinic crystal system in P21/c space group, unit cell parameters a = 16.7629 (12) Å, b = 13.9681 (10) Å, c = 5.8740 (4) Å, β = 96.3860 (12)° and Z = 4. Hirshfeld surface analysis revealed that the molecular structure is dominated by H⋯H, C⋯H/H⋯C, Br⋯F/F⋯Br and F⋯F contacts. The FT-IR spectrum was recorded and interpreted in details with the aid of Density Functional Theory (DFT) calculations and Potential Energy Distribution (PED) analysis. Average local ionization energies (ALIE) and Fukui functions have been used as quantum-molecular descriptors to locate the molecule sites that could be of importance from the aspect of reactivity. Degradation properties have been assessed by calculations of bond dissociation energies (BDE) for hydrogen abstraction and the rest of the single acyclic bonds, while molecular dynamics (MD) simulations were used in order to calculate radial distribution functions and determine the atoms with significant interactions with water. In order to understand how the title molecule inhibits and hence increases the catalytic efficiency of MOA-B enzyme, molecular docking study was performed.

Fabrication and Characterizations of Ethanol Sensor Based on CuO Nanoparticles.

PubMed

Al-Hadeethi, Yas; Umar, Ahmad; Kumar, Rajesh; Al-Heniti, Saleh H; Raffah, Bahaaudin M

2018-04-01

In this paper, we report the synthesis, characterization and ethanol sensing applications of CuO nanoparticles. The CuO nanoparticles were prepared by a facile, low-temperature hydrothermal method and characterized in detail in terms of their structural, morphological, compositional and crystalline properties, through different characterization techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectroscopy. The detailed studies revealed that the synthesized CuO nanoparticles were well-crystalline and possessed monoclinic crystal structure. The synthesized CuO nanoparticles were utilized for the fabrication of highly sensitive ethanol gas sensor. At an optimized temperature of 320 °C, high sensitivity (Ra/Rg) of 39.29 was observed for 200 ppm of ethanol gas. Additionally, very low response (τres = 14 s) and recovery (τrec = 30 s) times were observed for 100 ppm of ethanol.

New transition metal complexes and their ring-opened polymers

NASA Astrophysics Data System (ADS)

Apodaca, Paula

An exciting new class of metallacycle (eta5-C5 H4Fe) (CO)2CH2SiR2 that undergoes ring-opening polymerization was recently reported by Sharma et al. [1]. We are interested in further expanding this research area by synthesizing related cyclopentadienyl derivatives containing Fe, Mo, and W in combination with other elements of the group 14. We report here the synthesis and crystal structure characterization of new germa-metallacyclobutanes of Mo and W. In addition, we have successfully synthesized and characterized new ring-opening polymers of the related germanium systems [(eta5-C5 H4Fe)(CO) 2(CH2GeR2)] n. The new polymers were characterized using various spectroscopic techniques and gel permeation chromatography. The recent report on the synthesis of a new class of siloxane polymers based upon base-catalyzed ring opening of phenylene-bridged cyclic siloxanes [2] encouraged us to investigate the related ferrocenyl (Fc, (C5H 5)Fe(C5H4)) siloxane systems. The incorporation of ferrocene could provide new materials with all the interesting properties usually associated with these groups such as thermal and photochemical stability, electrochemical activity and potentially conducting materials. Thus far a new required organometallic monomer containing Fc-R, where R = disilaoxacyclopentene 5 has been synthesized and completely characterized. Based-induced ring-opening polymerizations of 5 were attempted under different reaction conditions and produced, inter alia: (C5H5)Fe(C 5H4)C(SiMe2OH)=CH(SiMe2R), R = nBu (2), tBu (3), Ph (4). The single crystal X-ray structures and full spectroscopic analysis of such products has been accomplished. Furthermore, the reactivity of the ferrocenyl silanols concerning condensation and their behavior under acidic conditions has been investigated. 1Sharma, H.; Cervantes-Lee, F.; Pannell, K. H. J. Am. Chem. Soc. 2004, 126, 1326. 2 Loy, A. D.; Rahimian, K.; Samara, M. Angew. Chem. 1999, 38, 45.

Synthesis of a potential semiconductor neutron detector crystal LiGa(Se/Te)2: materials purity and compatibility effects

NASA Astrophysics Data System (ADS)

Stowe, Ashley C.; Morrell, J.; Battacharya, Pijush; Tupitsyn, Eugene; Burger, Arnold

2011-09-01

Lithium containing AIBIIICVI semiconductors are being considered as alternative materials for room temperature neutron detection. One of the primary challenges in growing a high quality crystal of such a material is the reactivity of lithium metal. The presence of nitrides, oxides, and a variety of alkali and alkaline earth metal impurities prevent pure synthesis and truncate crystal growth by introducing multiple nucleation centers during growth. Multiple lithium metal purification methods have been investigated which ultimately raised the metal purity to 99.996%. Multi-cycle vacuum distillation removed all but 40 ppm of metal impurities in lithium metal. LiGa(Se/Te)2 was then synthesized with the high purity lithium metal by a variety of conditions. Lithium metal reacts violently with many standard crucible materials, and thermodynamic studies were undertaken to insure that an appropriate crucible choice was made, with high purity iron and boron nitride crucibles being the least reactive practical materials. Once conditions were optimized for synthesis of the chalcopyrite, vertical Bridgman crystal growth resulted in red crystals. The optical, electronic, and thermodynamic properties were collected.

Synthesis of Aluminium Nanoparticles in A Water/Polyethylene Glycol Mixed Solvent using μ-EDM

NASA Astrophysics Data System (ADS)

Sahu, R. K.; Hiremath, Somashekhar S.

2017-08-01

Nanoparticles present a practical way of retaining the results of the property at the atomic or molecular level. Due to the recent use of nanoparticles in scientific, industrial and medical applications, synthesis of nanoparticles and their characterization have become considerably important. Currently, aluminium nanoparticles have attracted significant research attention because of their reasonable cost, unique properties and interdisciplinary emerging applications. The present paper reports the synthesis of aluminium nanoparticles in the mixture of Deionized water (DI water) and Polyethylene Glycol (PEG) using a developed micro-Electrical Discharge Machining (μ-EDM) method. PEG was used as a stabilizer to prevent nanoparticles from agglomeration produced during the μ -EDM process. The synthesized aluminium nanoparticles were examined by Transmission Electron Microscopy (TEM), Energy Dispersive Analysis by X-rays (EDAX) and Selected Area Electron Diffraction (SAED) pattern to determine their size, shape, chemical nature and crystal structure. The average size of the polyhedral aluminium nanoparticles is found to be 196 nm.

Hierarchical macro-mesoporous structures in the system TiO{sub 2}-Al{sub 2}O{sub 3}, obtained by hydrothermal synthesis using Tween-20 as a directing agent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia-Benjume, M.L.; Espitia-Cabrera, M.I.; Contreras-Garcia, M.E., E-mail: eucontre@zeus.umich.mx

2009-12-15

Macro-mesoporous powders of titania, alumina, and mixed titania-20%alumina systems were obtained by hydrothermal synthesis employing surfactant Tween-20 as structural directing agent in order to promote the textural properties of titania. The effect of the alumina in the titania phase and on textural properties was analyzed. The obtained powders presented a macroporous channel structure that was characterized by X-ray diffractometry, scanning and transmission electron microscopy, N{sub 2} adsorption-desorption analysis, pore size distribution, Fourier transform infrared spectrometry, and thermogravimetric analysis. It was found that alumina content retarded the anatase phase crystallization and increased the Brunauer-Emmet-Teller surface area from 136 to 210 m{supmore » 2}/g. The powders calcined at 400 deg. C are thermally stable and possess an interconnected macro-mesoporous hierarchical structure; the results indicate that this synthesis can be employed to prepare mixed titania-alumina with good textural properties.« less

Synthesis and characterization of TEP-EDTA-regulated bioactive hydroxyapatite

NASA Astrophysics Data System (ADS)

