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Sample records for 3d metal-organic frameworks

  1. 3D metal-organic frameworks based on elongated tetracarboxylate building blocks for hydrogen storage.

    PubMed

    Ma, Liqing; Lee, Jeong Yong; Li, Jing; Lin, Wenbin

    2008-05-19

    Two 3D metal-organic frameworks (MOFs) with a new biphenol-derived tetracarboxylate linker and Cu(II) and Zn(II) metal-connecting points were synthesized and characterized by single-crystal X-ray crystallographic studies. The two isostructural MOFs exhibit distorted PtS network topology and show markedly different framework stability. The porosity and hydrogen uptake of the frameworks were determined by gas adsorption experiments. PMID:18416546

  2. Highly selective luminescence sensing of nitrite and benzaldehyde based on 3d-4f heterometallic metal-organic frameworks.

    PubMed

    Du, Pei-Yao; Gu, Wen; Liu, Xin

    2016-06-01

    Framework-isomeric three-dimensional (3D) Zn-Ln heterometallic metal-organic frameworks, {[Ln2Zn(abtc)2(H2O)4]·2H2O}∞ {Ln = Sm(1), Tb(2)}, were synthesized using a convenient solvothermal reaction. They can serve as excellent sensors for the specific identification of benzaldehyde and NO2(-) through a fluorescence quenching process. PMID:27117937

  3. 3D porous metal-organic framework as an efficient electrocatalyst for nonenzymatic sensing application.

    PubMed

    Zhang, Daojun; Zhang, Jingchao; Zhang, Renchun; Shi, Huaizhong; Guo, Yuanyuan; Guo, Xiuli; Li, Sujuan; Yuan, Baiqing

    2015-11-01

    Novel electroactive materials with high surface area and stability have great potential for electrochemical sensor. Herein, we demonstrate the exploitation of a porous Cu-based metal-organic framework (Cu-MOF) with large pore size as nonenzymatic sensors for the electrochemical determination of hydrogen peroxide (H2O2) and glucose. The Cu-MOF shows high stability even in NaOH solution. The as-prepared Cu-MOF modified carbon paste electrode (CPE) presents a well-behaved redox event from electroactive metal centers in the MOF at the physiological pH which can be utilized to catalyze the electroreduction of H2O2. It also exhibited excellent electrocatalytic activity towards the oxidation of glucose in alkaline solution. The results showed that the nonenzymatic sensors based on the Cu-MOF display excellent analytical performances, which make it a promising candidate in electrochemical sensor. PMID:26452944

  4. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (<2 nm diameter) and mesopores (2-4 nm), derived from carbonization of unique porous metal organic frameworks (MOFs). Owning to the synergistic effect of micropores and mesopores, the hybrid-porous carbon has exceptionally high ion-accessible surface area and low ion diffusion resistance, which is desired for supercapacitor applications. When applied as electrode materials in supercapacitors, 3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  5. Homochiral 3D metal-organic frameworks from chiral 1D rods: 6-way helical packing.

    PubMed

    Shin, Sung Min; Moon, Dohyun; Jeong, Kyung Seok; Kim, Jaheon; Thallapally, Praveen K; Jeong, Nakcheol

    2011-09-01

    The chiral 3D MOFs resulted from the packing of chiral 1D SBBs were studied. It was demonstrated that the final packing pattern is sensitively dependent on the dimension of SBBs. In addition, we were able to identify a new plywood-like network from ligand 2H(2) exhibiting an unprecedented six-way chiral helical packing motif, which extends the list of invariant rod packings. PMID:21773637

  6. Densely Packed Lanthanide Cubane Based 3D Metal-Organic Frameworks for Efficient Magnetic Refrigeration and Slow Magnetic Relaxation.

    PubMed

    Biswas, Soumava; Mondal, Amit Kumar; Konar, Sanjit

    2016-03-01

    Two isostructural densely packed squarato-bridged lanthanide-based 3D metal-organic frameworks (MOFs) [Ln5(μ3-OH)5(μ3-O)(CO3)2(HCO2)2(C4O4)(H2O)2] [Ln = Gd (1) and Dy (2)] show giant cryogenic magnetic refrigeration (for 1) and slow magnetic relaxation (for 2). The structural analyses reveal the presence of a self-assembled crown-shaped building unit with a cubane-based rectangular moiety that leads to a special array of metal centers in 3D space in the complexes. Magnetic investigations confirm that complex 1 exhibits one of the largest cryogenic magnetocaloric effects among the molecular magnetic refrigerant materials reported so far (-ΔSm = 64.0 J kg(-1) K(-1) for ΔH = 9 T at 3 K). The cryogenic cooling effect (of 1) is also quite comparable with that of the commercially used magnetic refrigerant gadolinium-gallium garnet, whereas for complex 2, slow relaxation of magnetization was observed below 10 K. PMID:26881286

  7. 3D metal-organic framework as highly efficient biosensing platform for ultrasensitive and rapid detection of bisphenol A.

    PubMed

    Wang, Xue; Lu, Xianbo; Wu, Lidong; Chen, Jiping

    2015-03-15

    As is well known, bisphenol A (BPA), usually exists in daily plastic products, is one of the most important endocrine disrupting chemicals. In this work, copper-centered metal-organic framework (Cu-MOF) was synthesized, which was characterized by SEM, TEM, XRD, FTIR and electrochemical method. The resultant Cu-MOF was explored as a robust electrochemical biosensing platform by choosing tyrosinase (Tyr) as a model enzyme for ultrasensitive and rapid detection of BPA. The Cu-MOF provided a 3D structure with a large specific surface area, which was beneficial for enzyme and BPA absorption, and thus improved the sensitivity of the biosensor. Furthermore, Cu-MOF as a novel sorbent could increase the available BPA concentration to react with tyrosinase through π-π stacking interactions between BPA and Cu-MOF. The Tyr biosensor exhibited a high sensitivity of 0.2242A M(-1) for BPA, a wide linear range from 5.0×10(-8) to 3.0×10-6moll(-1), and a low detection limit of 13nmoll(-1). The response time for detection of BPA is less than 11s. The proposed method was successfully applied to rapid and selective detection of BPA in plastic products with satisfactory results. The recoveries are in the range of 94.0-101.6% for practical applications. With those remarkable advantages, MOFs-based 3D structures show great prospect as robust biosensing platform for ultrasensitive and rapid detection of BPA. PMID:25461172

  8. A nanoporous 3D zinc(II) metal-organic framework for selective absorption of benzaldehyde and formaldehyde

    NASA Astrophysics Data System (ADS)

    Moradpour, Tahereh; Abbasi, Alireza; Van Hecke, Kristof

    2015-08-01

    A new 3D nanoporous metal-organic framework (MOF), [[Zn4O(C24H15N6O6)2(H2O)2]·6H2O·DMF]n (1) based on 4,4‧,4″-s-triazine-1,3,5-triyltri-p-aminobenzoate (TATAB) ligand was solvothermally synthesized and characterized by single-crystal X-ray diffraction, Powder X-ray diffraction (PXRD), infrared spectroscopy (IR) and Brunauer-Emmett-Teller (BET) analyses. X-ray single crystal diffraction analysis reveals that 1 exhibits a 3D network with new kvh1 topology. Semi-empirical (AM1) calculations were carried out to obtain stable conformers for TATAB ligand. In addition, the absorption of two typical aldehydes (benzaldehyde and formaldehyde) in the presence of 1 was investigated and the effect of the aldehyde concentration, exposure time and temperature was studied. It was found that compound 1 has a potential for the absorption of aldehydes under mild conditions.

  9. Positional isomerism-driven two 3D pillar-layered metal-organic frameworks: Syntheses, topological structures and photoluminescence properties

    NASA Astrophysics Data System (ADS)

    Sun, Yayong; Zhao, Siwei; Ma, Haoran; Han, Yi; Liu, Kang; Wang, Lei

    2016-06-01

    Two novel three-dimensional (3D) pillar-layered metal-organic frameworks (MOFs), namely [Zn2(μ2-OH)(boaba)(1,4-bmimb)]n (1) and {[Zn5K2(μ2-H2O)2(boaba)4(1,2-bmimb)2(H2O)2]·H2O}n (2), were prepared by hydrothermal reactions (H3boaba=3,5-bis-oxyacetate-benzoic acid; 1,4-bmimb=1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene; 1,2-bmimb =1,2-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene). Notably, 1 exhibits a (3,5)-connected binodal (63)(69·8)-gra net with binuclear [Zn2(μ2-OH)(COO)]2+ clusters, while 2 shows a novel (4,4,5,9)-connected 4-nodal net constructed from the unique Zn(II)-K(I) heterometal rod-like substructures. The results indicate that the disposition of the 2-methylimidazolyl groups of bis(imidazole) ligands have a significant effect on structural diversity. Moreover, the photoluminescence properties of 1 and 2 have been investigated.

  10. Synthesis, structure and electrochemical behavior of a 3D crystalline copper(II) metal-organic framework

    NASA Astrophysics Data System (ADS)

    Bai, Hong-Ye; Fan, Wei-Qiang; Liu, Chun-Bo; Shi, Wei-Dong; Yan, Yong-Sheng

    2014-05-01

    Using an flexible amide-type tripodal ligand N,N‧,N″-tris(3-pyridyl)-1,3,5-benzenetricarboxamide (L) and 1,4-benzenedicarboxylic acid (H2bdc), a three-dimensional copper(II) metal-organic framework (MOF) formulated as [Cu(bdc)(L)]n has been hydrothermally synthesized and structurally characterized by IR, elemental, X-ray single-crystal diffraction and thermal analysis. The complex crystallizes in the triclinic, space group P - 1, a = 8.891(2) Å, b = 11.760(2) Å, c = 15.348(3) Å, α = 96.73(3)°, β = 105.96(3)°, γ = 106.47(3)°, V = 1446.2(5) Å3, Mr = 666.10, Dc = 1.530 g/cm3, Z = 2, F(000) = 682, GOOF = 1.0560, μ(MoKα) = 0.817 mm-1, R = 0.0366 and wR = 0.0885. The structural analyses reveal that the title compound consists of one Cu(II) atom, two halves of bdc, and one L ligand. Each Cu(II) atom is linked by two bdc ligands and three L ligands to form a three-dimensional network. In addition, the electrochemical behavior of title compound has been studied. CCDC No. 990526.

  11. 3D architecture constructed via the confined growth of MoS2 nanosheets in nanoporous carbon derived from metal-organic frameworks for efficient hydrogen production

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhou, Xiaoli; Ding, Tao; Wang, Chunde; Yang, Qing

    2015-10-01

    The design and synthesis of robust, high-performance and low-cost three-dimensional (3D) hierarchical structured materials for the electrochemical reduction of water to generate hydrogen is of great significance for practical water splitting applications. In this study, we develop an in situ space-confined method to synthesize an MoS2-based 3D hierarchical structure, in which the MoS2 nanosheets grow in the confined nanopores of metal-organic frameworks (MOFs)-derived 3D carbons as electrocatalysts for efficient hydrogen production. Benefiting from its unique structure, which has more exposed active sites and enhanced conductivity, the as-prepared MoS2/3D nanoporous carbon (3D-NPC) composite exhibits remarkable electrocatalytic activity for the hydrogen evolution reaction (HER) with a small onset overpotential of ~0.16 V, large cathodic currents, small Tafel slope of 51 mV per decade and good durability. We anticipate that this in situ confined growth provides new insights into the construction of high performance catalysts for energy storage and conversion.The design and synthesis of robust, high-performance and low-cost three-dimensional (3D) hierarchical structured materials for the electrochemical reduction of water to generate hydrogen is of great significance for practical water splitting applications. In this study, we develop an in situ space-confined method to synthesize an MoS2-based 3D hierarchical structure, in which the MoS2 nanosheets grow in the confined nanopores of metal-organic frameworks (MOFs)-derived 3D carbons as electrocatalysts for efficient hydrogen production. Benefiting from its unique structure, which has more exposed active sites and enhanced conductivity, the as-prepared MoS2/3D nanoporous carbon (3D-NPC) composite exhibits remarkable electrocatalytic activity for the hydrogen evolution reaction (HER) with a small onset overpotential of ~0.16 V, large cathodic currents, small Tafel slope of 51 mV per decade and good durability. We

  12. Three-dimensional (3-D) metal-organic frameworks with 3-pyridin-4-yl-benzoate defining new (3,6)-connected net topologies

    SciTech Connect

    Jiang Xiujuan; Du Miao; Sun Yan; Guo, Jian-Hua; Li, Jin-Shan

    2009-11-15

    Reactions of different metal salts with 3-pyridin-4-yl-benzoic acid (3,4-Hpybz) under ambient condition afford a series of 3-D metal-organic frameworks with two new types of (3,6)-connected net topologies. In the isomorphic complexes [M{sub 2}(mu-H{sub 2}O)(3,4-pybz){sub 4}]{sub n} (M{sup II}=Mn{sup II} for 1, Zn{sup II} for 2, or Cd{sup II} for 3), the octahedral metal nodes are extended by the 3-connected pybz tectons to constitute 3-D arrays with the Schlaefli symbol of (3.4.5)(3{sup 2}.4{sup 4}.5{sup 5}.6{sup 2}.7{sup 2}), whereas [Pb(3,4-pybz){sub 2}]{sub n} (4) shows a completely different 3-D (4{sup 2}.6){sub 2}(4{sup 4}.6{sup 2}.8{sup 9}) framework, which represents a subnet of the (4,8)-connected fluorite lattice. - Graphical abstract: This work presents a series of 3-D metal-organic frameworks with 3-pyridin-4-yl-benzoate, which display new (3,6)-connected net topologies of (3.4.5)(3{sup 2}.4{sup 4}.5{sup 5}.6{sup 2}.7{sup 2}) for Mn{sup II}/Zn{sup II}/Cd{sup II} and (4{sup 2}.6){sub 2}(4{sup 4}.6{sup 2}.8{sup 9}) for Pb{sup II} species.

  13. Potassium 4,4'-Bis(dinitromethyl)-3,3'-azofurazanate: A Highly Energetic 3D Metal-Organic Framework as a Promising Primary Explosive.

    PubMed

    Tang, Yongxing; He, Chunlin; Mitchell, Lauren A; Parrish, Damon A; Shreeve, Jean'ne M

    2016-04-25

    Environmentally acceptable alternatives to toxic lead-based primary explosives are becoming increasingly important for energetic materials. In this study, potassium 4,4'-bis(dinitromethyl)-3,3'-azofurazanate, comprising two dinitromethyl groups and an azofurazan moiety, was synthesized and isolated as a new energetic 3D metal-organic framework (MOF). Several attractive properties, including a density of 2.039 g cm(-3) , a decomposition temperature of 229 °C, a detonation velocity of 8138 m s(-1) , a detonation pressure of 30.1 GPa, an impact sensitivity of 2 J, and friction sensitivity of 20 N make 4 a good candidate as a green primary explosive. PMID:27008350

  14. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization

    PubMed Central

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g−1 at 1.2 V in 500 mg l−1 NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  15. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization.

    PubMed

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g(-1) at 1.2 V in 500 mg l(-1) NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  16. A 3D chiral metal-organic framework based on left-handed helices containing 3-amino-1 H-1,2,4-triazole ligand

    SciTech Connect

    Liu, Bing; Yang, Tian-Yi; Feng, Hui-Jun; Zhang, Zong-Hui; Xu, Ling

    2015-10-15

    A chiral metal-organic framework, [Cu(atr)(OH)]·0.5H{sub 2}O·0.5en (1) (Hatr=3-amino-1 H-1,2,4-triazole, en=ethylenediamine), was constructed via diffusion reaction of the achiral Hatr ligand and CuSO{sub 4} as starting materials. Compound 1 crystallizes in the chiral space group P3{sub 2}21 and features a porous metal-organic framework with 44.1% solvent-accessible volume fabricated by left-handed helices with a pitch height of l{sub p}=10.442 Å. Six helices gather around in a cycle forming a large honeycomb channel with a 6.58 Å inner diameter. Cu(II) center and atr{sup ‒} ligand regarded as 3-connected nodes, compound 1 can be simplified to a 3-c uninodal (4.12{sup 2}) (qtz-h) topological network. A gradual decreasing in the magnetic moment depending on temperature decreasing indicates an antiferromagnetic interaction in 1. The powder XRD confirms the bulk sample is a single crystal pure phase, and the thermogravimetric analysis shows the thermal stability of 1 is up to ca. 240 °C. - Highlights: • The present 3D chiral MOF is built from achiral Hatr ligand. • Six left-handed helices gather into a honeycomb channel in chiral sp P3{sub 2}21. • Compound 1 shows a 3-c uninodal (4.12{sup 2}) or qtz-h topological network. • Compound 1 indicates an antiferromagnetic interaction.

  17. 3d-4f Metal-Organic Framework with Dual Luminescent Centers That Efficiently Discriminates the Isomer and Homologues of Small Organic Molecules.

    PubMed

    Zeng, Guang; Xing, Shanghua; Wang, Xiuru; Yang, Yulin; Ma, Dingxuan; Liang, Hongwei; Gao, Lu; Hua, Jia; Li, Guanghua; Shi, Zhan; Feng, Shouhua

    2016-02-01

    A 3d-4f luminescent metal-organic framework (MOF), [Tb2(Cu8I8)(C12H8NO2)6(H2O)4]·5C4H8O2 (4), and three analogues {[La2(Cu8I8)(C12H8NO2)6(C4H8O2)2(H2O)2]·3C4H8O2·2H2O (1), [Ce2(Cu8I8)(C12H8NO2)6(H2O)4]·5C4H8O2 (2), and [Eu2(Cu8I8)(C12H8NO2)6(H2O)4]·5C4H8O2 (3)}, were self-assembled from copper(I) halide clusters and lanthanide metal ions with an organic linker [3-(pyridin-4-yl)benzoic acid] under solvothermal conditions. Compound 4 with high quantum yield (Φ = 68%) exhibits reversible luminescence behavior, accompanying the removal and recovery of guest molecules (1,4-dioxane). Because of the unique porous structure and dual luminescent centers of compound 4, it can efficiently differentiate benzene series with different sizes and provide readouts in corresponding optical signals. Furthermore, it also can unambiguously discriminate the isomers, homologues, and other small molecules with similar structural motifs from one another. The luminescent color of the MOF sensor in different guest solvents has obvious changes that can be clearly distinguished by the naked eye. This multicolor luminescence originates from emissions of the dual luminescent centers, and the emissions have shifted, enhanced, weakened, or quenched to different degrees. PMID:26756250

  18. Magnetism in a number of Metal Organic Frameworks (MOFs) with 1D and 3D characteristics: An experimental and analytical study

    NASA Astrophysics Data System (ADS)

    Hamida, Youcef

    Metal Organic Frameworks (MOFs) exhibit many excellent physical properties including magnetic properties for potential applications in devices. More importantly for the subject of this thesis, MOFs are ideal for the realization of low dimensional magnetism because of the large selection of ligands connecting magnetic centers in making the framework. The materials studied in this thesis include ten magnetic MOFs of the form M(L1)(L2) [M = Cu, Ni, Co, Fe, Mn; L1 = NDC, bpdc, BDC, BODC, N3; L2 = DMF, H2O, TED, bpy]. Polycrystalline powder samples as well as single crystal samples were synthesized. Their crystal structures were determined, and their magnetic and thermodynamic properties were measured and analyzed. Eight of these materials were characterized as 1D magnets and two as 3D magnets. In the 1D case it is found that above Tm [the temperature at which the magnetic susceptibility chi(T) has a peak] the magnetic behavior of MOFs (S ≥ 1) can be well described with the Classical Fisher Model (CFM). Near and below TC the spins take a more definite orientation than allowed for in the CFM and hence the Ising Model (IM) was used for fitting. Both CFM and IM yield fairly consistent intrachain couplings ( J) when applied in their appropriate temperature region. To estimate the interchain exchange (J'), the susceptibility for a magnetic chain in the mean field of neighboring chains is used. In all cases, as expected, the ratio of J to J' was less than 10%. The special case of Cu(N3)2bpy ( S = ½) was analyzed with the spin ½ IM. Although the specific heat data (Ctotal) for most of the 1D MOFs showed no clear phase transition, a low temperature fit to the electron-phonon specific heats yielded apparent heavy fermion-like gamma values on the order of several hundred mJ/mol K2. The lattice specific heat (Clattice) was estimated using a Debye-Einstein hybrid model. Subtracting Clattice from Ctotal, magnetic specific heat ( CM) with a broad peak characteristic of low

  19. Heterometallic modular metal-organic 3D frameworks assembled via new tris-β-diketonate metalloligands: nanoporous materials for anion exchange and scaffolding of selected anionic guests.