Haders, Daniel Joseph, II

Hydroxyapatite (HA), Ca10(PO4)6(OH) 2, the stoichiometric equivalent of the ceramic phase of bone, is the preferred material for hard tissue replacement due to its bioactivity. However, bioinert metals are utilized in load-bearing orthopedic applications due to the poor mechanical properties of HA. Consequently, attention has been given to HA coatings for metallic orthopedic implants to take advantage of the bioactivity of HA and the mechanical properties of metals. Commercially, the plasma spray process (PS-HA) is the method most often used to deposit HA films on metallic implants. Since its introduction in the 1980's, however, concerns have been raised about the consequences of PS-HA's low crystallinity, lack of phase purity, lack of film-substrate chemical adhesion, passivation properties, and difficulty in coating complex geometries. Thus, there is a need to develop inexpensive reproducible next-generation HA film deposition techniques, which deposit high crystallinity, phase pure, adhesive, passivating, conformal HA films on clinical metallic substrates. The aim of this dissertation was to intelligently synthesize and characterize the material and biological properties of HA films on metallic substrates synthesized by hydrothermal crystallization, using thermodynamic phase diagrams as the starting point. In three overlapping interdisciplinary studies the potential of using ethylenediamine-tetraacetic acid/triethyl phosphate (EDTA/TEP) doubly regulated hydrothermal crystallization to deposit HA films, the TEP-regulated, time-and-temperature-dependent process by which films were deposited, and the bioactivity of crystallographically engineered films were investigated. Films were crystallized in a 0.232 molal Ca(NO3)2-0.232 molal EDTA-0.187 molal TEP-1.852 molal KOH-H2O chemical system at 200°C. Thermodynamic phase diagrams demonstrated that the chosen conditions were expected to produce Ca-P phase pure HA, which was experimentally confirmed. EDTA regulation of Ca2+ concentration enabled the HA crystallization process to be growth dominated, producing films composed of high crystallinity, hexagonal grains on multiple metallic substrates. TEP regulation of HA crystallization enabled the deposition of an adhesive CaTiO3 intermediate layer, and then HA in a continuous, phase sequenced process on Ti6Al4V substrates, the first such process reported in the hydrothermal HA literature. The HA film was found to be deposited by a passivating competitive growth mechanism that enabled the [0001] crystallographic orientation of hexagonal single crystals to be engineered with synthesis time. Bioactivity analysis demonstrated that films were bioactive and bone bonding. Together, these results suggest that these HA films are candidates for use on metallic orthopedic implants, namely Ti6Al4V.

Biosynthesis of silver nanoparticles using fresh extracts of Tridax procumbens linn.

PubMed

Bhati-Kushwaha, Himakshi

2014-04-01

A simple and eco-friendly method for the synthesis of biogenic nanoparticles (NP's) using an aqueous solution of T. procumbens fresh plant extract (leaf and stem) as a bioreductant is reported. The prepared biogenic nanoparticles were well characterized using U.V. visible spectroscopy, scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy. The particles were confirmed to be elemental crystal by X-ray diffraction. The potential applications of biosynthesized nanoparticles as antimicrobial (antibacterial and antifungal) against pathogens Escherichia coli, Vibrio cholerae, Aspergillus niger and Aspergillusflavus were demonstrated.

Synthesis, Crystal Structures and Properties of Ferrocenyl Bis-Amide Derivatives Yielded via the Ugi Four-Component Reaction.

PubMed

Zhao, Mei; Shao, Guang-Kui; Huang, Dan-Dan; Lv, Xue-Xin; Guo, Dian-Shun

2017-05-04

Ten ferrocenyl bis-amide derivatives were successfully synthesized via the Ugi four-component reaction by treating ferrocenecarboxylic acid with diverse aldehydes, amines, and isocyanides in methanol solution. Their chemical structures were fully characterized by IR, NMR, HR-MS, and X-ray diffraction analyses. They feature unique molecular morphologies and create a 14-membered ring motif in the centro-symmetric dimers generated in the solid state. Moreover, the electrochemical behavior of these ferrocenyl bis-amides was assessed by cyclic voltammetry.

Ferroelectric fluoride compositions and methods of making and using same

DOEpatents

Halasyamani, P Shiv; Chang, Hong-Young

2015-04-07

A method for synthesis of a ferroelectric material characterized by the general formula A.sub.xB.sub.yF.sub.z where A is an alkaline earth metal, B is transition metal or a main group metal, x and y each range from about 1 to about 5, and z ranges from about 1 to about 20 comprising contacting an alkaline earth metal fluoride, a difluorometal compound and a fluoroorganic acid in a medium to form a reaction mixture; and subjecting the reaction mixture to conditions suitable for hydrothermal crystal growth.

Synthesis and characterization of Cu3(BTC)2 membranes by thermal spray seeding and secondary growth.

PubMed

Noh, Seung-Jun; Kwon, Hyuk Taek; Kim, Jinsoo

2013-08-01

Crack-free Cu3(BTC)2 membranes were successfully prepared by thermal spray seeding and secondary growth method. Thermal spray seeding method, combining thermal seeding and pressurized spraying, uniformly distributed seed solution on the support, anchoring seed crystals tightly on the support. After secondary growth of the seeded support in the autoclave, continuous crack-free membrane was obtained by controlling cooling and drying steps. The gas permeation test was conducted at various temperatures using H2, CO2, CH4 and N2 gases.

Simultaneous phase and morphology controllable synthesis of copper selenide films by microwave-assisted nonaqueous approach

NASA Astrophysics Data System (ADS)

Li, Jing; Fa, Wenjun; Li, Yasi; Zhao, Hongxiao; Gao, Yuanhao; Zheng, Zhi

2013-02-01

Copper selenide films with different phase and morphology were synthesized on copper substrate through controlling reaction solvent by microwave-assisted nonaqueous approach. The films were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that the pure films could be obtained using cyclohexyl alcohol or benzyl alcohol as solvent. The cubic Cu2-xSe dendrites were synthesized in cyclohexyl alcohol reaction system and hexagonal CuSe flaky crystals were obtained with benzyl alcohol as solvent.

Synthesis, crystal structure, and spectroscopic characterization of trans-bis[(mu-1,3-bis(4-pyridyl)propane)(mu-(3-thiopheneacetate-O))(3-thiopheneacetate-O)]dicopper(II), [[Cu2(O2CCH2C4H3S)4mu-(BPP)2

PubMed

Marinho, Maria Vanda; Yoshida, Maria Irene; Guedes, Kassilio J; Krambrock, Klaus; Bortoluzzi, Adailton J; Hörner, Manfredo; Machado, Flávia C; Teles, Wagner M

2004-02-23

From the reaction between a dinuclear paddle-wheel carboxylate, namely [Cu2mu-(O2CCH2C4H3S)4] (1), and the flexible ligand 1,3-bis(4-pyridyl)propane (BPP) a neutral 2-D coordination polymer [[Cu2(O2CCH2C4H3S)4mu-(BPP)2

Synthesis and Raman scattering of GaN nanorings, nanoribbons and nanowires

NASA Astrophysics Data System (ADS)

Li, Z. J.; Chen, X. L.; Li, H. J.; Tu, Q. Y.; Yang, Z.; Xu, Y. P.; Hu, B. Q.

Low-dimensional GaN materials, including nanorings, nanoribbons and smooth nanowires have been synthesized by reacting gallium and ammonia using Ag particles as a catalyst on the substrate of MgO single crystals. They were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). EDX, XRD indicated that the low-dimensional nanomaterials were wurtzite GaN. New features are found in Raman scatterings for these low-dimensional GaN materials, which are different from the previous observations of GaN materials.

Synthesis, characterization and monoamine transporter activity of the new psychoactive substance mexedrone and its N-methoxy positional isomer, N-methoxymephedrone

PubMed Central

McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V.; Power, John D.; Dowling, Geraldine; Twamley, Brendan; O'Brien, John; Talbot, Brian; Walther, Donna; Partilla, John S.; Baumann, Michael H.; Brandt, Simon D.

2017-01-01

3-Methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone) appeared in 2015 and was advertised by UK Internet retailers as a non-controlled mephedrone derivative (2-(methylamino)-1-(4-methylphenyl)propan-1-one), which was of particular interest to countries who operate generic drugs legislation. This study describes the synthesis and analytical characterization of mexedrone and the differentiation from its isomer, N-methoxymephedrone, which was predicted to be a suitable candidate before the identity of mexedrone was revealed. A full analytical characterization is described using various chromatographic, spectroscopic and mass spectrometric platforms and X-ray crystal structure analysis. The analytical data obtained for a vendor sample were consistent with the synthesized mexedrone reference standard and analytical differentiation between the mexedrone and N-methoxymephedrone positional isomers was achieved. Furthermore, α-chloromethylmephedrone was identified as a by-product during mexedrone synthesis. All three substances were also studied for their uptake and releasing properties at dopamine transporters (DAT), norepinephrine transporters (NET) and serotonin transporters (SERT) using in vitro monoamine transporter assays in rat brain synaptosomes and compared to mephedrone. Mexedrone was a weak non-selective uptake blocker with IC50 values in the low μM range. It was also devoid of releasing activity at DAT and NET but displayed weak releasing activity at SERT (EC50= 2.5 μM). The isomer N-methoxymephedrone was found to be a weak uptake blocker at DAT, NET and SERT, as well as a fully efficacious substrate-type releasing agent across all three transporters with EC50 values in the low micromolar range. The synthesis by-product α-chloromethylmephedrone was inactive in all assays. PMID:27524685

Synthesis, characterization and monoamine transporter activity of the new psychoactive substance mexedrone and its N-methoxy positional isomer, N-methoxymephedrone.

PubMed

McLaughlin, Gavin; Morris, Noreen; Kavanagh, Pierce V; Power, John D; Dowling, Geraldine; Twamley, Brendan; O'Brien, John; Talbot, Brian; Walther, Donna; Partilla, John S; Baumann, Michael H; Brandt, Simon D

2017-03-01

3-Methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone) appeared in 2015 and was advertised by UK Internet retailers as a non-controlled mephedrone derivative (2-(methylamino)-1-(4-methylphenyl)propan-1-one), which was of particular interest to countries who operate generic drugs legislation. This study describes the synthesis and analytical characterization of mexedrone and the differentiation from its isomer, N-methoxymephedrone, which was predicted to be a suitable candidate before the identity of mexedrone was revealed. A full analytical characterization is described using various chromatographic, spectroscopic and mass spectrometric platforms and X-ray crystal structure analysis. The analytical data obtained for a vendor sample were consistent with the synthesized mexedrone reference standard and analytical differentiation between the mexedrone and N-methoxymephedrone positional isomers was achieved. Furthermore, α-chloromethylmephedrone was identified as a by-product during mexedrone synthesis. All three substances were also studied for their uptake and releasing properties at dopamine transporters (DAT), norepinephrine transporters (NET) and serotonin transporters (SERT) using in vitro monoamine transporter assays in rat brain synaptosomes and compared to mephedrone. Mexedrone was a weak non-selective uptake blocker with IC 50 values in the low μM range. It was also devoid of releasing activity at DAT and NET but displayed weak releasing activity at SERT (EC 50  = 2.5 μM). The isomer N-methoxymephedrone was found to be a weak uptake blocker at DAT, NET and SERT, as well as a fully efficacious substrate-type releasing agent across all three transporters with EC 50 values in the low micromolar range. The synthesis by-product α-chloromethylmephedrone was inactive in all assays. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

1-(2-biphenyl)-3-methyltriazenide-N-oxide as a template for intramolecular copper(II)⋯arene-π interactions

NASA Astrophysics Data System (ADS)

Paraginski, Gustavo Luiz; Hörner, Manfredo; Back, Davi Fernando; Wohlmuth Alves dos Santos, Aline Joana Rolina; Beck, Johannes

2016-01-01

Deprotonated triazene N-oxides are able to chelate metal ions resulting in five-membered rings without carbon atoms. A new ligand 1-(2-biphenyl)-3-methyltriazenide-N-oxide (1) and its mononuclear Cu(II) complex (2) were synthesized to verify the capability of this ligand to promote Cu(II)⋯arene-π interactions. Ligand 1 and complex 2 have been characterized by elemental analysis, mass spectrometry (ESI(+)-TOF), IR, and UV-Vis spectroscopy. In addition, ligand 1 was characterized by 1H and 13C NMR and complex 2 by X-ray diffraction on single crystal. The crystal structure of complex 2 reveals a distorted tetrahedral geometry of Cu(II) in the first coordination sphere, which expands to a distorted octahedral environment by two symmetrically independent intramolecular metal⋯arene-π interactions. These interactions are provided by ortho-phenyl rings of both triazene N-oxide ligands 1. The aim of this work was to contribute to the architecture of new Cu(II)⋯arene-π complexes based on the synthesis of appropriated ligand for intramolecular interactions

Lanthanum cerate (La2Ce2O7): hydrothermal synthesis, characterization and optical properties

NASA Astrophysics Data System (ADS)

Khademinia, Shahin; Behzad, Mahdi

2015-03-01

La2Ce2O7 nano-powders were synthesized via a hydrothermal reaction in a deionized water (S 1) and in a 2 M NaOH aqueous solution (S 2) at 180 °C for 48 h. La(NO3)3·H2O and (NH4)2Ce(NO3)6 were used in the stoichiometric 1:1 La:Ce molar ratio as raw materials. The obtained materials were crystallized in a cubic crystal structure with space group. The synthesized materials were characterized by powder X-ray diffraction technique and Fourier-transform infrared spectroscopy. To investigate the effect of the basic solution on the morphology of the obtained materials, the morphologies of the synthesized materials were studied by field emission scanning electron microscopy technique. The technique showed that the morphology of La2Ce2O7 samples changed from grain to rod-like structure in presence of the basic solution. Cell parameter refinements showed that these parameters were larger for S2 than those for S 1. Photoluminescence and ultraviolet visible spectra of the synthesized nanomaterials were also investigated.

Synthesis, Characterization, Detonation Performance, and DFT Calculation of HMX/PNO Cocrystal Explosive

NASA Astrophysics Data System (ADS)

Lin, He; Chen, Jian-Fu; Zhu, Shun-Guan; Li, Hong-Zhen; Huang, Yong

2017-01-01

A novel 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)/pyridine-N-oxide (PNO) cocrystal at 1:1 molar ratio was synthesized by a solvent evaporation method, and its crystal structure was determined using X-ray diffraction (XRD). It crystallizes in the orthorhombic system with the Pbcn space group and cell parameters a = 12.712(3)Å, b = 9.315(3)Å, c = 12.909(3)Å. In addition, detonation performance of this cocrystal was estimated. The predicted detonation velocity and detonation pressure of this cocrystal are 7.47 km/s and 23.20 GPa, respectively, suggesting that it is less powerful than β-HMX. Finally, density functional theory, involving binding energy, atoms in molecule (AIM) theory, natural bond orbital (NBO) analysis, band structure, and density of states, was adopted to characterize the driving forces for the formation of this cocrystal. The results show that driving forces are dominated by the interactions between O atoms of PNO and methylene groups of HMX. It is expected that this research provides some bases for further HMX cocrystal design and preparation.

Organic compounds containing methoxy and cyanoacrylic acid: Synthesis, characterization, crystal structures, and theoretical studies

NASA Astrophysics Data System (ADS)

Khalaji, A. D.; Maddahi, E.; Dusek, M.; Fejfarova, K.; Chow, T. J.

2015-12-01

Metal-free organic compounds 24-SC (( E)-2-cyano-3-(2,4-dimethoxyphenyl)acrylic acid) and 34-SC (( E)-2-cyano-3-(3,4-dimethoxyphenyl)acrylic acid), containing methoxy groups as a donor and the acrylic acid as an acceptor were synthesized and characterized by CHN, FT-IR, UV-Vis, 1H-NMR and single crystal X-ray diffraction and used as photosensitizers for the application of dye-sensitized solar cells (DSSC). The sensitizing characteristics of them were evaluated. Both compounds contain the natural molecule, its anionic form and the piperidinium cation and they differ by number of these molecules in the asymmetric unit. To get further insight into the effect of molecular structure on the performance of DSSC, their geometry and energies of HOMO and LUMO were optimized by density functional theory calculation at the B3LYP/6-31G(d) level with Gaussian 03. Overall conversion efficiencies of 0.78 under full sunlight irradiation are obtained for DSSCs based on the new metal-free organic dyes 24-SC and 34-SC.