    PubMed

    Carlucci, Lucia; Ciani, Gianfranco; Maggini, Simona; Proserpio, Davide M; Visconti, Marco

    2010-11-01

    The modular engineering of heterometallic nanoporous metal-organic frameworks (MOFs) based on novel tris-chelate metalloligands, prepared using the functionalised β-diketone 1,3-bis(4'-cyanophenyl)-1,3-propanedione (HL), is described. The complexes [M(III)L(3)] (M=Fe(3+), Co(3+)) and [M(II)L(3)](NEt(4)) (M=Mn(2+), Co(2+), Zn(2+), Cd(2+)) have been synthesised and characterised, all of which exhibit a distorted octahedral chiral structure. The presence of six exo-oriented cyano donor groups on each complex makes it a suitable building block for networking through interactions with external metal ions. We have prepared two families of MOFs by reacting the metalloligands [M(III)L(3)] and [M(II)L(3)](-) with many silver salts AgX (X=NO(3)(-), BF(4)(-), PF(6)(-), AsF(6)(-), SbF(6)(-), CF(3)SO(3)(-), tosylate), specifically the [M(III)L(3)Ag(3)]X(3)·Solv and [M(II)L(3)Ag(3)]X(2)·Solv network species. Very interestingly, all of these network species exhibit the same type of 3D structure and crystallise in the same trigonal space group with similar cell parameters, in spite of the different metal ions, ionic charges and X(-) counteranions of the silver salts. We have also succeeded in synthesising trimetallic species such as [Zn(x)Fe(y)L(3)Ag(3)](ClO(4))((2x+3y))·Solv and [Zn(x)Cd(y)L(3)Ag(3)](ClO(4))(2)·Solv (with x+y=1). All of the frameworks can be described as sixfold interpenetrated pcu nets, considering the Ag(+) ions as simple digonal spacers. Each individual net is homochiral, containing only Δ or Λ nodes; the whole array contains three nets of type Δ and three nets of type Λ. Otherwise, taking into account the presence of weak Ag-C σ bonds involving the central carbon atoms of the β-diketonate ligands of adjacent nets, the six interpenetrating pcu networks are joined into a unique non-interpenetrated six-connected frame with the rare acs topology. The networks contain large parallel channels of approximate hexagonal-shaped sections that represent 37

  20. A two-fold interpenetrating 3D metal-organic framework material constructed from helical chains linked via 4,4'-H{sub 2}bpz fragments

    SciTech Connect

    Xie Yiming; Zhao Zhenguo; Wu Xiaoyuan; Zhang Qisheng; Chen Lijuan; Wang Fei; Chen Shanci; Lu Canzhong

    2008-12-15

    A 3-connected dia-f-type metal-organic framework compound {l_brace}[Ag(L){sub 3/2}H{sub 2}PO{sub 4}]{r_brace}{sub n} (1) has been synthesized by self-assembly of 4,4'-H{sub 2}bpz (L=4,4'-H{sub 2}bpz=3,3',5,5'-tetramethyl-4,4'-bipyrazole) and Ag{sub 4}P{sub 2}O{sub 7} under hydrothermal conditions. It crystallizes in the tetragonal space group I4{sub 1}/acd with a=21.406(4) A, b=21.406(4) A, c=36.298(8) A, Z=32. X-ray single-crystal diffraction reveals that 1 has a three-dimensional framework with an unprecedented alternate left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net. Photoluminescent investigation reveals that the title compound displays interesting emissions in a wide region, which shows that the title compound may be a good potential candidate as a photoelectric material. - Graphical abstract: A 3-connected dia-f-type metal-organic framework compound [Ag(4,4'-bpz){sub 3/2}H{sub 2}PO{sub 4}] shows unprecedented alternating left- and right-handed helices structure, featuring a non-uniform two-fold interpenetrated (4.14{sup 2}) net.

  1. A 3D chiral metal-organic framework based on left-handed helices containing 3-amino-1 H-1,2,4-triazole ligand

    NASA Astrophysics Data System (ADS)

    Liu, Bing; Yang, Tian-Yi; Feng, Hui-Jun; Zhang, Zong-Hui; Xu, Ling

    2015-10-01

    A chiral metal-organic framework, [Cu(atr)(OH)]·0.5H2O·0.5en (1) (Hatr=3-amino-1 H-1,2,4-triazole, en=ethylenediamine), was constructed via diffusion reaction of the achiral Hatr ligand and CuSO4 as starting materials. Compound 1 crystallizes in the chiral space group P3221 and features a porous metal-organic framework with 44.1% solvent-accessible volume fabricated by left-handed helices with a pitch height of lp=10.442 Å. Six helices gather around in a cycle forming a large honeycomb channel with a 6.58 Å inner diameter. Cu(II) center and atr‒ ligand regarded as 3-connected nodes, compound 1 can be simplified to a 3-c uninodal {4.122} (qtz-h) topological network. A gradual decreasing in the magnetic moment depending on temperature decreasing indicates an antiferromagnetic interaction in 1. The powder XRD confirms the bulk sample is a single crystal pure phase, and the thermogravimetric analysis shows the thermal stability of 1 is up to ca. 240 °C.

  2. Flexible metal-organic frameworks.

    PubMed

    Schneemann, A; Bon, V; Schwedler, I; Senkovska, I; Kaskel, S; Fischer, R A

    2014-08-21

    Advances in flexible and functional metal-organic frameworks (MOFs), also called soft porous crystals, are reviewed by covering the literature of the five years period 2009-2013 with reference to the early pertinent work since the late 1990s. Flexible MOFs combine the crystalline order of the underlying coordination network with cooperative structural transformability. These materials can respond to physical and chemical stimuli of various kinds in a tunable fashion by molecular design, which does not exist for other known solid-state materials. Among the fascinating properties are so-called breathing and swelling phenomena as a function of host-guest interactions. Phase transitions are triggered by guest adsorption/desorption, photochemical, thermal, and mechanical stimuli. Other important flexible properties of MOFs, such as linker rotation and sub-net sliding, which are not necessarily accompanied by crystallographic phase transitions, are briefly mentioned as well. Emphasis is given on reviewing the recent progress in application of in situ characterization techniques and the results of theoretical approaches to characterize and understand the breathing mechanisms and phase transitions. The flexible MOF systems, which are discussed, are categorized by the type of metal-nodes involved and how their coordination chemistry with the linker molecules controls the framework dynamics. Aspects of tailoring the flexible and responsive properties by the mixed component solid-solution concept are included, and as well examples of possible applications of flexible metal-organic frameworks for separation, catalysis, sensing, and biomedicine. PMID:24875583

  3. Metal-organic frameworks from zinc sulfite clusters, chains, and sheets: 4-connected, (3,4)-connected 3-D frameworks and 2-D arrays of catenane-like interlocking rings.

    PubMed

    Nguyen, Dan-Tam; Chew, Emily; Zhang, Qichun; Choi, Alice; Bu, Xianhui

    2006-12-25

    Even though open-framework solids have been made in a variety of compositions such as silicates, phosphates, germanates, borates, and phosphites, few are known that are based on trigonal-pyramidal sulfite anions. We report here the first synthetic and structural studies of metal-organic framework materials in the zinc sulfite composition. It is demonstrated here that Zn2+ and SO32- can form various neutral inorganic subunits that can be 0-D clusters, 1-D chains, or 2-D sheets. These inorganic subunits of different dimensionality can subsequently be connected into extended frameworks of higher dimensionality through bifunctional ligands. In (ZnSO3)2en, infinite corrugated ZnSO3 layers are pillared by ethylenediamine (en) molecules into a 3-D network that can be classified as a (3,4)-connected net based on tetrahedral Zn nodes and trigonal-pyramidal S nodes. In (ZnSO3)pip, infinite ZnSO3 chains are cross-linked with piperazine molecules into a 3-D framework that can be classified as 4-connected net based on tetrahedral Zn nodes only. In (ZnSO3)2(TMDPy)2, (ZnSO3)2 dimers are doubly bridged by trimethylenedipyridine molecules into an infinite chain with a string of circles. Each circle along the chain is interlocked with another circle from a chain in the perpendicular direction, creating a 2-D pattern with an infinite-square array of catenane-like units. PMID:17173428

  4. Amorphous metal-organic frameworks.

    PubMed

    Bennett, Thomas D; Cheetham, Anthony K

    2014-05-20

    Crystalline metal-organic frameworks (MOFs) are porous frameworks comprising an infinite array of metal nodes connected by organic linkers. The number of novel MOF structures reported per year is now in excess of 6000, despite significant increases in the complexity of both component units and molecular networks. Their regularly repeating structures give rise to chemically variable porous architectures, which have been studied extensively due to their sorption and separation potential. More recently, catalytic applications have been proposed that make use of their chemical tunability, while reports of negative linear compressibility and negative thermal expansion have further expanded interest in the field. Amorphous metal-organic frameworks (aMOFs) retain the basic building blocks and connectivity of their crystalline counterparts, though they lack any long-range periodic order. Aperiodic arrangements of atoms result in their X-ray diffraction patterns being dominated by broad "humps" caused by diffuse scattering and thus they are largely indistinguishable from one another. Amorphous MOFs offer many exciting opportunities for practical application, either as novel functional materials themselves or facilitating other processes, though the domain is largely unexplored (total aMOF reported structures amounting to under 30). Specifically, the use of crystalline MOFs to detect harmful guest species before subsequent stress-induced collapse and guest immobilization is of considerable interest, while functional luminescent and optically active glass-like materials may also be prepared in this manner. The ion transporting capacity of crystalline MOFs might be improved during partial structural collapse, while there are possibilities of preparing superstrong glasses and hybrid liquids during thermal amorphization. The tuning of release times of MOF drug delivery vehicles by partial structural collapse may be possible, and aMOFs are often more mechanically robust than

  5. Gas adsorption on metal-organic frameworks

    DOEpatents

    Willis, Richard R.; Low, John J. , Faheem, Syed A.; Benin, Annabelle I.; Snurr, Randall Q.; Yazaydin, Ahmet Ozgur

    2012-07-24

    The present invention involves the use of certain metal organic frameworks that have been treated with water or another metal titrant in the storage of carbon dioxide. The capacity of these frameworks is significantly increased through this treatment.

  6. Towards multifunctional lanthanide-based metal-organic frameworks.

    PubMed

    Tobin, Gerard; Comby, Steve; Zhu, Nianyong; Clérac, Rodolphe; Gunnlaugsson, Thorfinnur; Schmitt, Wolfgang

    2015-09-01

    We report the synthesis, structure and physicochemical attributes of a new holmium(III)-based metal-organic framework whose 3D network structure gives rise to porosity; the reported structure-type can be varied using a range of different lanthanide ions to tune the photophysical properties and produce ligand-sensitised near-infrared (NIR) and visible light emitters. PMID:26207535

  7. Nets, tiles, and metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    O'Keeffe, Michael

    2014-12-01

    An account is given of the basic nets that are important in the description and design of metal-organic framework (MOF) structures. These are generally of minimal transitivity, a concept which is explained. Derived nets are defined and the advantages of using derived nets to describe the topology of MOF frameworks with multiple branch points are emphasized.

  8. Porosity in metal-organic framework glasses.

    PubMed

    Thornton, A W; Jelfs, K E; Konstas, K; Doherty, C M; Hill, A J; Cheetham, A K; Bennett, T D

    2016-03-01

    The porosity of a glass formed by melt-quenching a metal-organic framework, has been characterized by positron annihilation lifetime spectroscopy. The results reveal porosity intermediate between the related open and dense crystalline frameworks ZIF-4 and ZIF-zni. A structural model for the glass was constructed using an amorphous polymerization algorithm, providing additional insight into the gas-inaccessible nature of porosity and the possible applications of hybrid glasses. PMID:26800518

  9. Minerals with metal-organic framework structures.

    PubMed

    Huskić, Igor; Pekov, Igor V; Krivovichev, Sergey V; Friščić, Tomislav

    2016-08-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals. PMID:27532051

  10. Minerals with metal-organic framework structures

    PubMed Central

    Huskić, Igor; Pekov, Igor V.; Krivovichev, Sergey V.; Friščić, Tomislav

    2016-01-01

    Metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. We now demonstrate an unexpected link between mineralogy and MOF chemistry by discovering that the rare organic minerals stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials and represent, so far, unique examples of open framework architectures in organic minerals. PMID:27532051

  11. Purification of metal-organic framework materials

    SciTech Connect

    Farha, Omar K.; Hupp, Joseph T.

    2012-12-04

    A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

  12. Purification of metal-organic framework materials

    SciTech Connect

    Farha, Omar K.; Hupp, Joseph T.

    2015-06-30

    A method of purification of a solid mixture of a metal-organic framework (MOF) material and an unwanted second material by disposing the solid mixture in a liquid separation medium having a density that lies between those of the wanted MOF material and the unwanted material, whereby the solid mixture separates by density differences into a fraction of wanted MOF material and another fraction of unwanted material.

  13. Multiphoton harvesting metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Quah, Hong Sheng; Chen, Weiqiang; Schreyer, Martin K.; Yang, Hui; Wong, Ming Wah; Ji, Wei; Vittal, Jagadese J.

    2015-08-01

    Multiphoton upconversion is a process where two or more photons are absorbed simultaneously to excite an electron to an excited state and, subsequently, the relaxation of electron gives rise to the emission of a photon with frequency greater than those of the absorbed photons. Materials possessing such property attracted attention due to applications in biological imaging, photodynamic therapy, three-dimensional optical data storage, frequency-upconverted lasing and optical power limiting. Here we report four-photon upconversion in metal-organic frameworks containing the ligand, trans, trans-9,10-bis(4-pyridylethenyl)anthracene. The ligand has a symmetrical acceptor-π-donor-π-acceptor structure and a singlet biradical electronic ground state, which boosted its multiphoton absorption cross-sections. We demonstrate that the upconversion efficiency can be enhanced by Förster resonance energy transfer within host-guest metal-organic frameworks consisting of encapsulated high quantum yielding guest molecules. Using these strategies, metal-organic framework materials, which can exhibit frequency-upconverted photoluminescence excited by simultaneous multiphoton absorption, can be rationally designed and synthesized.

  14. Photochemistry in a 3D metal-organic framework (MOF): monitoring intermediates and reactivity of the fac-to-mer photoisomerization of Re(diimine)(CO)3Cl incorporated in a MOF.

    PubMed

    Easun, Timothy L; Jia, Junhua; Calladine, James A; Blackmore, Danielle L; Stapleton, Christopher S; Vuong, Khuong Q; Champness, Neil R; George, Michael W

    2014-03-01

    The mechanism and intermediates in the UV-light-initiated ligand rearrangement of fac-Re(diimine)(CO)3Cl to form the mer isomer, when incorporated into a 3D metal-organic framework (MOF), have been investigated. The structure hosting the rhenium diimine complex is a 3D network with the formula {Mn(DMF)2[LRe(CO)3Cl]}∞ (ReMn; DMF = N,N-dimethylformamide), where the diimine ligand L, 2,2'-bipyridine-5,5'-dicarboxylate, acts as a strut of the MOF. The incorporation of ReMn into a KBr disk allows spatial distribution of the mer-isomer photoproduct in the disk to be mapped and spectroscopically characterized by both Fourier transform infrared and Raman microscopy. Photoisomerization has been monitored by IR spectroscopy and proceeds via dissociation of a CO to form more than one dicarbonyl intermediate. The dicarbonyl species are stable in the solid state at 200 K. The photodissociated CO ligand appears to be trapped within the crystal lattice and, upon warming above 200 K, readily recombines with the dicarbonyl intermediates to form both the fac-Re(diimine)(CO)3Cl starting material and the mer-Re(diimine)(CO)3Cl photoproduct. Experiments over a range of temperatures (265-285 K) allow estimates of the activation enthalpy of recombination for each process of ca. 16 (±6) kJ mol(-1) (mer formation) and 23 (±4) kJ mol(-1) (fac formation) within the MOF. We have compared the photochemistry of the ReMn MOF with a related alkane-soluble Re(dnb)(CO)3Cl complex (dnb = 4,4'-dinonyl-2,2'-bipyridine). Time-resolved IR measurements clearly show that, in an alkane solution, the photoinduced dicarbonyl species again recombines with CO to both re-form the fac-isomer starting material and form the mer-isomer photoproduct. Density functional theory calculations of the possible dicarbonyl species aids the assignment of the experimental data in that the ν(CO) IR bands of the CO loss intermediate are, as expected, shifted to lower energy when the metal is bound to DMF rather than to an

  15. Defects and disorder in metal organic frameworks.

    PubMed

    Cheetham, Anthony K; Bennett, Thomas D; Coudert, François-Xavier; Goodwin, Andrew L

    2016-03-14

    The wide-ranging properties of metal organic frameworks (MOFs) rely in many cases on the presence of defects within their structures and the disorder that is inevitably associated with such defects. In the present work we review several aspects of defects in MOFs, ranging from simple substitutional defects at metal cation or ligand positions, to correlated defects on a larger length scale and the extreme case of disorder associated with amorphous MOFs. We consider both porous and dense MOFs, and focus particularly on the way in which defects and disorder can be used to tune physical properties such as gas adsorption, catalysis, photoluminescence, and electronic and mechanical properties. PMID:26836459

  16. Polyrotaxane metal-organic frameworks (PMOFs).

    PubMed

    Yang, Jin; Ma, Jian-Fang; Batten, Stuart R

    2012-08-18

    Polyrotaxane metal-organic frameworks (PMOFs), a relatively rare branch of entangled networks, have received significant attention due to their unusual entanglement topologies. The PMOFs we described here are still at an early stage of development. This feature article summarizes the recent developments in structural types of PMOFs from our own group and others. We make some generalizations about the various classes of PMOFs, and develop the definitions and nomenclature of these entanglements, including classification into trivial and nontrivial polyrotaxanes, and limits on what constitutes a (nontrivial) polyrotaxane. Finally, the synthetic strategies toward the design and preparation of new PMOFs are elucidated. PMID:22745934

  17. Metal-organic frameworks for photocatalysis.

    PubMed

    Li, Ying; Xu, Hua; Ouyang, Shuxin; Ye, Jinhua

    2016-03-01

    Photocatalysis is a promising technology to convert solar energy into chemical energy. Recently, metal-organic frameworks (MOFs) have emerged as novel photocatalysts owing to their inherent structural characteristics of a large surface area and a well-ordered porous structure. Most importantly, via modulation of the organic linker/metal clusters or incorporation with metal/complex catalysts, not only the reactant adsorption and light absorption but also the charge separation and reactant activation will be largely promoted, leading to superior photocatalytic performance. In this article, we will first introduce the photophysical/chemical properties of MOFs; then various strategies of modification of MOFs towards better photocatalytic activity will be presented; finally, we will address the challenge and further perspective in MOF-based photocatalysis. PMID:26535907

  18. Stimulus-responsive metal-organic frameworks.

    PubMed

    Nagarkar, Sanjog S; Desai, Aamod V; Ghosh, Sujit K

    2014-09-01

    Materials that can recognize the changes in their local environment and respond by altering their inherent physical and/or chemical properties are strong candidates for future "smart" technology materials. Metal-organic frameworks (MOFs) have attracted a great deal of attention in recent years owing to their designable architecture, host-guest chemistry, and softness as porous materials. Despite this fact, studies on the tuning of the properties of MOFs by external stimuli are still rare. This review highlights the recent developments in the field of stimulus-responsive MOFs or so-called smart MOFs. In particular, the various stimuli used and the utility of stimulus-responsive smart MOFs for various applications such as gas storage and separation, sensing, clean energy, catalysis, molecular motors, and biomedical applications are highlighted by using representative examples. Future directions in the developments of stimulus-responsive smart MOFs and their applications are proposed from a personal perspective. PMID:24844581

  19. Biomimetic catalysis of metal-organic frameworks.

    PubMed

    Chen, Yao; Ma, Shengqian

    2016-06-14

    Metal-organic frameworks (MOFs) have attracted great attention as a new type of prospective material with various merits and functionalities. MOFs can either act as biomimetic catalysts to mimic enzymatic activities or serve as hosts to encapsulate bio-active species for biomimetic catalysis. However, in comparison with the dramatic development of MOFs in other catalytic fields, MOF-based biomimetic catalysis is still in its infancy and is yet to be systematically and comprehensively explored. Herein, the principles and strategies for the design and synthesis of MOF-based biomimetic catalysts, especially the structural features of representative MOFs that are related to biomimetic catalysis, are summarized and reviewed. In addition, recent advances in biomimetic catalysis of MOFs and the relationships between their catalytic performances and the structural specificities are discussed in detail as well. PMID:27041152

  20. An Electrically Switchable Metal-Organic Framework

    PubMed Central

    Fernandez, Carlos A.; Martin, Paul C.; Schaef, Todd; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-01-01

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication. PMID:25135307

  1. An Electrically Switchable Metal-Organic Framework

    NASA Astrophysics Data System (ADS)

    Fernandez, Carlos A.; Martin, Paul C.; Schaef, Todd; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-08-01

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  2. An Electrically Switchable Metal-Organic Framework

    SciTech Connect

    Fernandez, Carlos A.; Martin, Paul F.; Schaef, Herbert T.; Bowden, Mark E.; Thallapally, Praveen K.; Dang, Liem X.; Xu, Wu; Chen, Xilin; McGrail, B. Peter

    2014-08-19

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ 5 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  3. An Electrically Switchable Metal-Organic Framework

    SciTech Connect

    Fernandez, CA; Martin, PC; Schaef, T; Bowden, ME; Thallapally, PK; Dang, L; Xu, W; Chen, XL; McGrail, BP

    2014-08-19

    Crystalline metal organic framework (MOF) materials containing interconnected porosity can be chemically modified to promote stimulus-driven (light, magnetic or electric fields) structural transformations that can be used in a number of devices. Innovative research strategies are now focused on understanding the role of chemical bond manipulation to reversibly alter the free volume in such structures of critical importance for electro-catalysis, molecular electronics, energy storage technologies, sensor devices and smart membranes. In this letter, we study the mechanism for which an electrically switchable MOF composed of Cu(TCNQ) (TCNQ = 7,7,8,8-tetracyanoquinodimethane) transitions from a high-resistance state to a conducting state in a reversible fashion by an applied potential. The actual mechanism for this reversible electrical switching is still not understood even though a number of reports are available describing the application of electric-field-induced switching of Cu(TCNQ) in device fabrication.

  4. Metal-organic framework materials with ultrahigh surface areas

    SciTech Connect

    Farha, Omar K.; Hupp, Joseph T.; Wilmer, Christopher E.; Eryazici, Ibrahim; Snurr, Randall Q.; Gomez-Gualdron, Diego A.; Borah, Bhaskarjyoti

    2015-12-22

    A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m.sup.2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.

  5. Thermodynamics of metal-organic frameworks

    SciTech Connect

    Wu, Di; Navrotsky, Alexandra

    2015-03-15

    Although there have been extensive studies over the past decade in the synthesis and application of metal-organic frameworks (MOFs), investigation of their thermodynamic stability and of the energetics of guest–host interactions has been much more limited. This review summarizes recent progress in experimental (calorimetric) determination of the thermodynamics of MOF materials. The enthalpies of MOFs relative to dense phase assemblages suggest only modest metastability, with a general increase of enthalpy with increasing molar volume, which becomes less pronounced at higher porosity. The energy landscape of nanoporous materials (inorganic and hybrid) consists of a pair of parallel patterns within a fairly narrow range of metastability of 5–30 kJ per mole of tetrahedra in zeolites and mesoporous silicas or per mole of metal in MOFs. Thus strong thermodynamic instability does not seem to limit framework formation. There are strong interactions within the chemisorption range for small molecule–MOF interactions with defined chemical binding at the metal centers or other specific locations. Coexistence of surface binding and confinement can lead to much stronger guest–host interactions. - Graphical abstract: Energy landscape of inorganic and hybrid porous materials. - Highlights: • Thermochemical data on various MOF structures were experimentally determined. • MOFs are moderately unstable relative to their dense phase assemblage. • Overall energetic landscape of porous materials was revealed. • Guest–host interactions in MOFs were evaluated directly using calorimetry. • Confinement effect and defined chemical binding lead to strong interactions.

  6. Bi–Mn mixed metal organic oxide: A novel 3d-6p mixed metal coordination network

    SciTech Connect

    Shi, Fa-Nian; Rosa Silva, Ana; Bian, Liang

    2015-05-15

    A new terminology of metal organic oxide (MOO) was given a definition as a type of coordination polymers which possess the feature of inorganic connectivity between metals and the direct bonded atoms and show 1D, 2D or 3D inorganic sub-networks. One such compound was shown as an example. A 3d-6p (Mn–Bi. Named MOOMnBi) mixed metals coordination network has been synthesized via hydrothermal method. The new compound with the molecular formula of [MnBi{sub 2}O(1,3,5-BTC){sub 2}]{sub n} (1,3,5-BTC stands for benzene-1,3,5-tricarboxylate) was characterized via single crystal X-ray diffraction technique that revealed a very interesting 3-dimensional (3D) framework with Bi{sub 4}O{sub 2}(COO){sub 12} clusters which are further connected to Mn(COO){sub 6} fragments into a 2D MOO. The topology study indicates an unprecedented topological type with the net point group of (4{sup 13}.6{sup 2})(4{sup 13}.6{sup 8})(4{sup 16}.6{sup 5})(4{sup 18}.6{sup 10})(4{sup 22}.6{sup 14})(4{sup 3}) corresponding to 3,6,7,7,8,9-c hexa-nodal net. MOOMnBi shows catalytic activity in the synthesis of (E)-α,β-unsaturated ketones. - Graphical abstract: This metal organic framework (MOF) is the essence of a 2D metal organic oxide (MOO). - Highlights: • New concept of metal organic oxide (MOO) was defined and made difference from metal organic framework. • New MOO of MOOMnBi was synthesized by hydrothermal method. • Crystal structure of MOOMnBi was determined by single crystal X-ray analysis. • The catalytic activity of MOOMnBi was studied showing reusable after 2 cycles.

  7. Metal-organic frameworks for oxygen storage.

    PubMed

    DeCoste, Jared B; Weston, Mitchell H; Fuller, Patrick E; Tovar, Trenton M; Peterson, Gregory W; LeVan, M Douglas; Farha, Omar K

    2014-12-15

    We present a systematic study of metal-organic frameworks (MOFs) for the storage of oxygen. The study starts with grand canonical Monte Carlo simulations on a suite of 10,000 MOFs for the adsorption of oxygen. From these data, the MOFs were down selected to the prime candidates of HKUST-1 (Cu-BTC) and NU-125, both with coordinatively unsaturated Cu sites. Oxygen isotherms up to 30 bar were measured at multiple temperatures to determine the isosteric heat of adsorption for oxygen on each MOF by fitting to a Toth isotherm model. High pressure (up to 140 bar) oxygen isotherms were measured for HKUST-1 and NU-125 to determine the working capacity of each MOF. Compared to the zeolite NaX and Norit activated carbon, NU-125 has an increased excess capacity for oxygen of 237% and 98%, respectively. These materials could ultimately prove useful for oxygen storage in medical, military, and aerospace applications. PMID:25319881

  8. Metal-Organic Frameworks as Platforms for Functional Materials.

    PubMed

    Cui, Yuanjing; Li, Bin; He, Huajun; Zhou, Wei; Chen, Banglin; Qian, Guodong

    2016-03-15

    , carbon dioxide capture, and separations. The intrinsic optical and photonic properties of metal ions and organic ligands, and guest molecules and/or ions can be collaboratively assembled and/or encapsulated into their frameworks, so we have realized a series of novel MOF materials as ratiometric luminescent thermometers, O2 sensors, white-light-emitting materials, nonlinear optical materials, two-photon pumped lasing materials, and two-photon responsive materials for 3D patterning and data storage. Thanks to the interplay of the dual functionalities of metal-organic frameworks (the inherent porosity, and the intrinsic physical and chemical properties of inorganic and organic building blocks and encapsulated guest species), our research efforts have led to the development of functional MOF materials beyond our initial imaginations. PMID:26878085

  9. Thermodynamics of Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Hughes, James Thomas

    Metal-Organic Frameworks (MOF) are crystalline nanoporous lattices constructed from the combination of cation and multi-dentate organic molecules. MOFs can display both chemical and thermal robustness while having large surface areas and pore volumes. In addition the modular composition of MOFs allows a degree of design and control of MOF structures. These unique physical properties have attracted wide interest and position MOFs to make meaningful contributions towards many applications, such as adsorption, catalysis, separation, and sensing. Despite the extensive investigative work over the last decade on MOF materials, the initial synthesis is still done by trial and error. Of the identified structures some MOFs are robust while others are fragile. It is unclear what role thermodynamics plays in the formation energies of MOFs and guest molecules interactions within the pores. Better understanding of thermochemical properties of MOFs is critical if MOF synthesis is to obtain true predictive design. To address these questions aqueous solution calorimetry was performed on ten different frameworks in both the as-synthesized and activated state. To understand the structural energetics of MOFs, the heat of formation from dense states (metal oxide and protonated organic linkers) to the open MOF framework was measured. Chapter 2 discusses the new aqueous calorimetry methodology developed to measure the enthalpy of solution for hybrid materials. Chapters 3, 4 and 5 detail the enthalpies of formation from their dense states of the frameworks: (MOF-5, ZIF-zni, ZIF-1, ZIF-3, ZIF-4, ZIF-7, ZIF-8, ZIF-9 and Cu-HKUST-1). These chapters also compare the MOF heat of formation energetics to those of zeolites, zeotypes and mesoporous silica materials. Finding that MOFs are metastable with respect to their dense states (metal oxide and protonated organic), following the current destabilization trend of the main group porous materials. The thermochemical effect of solvent on the MOF

  10. Hydrogen Storage in Metal-Organic Frameworks

    SciTech Connect

    Omar M. Yaghi

    2012-04-26

    Conventional storage of large amounts of hydrogen in its molecular form is difficult and expensive because it requires employing either extremely high pressure gas or very low temperature liquid. Because of the importance of hydrogen as a fuel, the DOE has set system targets for hydrogen storage of gravimetric (5.5 wt%) and volumetric (40 g L-1) densities to be achieved by 2015. Given that these are system goals, a practical material will need to have higher capacity when the weight of the tank and associated cooling or regeneration system is considered. The size and weight of these components will vary substantially depending on whether the material operates by a chemisorption or physisorption mechanism. In the latter case, metal-organic frameworks (MOFs) have recently been identified as promising adsorbents for hydrogen storage, although little data is available for their sorption behavior. This grant was focused on the study of MOFs with these specific objectives. (1) To examine the effects of functionalization, catenation, and variation of the metal oxide and organic linkers on the low-pressure hydrogen adsorption properties of MOFs. (2) To develop a strategy for producing MOFs with high surface area and porosity to reduce the dead space and increase the hydrogen storage capacity per unit volume. (3) To functionalize MOFs by post synthetic functionalization with metals to improve the adsorption enthalpy of hydrogen for the room temperature hydrogen storage. This effort demonstrated the importance of open metal sites to improve the adsorption enthalpy by the systematic study, and this is also the origin of the new strategy, which termed isoreticular functionalization and metalation. However, a large pore volume is still a prerequisite feature. Based on our principle to design highly porous MOFs, guest-free MOFs with ultrahigh porosity have been experimentally synthesized. MOF-210, whose BET surface area is 6240 m2 g-1 (the highest among porous solids), takes up

  11. Melt-Quenched Glasses of Metal-Organic Frameworks.

    PubMed

    Bennett, Thomas D; Yue, Yuanzheng; Li, Peng; Qiao, Ang; Tao, Haizheng; Greaves, Neville G; Richards, Tom; Lampronti, Giulio I; Redfern, Simon A T; Blanc, Frédéric; Farha, Omar K; Hupp, Joseph T; Cheetham, Anthony K; Keen, David A

    2016-03-16

    Crystalline solids dominate the field of metal-organic frameworks (MOFs), with access to the liquid and glass states of matter usually prohibited by relatively low temperatures of thermal decomposition. In this work, we give due consideration to framework chemistry and topology to expand the phenomenon of the melting of 3D MOFs, linking crystal chemistry to framework melting temperature and kinetic fragility of the glass-forming liquids. Here we show that melting temperatures can be lowered by altering the chemistry of the crystalline MOF state, which provides a route to facilitate the melting of other MOFs. The glasses formed upon vitrification are chemically and structurally distinct from the three other existing categories of melt-quenched glasses (inorganic nonmetallic, organic, and metallic), and retain the basic metal-ligand connectivity of crystalline MOFs, which connects their mechanical properties to their starting chemical composition. The transfer of functionality from crystal to glass points toward new routes to tunable, functional hybrid glasses. PMID:26885940

  12. Contrasting low-dimensional magnetism in the 3D metal-organic frameworks [Cu(VF6)(pyz)2]4H2O and [Cu(HF2)(pyz)2]SbF6 (pyz = pyrazine)

    NASA Astrophysics Data System (ADS)

    Manson, Jamie; Schlueter, John; Goddard, Paul; Singleton, John; McDonald, Ross; Ayala-Valenzuela, Oscar; Lancaster, Tom; Blundell, Stephen

    2012-02-01

    [Cu(VF6)(pyz)2]4H2O (1) and [Cu(HF2)(pyz)2]SbF6 (2) form tetragonal frameworks that consist of 2D [Cu(pyz)2]^2+ square lattices that are linked in 3D by bridging VF6^2- (1) or HF2^- (2) anions. Magnetic susceptibility data shows apparent paramagnetism, although not simple Curie-Weiss behavior, in 1. For 2, a broad maximum in χ(T) at 12.5 K and a sharp kink at 4.3 K indicate short- (SRO) and long-range (LRO) magnetic ordering, respectively. Additional experimental data for 1 (e.g., heat capacity and μ^+SR) however, indicate that a LRO state occurs below 3.6 K whereas pulsed-field magnetization data suggest a superposition of AFM Cu^2+ layers and fluctuating V^4+ moments. The structural and magnetic behavior of 1 and 2 will be described as well as possible new directions.

  13. Crystal transformation synthesis of a highly stable fluorescent 3D indium-tetranuclear {In4(μ2-OH)3} building block based metal organic framework through a dinuclear complex.

    PubMed

    Wang, Xin-Ming; Fan, Rui-Qing; Qiang, Liang-Sheng; Wang, Ping; Yang, Yu-Lin; Wang, Yu-Lei

    2014-11-21

    A rare 3D tetranuclear {In4(μ2-OH)3} building block based MOF {[In4/3(μ2-OH)(2,6-pydc)(1,4-bda)0.5(H2O)]·2H2O}n (2) was obtained through a crystal transformation from a dimeric complex In3(2,6-pydc)3(1,4-bda)1.5(H2O)6 (1). With a 2D + 3D3D compact structure, 2 retains crystallinity in boiling water and organic solvents, exhibiting exceptional fluorescence quenching behaviour for the DMSO molecule. PMID:25135576

  14. Omar Yaghi on Chemistry and Metal Organic Frameworks

    SciTech Connect

    Omar Yaghi

    2012-07-23

    In this edited version of the hour long talk, Omar Yaghi, director of the Molecular Foundry, sat down in conversation with Jeff Miller, head of Public Affairs, on July 11th, 2012 to discuss his fascination with the hidden world of chemistry and his work on Metal Organic Frameworks.

  15. Omar Yaghi on Chemistry and Metal Organic Frameworks

    ScienceCinema

    Omar Yaghi

    2013-06-24

    In this edited version of the hour long talk, Omar Yaghi, director of the Molecular Foundry, sat down in conversation with Jeff Miller, head of Public Affairs, on July 11th, 2012 to discuss his fascination with the hidden world of chemistry and his work on Metal Organic Frameworks.

  16. Metal-organic frameworks: Shuttling in the solid state

    NASA Astrophysics Data System (ADS)

    Olson, Mark A.

    2015-06-01

    Incorporating mechanically interlocked molecular shuttles within a metal-organic framework that has enough free space in the crystal lattice to permit volume-conserving translational motion sets the stage for defect-free molecular-electronic device fabrication and more.

  17. Metal-organic frameworks: A thin film opening

    NASA Astrophysics Data System (ADS)

    Sumby, Christopher J.

    2016-04-01

    The properties of metal-organic frameworks -- promising for a myriad of applications -- can be commonly tuned by judicious choice of the building blocks used to prepare the material. Now, simply downsizing a rigid, non-porous MOF to a thin film has been shown to endow it with dynamic, gate-opening-type guest uptake behaviour.

  18. A biomimetic tongue by photoluminescent metal-organic frameworks.

    PubMed

    Lee, Tu; Lin Lee, Hung; Hsun Tsai, Meng; Cheng, Shao-Liang; Lee, Sheng-Wei; Hu, Jung-Chih; Chen, Lien-Tai

    2013-05-15

    The taste sensing capabilities of a "biomimetic tongue" based on the photoluminescence (PL) responses of metal-organic frameworks (MOFs), [In(OH)(bdc)]n (bdc=1,4-benzenedicarboxylate), [Tb(btc)]n (MOF-76, btc=benzene-1,3,5-tricarboxylate), and [Ca3(btc)2(DMF)2(H2O)2]·3H2O are proven on aqueous solutions of five basic tastants: sucrose (sweet), caffeine (bitter), citric acid (sour), sodium chloride (salty) and monosodium glutamate (umami). For [In(OH)(bdc)]n, the tastant interacts stereochemically with poly(acrylic acid) (PAA) and alters its conformations. The frequency and magnitude of chelation between COO(-) pendant groups of PAA and In(3+) nodes of [In(OH)(bdc)]n framework influence the corresponding PL reponses. For MOF-76, the tastant interacts with incorporated water in MOF-76 through hydrogen bonding. The limitation of O-H bond stretching of water results in the enhancement of the PL intensity. For [Ca3(BTC)2(DMF)2(H2O)2]·3H2O, it is added as a third MOF component to increase the precision on taste discrimination. The significance of MOF-based "biomimetic tongue" includes: (1) PAA on [In(OH)(bdc)]n mimics the taste receptor cells (TRCs) for their structural flexibility, (2) the Weber-Fechner law of human sensing that sensation is proportional to the logarithm of the stimulus intensity is observed between the PL emission response of MOF-76 and the concentration of tastant, (3) the strength of taste is quantified by the τ scale and the PL emission intensity of MOF-76, which are dependent on the logarithmic tastant concentration, (4) the tastant is identified by the shape of the 3D principal component analysis contour map (i.e., pattern recognition method), and (5) the fabrication of [In(OH)(bdc)]n/PAA film by brushing is illustrated. PMID:23277340

  19. A metal-organic framework-derived bifunctional oxygen electrocatalyst

    NASA Astrophysics Data System (ADS)

    Xia, Bao Yu; Yan, Ya; Li, Nan; Wu, Hao Bin; Lou, Xiong Wen (David); Wang, Xin

    2016-01-01

    Oxygen electrocatalysis is of great importance for many energy storage and conversion technologies, including fuel cells, metal-air batteries and water electrolysis. Replacing noble metal-based electrocatalysts with highly efficient and inexpensive non-noble metal-based oxygen electrocatalysts is critical for the practical applications of these technologies. Here we report a general approach for the synthesis of hollow frameworks of nitrogen-doped carbon nanotubes derived from metal-organic frameworks, which exhibit higher electrocatalytic activity and stability for oxygen reduction and evolution than commercial Pt/C electrocatalysts. The remarkable electrochemical properties are mainly attributed to the synergistic effect from chemical compositions and the robust hollow structure composed of interconnected crystalline nitrogen-doped carbon nanotubes. The presented strategy for controlled design and synthesis of metal-organic framework-derived functional nanomaterials offers prospects in developing highly active electrocatalysts in electrochemical energy devices.