Synthesis, characterization, and thermal analysis of a new energetic salt based on 1'-hydroxy-1H,1'H-5,5'-bitetrazol-1-olate

NASA Astrophysics Data System (ADS)

Niu, Chunhuan; Jin, Bo; Shang, Yu; Liu, Qiangqiang; Peng, Rufang

2018-04-01

4-Amino-1,2,4-triazolium 1'-hydroxy-1H,1'H-5,5'-bitetrazol-1-olate (ATHBTO) was synthesized by reacting 4-amino-1,2,4-triazole (AT) and 1H,1‧H-5,5‧-bistetrazole-1,1‧-diolate dihydrate (H2BTO.2H2O). Its crystal structure was characterized through single-crystal X-ray diffraction. Meanwhile, FTIR, 1H NMR, 13C NMR, and elemental analysis were also introduced to analyze its composition. The thermal stability was investigated by differential scanning calorimetry, thermogravimetric analysis, and thermogravimetric tandem infrared spectrum. Results indicated that ATHBTO exhibited excellent resistance to thermal decompositions reaching 511.4 K and had a 64.6% mass loss between 475.7 and 552.3 K. The kinetics parameters were calculated by Kissinger's method and Ozawa-Doyle's method. Moreover, according to the Kamlet-Jacobs formula, the calculated detonation velocity and detonation pressure of ATHBTO attained 8218 m/s and 28.69 GPa, respectively.

Detection of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core photonic crystal fiber

NASA Astrophysics Data System (ADS)

Tiwari, Vidhu S.; Khetani, Altaf; Monfared, Ali Momenpour T.; Smith, Brett; Anis, Hanan; Trudeau, Vance L.

2012-03-01

The present work explores the feasibility of using surface enhanced Raman scattering (SERS) for detecting the neurotransmitters such as glutamate (GLU) and gamma-amino butyric acid (GABA). These amino acid neurotransmitters that respectively mediate fast excitatory and inhibitory neurotransmission in the brain, are important for neuroendocrine control, and upsets in their synthesis are also linked to epilepsy. Our SERS-based detection scheme enabled the detection of low amounts of GLU (10-7 M) and GABA (10-4 M). It may complement existing techniques for characterizing such kinds of neurotransmitters that include high-performance liquid chromatography (HPLC) or mass spectrography (MS). This is mainly because SERS has other advantages such as ease of sample preparation, molecular specificity and sensitivity, thus making it potentially applicable to characterization of experimental brain extracts or clinical diagnostic samples of cerebrospinal fluid and saliva. Using hollow core photonic crystal fiber (HC-PCF) further enhanced the Raman signal relative to that in a standard cuvette providing sensitive detection of GLU and GABA in micro-litre volume of aqueous solutions.

Crystal Structure of a UDP-glucose-specific Glycosyltransferase from a Mycobacterium Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fulton, Zara; McAlister, Adrian; Wilce, Matthew C.J.

2008-10-24

Glycosyltransferases (GTs) are a large and ubiquitous family of enzymes that specifically transfer sugar moieties to a range of substrates. Mycobacterium tuberculosis contains a large number of GTs, many of which are implicated in cell wall synthesis, yet the majority of these GTs remain poorly characterized. Here, we report the high resolution crystal structures of an essential GT (MAP2569c) from Mycobacterium avium subsp. paratuberculosis (a close homologue of Rv1208 from M. tuberculosis) in its apo- and ligand-bound forms. The structure adopted the GT-A fold and possessed the characteristic DXD motif that coordinated an Mn{sup 2+} ion. Atypical of most GTsmore » characterized to date, MAP2569c exhibited specificity toward the donor substrate, UDP-glucose. The structure of this ligated complex revealed an induced fit binding mechanism and provided a basis for this unique specificity. Collectively, the structural features suggested that MAP2569c may adopt a 'retaining' enzymatic mechanism, which has implications for the classification of other GTs in this large superfamily.« less

Nanoscale building blocks in a novel lithium arsenotungsten bronze: Synthesis and characterization

DOE PAGES

Zhao, Pei; Mangir Murshed, M.; Huq, Ashfia; ...

2015-02-19

Here we report on a novel compound Li 3AsW 7O 25 obtained by solid-state reaction and characterized by diffraction and spectroscopic methods. The bronze-type compound crystallizes in the orthorhombic space group Pbca with a=724.38(3) pm, b=1008.15(4) pm, c=4906.16(17) pm and Z=8. The structure is built up by chains of WO 6 octahedra interconnected by AsO 4 tetrahedra and WO 6 octahedra forming a polyhedral arrangement as seen in intergrowth tungsten bronzes. The X-ray single crystal structure refinement allows solving the complex arsenotungstate framework. The powder neutron diffraction data analysis locates the lithium atoms. Thermal analysis showed that Li 3AsW 7Omore » 25 is stable up to its melting at 1135(3) K followed by a decomposition at 1182(5) K. Finally, the Kubelka-Munk treatment of the UV-vis spectrum revealed a wide band gap in the range of 2.84-3.40 eV depending on the presumed electron transition type.« less

1-(4-(6-Fluorobenzo [d] isoxazol-3-yl) piperidin-1-yl)-2-(4-(hydroxymethyl)-1H-1,2,3-triazol-1-yl) ethanone: Synthesis, spectroscopic characterization, Hirshfeld surface analysis, cytotoxic studies and docking studies

NASA Astrophysics Data System (ADS)

Govindhan, M.; Viswanathan, V.; Karthikeyan, S.; Subramanian, K.; Velmurugan, D.

2017-08-01

Compound 1-(4-(6-fluorobenzo[d] isoxazol-3-yl) piperidin-1-yl)-2-(4-(hydroxymethyl)-1H-1, 2,3-triazol-1-yl) ethanone was synthesized in good yield by using click chemistry approach with 2-azido-1-(4-(6-flurobenzo[d]isooxazol-3-yl)piperidin-1-yl)ethanone as a starting material. The synthesized compound was characterized using IR, NMR and MS studies. Thermal stability of the compound was analyzed by using TGA and DSC technique. The single crystal XRD analysis was taken part, to confirm the structure of the compound. The intercontacts in the crystal structure are analyzed using Hirshfeld surfaces computational method. Cytotoxicity of the synthesized compound was evaluated and the results were reported. The binding analysis carried out between the newly synthesized molecule with human serum albumin using fluorescence spectroscopy technique to understand the pharmacokinetics nature of the compound for further biological application. The molecular docking studies were evaluated for the compound to elucidate insights of new molecules in carrier protein.

Synthesis and characterization of d10 metal complexes of 3-Me-5-FcPz: Structural, theoretical and third order nonlinear optical properties

NASA Astrophysics Data System (ADS)

Senthilkumar, Kabali; Thirumoorthy, Krishnan; Vinitha, G.; Soni, Kiran; Bhuvanesh, Nattamai S. P.; Palanisami, Nallasamy

2017-01-01

The d10 metal complexes based on 3-methyl-5-ferrocenyl-1H-pyrazole (L = 3-Me-5-FcPz) ligand [M(L)4(NO3)2] Zn=(1) and Cd=(2), [Hg(L)4(NO3)2].dmf (3) have been synthesized and characterized by FT-IR, NMR, UV-Vis and elemental analysis. The molecular structure of compound 2 and its crystal packing were determined by single crystal X-ray diffraction. The nitrate anions are also involved in intermolecular hydrogen bonding with adjacent ferrocene units and it forms zig-zag one-dimensional polymeric structure. UV-Vis investigations on the positive solvatochromic behavior of 1-3 revealed that the solvation of the push-pull character increases with increasing polarity. The third-order nonlinear optical (NLO) properties of 1-3 have been determined by Z-scan technique and the results indicate that compounds 1-3 exhibits the strong self-defocusing effect. The nonlinear susceptibility χ(3) values are calculated in the order of 10-6 esu.