  20. Bi-Mn mixed metal organic oxide: A novel 3d-6p mixed metal coordination network

    NASA Astrophysics Data System (ADS)

    Shi, Fa-Nian; Rosa Silva, Ana; Bian, Liang

    2015-05-01

    A new terminology of metal organic oxide (MOO) was given a definition as a type of coordination polymers which possess the feature of inorganic connectivity between metals and the direct bonded atoms and show 1D, 2D or 3D inorganic sub-networks. One such compound was shown as an example. A 3d-6p (Mn-Bi. Named MOOMnBi) mixed metals coordination network has been synthesized via hydrothermal method. The new compound with the molecular formula of [MnBi2O(1,3,5-BTC)2]n (1,3,5-BTC stands for benzene-1,3,5-tricarboxylate) was characterized via single crystal X-ray diffraction technique that revealed a very interesting 3-dimensional (3D) framework with Bi4O2(COO)12 clusters which are further connected to Mn(COO)6 fragments into a 2D MOO. The topology study indicates an unprecedented topological type with the net point group of {413.62}{413.68}{416.65}{418.610}{422.614}{43} corresponding to 3,6,7,7,8,9-c hexa-nodal net. MOOMnBi shows catalytic activity in the synthesis of (E)-α,β-unsaturated ketones.

  1. A dense metal-organic framework for enhanced magnetic refrigeration.

    PubMed

    Lorusso, Giulia; Sharples, Joseph W; Palacios, Elias; Roubeau, Olivier; Brechin, Euan K; Sessoli, Roberta; Rossin, Andrea; Tuna, Floriana; McInnes, Eric J L; Collison, David; Evangelisti, Marco

    2013-09-01

    The three-dimensional metal-organic framework Gd(HCOO)3 is characterized by a relatively compact crystal lattice of weakly interacting Gd(3+) spin centers interconnected via lightweight formate ligands, overall providing a remarkably large magnetic:non-magnetic elemental weight ratio. The resulting magnetocaloric effect per unit volume is decidedly superior in Gd(HCOO)3 than in the best known magnetic refrigerant materials for liquid-helium temperatures and low-moderate applied fields. PMID:23813875

  2. Polyoxometalate Cluster-Incorporated Metal-Organic Framework Hierarchical Nanotubes.

    PubMed

    Xu, Xiaobin; Chen, Shuangming; Chen, Yifeng; Sun, Hongyu; Song, Li; He, Wei; Wang, Xun

    2016-06-01

    A simple method to prepare metal-organic framework (MOF) nanotubes is developed by employing polyoxometalates (POMs) as modulators. The local structure of the MOF nanotubes is investigated combining XANES and EXAFS studies. These nanotubes show both an excellent catalytic performance in the detoxification of sulfur compounds in O2 atmosphere and a remarkable cycling stability as the anode material for lithium-ion batteries. PMID:27101564

  3. Evaluating metal-organic frameworks for natural gas storage

    SciTech Connect

    Mason, JA; Veenstra, M; Long, JR

    2014-01-01

    Metal-organic frameworks have received significant attention as a new class of adsorbents for natural gas storage; however, inconsistencies in reporting high-pressure adsorption data and a lack of comparative studies have made it challenging to evaluate both new and existing materials. Here, we briefly discuss high-pressure adsorption measurements and review efforts to develop metal-organic frameworks with high methane storage capacities. To illustrate the most important properties for evaluating adsorbents for natural gas storage and for designing a next generation of improved materials, six metal-organic frameworks and an activated carbon, with a range of surface areas, pore structures, and surface chemistries representative of the most promising adsorbents for methane storage, are evaluated in detail. High-pressure methane adsorption isotherms are used to compare gravimetric and volumetric capacities, isosteric heats of adsorption, and usable storage capacities. Additionally, the relative importance of increasing volumetric capacity, rather than gravimetric capacity, for extending the driving range of natural gas vehicles is highlighted. Other important systems-level factors, such as thermal management, mechanical properties, and the effects of impurities, are also considered, and potential materials synthesis contributions to improving performance in a complete adsorbed natural gas system are discussed.

  4. Hydrogen adsorption in an interpenetrated dynamic metal-organic framework.

    PubMed

    Chen, Banglin; Ma, Shengqian; Zapata, Fatima; Lobkovsky, Emil B; Yang, Jun

    2006-07-24

    A metal-organic framework Zn(NDC)(4,4'-Bpe)(0.5).xG [NDC = 2,6-naphthalenedicarboxylate; 4,4'-Bpe = 4,4'-trans-bis(4-pyridyl)ethylene; G = guest molecules] has been synthesized, structurally characterized, and rationalized to be a two-interpenetrated elongated primitive cubic net. Powder X-ray diffraction and adsorption studies reveal the dynamic feature of the framework, which can take up hydrogen of about 2.0 wt % at 77 K and 40 bar and 0.3 wt % at 298 K and 65 bar. PMID:16841969

  5. Selective gas sorption within a dynamic metal-organic framework.

    PubMed

    Chen, Banglin; Ma, Shengqian; Hurtado, Eric J; Lobkovsky, Emil B; Liang, Chengdu; Zhu, Haoguo; Dai, Sheng

    2007-10-15

    A microporous metal-organic framework 1 Co(NDC)(4,4'-Bipy)(0.5).G(x) (NDC = 2,6-naphthalenedicarboxylate; 4,4'-Bipy = 4,4'-bipyridine; G = guest molecules) was synthesized and structurally characterized of a doubly interpenetrated primitive cubic net. To make use of the framework flexibility, 1 was activated at temperatures of 150 and 200 degrees C to form 1a and 1b, respectively, exhibiting highly selective sorption behaviors of hydrogen over nitrogen-gas molecules. PMID:17880212

  6. Controlled partial interpenetration in metal-organic frameworks.

    PubMed

    Ferguson, Alan; Liu, Lujia; Tapperwijn, Stefanus J; Perl, David; Coudert, François-Xavier; Van Cleuvenbergen, Stijn; Verbiest, Thierry; van der Veen, Monique A; Telfer, Shane G

    2016-03-01

    Interpenetration, the entwining of multiple lattices, is a common phenomenon in metal-organic frameworks (MOFs). Typically, in interpenetrated MOFs the sub-lattices are fully occupied. Here we report a family of MOFs in which one sub-lattice is fully occupied and the occupancy level of the other can be controlled during synthesis to produce frameworks with variable levels of partial interpenetration. We also report an 'autocatenation' process, a transformation of non-interpenetrated lattices into doubly interpenetrated frameworks via progressively higher degrees of interpenetration that involves no external reagents. Autocatenation maintains crystallinity and can be triggered either thermally or by shear forces. The ligand used to construct these MOFs is chiral, and both racemic and enantiopure partially interpenetrated frameworks can be accessed. X-ray diffraction, nonlinear optical microscopy and theoretical calculations offer insights into the structures and dynamic behaviour of these materials and the growth mechanisms of interpenetrated MOFs. PMID:26892557

  7. Controlled partial interpenetration in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Ferguson, Alan; Liu, Lujia; Tapperwijn, Stefanus J.; Perl, David; Coudert, François-Xavier; van Cleuvenbergen, Stijn; Verbiest, Thierry; van der Veen, Monique A.; Telfer, Shane G.

    2016-03-01

    Interpenetration, the entwining of multiple lattices, is a common phenomenon in metal-organic frameworks (MOFs). Typically, in interpenetrated MOFs the sub-lattices are fully occupied. Here we report a family of MOFs in which one sub-lattice is fully occupied and the occupancy level of the other can be controlled during synthesis to produce frameworks with variable levels of partial interpenetration. We also report an ‘autocatenation’ process, a transformation of non-interpenetrated lattices into doubly interpenetrated frameworks via progressively higher degrees of interpenetration that involves no external reagents. Autocatenation maintains crystallinity and can be triggered either thermally or by shear forces. The ligand used to construct these MOFs is chiral, and both racemic and enantiopure partially interpenetrated frameworks can be accessed. X-ray diffraction, nonlinear optical microscopy and theoretical calculations offer insights into the structures and dynamic behaviour of these materials and the growth mechanisms of interpenetrated MOFs.

  8. Metal-Organic Frameworks for Highly Selective Separations

    SciTech Connect

    Omar M. Yaghi

    2009-09-28

    This grant was focused on the study of metal-organic frameworks with these specific objectives. (1) To examine the use of MOFs with well-defined open metal sites for binding of gases and small organics. (2) To develop a strategy for producing MOFs that combine large pore size with high surface area for their use in gas adsorption and separation of polycyclic organic compounds. (3) To functionalize MOFs for the storage of inert gases such as methane. A brief outline of our progress towards these objectives is presented here as it forms part of the basis for the ideas to be developed under the present proposal.

  9. The surface chemistry of metal-organic frameworks.

    PubMed

    McGuire, Christina V; Forgan, Ross S

    2015-03-28

    Metal-organic frameworks (MOFs) have received particular attention over the last 20 years as a result of their attractive properties offering potential applications in a number of areas. Typically, these characteristics are tuned by functionalisation of the bulk of the MOF material itself. This Feature Article focuses instead on modification of MOF particles at their surfaces only, which can also offer control over the bulk properties of the material. The differing surface modification techniques available to the synthetic chemist will be discussed, with a focus on the effect of surface modification of MOFs on their fundamental properties and application in adsorption, catalysis, drug delivery and other areas. PMID:25116412

  10. A porous metal-organic framework containing multiple active Cu(2+) sites for highly efficient cross dehydrogenative coupling reaction.

    PubMed

    Zhu, Shu-Lan; Ou, Sha; Zhao, Min; Shen, Hong; Wu, Chuan-De

    2015-02-01

    A novel 3D porous metal-organic framework was constructed from imidazole carboxylate linkers and copper(ii) nodes, which in situ generates multiple active Cu(II) sites in the nanosized channel walls for highly efficient cross dehydrogenative coupling reaction between 1,2,3,4-tetrahydroisoquinoline derivatives and nitroalkanes that are superior to the simple copper salts. PMID:25515613

  11. Metal-Organic Frameworks as Sensory Materials and Imaging Agents

    PubMed Central

    Liu, Demin; Lu, Kuangda; Poon, Christopher

    2014-01-01

    Metal-organic frameworks (MOFs) are a class of hybrid materials self-assembled from organic bridging ligands and metal ion/cluster connecting points. The combination of a variety of organic linkers, metal ions/clusters, and structural motifs can lead to an infinite array of new materials with interesting properties for many applications. In this Forum article, we discuss the design and applications of MOFs in chemical sensing and biological imaging. The first half of this article focuses on the development of MOFs as chemical sensors by highlighting how unique attributes of MOFs can be utilized to enhance sensitivity and selectivity. We also discuss some of the issues that need to be addressed in order to develop practically useful MOF sensors. The second half of this article focuses on the design and applications of nanoscale metal-organic frameworks (NMOFs) as imaging contrast agents. NMOFs possess several interesting attributes, such as high cargo loading capacity, ease of post-modification, tunable size and shape, and intrinsic biodegradability, to make them excellent candidates as imaging contrast agents. We discuss the use of representative NMOFs in magnetic resonance imaging (MRI), X-ray computed tomography (CT), and optical imaging (OI). Although still in their infancy, we believe that the compositional tunability and mild synthetic conditions of NMOF imaging agents should greatly facilitate their further development for clinical translation. PMID:24251853

  12. Metal-organic frameworks with dynamic interlocked components

    NASA Astrophysics Data System (ADS)

    Vukotic, V. Nicholas; Harris, Kristopher J.; Zhu, Kelong; Schurko, Robert W.; Loeb, Stephen J.

    2012-06-01

    The dynamics of mechanically interlocked molecules such as rotaxanes and catenanes have been studied in solution as examples of rudimentary molecular switches and machines, but in this medium, the molecules are randomly dispersed and their motion incoherent. As a strategy for achieving a higher level of molecular organization, we have constructed a metal-organic framework material using a [2]rotaxane as the organic linker and binuclear Cu(II) units as the nodes. Activation of the as-synthesized material creates a void space inside the rigid framework that allows the soft macrocyclic ring of the [2]rotaxane to rotate rapidly, unimpeded by neighbouring molecular components. Variable-temperature 13C and 2H solid-state NMR experiments are used to characterize the nature and rate of the dynamic processes occurring inside this unique material. These results provide a blueprint for the future creation of solid-state molecular switches and molecular machines based on mechanically interlocked molecules.

  13. Metal-organic frameworks for Xe/Kr separation

    DOEpatents

    Ryan, Patrick J.; Farha, Omar K.; Broadbelt, Linda J.; Snurr, Randall Q.; Bae, Youn-Sang

    2013-08-27

    Metal-organic framework (MOF) materials are provided and are selectively adsorbent to xenon (Xe) over another noble gas such as krypton (Kr) and/or argon (Ar) as a result of having framework voids (pores) sized to this end. MOF materials having pores that are capable of accommodating a Xe atom but have a small enough pore size to receive no more than one Xe atom are desired to preferentially adsorb Xe over Kr in a multi-component (Xe--Kr mixture) adsorption method. The MOF material has 20% or more, preferably 40% or more, of the total pore volume in a pore size range of 0.45-0.75 nm which can selectively adsorb Xe over Kr in a multi-component Xe--Kr mixture over a pressure range of 0.01 to 1.0 MPa.

  14. Metal-organic frameworks for Xe/Kr separation

    DOEpatents

    Ryan, Patrick J.; Farha, Omar K.; Broadbelt, Linda J.; Snurr, Randall Q.; Bae, Youn-Sang

    2014-07-22

    Metal-organic framework (MOF) materials are provided and are selectively adsorbent to xenon (Xe) over another noble gas such as krypton (Kr) and/or argon (Ar) as a result of having framework voids (pores) sized to this end. MOF materials having pores that are capable of accommodating a Xe atom but have a small enough pore size to receive no more than one Xe atom are desired to preferentially adsorb Xe over Kr in a multi-component (Xe--Kr mixture) adsorption method. The MOF material has 20% or more, preferably 40% or more, of the total pore volume in a pore size range of 0.45-0.75 nm which can selectively adsorb Xe over Kr in a multi-component Xe--Kr mixture over a pressure range of 0.01 to 1.0 MPa.

  15. Imparting biomolecules to a metal-organic framework material by controlled DNA tetrahedron encapsulation

    NASA Astrophysics Data System (ADS)

    Jia, Yongmei; Wei, Benmei; Duan, Ruixue; Zhang, Ying; Wang, Boya; Hakeem, Abdul; Liu, Nannan; Ou, Xiaowen; Xu, Shaofang; Chen, Zhifei; Lou, Xiaoding; Xia, Fan

    2014-08-01

    Recently, the incorporation of biomolecules in Metal-organic frameworks (MOFs) attracts many attentions because of controlling the functions, properties and stability of trapped molecules. Although there are few reports on protein/MOFs composites and their applications, none of DNA/MOFs composite is reported, as far as we know. Here, we report a new composite material which is self-assembled from 3D DNA (guest) and pre-synthesized MOFs (host) by electrostatic interactions and hydrophilic interactions in a well-dispersed fashion. Its biophysical characterization is well analyzed by fluorescence spectroscopy, quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). This new composite material keeps 3D DNA nanostructure more stable than only 3D DNA nanostructure in DI water at room temperature, and stores amounts of genetic information. It will make DNA as a guest for MOFs and MOFs become a new platform for the development of DNA nanotechnology.

  16. Increasing the Stability of Metal-Organic Frameworks

    DOE PAGESBeta

    Bosch, Mathieu; Zhang, Muwei; Zhou, Hong-Cai

    2014-01-01

    Metal-organic frameworks (MOFs) are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapsemore » upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.« less

  17. Recent progress in the synthesis of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Sun, Yujia; Zhou, Hong-Cai

    2015-10-01

    Metal-organic frameworks (MOFs) have attracted considerable attention for various applications due to their tunable structure, porosity and functionality. In general, MOFs have been synthesized from isolated metal ions and organic linkers under hydrothermal or solvothermal conditions via one-spot reactions. The emerging precursor approach and kinetically tuned dimensional augmentation strategy add more diversity to this field. In addition, to speed up the crystallization process and create uniform crystals with reduced size, many alternative synthesis routes have been explored. Recent advances in microwave-assisted synthesis and electrochemical synthesis are presented in this review. In recent years, post-synthetic approaches have been shown to be powerful tools to synthesize MOFs with modified functionality, which cannot be attained via de novo synthesis. In this review, some current accomplishments of post-synthetic modification (PSM) based on covalent transformations and coordinative interactions as well as post-synthetic exchange (PSE) in robust MOFs are provided.

  18. Magnetorheology of iron associated magnetic metal-organic framework nanoparticle

    NASA Astrophysics Data System (ADS)

    Quan, Xue Mei; Liu, Ying Dan; Choi, Hyoung Jin

    2015-05-01

    Metal-organic frameworks (MOFs) with zeolite-like structured materials have interesting characteristics because of their high surface areas and pore volumes. Among the various MOFs reported thus far, Fe-BTC was chosen as an additive to improve the dispersion stability of soft-magnetic carbonyl iron particle-based magnetorheological (MR) fluids. The morphology of the Fe-BTC additive was examined by TEM, and the behavior of the MR particles dispersed in silicone oil was examined using a rotational rheometer. With a typical magnetic property, the Fe-BTC additive added MR fluid showed similar MR behavior with that of the CI based MR fluid while its improved dispersion stability was observed.

  19. Flexible Zirconium Metal-Organic Frameworks as Bioinspired Switchable Catalysts.

    PubMed

    Yuan, Shuai; Zou, Lanfang; Li, Haixia; Chen, Ying-Pin; Qin, Junsheng; Zhang, Qiang; Lu, Weigang; Hall, Michael B; Zhou, Hong-Cai

    2016-08-26

    Flexible metal-organic frameworks (MOFs) are highly desirable in host-guest chemistry owing to their almost unlimited structural/functional diversities and stimuli-responsive pore architectures. Herein, we designed a flexible Zr-MOF system, namely PCN-700 series, for the realization of switchable catalysis in cycloaddition reactions of CO2 with epoxides. Their breathing behaviors were studied by successive single-crystal X-ray diffraction analyses. The breathing amplitudes of the PCN-700 series were modulated through pre-functionalization of organic linkers and post-synthetic linker installation. Experiments and molecular simulations confirm that the catalytic activities of the PCN-700 series can be switched on and off upon reversible structural transformation, which is reminiscent of sophisticated biological systems such as allosteric enzymes. PMID:27346468

  20. Metal-organic frameworks for lithium ion batteries and supercapacitors

    NASA Astrophysics Data System (ADS)

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang

    2015-03-01

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100-1000 m2 g-1) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m2 g-1), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs.

  1. Superexchange Charge Transport in Loaded Metal Organic Frameworks.

    PubMed

    Neumann, Tobias; Liu, Jianxi; Wächter, Tobias; Friederich, Pascal; Symalla, Franz; Welle, Alexander; Mugnaini, Veronica; Meded, Velimir; Zharnikov, Michael; Wöll, Christof; Wenzel, Wolfgang

    2016-07-26

    In the past, nanoporous metal-organic frameworks (MOFs) have been mostly studied for their huge potential with regard to gas storage and separation. More recently, the discovery that the electrical conductivity of a widely studied, highly insulating MOF, HKUST-1, improves dramatically when loaded with guest molecules has triggered a huge interest in the charge carrier transport properties of MOFs. The observed high conductivity, however, is difficult to reconcile with conventional transport mechanisms: neither simple hopping nor band transport models are consistent with the available experimental data. Here, we combine theoretical results and new experimental data to demonstrate that the observed conductivity can be explained by an extended hopping transport model including virtual hops through localized MOF states or molecular superexchange. Predictions of this model agree well with precise conductivity measurements, where experimental artifacts and the influence of defects are largely avoided by using well-defined samples and the Hg-drop junction approach. PMID:27359160

  2. Transformation of metal-organic frameworks for molecular sieving membranes.

    PubMed

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-01-01

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively. PMID:27090597

  3. Metal-Organic Frameworks as Catalysts for Oxidation Reactions.

    PubMed

    Dhakshinamoorthy, Amarajothi; Asiri, Abdullah M; Garcia, Hermenegildo

    2016-06-01

    This Concept is aimed at describing the current state of the art in metal-organic frameworks (MOFs) as heterogeneous catalysts for liquid-phase oxidations, focusing on three important substrates, namely, alkenes, alkanes and alcohols. Emphases are on the nature of active sites that have been incorporated within MOFs and on future targets to be set in this area. Thus, selective alkene epoxidation with peroxides or oxygen catalyzed by constitutional metal nodes of MOFs as active sites are still to be developed. Moreover, no noble metal-free MOF has been reported to date that can act as a general catalyst for the aerobic oxidation of primary and secondary aliphatic alcohols. In contrast, in the case of alkanes, a target should be to tune the polarity of MOF internal pores to control the outcome of the autooxidation process, resulting in the selective formation of alcohol/ketone mixtures at high conversion. PMID:27113486

  4. Metal-organic frameworks for artificial photosynthesis and photocatalysis.

    PubMed

    Zhang, Teng; Lin, Wenbin

    2014-08-21

    Solar energy is an alternative, sustainable energy source for mankind. Finding a convenient way to convert sunlight energy into chemical energy is a key step towards realizing large-scale solar energy utilization. Owing to their structural regularity and synthetic tunability, metal-organic frameworks (MOFs) provide an interesting platform to hierarchically organize light-harvesting antennae and catalytic centers to achieve solar energy conversion. Such photo-driven catalytic processes not only play a critical role in the solar to chemical energy conversion scheme, but also provide a novel methodology for the synthesis of fine chemicals. In this review, we summarize the fundamental principles of energy transfer and photocatalysis and provide an overview of the latest progress in energy transfer, light-harvesting, photocatalytic proton and CO2 reduction, and water oxidation using MOFs. The applications of MOFs in organic photocatalysis and degradation of model organic pollutants are also discussed. PMID:24769551

  5. Transformation of metal-organic frameworks for molecular sieving membranes

    PubMed Central

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-01-01

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively. PMID:27090597

  6. Transformation of metal-organic frameworks for molecular sieving membranes

    NASA Astrophysics Data System (ADS)

    Li, Wanbin; Zhang, Yufan; Zhang, Congyang; Meng, Qin; Xu, Zehai; Su, Pengcheng; Li, Qingbiao; Shen, Chong; Fan, Zheng; Qin, Lei; Zhang, Guoliang

    2016-04-01

    The development of simple, versatile strategies for the synthesis of metal-organic framework (MOF)-derived membranes are of increasing scientific interest, but challenges exist in understanding suitable fabrication mechanisms. Here we report a route for the complete transformation of a series of MOF membranes and particles, based on multivalent cation substitution. Through our approach, the effective pore size can be reduced through the immobilization of metal salt residues in the cavities, and appropriate MOF crystal facets can be exposed, to achieve competitive molecular sieving capabilities. The method can also be used more generally for the synthesis of a variety of MOF membranes and particles. Importantly, we design and synthesize promising MOF membranes candidates that are hard to achieve through conventional methods. For example, our CuBTC/MIL-100 membrane exhibits 89, 171, 241 and 336 times higher H2 permeance than that of CO2, O2, N2 and CH4, respectively.

  7. Chemical, thermal and mechanical stabilities of metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Howarth, Ashlee J.; Liu, Yangyang; Li, Peng; Li, Zhanyong; Wang, Timothy C.; Hupp, Joseph T.; Farha, Omar K.

    2016-03-01

    The construction of thousands of well-defined, porous, metal-organic framework (MOF) structures, spanning a broad range of topologies and an even broader range of pore sizes and chemical functionalities, has fuelled the exploration of many applications. Accompanying this applied focus has been a recognition of the need to engender MOFs with mechanical, thermal and/or chemical stability. Chemical stability in acidic, basic and neutral aqueous solutions is important. Advances over recent years have made it possible to design MOFs that possess different combinations of mechanical, thermal and chemical stability. Here, we review these advances and the associated design principles and synthesis strategies. We focus on how these advances may render MOFs effective as heterogeneous catalysts, both in chemically harsh condensed phases and in thermally challenging conditions relevant to gas-phase reactions. Finally, we briefly discuss future directions of study for the production of highly stable MOFs.

  8. Coordinative alignment of molecules in chiral metal-organic frameworks.

    PubMed

    Lee, Seungkyu; Kapustin, Eugene A; Yaghi, Omar M

    2016-08-19

    A chiral metal-organic framework, MOF-520, was used to coordinatively bind and align molecules of varying size, complexity, and functionality. The reduced motional degrees of freedom obtained with this coordinative alignment method allowed the structures of molecules to be determined by single-crystal x-ray diffraction techniques. The chirality of the MOF backbone also served as a reference in the structure solution for an unambiguous assignment of the absolute configuration of bound molecules. Sixteen molecules representing four common functional groups (primary alcohol, phenol, vicinal diol, and carboxylic acid), ranging in complexity from methanol to plant hormones (gibberellins, containing eight stereocenters), were crystallized and had their precise structure determined. We distinguished single and double bonds in gibberellins, and we enantioselectively crystallized racemic jasmonic acid, whose absolute configuration had only been inferred from derivatives. PMID:27540171

  9. Metal-Organic Framework for Emulsifying Carbon Dioxide and Water.

    PubMed

    Liu, Chengcheng; Zhang, Jianling; Zheng, Lirong; Zhang, Jing; Sang, Xinxin; Kang, Xinchen; Zhang, Bingxing; Luo, Tian; Tan, Xiuniang; Han, Buxing

    2016-09-12

    Forming emulsions of carbon dioxide (CO2 ) and water can largely expand the utility of CO2 . Herein we propose for the first time the utilization of a metal-organic framework (MOF) for emulsifying CO2 and water. Owing to the hybrid composition, MOF particles can easily assemble at the CO2 /water interface to create a rigid protective barrier around the dispersed droplet. The MOF-stabilized CO2 and water emulsion has exceptional stability compared to those emulsions stabilized by surfactants or other solids. Moreover, the CO2 and water emulsion stabilized by MOF is "tunable" due to the designable features of MOFs and adjustable character of CO2 . Such a novel kind of emulsion composed of CO2 , water, and MOF provides a facile route for constructing MOF superstructures with many advantages. The macroporous networks and hollow capsules of different kinds of MOFs have been successfully derived from CO2 and water emulsions. PMID:27529754

  10. Adsorption of pyridine onto the metal organic framework MIL-101.

    PubMed

    Kim, Mi Jin; Park, Se Min; Song, Sun-Jung; Won, Jiyeon; Lee, Jin Yong; Yoon, Minyoung; Kim, Kimoon; Seo, Gon

    2011-09-15

    The adsorption of pyridine onto the metal organic framework MIL-101 was investigated by experimental and theoretical methods. The amount of pyridine adsorbed on MIL-101 was extraordinarily large at 20 °C, corresponding to about 950 mg/g of dried MIL-101 and approximately half of the voids being filled. Most of the pyridine that had filled the voids was rapidly removed by evacuation at room temperature, but some of the pyridine was so strongly adsorbed that it was retained even under evacuation at 150 °C. Although IR spectra of the adsorbed pyridine indicated the adsorption of pyridine as pyridinium ions and coordinated pyridine at low temperatures, increasing the adsorption temperature induced partial cleavage of the pyridine rings. The high stabilization energy of pyridine on the coordinative unsaturated sites (CUS) of MIL-101, obtained by theoretical calculation, -103 kJ/mol, supported the strong adsorption of pyridine on the CUS. PMID:21700293

  11. Scalability of Continuous Flow Production of Metal-Organic Frameworks.

    PubMed

    Rubio-Martinez, Marta; Hadley, Trevor D; Batten, Michael P; Constanti-Carey, Keri; Barton, Tim; Marley, Dylan; Mönch, Andreas; Lim, Kok-Seng; Hill, Matthew R

    2016-05-10

    Achieving the large-scale production of metal-organic frameworks (MOFs) is crucial for their utilization in applied settings. For many MOFs, quality suffers from large-scale, batch reaction systems. We have developed continuous processes for their production which showed promise owing to their versatility and the high quality of the products. Here, we report the successful upscaling of this concept by more than two orders of magnitude to deliver unprecedented production rates and space-time-yields (STYs) while maintaining the product quality. Encouragingly, no change in the reaction parameters, obtained at small scale, was required. The production of aluminium fumarate was achieved at an STY of 97 159 kg m(-3)  day(-1) and a rate of 5.6 kg h(-1) . PMID:27075923

  12. Nanoscale Metal-Organic Framework-Hemoglobin Conjugates.

    PubMed

    Wang, Weiqi; Wang, Lei; Huang, Yubin; Xie, Zhigang; Jing, Xiabin

    2016-03-01

    A metal-organic framework (MOF)-protein conjugate, NH2 -MIL-125(Ti)-hemoglobin [MIL-125(Ti)-Hb], was synthesized by a covalent postmodification strategy. The crystalline structure was maintained after chemical and protein modification. The content of grafted Hb was tuned by the stoichiometric ratio and reached 50 wt % if the mass ratio of MIL-125(Ti)/Hb was 1:1.25 in the feed. The oxygen-transporting capacity of grafted Hb was kept, and the P50 (the half O2 pressure saturated with O2 ) and Hill coefficients of the MIL-125(Ti)-Hb conjugate were found to be 22.9 mm Hg and 2.35, respectively, which are close to the respective values of free Hb. All the results indicate that the MIL-125(Ti)-Hb conjugate could be potentially used as an oxygen carrier. PMID:26692560

  13. Governing metal-organic frameworks towards high stability.

    PubMed

    Li, Na; Xu, Jian; Feng, Rui; Hu, Tong-Liang; Bu, Xian-He

    2016-06-30

    Metal-organic frameworks (MOFs) constructed with metal ions/clusters and organic ligands have emerged as an important family of porous materials for various applications. However, the stability of this class of materials is crucial for their practical applications, which might be improved by varying their chemical composition and/or structurally tuning them. To fabricate MOFs with high stability, several strategies for enhancing the stability of MOFs have been developed, in which the strength of metal-ligand bonds is especially considered: the use of highly charged cations and higher pKa ligands, and varying the chemical functionality of linkers. On the other hand, the regulation of their structural architectures is also investigated: interpenetrated frameworks, multi-walled frameworks, and self-strengthening of the frameworks. In addition, the surface modification can also improve the stability of the materials. In this review, we introduce and summarize these strategies from the viewpoint of structural tuning and component choosing, providing useful instructions for the further design and synthesis of MOFs with high-level stability. PMID:27230794

  14. Synthesis and Characterization of Functionalized Metal-organic Frameworks

    PubMed Central

    Karagiaridi, Olga; Bury, Wojciech; Sarjeant, Amy A.; Hupp, Joseph T.; Farha, Omar K.

    2014-01-01

    Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy. PMID:25225784

  15. Guest-Induced Emergent Properties in Metal-Organic Frameworks.

    PubMed

    Allendorf, Mark D; Foster, Michael E; Léonard, François; Stavila, Vitalie; Feng, Patrick L; Doty, F Patrick; Leong, Kirsty; Ma, Eric Yue; Johnston, Scott R; Talin, A Alec

    2015-04-01

    Metal-organic frameworks (MOFs) are crystalline nanoporous materials comprised of organic electron donors linked to metal ions by strong coordination bonds. Applications such as gas storage and separations are currently receiving considerable attention, but if the unique properties of MOFs could be extended to electronics, magnetics, and photonics, the impact on material science would greatly increase. Recently, we obtained "emergent properties," such as electronic conductivity and energy transfer, by infiltrating MOF pores with "guest" molecules that interact with the framework electronic structure. In this Perspective, we define a path to emergent properties based on the Guest@MOF concept, using zinc-carboxylate and copper-paddlewheel MOFs for illustration. Energy transfer and light harvesting are discussed for zinc carboxylate frameworks infiltrated with triplet-scavenging organometallic compounds and thiophene- and fullerene-infiltrated MOF-177. In addition, we discuss the mechanism of charge transport in TCNQ-infiltrated HKUST-1, the first MOF with electrical conductivity approaching conducting organic polymers. These examples show that guest molecules in MOF pores should be considered not merely as impurities or analytes to be sensed but also as an important aspect of rational design. PMID:26262970

  16. Understanding DABCO Nanorotor Dynamics in Isostructural Metal-Organic Frameworks.

    PubMed

    Burtch, Nicholas C; Torres-Knoop, Ariana; Foo, Guo Shiou; Leisen, Johannes; Sievers, Carsten; Ensing, Bernd; Dubbeldam, David; Walton, Krista S

    2015-03-01

    Flexible framework dynamics present in the subset of metal-organic frameworks known as soft porous crystals give rise to interesting structural properties that are unique to this class of materials. In this work, we use experiments and molecular simulation to understand the highly dynamic nanorotor behavior of the 1,4-diazabicyclo[2.2.2]octane (DABCO) ligand in the pillared Zn-DMOF and Zn-DMOF-TM (TM = tetramethyl) structures. While DABCO is known to be displaced in the presence of water in the parent Zn-DMOF structure, the Zn-DMOF-TM variation is highly stable even after adsorbing significant amounts of water vapor. The dynamics of DABCO in the presence of water guest molecules is therefore also explored in the Zn-DMOF-TM structure via in situ NMR and IR experiments. This analysis shows that the rotational motion of the DABCO linkers is dependent on water content, but not a likely source of water instability because the dynamics are fast and largely unaffected by the presence of methyl functional groups. PMID:26262657

  17. Conductive metal-organic frameworks and networks: fact or fantasy?

    PubMed

    Hendon, Christopher H; Tiana, Davide; Walsh, Aron

    2012-10-14

    Electrical conduction is well understood in materials formed from inorganic or organic building blocks, but their combination to produce conductive hybrid frameworks and networks is an emerging and rapidly developing field of research. Self-assembling organic-inorganic compounds offer immense potential for functionalising material properties for a wide scope of applications including solar cells, light emitters, gas sensors and bipolar transparent conductors. The flexibility of combining two distinct material classes into a single solid-state system provides an almost infinite number of chemical and structural possibilities; however, there is currently no systematic approach established for designing new compositions and configurations with targeted electronic or optical properties. We review the current status in the field, in particular, the range of hybrid systems reported to date and the important role of materials modelling in the field. From theoretical arguments, the Mott insulator-to-metal transition should be possible in semiconducting metal-organic frameworks, but has yet to be observed. The question remains as to whether electro-active hybrid materials will evolve from chemical curiosities towards practical applications in the near term. PMID:22858739

  18. Colloidal-sized metal-organic frameworks: synthesis and applications.

    PubMed

    Sindoro, Melinda; Yanai, Nobuhiro; Jee, Ah-Young; Granick, Steve

    2014-02-18

    Colloidal metal-organic frameworks (CMOFs), nanoporous colloidal-sized crystals that are uniform in both size and polyhedral shape, are crystals composed of metal ions and organic bridging ligands, which can be used as building blocks for self-assembly in organic and aqueous liquids. They stand in contrast to conventional metal-organic frameworks (MOFs), which scientists normally study in the form of bulk crystalline powders. However, powder MOFs generally have random crystal size and shape and therefore do not possess either a definite mutual arrangement with adjacent particles or uniformity. CMOFs do have this quality, which can be important in vital uptake and release kinetics. In this Account, we present the diverse methods of synthesis, pore chemistry control, surface modification, and assembly techniques of CMOFs. In addition, we survey recent achievements and future applications in this emerging field. There is potential for a paradigm shift, away from using just bulk crystalline powders, towards using particles whose size and shape are regulated. The concept of colloidal MOFs takes into account that nanoporous MOFs, conventionally prepared in the form of bulk crystalline powders with random crystal size, shape, and orientation, may also form colloidal-sized objects with uniform size and morphology. Furthermore, the traditional MOF functions that depend on porosity present additional control over those MOF functions that depend on pore interactions. They also can enable controlled spatial arrangements between neighboring particles. To begin, we discuss progress regarding synthesis of MOF nano- and microcrystals whose crystal size and shape are well regulated. Next, we review the methods to modify the surfaces with dye molecules and polymers. Dyes are useful when seeking to observe nonluminescent CMOFs in situ by optical microscopy, while polymers are useful to tune their interparticle interactions. Third, we discuss criteria to assess the stability of CMOFs

  19. Anisotropic thermal expansion in a metal-organic framework.

    PubMed

    Madsen, Solveig Røgild; Lock, Nina; Overgaard, Jacob; Iversen, Bo Brummerstedt

    2014-06-01

    Ionothermal reaction between Mn(II)(acetate)2·4H2O and 1,3,5-benzenetricarboxylic acid (H3BTC) in either of the two ionic liquids 1-ethyl-3-methylimidazolium bromide (EMIMBr) and 1-ethyl-3-methylimidazolium tosylate (EMIMOTs) resulted in the formation of the new metal-organic framework (MOF) EMIM[Mn(II)BTC] (BTC = 1,3,5-benzenetricarboxylate). The compound crystallizes in the orthorhombic space group Pbca with unit-cell parameters of a = 14.66658 (12), b = 12.39497 (9), c = 16.63509 (14) Å at 100 K. Multi-temperature single-crystal (15-340 K) and powder X-ray diffraction studies (100-400 K) reveal strongly anisotropic thermal expansion properties. The linear thermal expansion coefficients, αL(l), attain maximum values at 400 K along the a- and b-axis, with αL(a) = 115 × 10(-6) K(-1) and αL(b) = 75 × 10(-6) K(-1). At 400 K a negative thermal expansion coefficient of -40 × 10(-6) K(-1) is observed along the c-axis. The thermal expansion is coupled to a continuous deformation of the framework, which causes the structure to expand in two directions. Due to the rigidity of the linker, the expansion in the ab plane causes the network to contract along the c-axis. Hirshfeld surface analysis has been used to describe the interaction between the framework structure and the EMIM cation that resides within the channel. This reveals a number of rather weak interactions and one governing hydrogen-bonding interactions. PMID:24892606

  20. Surface nano-architecture of a metal-organic framework

    NASA Astrophysics Data System (ADS)

    Makiura, Rie; Motoyama, Soichiro; Umemura, Yasushi; Yamanaka, Hiroaki; Sakata, Osami; Kitagawa, Hiroshi

    2010-07-01

    The rational assembly of ultrathin films of metal-organic frameworks (MOFs)-highly ordered microporous materials-with well-controlled growth direction and film thickness is a critical and as yet unrealized issue for enabling the use of MOFs in nanotechnological devices, such as sensors, catalysts and electrodes for fuel cells. Here we report the facile bottom-up fabrication at ambient temperature of such a perfect preferentially oriented MOF nanofilm on a solid surface (NAFS-1), consisting of metalloporphyrin building units. The construction of NAFS-1 was achieved by the unconventional integration in a modular fashion of a layer-by-layer growth technique coupled with the Langmuir-Blodgett method. NAFS-1 is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as demonstrated by synchrotron X-ray surface crystallography. The proposed structural model incorporates metal-coordinated pyridine molecules projected from the two-dimensional sheets that allow each further layer to dock in a highly ordered interdigitated manner in the growth of NAFS-1. We expect that the versatility of the solution-based growth strategy presented here will allow the fabrication of various well-ordered MOF nanofilms, opening the way for their use in a range of important applications.