The first octahedral cluster complexes with terminal formate ligands: synthesis, structure, and properties of K4[Re6S8(HCOO)6] and Cs4[Re6S8(HCOO)6].

PubMed

Brylev, Konstantin A; Mironov, Yuri V; Kozlova, Svetlana G; Fedorov, Vladimir E; Kim, Sung-Jin; Pietzsch, Hans-Jürgen; Stephan, Holger; Ito, Akitaka; Ishizaka, Shoji; Kitamura, Noboru

2009-03-02

The hexarhenium anionic cluster complex with terminal formate ligands [Re6S8(HCOO)6]4- was obtained by the room-temperature reaction between [Re6S8(OH)6]4- and formic acid in an aqueous solution. The cluster was crystallized as a potassium or cesium salt and characterized by X-ray single-crystal diffraction and elemental analyses, IR, 1H NMR, UV/vis, and luminescence spectroscopies. In particular, the emission quantum yield of the potassium salt of the Re6 cluster anion in the solid phase was determined for the first time. The electronic structures of [Re6S8(HCOO)6]4- and [Re6S8(OH)6]4- were also elucidated by DFT calculations.

CFA-7: an interpenetrated metal-organic framework of the MFU-4 family.

PubMed

Schmieder, Phillip; Grzywa, Maciej; Denysenko, Dmytro; Hambach, Manuel; Volkmer, Dirk

2015-08-07

The novel interpenetrated metal-organic framework CFA-7 (Coordination Framework Augsburg University-7), [Zn5Cl4(tqpt)3], has been synthesized containing the organic linker {H2-tqpt = 6,6,14,14-tetramethyl-6,14-dihydroquinoxalino[2,3-b]phenazinebistriazole}. Reaction of H2-tqpt and anhydrous ZnCl2 in N,N-dimethylformamide (DMF) yields CFA-7 as pseudo-cubic crystals. CFA-7 serves as precursor for the synthesis of isostructural frameworks with redox-active metal centers, which is demonstrated by postsynthetic metal exchange of Zn(2+) by different M(2+) (M = Co, Ni, Cu) ions. The novel framework is robust upon solvent removal and has been structurally characterized by single-crystal X-ray diffraction, TGA and IR spectroscopy, as well as gas sorption (Ar, CO2 and H2).

Synthesis and Crystal Structure of Dibromido{2-[(4-tert-butylmethylphenyl) iminomethyl]pyridine-κ2 N, N'}Zinc

NASA Astrophysics Data System (ADS)

Khalaj, M.; Ghazanfarpour-Darjani, M.; Seftejani, F. B.; Lalegani, A.

2017-12-01

The title compound [Zn( dip)Br2] was synthesized using the Schiff base bidentate ligand (E)-4- tert-butyl- N-(pyridine-2-ylmethylene)benzeneamine ( dip) and zinc(II) bromide salts. It has been characterized by elemental analysis, X-ray diffraction, and optical spectroscopy. The X-ray diffraction analysis demonstrates that in this structure, the zinc(II) ion is located on an inversion center and exhibits a ZnN2Br2 tetrahedral geometry. In this structure the dip ligand is coordinated with zinc(II) ion in a cyclic-bidentate fashion forming a five-membered metallocyclic ring. The compound crystallizes in the monoclinic sp. gr. P21/ m with a = 9.2700(13) Å, b = 7.6128(11) Å, c = 12.3880(17) Å, and β = 97.021(3)°.

The synthesis and characterization of iron nanoparticles

NASA Astrophysics Data System (ADS)

Bennett, Tyler

Nanoparticle synthesis has garnered attention for technological applications for catalysts, industrial processing, and medical applications. The size ranges for these is in the particles nanostructural domain. Pure iron nanoparticles have been of particular interest for their reactivity and relative biological inertness. Applications include cancer treatment and carrying medicine to a relevant site. Unfortunately, because of their reactivity, pure iron nanoparticles have been difficult to study. This is because of their accelerated tendency to form oxides in air, due to the increased surface area to volume ratio. Using synthesis processes with polyphenols or long chain amines, air stable iron nanoparticles have been produced with a diameter size range of ~ 2 to about ~10 nm, but apparently have transformed due to internal pressure and crystallographic defects to the FCC phase. The FCC crystals have been seen to form icosahedral and decahedral shapes. This size is within the range for use as a catalyst for the growth of both carbon nanotubes and boron nitride nanotubes as well for biomedical applications. The advantages of these kinds of catalysts are that nanotube growth can be for the first time separated from the catalyst formation. Additionally, the catalyst size can be preselected for a certain size nanotube to grow. In summary: (1) we found the size distributions of nanoparticles for various synthesis processes, (2) we discovered the right size range for growth of nanotubes from the iron nanoparticles, (3) the nanoparticles are under a very high internal pressure, (4) the nanoparticles are in the FCC phase, (5) they appear to be in icosahedral and decahedral structures, (6) they undergo room temperature twinning, (7) the FCC crystals are distorted due to carbon in octahedral sites, (8) the iron nanoparticles are stable in air, (9) adding small amounts of copper make the iron nanoparticles smaller.

Structural characterization and physicochemical features of new hybrid compound containing chlorate anions of cadmate (II)

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Gadri, Abdellatif; Ammar, Salah; Ben Salah, Abdelhamid; García-Granda, Santiago

2017-08-01

The present paper reports the synthesis of a single crystal of a new organic-inorganic hybrid compound, with the formula (C6H14N2) CdCl4·H2O, by slow evaporation method at room temperature. It was characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), Hirshfeld surface, spectroscopy measurement, thermal study and photoluminescence (PL) properties. A preliminary SCXRD structural analysis revealed that it crystallized in the monoclinic system (space group P21/c) with the following unit cell parameters: a = 12.95823(16) Å, b = 14.92449(16) Å, c = 7.13838(9) Å and β = 103.2108(12)° with Z = 4. The refinement converged to R = 0.0164 and ωR = 0.0393. Its atomic arrangement can be described as an alternation of organic and inorganic layers along the a-axis. The crystal packing was governed by the N-H⋯Cl and O-H⋯Cl hydrogen bonding interaction between the 1.2-diammoniumcyclohexane cations, the [CdCl42n-]n anions and water molecule. The Hirshfeld surface analysis was conducted to investigate intermolecular interactions and associated 2D fingerprint plots, revealing the relative contribution of these interactions in the crystal structure quantitatively. Furthermore, the room temperature infrared (IR) spectrum of the title compound was recorded and analyzed on the basis of data found in the literature. Besides, the thermal analysis studies were performed, but no phase transition was found in the temperature range between 30 and 450 °C. The optical and PL properties of the compound were investigated in the solid state at room temperature and exhibited three bands at 225, 268 and 315 nm and a strong fluorescence at 443 nm.

Synthesis, crystal structure and characterization of a new organic-inorganic hybrid material 4-(ammonium methyl) pipyridinium hexachloro stanate (II) trihydrate

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Ammar, Salah; Gadri, Abdellatif; Ben Salah, Abdelhamid; García-Granda, Santiago

2018-03-01

The present paper undertakes the study of (C6H16N2) SnCl6·3H2O which is a new hybrid compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. The single crystal X-ray diffraction studies revealed that the compound crystallizes in monoclinic Cc space group with cell parameters a = 8.3309(9) Å, b = 22.956(2) Å, c = 9.8381(9) Å, β = 101.334(9) ° and Z = 4. The atomic arrangement shows an alternation of organic and inorganic entities. The cohesion between these entities is performed via Nsbnd H⋯Cl, Nsbnd H⋯O, Osbnd H⋯Cl and Osbnd H⋯O hydrogen bonding to form a three-dimensional network. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electron microscope (SEM) was carried out. Furthermore, the room temperature infrared (IR) spectrum of the title compound was recorded and analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows four signals, confirming the solid state structure determined by X-ray diffraction. Besides, the thermal analysis studies were performed, but no phase transition was found in the temperature range between 30 and 450 °C. The optical and PL properties of the compound were investigated in the solid state at room temperature and exhibited three bands at 348 and 401 cm-1 and a strong fluorescence at 480 nm.

Two halide-containing cesium manganese vanadates: synthesis, characterization, and magnetic properties

DOE PAGES

Smith Pellizzeri, Tiffany M.; McGuire, Michael A.; McMillen, Colin D.; ...

2018-01-24

In this study, two new halide-containing cesium manganese vanadates have been synthesized by a high-temperature (580 °C) hydrothermal synthetic method from aqueous brine solutions. One compound, Cs 3Mn(VO 3) 4Cl, (1) was prepared using a mixed cesium hydroxide/chloride mineralizer, and crystallizes in the polar noncentrosymmetric space group Cmm2, with a = 16.7820(8) Å, b = 8.4765(4) Å, c = 5.7867(3) Å. This structure is built from sinusoidal zig-zag (VO 3) n chains that run along the b-axis and are coordinated to Mn 2+ containing (MnO 4Cl) square-pyramidal units that are linked together to form layers. The cesium cations reside betweenmore » the layers, but also coordinate to the chloride ion, forming a cesium chloride chain that also propagates along the b-axis. The other compound, Cs 2Mn(VO 3) 3F, (2) crystallizes in space group Pbca with a = 7.4286(2) Å, b = 15.0175(5) Å, c = 19.6957(7) Å, and was prepared using a cesium fluoride mineralizer. The structure is comprised of corner sharing octahedral Mn 2+ chains, with trans fluoride ligands acting as bridging units, whose ends are capped by (VO 3) n vanadate chains to form slabs. The cesium atoms reside between the manganese vanadate layers, and also play an integral part in the structure, forming a cesium fluoride chain that runs along the b-axis. Both compounds were characterized by single-crystal X-ray diffraction, powder X-ray diffraction, and single-crystal Raman spectroscopy. Additionally, the magnetic properties of 2 were investigated. Lastly, above 50 K, it displays behavior typical of a low dimensional system with antiferromagnetic interactions, as to be expected for linear chains of manganese(II) within the crystal structure.« less

Synthesis, characterization and relativistic DFT studies of fac-Re(CO)3(isonicotinic acid)2Cl complex

NASA Astrophysics Data System (ADS)

Zúñiga, César; Oyarzún, Diego P.; Martin-Transaco, Rudy; Yáñez-S, Mauricio; Tello, Alejandra; Fuentealba, Mauricio; Cantero-López, Plinio; Arratia-Pérez, Ramiro

2017-11-01

In this work, new fac-Re(CO)3(PyCOOH)2Cl from isonicotinic acid ligand has been prepared. The complex was characterized by structural (single-crystal X-ray diffraction), elemental analysis and spectroscopic (FTIR, NMR, UV-vis spectroscopy) methods. DFT and TDDFT calculations were performed to obtain the electronic transitions involved in their UV-Vis spectrum. The excitation energies agree with the experimental results. The TDDFT calculations suggest that experimental mixed absorption bands at 270 and 314 nm could be assigned to (MLCT-LLCT)/MLCT transitions. Natural Bond Orbitals (NBO) approach has enabled studying the effects of bonding interactions. E(2) energies confirm the occurrence of ICT (Intra-molecular Charge Transfer) within the molecule.

Synthesis and characterization of new N-heterocyclic carbene ligands: 1,3-Bis(acetamide)imidazol-3-ium bromide and 3-(acetamide)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide

NASA Astrophysics Data System (ADS)

Turkyilmaz, Murat; Uluçam, Gühergül; Aktaş, Şaban; Okan, S. Erol

2017-05-01

Two new pincer type N-heterocyclic carbene ligands were synthesized. The compounds were characterized by FTIR, NMR (1H, 13C) GC-MS and elemental analyses. They were also both modelled by DFT calculations as the crystal structure of 1,3-bis(acetamide)imidazol-3-ium bromide was determined by XRD which is an orthorhombic system with space group P21212. The structural analyses in gas phase were realized by comparing the experimental NMR and IR spectra with those of the theoretical calculations. In vitro biological activities of the molecules were determined and found that one of them exhibits significant cytotoxic activity.

Synthesis, characterization, and anticancer activity of a series of ketone-N(4)-substituted thiosemicarbazones and their ruthenium(II) arene complexes.

PubMed

Su, Wei; Qian, Quanquan; Li, Peiyuan; Lei, Xiaolin; Xiao, Qi; Huang, Shan; Huang, Chusheng; Cui, Jianguo

2013-11-04

A series of ketone-N(4)-substituted thiosemicarbazone (TSC) compounds (L1-L9) and their corresponding [(η(6)-p-cymene)Ru(II)(TSC)Cl](+/0) complexes (1-9) were synthesized and characterized by NMR, IR, elemental analysis, and HR-ESI-mass spectrometry. The molecular structures of L4, L9, 1-6, and 9 were determined by single-crystal X-ray diffraction analysis. The compounds were further evaluated for their in vitro antiproliferative activities against the SGC-7901 human gastric cancer, BEL-7404 human liver cancer, and HEK-293T noncancerous cell lines. Furthermore, the interactions of the compounds with DNA were followed by electrophoretic mobility spectrometry studies.

Heteroleptic Palladium(II) dithiocarbamates: Synthesis, characterization and in vitro biological screening

NASA Astrophysics Data System (ADS)

Khan, Shahan Zeb; Zia-ur-Rehman; Amir, Muhammad Kashif; Ullah, Imdad; Akhter, M. S.; Bélanger-Gariepy, Francine

2018-03-01

Two new heteroleptic Pd(II) complexes of sodium 4-(2-pyrimidyl)piperazine-1-carbodithioate with tris-p-flourophenylphosphine (1) and tris-p-chlorophenylphosphine (2) were prepared and characterized by elemental analysis, FT-IR, multinuclear NMR {1H, 13C and 31P} and single-crystal X-ray diffraction measurement. In both complexes, Pd exhibit pseudo square planner geometry mediated by SS chelate, P and Cl. In vitro cytotoxicity against five different cancer cell lines using staurosporine as a standard revealed 1 to be more cytotoxic than 2, though both complexes are more active than cisplatin. Subsequent DNA binding studies revealed that non-covalent complex-DNA interaction may be the reason for arresting cancer cell growth. Furthermore, 1 and 2 are potent antioxidant agents.

25th anniversary article: semiconductor nanowires--synthesis, characterization, and applications.

PubMed

Dasgupta, Neil P; Sun, Jianwei; Liu, Chong; Brittman, Sarah; Andrews, Sean C; Lim, Jongwoo; Gao, Hanwei; Yan, Ruoxue; Yang, Peidong

2014-04-09

Semiconductor nanowires (NWs) have been studied extensively for over two decades for their novel electronic, photonic, thermal, electrochemical and mechanical properties. This comprehensive review article summarizes major advances in the synthesis, characterization, and application of these materials in the past decade. Developments in the understanding of the fundamental principles of "bottom-up" growth mechanisms are presented, with an emphasis on rational control of the morphology, stoichiometry, and crystal structure of the materials. This is followed by a discussion of the application of nanowires in i) electronic, ii) sensor, iii) photonic, iv) thermoelectric, v) photovoltaic, vi) photoelectrochemical, vii) battery, viii) mechanical, and ix) biological applications. Throughout the discussion, a detailed explanation of the unique properties associated with the one-dimensional nanowire geometry will be presented, and the benefits of these properties for the various applications will be highlighted. The review concludes with a brief perspective on future research directions, and remaining barriers which must be overcome for the successful commercial application of these technologies. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of graphene oxide using modified Hummer's method

NASA Astrophysics Data System (ADS)

Kaur, Manpreet; Kaur, Harsimran; Kukkar, Deepak

2018-05-01

In the present study, a simple approach has been followed for the synthesis of graphene oxide (GO) using modified Hummers method in which graphite powder was oxidized in the presence of concentrated H2SO4 and KMnO4. The amount of NaNO3 and KMnO4 was varied to produce sheet like structure. The varied concentrations of NaNO3 and KMnO4 resulted in yielding large amount of the product. Structural, morphological and physicochemical features of the product were studied using UV-Visible spectrophotometer, Fourier Transform infrared spectroscopy (FTIR), and crystal structure was determined using X-ray powder diffraction (XRD). UV-Vis spectra of GO was observed at a maximum absorption of 230 nm due to (π-π*) transition of atomic carbon-carbon bonds. FTIR spectra revealed the presence of oxygen containing functional groups which ensures the complete exfoliation of graphite into graphene oxide X-ray powder diffraction pattern of the product showed the diffraction peak at (2θ = 26.7°) with an interlayer spacing of 0.334 nm. All the above characterizations successfully confirmed the formation of GO.