  1. CO2-Selective Nanoporous Metal-Organic Framework Microcantilevers

    PubMed Central

    Yim, Changyong; Lee, Moonchan; Yun, Minhyuk; Kim, Gook-Hee; Kim, Kyong Tae; Jeon, Sangmin

    2015-01-01

    Nanoporous anodic aluminum oxide (AAO) microcantilevers are fabricated and MIL-53 (Al) metal-organic framework (MOF) layers are directly synthesized on each cantilever surface by using the aluminum oxide as the metal ion source. Exposure of the MIL53-AAO cantilevers to various concentrations of CO2, N2, CO, and Ar induces changes in their deflections and resonance frequencies. The results of the resonance frequency measurements for the different adsorbed gas molecules are almost identical when the frequency changes are normalized by the molecular weights of the gases. In contrast, the deflection measurements show that only CO2 adsorption induces substantial bending of the MIL53-AAO cantilevers. This selective deflection of the cantilevers is attributed to the strong interactions between CO2 and the hydroxyl groups in MIL-53, which induce structural changes in the MIL-53 layers. Simultaneous measurements of the resonance frequency and the deflection are performed to show that the diffusion of CO2 into the nanoporous MIL-53 layers occurs very rapidly, whereas the binding of CO2 to hydroxyl groups occurs relatively slowly, which indicates that the adsorption of CO2 onto the MIL-53 layers and the desorption of CO2 from the MIL-53 layers are reaction limited. PMID:26035805

  2. Thermodynamics of the structural transition in metal-organic frameworks.

    PubMed

    Rodriguez, J; Beurroies, I; Coulet, M-V; Fabry, P; Devic, T; Serre, C; Denoyel, R; Llewellyn, P L

    2016-03-01

    A thermodynamic study of the structural large-pore (LP) to narrow pore (NP) transition in various Metal Organic Frameworks (MOFs) is presented. First, the pressure induced transition at a constant temperature is investigated using a Tian-Calvet microcalorimeter set-up equipped with a high pressure cell. This device permits simultaneous measurements of the mechanical work and heat associated with the LP → NP transition. It is shown that MIL-53(Al) and MIL-53(Cr) have similar thermodynamic and mechanical behaviour whilst the MIL-47(V) system is characterized by much higher transition energy and mechanical work. Second, the temperature induced transition at ambient pressure is studied by means of differential scanning calorimetry (DSC) combined with X-ray absorption spectroscopy. This set-up enables one to follow simultaneously the structural changes associated with the phase transition detected by DSC. The MIL-53(Cr)-Br functionalized MOF is chosen here as a case study where both energetics and structural changes are discussed. PMID:26574728

  3. Metal-organic framework composites: from fundamentals to applications

    NASA Astrophysics Data System (ADS)

    Li, Shaozhou; Huo, Fengwei

    2015-04-01

    Metal-organic frameworks (MOFs) are a class of crystallized porous polymeric materials consisting of metal ions or clusters linked together by organic bridging ligands. Due to their permanent porosity, rich surface chemistry and tuneable pore sizes, MOFs have emerged as one type of important porous solid and have attracted intensive interests in catalysis, gas adsorption, separation and storage over the past two decades. When compared with pure MOFs, the combination of MOFs with functional species or matrix materials not only shows enhanced properties, but also broadens the applications of MOFs in new fields, such as bio-imaging, drug delivery and electrical catalysis, owing to the interactions of the functional species/matrix with the MOF structures. Although the synthesis, chemical modification and potential applications of MOFs have been reviewed previously, there is an increasing awareness on the synthesis and applications of their composites, which have rarely been reviewed. This review aims to fill this gap and discuss the fabrication, properties, and applications of MOF composites. The remaining challenges and future opportunities in this field, in terms of processing techniques, maximizing composite properties, and prospects for applications, have also been indicated.

  4. Energy Transfer Dynamics in Metal-Organic Frameworks

    SciTech Connect

    Kent, Caleb A.; Mehl, Brian P.; Ma, Liqing; Papanikolas, John M.; Meyer, Thomas J.; Lin, Wenbin

    2010-09-22

    Isomorphous metal-organic frameworks (MOFs) based on {M[4,4'-(HO2C)2-bpy]2bpy2+ building blocks (where M = Ru or Os) were designed and synthesized to study the classic Ru to Os energy transfer process that has potential applications in light-harvesting with supramolecular assemblies. The crystalline nature of the MOFs allows precise determination of the distances between metal centers by X-ray diffraction, thereby facilitating the study of the Ru→Os energy transfer process. The mixed-metal MOFs with 0.3, 0.6, 1.4, and 2.6 mol % Os doping were also synthesized in order to study the energy transfer dynamics with a two-photon excitation at 850 nm. The Ru lifetime at 620 nm decreases from 171 ns in the pure Ru MOF to 29 ns in the sample with 2.6 mol % Os doping. In the mixed-metal samples, energy transfer was observed with an initial growth in Os emission corresponding with the rate of decay of the Ru excited state. These results demonstrate rapid, efficient energy migration and long distance transfer in isomorphous MOFs.

  5. Metal-organic frameworks for lithium ion batteries and supercapacitors

    SciTech Connect

    Ke, Fu-Sheng; Wu, Yu-Shan; Deng, Hexiang

    2015-03-15

    Porous materials have been widely used in batteries and supercapacitors attribute to their large internal surface area (usually 100–1000 m{sup 2} g{sup −1}) and porosity that can favor the electrochemical reaction, interfacial charge transport, and provide short diffusion paths for ions. As a new type of porous crystalline materials, metal-organic frameworks (MOFs) have received huge attention in the past decade due to their unique properties, i.e. huge surface area (up to 7000 m{sup 2} g{sup −1}), high porosity, low density, controllable structure and tunable pore size. A wide range of applications including gas separation, storage, catalysis, and drug delivery benefit from the recent fast development of MOFs. However, their potential in electrochemical energy storage has not been fully revealed. Herein, the present mini review appraises recent and significant development of MOFs and MOF-derived materials for rechargeable lithium ion batteries and supercapacitors, to give a glimpse into these potential applications of MOFs. - Graphical abstract: MOFs with large surface area and high porosity can offer more reaction sites and charge carriers diffusion path. Thus MOFs are used as cathode, anode, electrolyte, matrix and precursor materials for lithium ion battery, and also as electrode and precursor materials for supercapacitors. - Highlights: • MOFs have potential in electrochemical area due to their high porosity and diversity. • We summarized and compared works on MOFs for lithium ion battery and supercapacitor. • We pointed out critical challenges and provided possible solutions for future study.

  6. Destruction of chemical warfare agents using metal-organic frameworks.

    PubMed

    Mondloch, Joseph E; Katz, Michael J; Isley, William C; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W; Hall, Morgan G; DeCoste, Jared B; Peterson, Gregory W; Snurr, Randall Q; Cramer, Christopher J; Hupp, Joseph T; Farha, Omar K

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic Zr(IV) ions as the active sites and to their superb accessibility as a defining element of their efficacy. PMID:25774952

  7. Destruction of chemical warfare agents using metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Mondloch, Joseph E.; Katz, Michael J.; Isley, William C., III; Ghosh, Pritha; Liao, Peilin; Bury, Wojciech; Wagner, George W.; Hall, Morgan G.; Decoste, Jared B.; Peterson, Gregory W.; Snurr, Randall Q.; Cramer, Christopher J.; Hupp, Joseph T.; Farha, Omar K.

    2015-05-01

    Chemical warfare agents containing phosphonate ester bonds are among the most toxic chemicals known to mankind. Recent global military events, such as the conflict and disarmament in Syria, have brought into focus the need to find effective strategies for the rapid destruction of these banned chemicals. Solutions are needed for immediate personal protection (for example, the filtration and catalytic destruction of airborne versions of agents), bulk destruction of chemical weapon stockpiles, protection (via coating) of clothing, equipment and buildings, and containment of agent spills. Solid heterogeneous materials such as modified activated carbon or metal oxides exhibit many desirable characteristics for the destruction of chemical warfare agents. However, low sorptive capacities, low effective active site loadings, deactivation of the active site, slow degradation kinetics, and/or a lack of tailorability offer significant room for improvement in these materials. Here, we report a carefully chosen metal-organic framework (MOF) material featuring high porosity and exceptional chemical stability that is extraordinarily effective for the degradation of nerve agents and their simulants. Experimental and computational evidence points to Lewis-acidic ZrIV ions as the active sites and to their superb accessibility as a defining element of their efficacy.

  8. Atomistic Simulation of Protein Encapsulation in Metal-Organic Frameworks.

    PubMed

    Zhang, Haiyang; Lv, Yongqin; Tan, Tianwei; van der Spoel, David

    2016-01-28

    Fabrication of metal-organic frameworks (MOFs) with large apertures triggers a brand-new research area for selective encapsulation of biomolecules within MOF nanopores. The underlying inclusion mechanism is yet to be clarified however. Here we report a molecular dynamics study on the mechanism of protein encapsulation in MOFs. Evaluation for the binding of amino acid side chain analogues reveals that van der Waals interaction is the main driving force for the binding and that guest size acts as a key factor predicting protein binding with MOFs. Analysis on the conformation and thermodynamic stability of the miniprotein Trp-cage encapsulated in a series of MOFs with varying pore apertures and surface chemistries indicates that protein encapsulation can be achieved via maintaining a polar/nonpolar balance in the MOF surface through tunable modification of organic linkers and Mg-O chelating moieties. Such modifications endow MOFs with a more biocompatible confinement. This work provides guidelines for selective inclusion of biomolecules within MOFs and facilitates MOF functions as a new class of host materials and molecular chaperones. PMID:26730607

  9. Alkali-metal azides interacting with metal-organic frameworks.

    PubMed

    Armata, Nerina; Cortese, Remedios; Duca, Dario; Triolo, Roberto

    2013-01-14

    Interactions between alkali-metal azides and metal-organic framework (MOF) derivatives, namely, the first and third members of the isoreticular MOF (IRMOF) family, IRMOF-1 and IRMOF-3, are studied within the density functional theory (DFT) paradigm. The investigations take into account different models of the selected IRMOFs. The mutual influence between the alkali-metal azides and the π rings or Zn centers of the involved MOF derivatives are studied by considering the interactions both of the alkali-metal cations with model aromatic centers and of the alkali-metal azides with distinct sites of differently sized models of IRMOF-1 and IRMOF-3. Several exchange and correlation functionals are employed to calculate the corresponding interaction energies. Remarkably, it is found that, with increasing alkali-metal atom size, the latter decrease for cations interacting with the π-ring systems and increase for the azides interacting with the MOF fragments. The opposite behavior is explained by stabilization effects on the azide moieties and determined by the Zn atoms, which constitute the inorganic vertices of the IRMOF species. Larger cations can, in fact, coordinate more efficiently to both the aromatic center and the azide anion, and thus stabilizing bridging arrangements of the azide between one alkali-metal and two Zn atoms in an η(2) coordination mode are more favored. PMID:23161861

  10. Synthesis, structure and photoluminescent behavior of a novel pillar-layered {Zn3}-based metal-organic framework

    NASA Astrophysics Data System (ADS)

    Song, Xue-Zhi; Mu, Wen-Sheng; Han, Bing-Yan; Yan, Yang

    2016-09-01

    A novel 3D metal-organic framework (MOF) {[Zn3(bpdc)3 (p-4-bpmb)](DMF)2}n ( 1) (H2bpdc=biphenyl-4,4‧-dicarboxylic acid; p-4-bpmb=1,4-bis(pyridine-4-ylmethoxy)benzene) has been solvothermally synthesized and structurally characterized. Compound 1 exhibits a 3D pillar-layered framework based on the trinuclear {Zn3} building blocks, consisting of Zn-dicarboxylate layers and bipyridyl-derivative pillars. Furthermore, it features three-fold interpenetrating 8-connected hex-type topology. In addition, its thermal stability and luminescent property have also been investigated.

  11. Investigation of metal hydride nanoparticles templated in metal organic frameworks.

    SciTech Connect

    Jacobs, Benjamin W.; Herberg, Julie L.; Highley, Aaron M.; Grossman, Jeffrey; Wagner, Lucas; Bhakta, Raghu; Peaslee, D.; Allendorf, Mark D.; Liu, X.; Behrens, Richard, Jr.; Majzoub, Eric H.

    2010-11-01

    Hydrogen is proposed as an ideal carrier for storage, transport, and conversion of energy. However, its storage is a key problem in the development of hydrogen economy. Metal hydrides hold promise in effectively storing hydrogen. For this reason, metal hydrides have been the focus of intensive research. The chemical bonds in light metal hydrides are predominantly covalent, polar covalent or ionic. These bonds are often strong, resulting in high thermodynamic stability and low equilibrium hydrogen pressures. In addition, the directionality of the covalent/ionic bonds in these systems leads to large activation barriers for atomic motion, resulting in slow hydrogen sorption kinetics and limited reversibility. One method for enhancing reaction kinetics is to reduce the size of the metal hydrides to nano scale. This method exploits the short diffusion distances and constrained environment that exist in nanoscale hydride materials. In order to reduce the particle size of metal hydrides, mechanical ball milling is widely used. However, microscopic mechanisms responsible for the changes in kinetics resulting from ball milling are still being investigated. The objective of this work is to use metal organic frameworks (MOFs) as templates for the synthesis of nano-scale NaAlH4 particles, to measure the H2 desorption kinetics and thermodynamics, and to determine quantitative differences from corresponding bulk properties. Metal-organic frameworks (MOFs) offer an attractive alternative to traditional scaffolds because their ordered crystalline lattice provides a highly controlled and understandable environment. The present work demonstrates that MOFs are stable hosts for metal hydrides and their reactive precursors and that they can be used as templates to form metal hydride nanoclusters on the scale of their pores (1-2 nm). We find that using the MOF HKUST-1 as template, NaAlH4 nanoclusters as small as 8 formula units can be synthesized inside the pores. A detailed picture of

  12. Oriented Nano-Microstructure-Assisted Controllable Fabrication of Metal-Organic Framework Membranes on Nickel Foam.

    PubMed

    Sun, Yuxiu; Yang, Fan; Wei, Qi; Wang, Naixin; Qin, Xi; Zhang, Shaokang; Wang, Bin; Nie, Zuoren; Ji, Shulan; Yan, Hui; Li, Jian-Rong

    2016-03-01

    Oriented nano-microstructure-assisted controllable fabrication, a facile and versatile preparation strategy, is developed to fabricate metal-organic framework (MOF) membranes. With this method, several MOF membranes with tailored structures are prepared, including HKUST-1 (with 3D pores) and M3 (HCOO)6 (with 1D pores; M = Co, Mn, and Mg) membranes, which demonstrate good performances in gas separations. PMID:26808691

  13. Band gap modulation of functionalized metal-organic frameworks.

    PubMed

    Musho, Terence; Li, Jiangtan; Wu, Nianqiang

    2014-11-21

    Metal-organic frameworks (MOFs) have been envisioned as alternatives to planar metallic catalysts for solar-to-fuel conversion. This is a direct result of their porous structure and the ability to tailor their optical absorption properties. This study investigates the band gap modulation of Zr-UiO-66 MOFs from both the computational and experimental points of view for three linker designs that include benzenedicarboxylate (BDC), BDC-NO2, and BDC-NH2. Emphasis in this study was aimed at understanding the influence of the bonding between the aromatic ring and the functional group. A ground state density functional theory (DFT) calculation was carried out to investigate the projected density of states and the origins of the modulation. A time-dependent density functional theory (TDDFT) calculation of the hydrogen terminated linkers confirmed the modulation and accounted for the electron charge transfer providing comparable optical band gap predictions to experimental results. Computational results confirmed the hybridization of the carbon-nitrogen bond in conjunction with the donor state resulting from the NH2 functionalization. The NO2 functionalization resulted in an acceptor configuration with marginal modification to the valence band maximum. The largest modulation was BDC-NH2 with a band gap of 2.75 eV, followed by BDC-NO2 with a band gap of 2.93 eV and BDC with a band gap of 3.76 eV. The electron effective mass was predicted from the band structure to be 8.9 me for all MOF designs. PMID:25269595

  14. Adsorptive desulfurization and denitrogenation using metal-organic frameworks.

    PubMed

    Ahmed, Imteaz; Jhung, Sung Hwa

    2016-01-15

    With the increasing worldwide demand for energy, utilization of fossil fuels is increasing proportionally. Additionally, new and unconventional energy sources are also being utilized at an increasing rate day-by-day. These sources, along with some industrial processes, result in the exposal of several sulfur- and nitrogen-containing compounds (SCCs and NCCs, respectively) to the environment, and the exposure is one of the greatest environmental threats in the recent years. Although, several methods were established for the removal of these pollutants during the last few decades, recent advancements in adsorptive desulfurization and denitrogenation (ADS and ADN, respectively) with metal-organic frameworks (MOFs) make this the most promising and remarkable method. Therefore, many research groups are currently involved with ADS and ADN with MOFs, and the results are improving gradually by modifying the MOF adsorbents according to several specific adsorption mechanisms. In this review, ADS and ADN studies are thoroughly discussed for both liquid-phase and gas-phase adsorption. The MOF modification procedures, which are important for improved adsorption, are also described. To improve the knowledge among the scientific community, it is very important to understand the detailed chemistry and mechanism involved in a chemical process, which also creates the possibility and pathway for further developments in research and applications. Therefore, the mechanisms related to the adsorption procedures are also discussed in detail. From this review, it can be expected that the scientific community will obtain an understanding of the current state of ADS and ADN, their importance, and some encouragement and insight to take the research knowledge base to a higher level. PMID:26368800

  15. Hydrophobic and moisture-stable metal-organic frameworks.

    PubMed

    Fernandez, Carlos A; Nune, Satish K; Annapureddy, Harsha V; Dang, Liem X; McGrail, B Peter; Zheng, Feng; Polikarpov, Evgueni; King, David L; Freeman, Charles; Brooks, Kriston P

    2015-08-14

    Metal-organic frameworks (MOFs) have proved to be very attractive for applications including gas storage, separation, sensing and catalysis. In particular, CO(2) separation from flue gas in post-combustion processes is one of the main focuses of research among the scientific community. One of the major issues that are preventing the successful commercialization of these novel materials is their high affinity towards water that not only compromises gas sorption capacity but also the chemical stability. In this paper, we demonstrate a novel post-synthesis modification approach to modify MOFs towards increasing hydrophobic behaviour and chemical stability against moisture without compromising CO(2) sorption capacity. Our approach consists of incorporating hydrophobic moieties on the external surface of the MOFs via physical adsorption. The rationale behind this concept is to increase the surface hydrophobicity in the porous materials without the need of introducing bulky functionalities inside the pore which compromises the sorption capacity toward other gases. We herein report preliminary results on routinely studied MOF materials [MIL-101(Cr) and NiDOBDC] demonstrating that the polymer-modified MOFs retain CO(2) sorption capacity while reducing the water adsorption up to three times, with respect to the un-modified materials, via an equilibrium effect. Furthermore, the water stability of the polymer-functionalized MOFs is significantly higher than the water stability of the bare material. Molecular dynamic simulations demonstrated that this equilibrium effect implies a fundamental and permanent change in the water sorption capacity of MOFs. This approach can also be employed to render moisture stability and selectivity to MOFs that find applications in gas separations, catalysis and sensing where water plays a critical role in compromising MOF performance and recyclability. PMID:25970023

  16. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels

    NASA Astrophysics Data System (ADS)

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-02-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm-3 was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures.

  17. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels

    PubMed Central

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-01-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm−3 was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures. PMID:26892258

  18. High-internal-phase emulsions stabilized by metal-organic frameworks and derivation of ultralight metal-organic aerogels.

    PubMed

    Zhang, Bingxing; Zhang, Jianling; Liu, Chengcheng; Peng, Li; Sang, Xinxin; Han, Buxing; Ma, Xue; Luo, Tian; Tan, Xiuniang; Yang, Guanying

    2016-01-01

    To design high-internal-phase emulsion (HIPE) systems is of great interest from the viewpoints of both fundamental researches and practical applications. Here we demonstrate for the first time the utilization of metal-organic framework (MOF) for HIPE formation. By stirring the mixture of water, oil and MOF at room temperature, the HIPE stabilized by the assembly of MOF nanocrystals at oil-water interface could be formed. The MOF-stabilized HIPE provides a novel route to produce highly porous metal-organic aerogel (MOA) monolith. After removing the liquids from the MOF-stabilized HIPE, the ultralight MOA with density as low as 0.01 g·cm(-3) was obtained. The HIPE approach for MOA formation has unique advantages and is versatile in producing different kinds of ultralight MOAs with tunable porosities and structures. PMID:26892258

  19. A novel metal-organic framework for high storage and separation of acetylene at room temperature

    NASA Astrophysics Data System (ADS)

    Duan, Xing; Wang, Huizhen; Ji, Zhenguo; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2016-09-01

    A novel 3D microporous metal-organic framework with NbO topology, [Cu2(L)(H2O)2]•(DMF)6·(H2O)2 (ZJU-10, ZJU = Zhejiang University; H4L =2‧-hydroxy-[1,1‧:4‧,1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid; DMF =N,N-dimethylformamide), has been synthesized and structurally characterized. With suitable pore sizes and open Cu2+ sites, ZJU-10a exhibits high BET surface area of 2392 m2/g, as well as moderately high C2H2 volumetric uptake capacity of 132 cm3/cm3. Meanwhile, ZJU-10a is a promising porous material for separation of acetylene from methane and carbon dioxide gas mixtures at room temperature.

  20. A Stable Polyoxometalate-Pillared Metal-Organic Framework for Proton-Conducting and Colorimetric Biosensing.

    PubMed

    Zhou, En-Long; Qin, Chao; Huang, Peng; Wang, Xin-Long; Chen, Wei-Chao; Shao, Kui-Zhan; Su, Zhong-Min

    2015-08-10

    A stable metal-organic framework pillared by Keggin-type polyoxometalate, Cu6 (Trz)10 (H2O)4 [H2 SiW12 O40 ]⋅8 H2O (Trz=1,2,4-triazole) (1), has been prepared under hydrothermal condition. The 2D layer structure with a 22-member ring was formed by Cu(2+) ions, which are connected with each other via the Trz ligands on the ab plane. Thus, the 2D layers are further interconnected through Keggin polyoxoanions to generate a 3D porous network with a small 1D channel. Moreover, the presence of polyoxoanions make it exhibit selective adsorption of water and proton-conducting properties. Additionally it showed efficient intrinsic peroxidase-like activity, providing a simple and sensitive colorimetric assay to detect H2O2 . PMID:26179161

  1. Carbon Dioxide Separation with Novel Microporous Metal Organic Frameworks

    SciTech Connect

    Richard Willis; Annabelle Benin; John Low; Ganesh Venimadhavan; Syed Faheem; David Lesch; Adam Matzger; Randy Snurr

    2008-02-04

    The goal of this program was to develop a low cost novel sorbent to remove carbon dioxide from flue gas and gasification streams in electric utilities. Porous materials named metal-organic frameworks (MOFs) were found to have good capacity and selectivity for the capture of carbon dioxide. Several materials from the initial set of reference MOFs showed extremely high CO{sub 2} adsorption capacities and very desirable linear isotherm shapes. Sample preparation occurred at a high level, with a new family of materials suitable for intellectual property protection prepared and characterized. Raman spectroscopy was shown to be useful for the facile characterization of MOF materials during adsorption and especially, desorption. Further, the development of a Raman spectroscopic-based method of determining binary adsorption isotherms was initiated. It was discovered that a stronger base functionality will need to be added to MOF linkers in order to enhance CO{sub 2} selectivity over other gases via a chemisorption mechanism. A concentrated effort was expended on being able to accurately predict CO{sub 2} selectivities and on the calculation of predicted MOF surface area values from first principles. A method of modeling hydrolysis on MOF materials that correlates with experimental data was developed and refined. Complimentary experimental data were recorded via utilization of a combinatorial chemistry heat treatment unit and high-throughput X-ray diffractometer. The three main Deliverables for the project, namely (a) a MOF for pre-combustion (e.g., IGCC) CO{sub 2} capture, (b) a MOF for post-combustion (flue gas) CO{sub 2} capture, and (c) an assessment of commercial potential for a MOF in the IGCC application, were completed. The key properties for MOFs to work in this application - high CO{sub 2} capacity, good adsorption/desorption rates, high adsorption selectivity for CO{sub 2} over other gases such as methane and nitrogen, high stability to contaminants, namely

  2. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    DOEpatents

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2016-08-02

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  3. Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

    DOEpatents

    McGrail, B. Peter; Brown, Daryl R.; Thallapally, Praveen K.

    2014-08-05

    Methods for releasing associated guest materials from a metal organic framework are provided. Methods for associating guest materials with a metal organic framework are also provided. Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Thermal energy transfer assemblies are provided. Methods for transferring thermal energy are also provided.

  4. Syntheses, structures and physical properties of transition metal-organic frameworks assembled from trigonal heterofunctional ligands.

    PubMed

    Song, Shu-Yan; Song, Xue-Zhi; Zhao, Shu-Na; Qin, Chao; Su, Sheng-Qun; Zhu, Min; Hao, Zhao-Min; Zhang, Hong-Jie

    2012-09-14

    Six novel metal-organic frameworks (MOFs), {Mn(bpydb)(bpyHdbH)}(n) (1) {[Co(2)(bpydb)(2)](H(2)O)(0.5)}(n) (2), {[Ni(0.5)(bpydbH)(H(2)O)](DMF)(2)}(n) (3), {[Cu(2)(bpydb)(2)](H(2)O)(0.5)}(n) (4), {Zn(bpyHdb)(2)}(n) (5) and {[Cd(0.5)(bpydb)(0.5)(DMF)](H(2)O)}(n) (6), were successfully synthesized by assembling transition metal salts with trigonal heterofunctional ligand 4,4'-(4,4'-bipyridine-2,6-diyl) dibenzoic acid (bpydbH(2)) under hydrothermal and/or solvothermal conditions. Compound 1 features a rare 4-fold interpenetrating (3,5)-connected framework with hms-type topology. Isostructural compounds 2 and 4, constructed by M(2)(COO)(4) secondary building units, exhibit a robust 3D framework with alb topological type in 2-fold interpenetrating mode. Compound 3 consists of 2D (4,4) networks, which are further assembled into the new topological framework with the symbol (5(3)·6(2)·8)(5(3)·6(3))(2) through O-HO interactions. Compound 5 manifests a novel 4-connected interpenetrating framework, constructed by 2D (4,4) layers and interbedded N-HO interactions. Non-interpenetrating honeycomb networks are observed in compound 6, and further packed into a 3D framework featuring 1D channels. The magnetic susceptibility of compound 2 indicates antiferromagnetic interactions between cobalt ions. The photoluminescent properties of 5 and 6 were investigated in the solid state at room temperature. PMID:22814798

  5. Metal organic frameworks for enzyme immobilization in biofuel cells

    NASA Astrophysics Data System (ADS)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  6. Studies of gas adsorption in flexible Metal-Organic frameworks

    NASA Astrophysics Data System (ADS)

    Sircar, Sarmishtha

    Flexible Metal-Organic frameworks that exhibit a gate-opening (GO) adsorption mechanism have potential for gas separations and gas storage. The GO phenomenon occurs when molecular gates in the structure expand/contract in response to the activation/de-activation of a system variable e.g. temperature, pressure or gas. Sharp discontinuities in the isotherm leading to S-shapes and large adsorption-desorption hysteresis are typical of this phenomenon. This study investigates the kinetics and thermodynamics of the GO behavior by combining adsorption measurements and analytical modeling of adsorption kinetics and capacity as a function of adsorbate, GO pressure, and temperature. Basic understanding of GO mechanism will help harness GO-MOF's as adsorbents for gas separations and storage. Experiments were performed on two precharacterized MOFs with verified GO behavior. These are (1) Zn2(bpdc)2(bpee), which expands from a relative amorphous to crystalline structure and (2) Cu[(dhbc) 2(4,4f-bpy)]H2O, a mutually interdigitated 2-D structure (bpdc = biphenyldicarboxylate, bpee = 1,2]bipyridylethene; DMF = N,N-dimethyl formamide, dhbc= 2,5-dihydroxybenzoic acid, bpy=bipyridine). Both sub- and super-critical adsorption data were collected using three adsorption units: a standard low-pressure volumetric adsorption unit, a commercial high-pressure gravimetric analyzer and a custom-built high-pressure differential volumetric unit. Collected laboratory data were combined with published adsorption rate and isotherm data for analysis to broaden the range of data collection. The accuracy of the high-pressure differential unit was improved by over 300-fold by changing analytical methods of processing data to establish a reliable null correction. A pronounced effect of the allowed experimental time was found at cryogenic temperatures on (1). Tightening the stability criteria used by the adsorption equipment to determine equilibration increased the experimental time from the order of

  7. A luminescent microporous metal-organic framework for the recognition and sensing of anions.

    PubMed

    Chen, Banglin; Wang, Liangbo; Zapata, Fatima; Qian, Guodong; Lobkovsky, Emil B

    2008-05-28

    A luminescent microporous metal-organic framework Tb(BTC)G has been developed for the recognition and sensing of anions, exhibiting a high-sensitivity sensing function with respect to fluoride. PMID:18452294

  8. Rapidly assessing the activation conditions and porosity of metal-organic frameworks using thermogravimetric analysis

    SciTech Connect

    McDonald, TM; Bloch, ED; Long, JR

    2015-01-01

    A methodology utilizing a thermogravimetric analyzer to monitor propane uptake following incremental increases of the temperature is demonstrated as a means of rapidly identifying porous materials and determining the optimum activation conditions of metal-organic frameworks.

  9. A porous metal-organic framework with -COOH groups for highly efficient pollutant removal.

    PubMed

    Zhang, Qi; Yu, Jiancan; Cai, Jianfeng; Song, Ruijing; Cui, Yuanjing; Yang, Yu; Chen, Banglin; Qian, Guodong

    2014-11-28

    A new metal-organic framework with -COOH groups has been realized and demonstrates strong interactions with methylene blue and thus the complete removal of methylene blue from aqueous solution. PMID:25303384

  10. Metal-organic framework materials based on icosahedral boranes and carboranes

    DOEpatents

    Mirkin, Chad A.; Hupp, Joseph T.; Farha, Omar K.; Spokoyny, Alexander M.; Mulfort, Karen L.

    2010-11-02

    Disclosed herein are metal-organic frameworks of metals and boron rich ligands, such as carboranes and icosahedral boranes. Methods of synthesizing and using these materials in gas uptake are disclosed.

  11. Bioinspired Design of Ultrathin 2D Bimetallic Metal-Organic-Framework Nanosheets Used as Biomimetic Enzymes.

    PubMed

    Wang, Yixian; Zhao, Meiting; Ping, Jianfeng; Chen, Bo; Cao, Xiehong; Huang, Ying; Tan, Chaoliang; Ma, Qinglang; Wu, Shixin; Yu, Yifu; Lu, Qipeng; Chen, Junze; Zhao, Wei; Ying, Yibin; Zhang, Hua

    2016-06-01

    With the bioinspired design of organic ligands and metallic nodes, novel ultrathin 2D bimetallic metal-organic-framework nanosheets are successfully synthesized, which can serve as advanced 2D biomimetic nanomaterials to mimic heme proteins. PMID:27008574

  12. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K; Hupp, Joseph T

    2013-06-25

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  13. Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration

    DOEpatents

    Farha, Omar K.; Hupp, Joseph T.

    2012-09-11

    Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.

  14. 1D to 3D and Chiral to Noncentrosymmetric Metal-Organic Complexes Controlled by the Amount of DEF Solvent: Photoluminescent and NLO Properties.

    PubMed

    Wen, Yuehong; Sheng, Tianlu; Zhuo, Chao; Zhu, Xiaoquan; Hu, Shengmin; Cao, Wenhai; Li, Haoran; Zhang, Hao; Wu, Xintao

    2016-05-01

    A mixture of 2D and 1D metal-organic complexes, [ZnL(H2O)2·G1·DEF·2H2O]n (1a: G1 = naphthalene-2,7-disulfonate; DEF = N,N-diethylformamide) and [ZnL(H2O)3·G1·DEF·2H2O]n (2), has been prepared from a hydrogenated Schiff base L and Zn(II) in a DEF-contained solvent system under mild conditions. The yields of 1a and 2 are equivalent; however, they can be tuned by varying the amount of DEF solvent. Increasing the use of DEF tends to form pure 1a, while decreasing it generates 2. Without DEF, another novel 3D four-connected CdSO4 (cds) framework [ZnL(H2O)2·G1·2H2O]n (3) composed of alternated right-handed and left-handed helical chains has been constructed. The amount of DEF solvent has a significant impact on the diverse coordination architectures of 1-3, which is rare in the preparation of metal-organic complexes. The photoluminescence of complexes 1-3 along with naphthalene-2,7-disulfonate has been investigated in the solid state. The luminescent emission of G1 was enhanced greatly after being confined into metal-organic networks. In addition, complexes 1-3 display second-harmonic generation efficiencies, which are approximately 0.58, 0.42, 0.32, and 0.52 times as much as that of potassium dihydrogen phosphate. PMID:27093469

  15. Hydrothermal synthesis and structural characterization of metal-organic frameworks based on new tetradentate ligands.

    PubMed

    Liang, Yue; Yuan, Wei-Guan; Zhang, Shu-Fang; He, Zhan; Xue, Junru; Zhang, Xia; Jing, Lin-Hai; Qin, Da-Bin

    2016-01-28

    The hydrothermal reaction of two new tetradentate ligands with different metal salts of cadmium nitrate, zinc chloride, cobalt nitrate and deprotonated terephthalic acid (H2tp), isophthalic acid (H2ip), 4,4'-oxybisbenzoic acid (H2obba) in H2O/DMF or H2O/methanol gave three metal-organic frameworks (MOFs): {[Zn2(L1)(tp)(formate)2]·H2O}n (), {[Cd2(L2)(ip)2]·2H2O}n (), {[Co2(L2)(obba)2]}n () (L1 = 1,2-bis {2,6-bis [(1H-imidazol-1-yl) methyl]-4-methylphenoxy} ethane, L2 = 1,3-bis {2,6-bis [(1H-imidazol-1-yl) methyl]-4-methylphenoxy} propane). The structures of the frameworks are established by single-crystal X-ray diffraction. Compound is a three-dimensional (3D) framework with a 2-fold interpenetrated form, which exhibits a 2-nodal (3,4)-connected fsh-3,4-P21/c net with a {8(3)}2{8(5)·10} topology. Compound has a 2-nodal (4,8)-connected 3D framework where the dinuclear cadmium cluster secondary building units (SBUs) assemble with isophthalate and ligand L2 to construct a rare topological type sqc22 net with a {3(2)·5(4)}{3(4)·4(4)·5(10)·6(10)} topology. Whereas, Compound can be extended to a 2D interlocked (4,4)-connected 4,4 L28 net with the point symbol {4·6(4)·8}2{4(2)·6(4)}. L1 and L2 are tetradentate ligands with diverse linkers and display different coordination modes. In addition, the thermal stability and photochemical properties of the frameworks are also investigated. PMID:26674324

  16. Highly mesoporous metal-organic framework assembled in a switchable solvent

    NASA Astrophysics Data System (ADS)

    Peng, Li; Zhang, Jianling; Xue, Zhimin; Han, Buxing; Sang, Xinxin; Liu, Chengcheng; Yang, Guanying

    2014-07-01

    The mesoporous metal-organic frameworks are a family of materials that have pore sizes ranging from 2 to 50 nm, which have shown promising applications in catalysis, adsorption, chemical sensing and so on. The preparation of mesoporous metal-organic frameworks usually needs the supramolecular or cooperative template strategy. Here we report the template-free assembly of mesoporous metal-organic frameworks by using CO2-expanded liquids as switchable solvents. The mesocellular metal-organic frameworks with large mesopores (13-23 nm) are formed, and their porosity properties can be easily adjusted by controlling CO2 pressure. Moreover, the use of CO2 can accelerate the reaction for metal-organic framework formation from metal salt and organic linker due to the viscosity-lowering effect of CO2, and the product can be recovered through CO2 extraction. The as-synthesized mesocellular metal-organic frameworks are highly active in catalysing the aerobic oxidation of benzylic alcohols under mild temperature at atmospheric pressure.

  17. Unraveling the multi-functional behavior in a series of Metal Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Sanda, Suresh; Biswas, Soumava; Parshamoni, Srinivasulu; Konar, Sanjit

    2015-09-01

    Three new 2D/3D Metal-Organic Frameworks (MOFs), {[Zn(2,6-ndc)(aldrithiol)]·3(H2O)}n (1), {[Co(2,6-ndc)(aldrithiol)(H2O)2]·2(H2O)}n (2), {[Cd2(2,6-ndc)2(aldrithiol)2(H2O)2]·(aldrithiol)·(EtOH)·3(H2O)}n (3), (2,6-ndc = 2,6-naphthalene dicarboxylic acid; aldrithiol = 4,4'-dipyridyl disulphide) have been synthesized and structurally characterized. Compounds 1 and 2 have 2D layered architectures with similar framework topology whereas 3 is a 2-fold interwoven three dimensional framework. Sorption studies reveal that compounds 1-3 selectively adsorbs CO2 over other gases and H2O over other solvents. Proton conductivity study of compounds 1 and 2 show highest values of 6.73 x 10-7 S.cm-1, 1.96 x 10-5 S.cm-1 at 318 K and 95% RH and these values are humidity dependent. Photoluminescent properties of compounds 1 and 3 show metal perturbed (π*-π and π*-n) intra ligand charge transfer transitions. Additionally, Compound 3 also displays reversible adsorption of molecular iodine.