2-Seleno-1-alkylbenzimidazoles and their Diselenides: Synthesis and Structural Characterization of a 2-Seleno-1-methylbenzimidazole Complex of Mercury‡

PubMed Central

Palmer, Joshua H.; Parkin, Gerard

2012-01-01

2-Seleno-1-methylbenzimidazole, H(sebenzimMe), can be synthesized from 1-methylbenzimidazole by sequential treatment with (i) BunLi, (ii) elemental selenium and (iii) HCl(aq). This method is also applicable to the synthesis of 2-seleno-1-t-butylbenzimidazole, H(sebenzimBut). Single crystal X–ray diffraction and NMR spectroscopic data demonstrate that H(sebenzimMe) and H(sebenzimBut) exist as the selone rather than the selenol tautomers, which is in accord with the results of density functional theory (B3LYP) calculations. The data also indicate that the selone is best represented as a C+–Se− zwitterion rather than as a C=Se doubly bonded species. Aerobic oxidation of H(sebenzimMe) and H(sebenzimBut) in the presence of Et3N yields the diselenides, (sebenzimMe)2 and (sebenzimBut)2. In addition, H(sebenzimMe) reacts with HgCl2 to give [H(sebenzimMe)]2HgCl2, the first structurally characterized example of a 2-seleno-1-alkylimidazole mercury complex. PMID:23543946

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaefer, Michael, E-mail: mvschaefer@mail.usf.edu, E-mail: axk650@case.edu, E-mail: mohan@case.edu, E-mail: schlaf@mail.usf.edu; Kumar, Ajay, E-mail: mvschaefer@mail.usf.edu, E-mail: axk650@case.edu, E-mail: mohan@case.edu, E-mail: schlaf@mail.usf.edu; Mohan Sankaran, R., E-mail: mvschaefer@mail.usf.edu, E-mail: axk650@case.edu, E-mail: mohan@case.edu, E-mail: schlaf@mail.usf.edu

Microplasma-assisted gas-phase nucleation has emerged as an important new approach to produce high-purity, nanometer-sized, and narrowly dispersed particles. This study aims to integrate this technique with vacuum conditions to enable synthesis and deposition in an ultrahigh vacuum compatible environment. The ultimate goal is to combine nanoparticle synthesis with photoemission spectroscopy-based electronic structure analysis. Such measurements require in vacuo deposition to prevent surface contamination from sample transfer, which can be deleterious for nanoscale materials. A homebuilt microplasma reactor was integrated into an existing atomic layer deposition system attached to a surface science multi-chamber system equipped with photoemission spectroscopy. As proof-of-concept, wemore » studied the decomposition of ferrocene vapor in the microplasma to synthesize iron oxide nanoparticles. The injection parameters were optimized to achieve complete precursor decomposition under vacuum conditions, and nanoparticles were successfully deposited. The stoichiometry of the deposited samples was characterized in situ using X-ray photoelectron spectroscopy indicating that iron oxide was formed. Additional transmission electron spectroscopy characterization allowed the determination of the size, shape, and crystal lattice of the particles, confirming their structural properties.« less

Synthesis and characterization of fluorapatite-titania (FAp-TiO 2) nanocomposite via mechanochemical process

NASA Astrophysics Data System (ADS)

Ebrahimi-Kahrizsangi, Reza; Nasiri-Tabrizi, Bahman; Chami, Akbar

2010-09-01

In this paper, synthesis of bionanocomposite of fluorapatite-titania (FAp-TiO 2) was studied by using one step mechanochemical process. Characterization of the products was accomplished by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Based on XRD patterns and FT-IR spectroscopy, correlation between the structural features of the nanostructured FAp-TiO 2 and the process conditions was discussed. Variations in crystallite size, lattice strain, and volume fraction of grain boundary were investigated during milling and the following heat treatment. Crystallization of the nanocomposite occurred after thermal treatment at 650 °C. Morphological features of powders were influenced by the milling time. The resulting FAp-20 wt.%TiO 2 nanocomposite powder exhibited an average particle size of 15 nm after 20 h of milling. The results show that the one step mechanosynthesis technique is an effective route to prepare FAp-based nanocomposites with excellent morphological and structural features.

Comparison of a rational vs. high throughput approach for rapid salt screening and selection.

PubMed

Collman, Benjamin M; Miller, Jonathan M; Seadeek, Christopher; Stambek, Julie A; Blackburn, Anthony C

2013-01-01

In recent years, high throughput (HT) screening has become the most widely used approach for early phase salt screening and selection in a drug discovery/development setting. The purpose of this study was to compare a rational approach for salt screening and selection to those results previously generated using a HT approach. The rational approach involved a much smaller number of initial trials (one salt synthesis attempt per counterion) that were selected based on a few strategic solubility determinations of the free form combined with a theoretical analysis of the ideal solvent solubility conditions for salt formation. Salt screening results for sertraline, tamoxifen, and trazodone using the rational approach were compared to those previously generated by HT screening. The rational approach produced similar results to HT screening, including identification of the commercially chosen salt forms, but with a fraction of the crystallization attempts. Moreover, the rational approach provided enough solid from the very initial crystallization of a salt for more thorough and reliable solid-state characterization and thus rapid decision-making. The crystallization techniques used in the rational approach mimic larger-scale process crystallization, allowing smoother technical transfer of the selected salt to the process chemist.

Facile Preparation of Light Emitting Organic Metal Halide Crystals with Near-Unity Quantum Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chenkun; Worku, Michael; Neu, Jennifer

Here, we report the synthesis and characterization of (Ph 4P) 2SbCl 5, a novel ionically bonded organic metal halide hybrid with a zero-dimensional (0D) structure at the molecular level. By cocrystallization of tetraphenylphosphonium (Ph 4P +) and antimony (Sb 3+) chloride salts, (Ph 4P) 2SbCl 5 bulk single crystals can be prepared in high yield, which exhibit a highly efficient broadband red emission peaked at 648 nm with a photoluminescence quantum efficiency (PLQE) of around 87%. Density functional theory (DFT) calculations reveal the origin of emission as phosphorescence from the excitons localized at SbCl 5 2– with strong excited-state structuralmore » distortion. Interestingly, (Ph 4P) 2SbCl 5 bulk crystals with a PLQE of around 100% can be prepared via a rapid crystal growth process within minutes, followed by a spontaneous structural transformation. It was found that the rapid growth process yielded a yellow emitting kinetically favored metastable product containing solvent molecules, which turned into the red emitting thermodynamically stable product slowly at room temperature or quickly upon thermal treatment.« less

Synthesis, antityrosinase activity of curcumin analogues, and crystal structure of (1E,4E)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chantrapromma, S., E-mail: suchada.c@psu.ac.th; Ruanwas, P.; Boonnak, N.

2016-12-15

Five derivatives of curcumin analogue (R = OCH{sub 2}CH{sub 3} (1), R = N(CH{sub 3}){sub 2} (2), R = 2,4,5-OCH{sub 3} (3), R = 2,4,6-OCH{sub 3} (4), and R = 3,4,5-OCH{sub 3} (5)) were synthesized and characterized by {sup 1}H NMR, FT-IR and UV–Vis spectroscopy. The synthesized derivatives were screened for antityrosinase activity, and found that 4 and 5 possess such activity. The crystal structure of 1 was determined by single crystal X-ray diffraction: monoclinic, sp. gr. P2{sub 1}/c, a = 17.5728(15) Å, b = 5.9121(5) Å, c = 19.8269(13) Å, β = 121.155(5)°, Z = 4. The molecule 1more » is twisted with the dihedral angle between two phenyl rings being 15.68(10)°. In the crystal packing, the molecules 1 are linked into chains by C−H···π interactions and further stacked by π···π interactions with the centroid–centroid distance of 3.9311(13) Å.« less

2-Methylpyridinium/pyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olates as potent anticonvulsant agents—synthesis and crystal structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mangaiyarkarasi, G.; Kalaivani, D., E-mail: kalaivbalaj@yahoo.co.in

2013-12-15

The molecular salt, 2-methylpyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropy-rimidin-4-olate) (I), is prepared from the ethanolic solution of 1-chloro-2,4-dinitrobenzene, pyrimidine-2,4,6-(1H,3H,5H)-trione (barbituric acid) and 2-methylpyridine at room temperature, and the molecular salt, pyridinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate (II), is prepared from the same reactants, by dissolving them in hot DMSO and ethanol mixture at 70°C. The structures of I and II are characterized by visible, IR, {sup 1}H-NMR, {sup 13}C-NMR and elemental analysis and confirmed by single crystal X-ray analysis. Both the salts crystallize in triclinic crystal system with sp. gr. P-bar1. They possess noticeable anticonvulsant activity even at low concentration (25 mg/kg). Acute toxicity studies of these complexesmore » indicate that LD{sub 50} values are greater than 1500 mg/kg and the tested animals do not show any behavioural changes.« less

Facile Preparation of Light Emitting Organic Metal Halide Crystals with Near-Unity Quantum Efficiency

DOE PAGES

Zhou, Chenkun; Worku, Michael; Neu, Jennifer; ...

2018-03-12

Here, we report the synthesis and characterization of (Ph 4P) 2SbCl 5, a novel ionically bonded organic metal halide hybrid with a zero-dimensional (0D) structure at the molecular level. By cocrystallization of tetraphenylphosphonium (Ph 4P +) and antimony (Sb 3+) chloride salts, (Ph 4P) 2SbCl 5 bulk single crystals can be prepared in high yield, which exhibit a highly efficient broadband red emission peaked at 648 nm with a photoluminescence quantum efficiency (PLQE) of around 87%. Density functional theory (DFT) calculations reveal the origin of emission as phosphorescence from the excitons localized at SbCl 5 2– with strong excited-state structuralmore » distortion. Interestingly, (Ph 4P) 2SbCl 5 bulk crystals with a PLQE of around 100% can be prepared via a rapid crystal growth process within minutes, followed by a spontaneous structural transformation. It was found that the rapid growth process yielded a yellow emitting kinetically favored metastable product containing solvent molecules, which turned into the red emitting thermodynamically stable product slowly at room temperature or quickly upon thermal treatment.« less

1D cyanide complexes with 2-pyridinemethanol: Synthesis, crystal structures and spectroscopic properties

NASA Astrophysics Data System (ADS)

Sayın, Elvan; Kürkçüoğlu, Güneş Süheyla; Yeşilel, Okan Zafer; Hökelek, Tuncer

2015-12-01

Two new one-dimensional coordination polymers, [Cu(hmpH)2Pd(μ-CN)2(CN)2]n (1) and [Cu(hmpH)2Pt(μ-CN)2(CN)2]n (2), (hmpH = 2-pyridinemethanol), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. Single crystal X-ray diffraction analysis indicates that complexes 1 and 2 are isomorphous and isostructural, and crystallize in the triclinic system and P-1 space group. The Pd(II) or Pt(II) ions are four coordinated with four cyanide-carbon atoms in a square planar geometry. Cu(II) ion displays a distorted octahedral coordination by two N-atoms and two O-atoms of hmpH ligands, two bridging cyanide groups. In one dimensional structure of the complexes, [M(CN)4]2- (M = Pd(II) or Pt(II)) anions and [Cu(hmpH)2]2+ cations are linked via bridging cyanide ligands. In the complexes, the presence of intramolecular C-H⋯M (M = Pd(II) or Pt(II)) interactions with distance values of 3.00-2.95 Å are established, respectively.

Synthesis of porous Cu-BTC with ultrasonic treatment: Effects of ultrasonic power and solvent condition.

PubMed

Israr, Farrukh; Kim, Duk Kyung; Kim, Yeongmin; Oh, Seung Jin; Ng, Kim Choon; Chun, Wongee

2016-03-01

Cu-BTC (BTC=1,3,5-benzenetricarboxylate) metal organic framework (MOF) was synthesized using different solvent conditions with ultrasonic treatment. Solvent mixtures of water/N,N-dimethylformamide (DMF), water/ethanol were used for the reactions with or without a variety of bases under 20 kHz ultrasonically treated conditions. Prepared crystals were purified through 30 min of sonication to remove unreacted chemicals. Treatment time and ultrasonic power effects were compared to get optimum synthetic condition. The characterization of MOF powders was performed by scanning electron microscopy, X-ray powder diffraction, infrared-spectroscopy, thermo-gravimetric analysis and specific surface determination using the BET method. Isolated crystal yields varied with different solvent and applied ultrasonic power conditions. A high isolated crystal yield of 86% was obtained from water/ethanol/DMF solvent system after 120 min of ultrasonic treatment at 40% power of 750 W. Different solvent conditions led to the formation of Cu-BTC with different surface area, and an extremely high surface area of 1430 m(2)/g was obtained from the crystals taken with the solvent condition of water:DMF=70:30. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis, crystal structure investigation and magnetism of the complex metal-rich boride series Crx(Rh1-yRuy)7-xB3 (x=0.88-1; y=0-1) with Th7Fe3-type structure

NASA Astrophysics Data System (ADS)

Misse, Patrick R. N.; Mbarki, Mohammed; Fokwa, Boniface P. T.

2012-08-01

Powder samples and single crystals of the new complex boride series Crx(Rh1-yRuy)7-xB3 (x=0.88-1; y=0-1) have been synthesized by arc-melting the elements under purified argon atmosphere on a water-cooled copper crucible. The products, which have metallic luster, were structurally characterized by single-crystal and powder X-ray diffraction as well as EDX measurements. Within the whole solid solution range the hexagonal Th7Fe3 structure type (space group P63mc, no. 186, Z=2) was identified. Single-crystal structure refinement results indicate the presence of chromium at two sites (6c and 2b) of the available three metal Wyckoff sites, with a pronounced preference for the 6c site. An unexpected Rh/Ru site preference was found in the Ru-rich region only, leading to two different magnetic behaviors in the solid solution: The Rh-rich region shows a temperature-independent (Pauli) paramagnetism whereas an additional temperature-dependent paramagnetic component is found in the Ru-rich region.

Synthesis, crystal structure, and properties of new lead barium borate with B3O6 plane hexagonal rings

NASA Astrophysics Data System (ADS)

Zhao, Wenwu

2017-08-01

A new lead barium borate Ba8.02Pb0.98(B3O6)6 with B3O6 plane hexagonal rings was synthesized through spontaneous nucleation from a high-temperature solution utilizing PbO, H3BO3, and BaF2 as reagents. Its crystal structure was determined from single-crystal X-ray diffraction data and further characterized by FT-IR. It crystallizes in space group R32 and the crystallographic structure of Ba8.02Pb0.98(B3O6)6 can be described as a layer-like structure, there is stacking along the c-axis of B3O6 plane hexagonal rings with the Ba2 and Pb/Ba1 atoms alternately occupying sites between the B3O6 sheets. A comparison of the structures of Ba8.02Pb0.98(B3O6)6, PbBa2(B3O6)2 and α-BaB2O4 is presented. UV-Vis-NIR diffuse-reflectance spectrum indicates that the absorption edge of Ba8.02Pb0.98(B3O6)6 is about 399 nm.