  18. Studies of gas adsorption in flexible Metal-Organic frameworks

    NASA Astrophysics Data System (ADS)

    Sircar, Sarmishtha

    Flexible Metal-Organic frameworks that exhibit a gate-opening (GO) adsorption mechanism have potential for gas separations and gas storage. The GO phenomenon occurs when molecular gates in the structure expand/contract in response to the activation/de-activation of a system variable e.g. temperature, pressure or gas. Sharp discontinuities in the isotherm leading to S-shapes and large adsorption-desorption hysteresis are typical of this phenomenon. This study investigates the kinetics and thermodynamics of the GO behavior by combining adsorption measurements and analytical modeling of adsorption kinetics and capacity as a function of adsorbate, GO pressure, and temperature. Basic understanding of GO mechanism will help harness GO-MOF's as adsorbents for gas separations and storage. Experiments were performed on two precharacterized MOFs with verified GO behavior. These are (1) Zn2(bpdc)2(bpee), which expands from a relative amorphous to crystalline structure and (2) Cu[(dhbc) 2(4,4f-bpy)]H2O, a mutually interdigitated 2-D structure (bpdc = biphenyldicarboxylate, bpee = 1,2]bipyridylethene; DMF = N,N-dimethyl formamide, dhbc= 2,5-dihydroxybenzoic acid, bpy=bipyridine). Both sub- and super-critical adsorption data were collected using three adsorption units: a standard low-pressure volumetric adsorption unit, a commercial high-pressure gravimetric analyzer and a custom-built high-pressure differential volumetric unit. Collected laboratory data were combined with published adsorption rate and isotherm data for analysis to broaden the range of data collection. The accuracy of the high-pressure differential unit was improved by over 300-fold by changing analytical methods of processing data to establish a reliable null correction. A pronounced effect of the allowed experimental time was found at cryogenic temperatures on (1). Tightening the stability criteria used by the adsorption equipment to determine equilibration increased the experimental time from the order of

  19. A green strategy to prepare metal oxide superstructure from metal-organic frameworks.

    PubMed

    Song, Yonghai; Li, Xia; Wei, Changting; Fu, Jinying; Xu, Fugang; Tan, Hongliang; Tang, Juan; Wang, Li

    2015-01-01

    Metal or metal oxides with diverse superstructures have become one of the most promising functional materials in sensor, catalysis, energy conversion, etc. In this work, a novel metal-organic frameworks (MOFs)-directed method to prepare metal or metal oxide superstructure was proposed. In this strategy, nodes (metal ions) in MOFs as precursors to form ordered building blocks which are spatially separated by organic linkers were transformed into metal oxide micro/nanostructure by a green method. Two kinds of Cu-MOFs which could reciprocally transform by changing solvent were prepared as a model to test the method. Two kinds of novel CuO with three-dimensional (3D) urchin-like and 3D rods-like superstructures composed of nanoparticles, nanowires and nanosheets were both obtained by immersing the corresponding Cu-MOFs into a NaOH solution. Based on the as-formed CuO superstructures, a novel and sensitive nonenzymatic glucose sensor was developed. The small size, hierarchical superstructures and large surface area of the resulted CuO superstructures eventually contribute to good electrocatalytic activity of the prepared sensor towards the oxidation of glucose. The proposed method of hierarchical superstructures preparation is simple, efficient, cheap and easy to mass production, which is obviously superior to pyrolysis. It might open up a new way for hierarchical superstructures preparation. PMID:25669731

  20. A Green Strategy to Prepare Metal Oxide Superstructure from Metal-Organic Frameworks

    PubMed Central

    Song, Yonghai; Li, Xia; Wei, Changting; Fu, Jinying; Xu, Fugang; Tan, Hongliang; Tang, Juan; Wang, Li

    2015-01-01

    Metal or metal oxides with diverse superstructures have become one of the most promising functional materials in sensor, catalysis, energy conversion, etc. In this work, a novel metal-organic frameworks (MOFs)-directed method to prepare metal or metal oxide superstructure was proposed. In this strategy, nodes (metal ions) in MOFs as precursors to form ordered building blocks which are spatially separated by organic linkers were transformed into metal oxide micro/nanostructure by a green method. Two kinds of Cu-MOFs which could reciprocally transform by changing solvent were prepared as a model to test the method. Two kinds of novel CuO with three-dimensional (3D) urchin-like and 3D rods-like superstructures composed of nanoparticles, nanowires and nanosheets were both obtained by immersing the corresponding Cu-MOFs into a NaOH solution. Based on the as-formed CuO superstructures, a novel and sensitive nonenzymatic glucose sensor was developed. The small size, hierarchical superstructures and large surface area of the resulted CuO superstructures eventually contribute to good electrocatalytic activity of the prepared sensor towards the oxidation of glucose. The proposed method of hierarchical superstructures preparation is simple, efficient, cheap and easy to mass production, which is obviously superior to pyrolysis. It might open up a new way for hierarchical superstructures preparation. PMID:25669731

  1. A water-stable metal-organic framework of a zwitterionic carboxylate with dysprosium: a sensing platform for Ebolavirus RNA sequences.

    PubMed

    Qin, Liang; Lin, Li-Xian; Fang, Zhi-Ping; Yang, Shui-Ping; Qiu, Gui-Hua; Chen, Jin-Xiang; Chen, Wen-Hua

    2016-01-01

    We herein report a water-stable 3D dysprosium-based metal-organic framework (MOF) that can non-covalently interact with probe ss-DNA. The formed system can serve as an effective fluorescence sensing platform for the detection of complementary Ebolavirus RNA sequences with the detection limit of 160 pM. PMID:26502791

  2. Assembly of new polyoxometalate-templated metal-organic frameworks based on flexible ligands

    NASA Astrophysics Data System (ADS)

    Li, Na; Mu, Bao; Lv, Lei; Huang, Rudan

    2015-03-01

    Four new polyoxometalate(POM)-templated metal-organic frameworks based on flexible ligands, namely, [Cu6(bip)12(PMoVI12O40)2(PMoVMoVI11O40O2)]·8H2O(1), [CuI3CuII3(bip)12(PMoVI12O40)2(PMoV12O34)]·8H2O(2), [Ni6(bip)12(PMoVI12O40)(PMoVI11MoVO40)2]Cl·6H2O(3), [CoII3CoIII2(H2bib)2(Hbib)2(PW9O34)2(H2O)6]·6H2O(4) (bip=1,3-bis(imidazolyl)propane, bib=1,4-bis(imidazolyl)butane) have been obtained under hydrothermal condition and characterized by single-crystal X-ray diffraction analyses, elemental analyses, and thermogravimetric (TG) analyses. The studies of single crystal X-ray indicate that compounds 1-3 crystallize in the trigonal space group P-3, and compound 4 crystallizes in the triclinic space group P-1. Compounds 1 and 3 represent 3D frameworks, and POMs as the guest molecules are incorporated into the cages which are composed of the ligands and metals, while compounds 2 and 4 show 3D frameworks by hydrogen bonds. This compounds provide new examples of host-guest compounds based on flexible bis(imidazole) ligands. In addition, the electrochemical property and the catalytic property of compound 1 have also been investigated.

  3. Aminopyridine derivatives controlled the assembly and various properties of Cu-BTC metal-organic frameworks.

    PubMed

    Wang, Xiuli; Le, Mao; Lin, Hongyan; Luan, Jian; Liu, Guocheng; Liu, Danna

    2015-08-21

    Three Cu(ii) metal-organic frameworks (MOFs) based on 1,3,5-benzenetricarboxylic acid (H3BTC) and three aminopyridine derivatives with different lengths and coordination groups, namely [Cu2(3-azpy)(HBTC)(H2BTC)(μ3-OH)(H2O)2] (), [Cu2(3-ppca)(BTC)(H2O)3]·H2O (), [Cu2(3-ebpba)(BTC)(μ3-OH)] () [3-azpy = 3,3'-azopyridine, 3-ppca = N-(pyridin-3-yl)pyrazine-2-carboxamide, 3-ebpba = (E)-4,4'-(ethene-1,2-diyl)bis(N-pyridin-3-yl)benzamide)], have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, PXRD, TG and single crystal X-ray diffraction analyses. The title MOFs display versatile structural features with 2D and 3D frameworks. Complex exhibits a 2D layer, which is constructed from the 3-azpy bridging ligands and a 1D ladder-like Cu-BTC chain with tetranuclear copper clusters. The 3-azpy was in situ transformed from 3-aminopyridine under the hydrothermal conditions. Complex shows a rare 3D framework, which features a (3,3,3,3)-connected topology with a Schläfli symbol of {8·10·12}2{8(2)·10}2. Complex exhibits a (3,8)-connected {4·6(2)}2{4(2)·6(22)·7·8(3)} topology based on tetranuclear copper clusters. The influence of aminopyridine-based ligands on the structures and properties of the title complexes has been discussed. The electrocatalytic and photocatalytic properties of complexes have also been investigated in detail. PMID:26161934

  4. Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

    NASA Astrophysics Data System (ADS)

    Liang, Kang; Ricco, Raffaele; Doherty, Cara M.; Styles, Mark J.; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J.; Doonan, Christian J.; Falcaro, Paolo

    2015-06-01

    Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.

  5. Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

    PubMed Central

    Liang, Kang; Ricco, Raffaele; Doherty, Cara M.; Styles, Mark J.; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J.; Doonan, Christian J.; Falcaro, Paolo

    2015-01-01

    Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules. PMID:26041070

  6. Unusual N-H activation of 2-aminopyrimidine: supramolecular assembly into an Ag(I) metal-organic framework.

    PubMed

    Liu, Fu-Ling; Xu, Zheng-Hu; Zhang, Xi-Ying; Wang, Xing-Po; Sun, Di

    2014-02-01

    A rare example of coordination at the amino group of NH2 pym (2-aminopyrimidine) relevant to N-H activation is described that leads to a novel Ag(I) -imide 3D metal-organic framework (MOF). The coordination of Ag(I) to NH2 pym produced an electron-withdrawing effect and thus increased its acidity, which facilitated the N-H activation and the subsequent formation of the Ag-imide bond. A cooperative metalation/deprotonation process for the N-H activation of NH2 pym is suggested. Interestingly, photoluminescence of 1 is switched on at the low temperature of 77 K. PMID:24227790

  7. A multifunctional lanthanide metal-organic framework supported by Keggin type polyoxometalates.

    PubMed

    Zhu, Wen-Hua; Zeng, Min; Wang, Juan; Li, Chen-Yang; Tian, Li-Hong; Yin, Jia-Cheng; Liu, Yu-Kun

    2016-06-21

    A neodymium metal-organic framework with 1D nanotubular channels incorporating Keggin type [SiWWO38](3-) has been synthesized by utilizing pyridine-2,5-dicarboxylic acid as an organic ligand. It represents an unusual polyoxometalate-templated framework with the multifunctionality of magnetism, near-infrared luminescence and the selective adsorption of Rhodamine B dye molecules. PMID:27242190

  8. Adsorption of two gas molecules at a single metal site in a metal-organic framework.

    PubMed

    Runčevski, Tomče; Kapelewski, Matthew T; Torres-Gavosto, Rodolfo M; Tarver, Jacob D; Brown, Craig M; Long, Jeffrey R

    2016-07-01

    One strategy to markedly increase the gas storage capacity of metal-organic frameworks is to introduce coordinatively-unsaturated metal centers capable of binding multiple gas molecules. Herein, we provide an initial demonstration that a single metal site within a framework can support the terminal coordination of two gas molecules-specifically hydrogen, methane, or carbon dioxide. PMID:27284590

  9. Integration of metal-organic frameworks into an electrochemical dielectric thin film for electronic applications

    PubMed Central

    Li, Wei-Jin; Liu, Juan; Sun, Zhi-Hua; Liu, Tian-Fu; Lü, Jian; Gao, Shui-Ying; He, Chao; Cao, Rong; Luo, Jun-Hua

    2016-01-01

    The integration of porous metal-organic frameworks onto the surface of materials, for use as functional devices, is currently emerging as a promising approach for gas sensing and flexible displays. However, research focused on potential applications in electronic devices is in its infancy. Here we present a facile strategy by which interpenetrated, crystalline metal-organic framework films are deposited onto conductive metal-plate anodes via in situ temperature-controlled electrochemical assembly. The nanostructure of the surface as well as the thickness and uniformity of the film are well controlled. More importantly, the resulting films exhibit enhanced dielectric properties compared to traditional inorganic or organic gate dielectrics. This study demonstrates the successful implementation of the rational design of metal-organic framework thin films on conductive supports with high-performance dielectric properties. PMID:27282348

  10. Integration of metal-organic frameworks into an electrochemical dielectric thin film for electronic applications

    NASA Astrophysics Data System (ADS)

    Li, Wei-Jin; Liu, Juan; Sun, Zhi-Hua; Liu, Tian-Fu; Lü, Jian; Gao, Shui-Ying; He, Chao; Cao, Rong; Luo, Jun-Hua

    2016-06-01

    The integration of porous metal-organic frameworks onto the surface of materials, for use as functional devices, is currently emerging as a promising approach for gas sensing and flexible displays. However, research focused on potential applications in electronic devices is in its infancy. Here we present a facile strategy by which interpenetrated, crystalline metal-organic framework films are deposited onto conductive metal-plate anodes via in situ temperature-controlled electrochemical assembly. The nanostructure of the surface as well as the thickness and uniformity of the film are well controlled. More importantly, the resulting films exhibit enhanced dielectric properties compared to traditional inorganic or organic gate dielectrics. This study demonstrates the successful implementation of the rational design of metal-organic framework thin films on conductive supports with high-performance dielectric properties.

  11. A Combined Experimental and Computational Study on the Stability of Nanofluids Containing Metal Organic Frameworks.

    PubMed

    Annapureddy, Harsha V R; Nune, Satish K; Motkuri, Radha Kishan; McGrail, B Peter; Dang, Liem X

    2015-07-23

    Computational studies on nanofluids composed of metal organic frameworks were performed using molecular modeling techniques. Grand Canonical Monte Carlo simulations were used to study the adsorption behavior of 1,1,1,3,3-pentafluoropropane (R-245fa) in a MIL-101 metal organic frameworks at various temperatures. To understand the stability of the nanofluid composed of MIL-101 particles, we performed molecular dynamics simulations to compute potentials of mean force between hypothetical MIL-101 fragments terminated with two different kinds of modulators in R-245fa and water. Our computed potentials of mean force results indicate that the metal organic frameworks particles tend to disperse better in water than in R-245fa. The reasons for this difference in dispersion were analyzed and are discussed in the paper. Our results agree with experimental results indicating that the potential models employed and modeling approaches provide good descriptions of molecular interactions and the reliabilities. PMID:25569021

  12. Structure and applications of metal-organic framework based on cyanide and 3,5-dichloropyridine

    NASA Astrophysics Data System (ADS)

    Etaiw, Safaa El-din H.; El-bendary, Mohamed M.

    2013-06-01

    The reaction of the aqueous/acetonitrile solutions of K3[Cu(CN)4] and 3,5-dichloropyridine (3,5-dClpy), in the presence of Me3SnCl affords a new metal-organic framework (MOF), 3∞[(CuCN)2·(3,5-dClpy)2], 1. The structure of the MOF 1 was characterized by IR, UV-visible, TGA and X-ray single crystal analysis. The structure of MOF 1 consists of CuCN building blocks which are connected by CN group forming 1D-zig-zag chains. Each chain is bridged to another chain by hydrogen bonding organizing 2D-sheets. The structure of 1 is further close packed by hydrogen bonds, π-π stacking and lp-π interactions creating 3D-network. The emission spectra and the thermodynamic parameters from TGA of the MOF 1 were discussed. The MOF 1 was used as heterogeneous catalyst for the oxidative discoloration of methylene blue dye (MB) by dilute solution of hydrogen peroxide as oxidant. The in vitro cytotoxic activity has been evaluated against the human breast cancer cell lines MCF-7. The cytotoxic effect of the MOF 1 on the viability of MCF-7 cells was determined by MTT assay.

  13. High adsorption capacity of two Zn-based metal-organic frameworks by ultrasound assisted synthesis.

    PubMed

    Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

    2016-11-01

    Micro- and nano-rods and plates of two 3D, porous Zn(II)-based metal-organic frameworks [Zn(oba)(4-bpdh)0.5]n·(DMF)1.5 (TMU-5) and [Zn(oba)(4-bpmb)0.5]n (DMF)1.5 (TMU-6) were prepared by sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. These MOFs were synthesized using a non-linear dicarboxylate (H2oba=4,4-oxybisbenzoic acid) and two linear N-donor (4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene and 4-bpmb=N(1),N(4)-bis((pyridin-4-yl)methylene)benzene-1,4-diamine) ligands by ultrasonic irradiation. Sonication time and concentration of initial reagents influencing size and morphology of nano-structured MOFs, were also studied. Calcination of TMU-5 and TMU-6 at 550°C under air atmosphere yields ZnO nanoparticles. TMU-5 and TMU-6 exhibited maximum percent adsorption of 96.2% and 92.8% of 100ppm rhodamine B dye, respectively, which obeys first order reaction kinetics. PMID:27245956

  14. Two metal-organic frameworks with different configurations constructed from a flexible tripodal triaromatic acid

    NASA Astrophysics Data System (ADS)

    Liang, Li-Li; Xu, Lei; Xue, Hong-Bao; Tao, Zhao-Lin; Chen, Fei-Jian

    2016-12-01

    Two metal-organic frameworks [Ce2(L)2(DMF)4] (1), and [Ni3(HL2-)4(bpe)3(H2O)4]·[H2N(CH3)2+]2(DMF)6(H2O)8 (2) (H3L = 4,4‧,4″-{[(2,4,6-trimethylbenzene-1,3,5-triyl)tris-(methylene)] tris(oxy)}tribenzoic acid, bpe = trans-4,4‧-bipyridylethylene) have been solvothermally synthesized from a flexible tripodal ligand. Single-crystal X-ray diffraction shows that compound 1 features a 3,6-connected double-layer network which is further connected by weak π-π interactions between benzene rings to form a 3D porous network. Compound 2 exhibits an unprecedented (4,5)-connected (33.42.5.62.72)2(6.84.10) topology based on zigzag chains and straight chains. In addition, thermal stabilities and luminescent properties of 1 and 2 were investigated in the solid state.

  15. Multirate delivery of multiple therapeutic agents from metal-organic frameworks

    SciTech Connect

    McKinlay, Alistair C.; Allan, Phoebe K.; Renouf, Catherine L.; Duncan, Morven J.; Wheatley, Paul S.; Warrender, Stewart J.; Dawson, Daniel; Ashbrook, Sharon E.; Gil, Barbara; Marszalek, Bartosz; Düren, Tina; Williams, Jennifer J.; Charrier, Cedric; Mercer, Derry K.; Teat, Simon J.; Morris, Russell E.

    2014-12-01

    The highly porous nature of metal-organic frameworks (MOFs) offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

  16. A mixed molecular building block strategy for the design of nested polyhedron metal-organic frameworks.

    PubMed

    Tian, Dan; Chen, Qiang; Li, Yue; Zhang, Ying-Hui; Chang, Ze; Bu, Xian-He

    2014-01-13

    A mixed molecular building block (MBB) strategy for the synthesis of double-walled cage-based porous metal-organic frameworks (MOFs) is presented. By means of this method, two isostructural porous MOFs built from unprecedented double-walled metal-organic octahedron were obtained by introducing two size-matching C3 -symmetric molecular building blocks with different rigidities. With their unique framework structures, these MOFs provide, to the best of our knowledge, the first examples of double-walled octahedron-based MOFs. PMID:24282117

  17. Metal-organic frameworks as host materials of confined supercooled liquids

    NASA Astrophysics Data System (ADS)

    Fischer, J. K. H.; Sippel, P.; Denysenko, D.; Lunkenheimer, P.; Volkmer, D.; Loidl, A.

    2015-10-01

    In this work, we examine the use of metal-organic framework (MOF) systems as host materials for the investigation of glassy dynamics in confined geometry. We investigate the confinement of the molecular glass former glycerol in three MFU-type MOFs with different pore sizes (MFU stands for "Metal-Organic Framework Ulm-University") and study the dynamics of the confined liquid via dielectric spectroscopy. In accord with previous reports on confined glass formers, we find different degrees of deviations from bulk behavior depending on pore size, demonstrating that MOFs are well-suited host systems for confinement investigations.

  18. Tunable electrical conductivity in metal-organic framework thin film devices

    DOEpatents

    Talin, Albert Alec; Allendorf, Mark D.; Stavila, Vitalie; Leonard, Francois

    2016-05-24

    A composition including a porous metal organic framework (MOF) including an open metal site and a guest species capable of charge transfer that can coordinate with the open metal site, wherein the composition is electrically conductive. A method including infiltrating a porous metal organic framework (MOF) including an open metal site with a guest species that is capable of charge transfer; and coordinating the guest species to the open metal site to form a composition including an electrical conductivity greater than an electrical conductivity of the MOF.

  19. A 3D radiative transfer framework. VI. PHOENIX/3D example applications

    NASA Astrophysics Data System (ADS)

    Hauschildt, P. H.; Baron, E.

    2010-01-01

    Aims: We demonstrate the application of our 3D radiative transfer framework in the model atmosphere code PHOENIX for a number of spectrum synthesis calculations for very different conditions. Methods: The 3DRT framework discussed in the previous papers of this series was added to our general-purpose model atmosphere code PHOENIX/1D and an extended 3D version PHOENIX/3D was created. The PHOENIX/3D code is parallelized via the MPI library using a hierarchical domain decomposition and displays very good strong scaling. Results: We present the results of several test cases for widely different atmosphere conditions and compare the 3D calculations with equivalent 1D models to assess the internal accuracy of the 3D modeling. In addition, we show the results for a number of parameterized 3D structures. Conclusions: With presently available computational resources it is possible to solve the full 3D radiative transfer (including scattering) problem with the same micro-physics as included in 1D modeling.

  20. Unraveling the multi-functional behavior in a series of Metal Organic Frameworks

    SciTech Connect

    Sanda, Suresh; Biswas, Soumava; Parshamoni, Srinivasulu; Konar, Sanjit

    2015-09-15

    Three new 2D/3D Metal-Organic Frameworks (MOFs), ([Zn(2,6-ndc)(aldrithiol)]·3(H{sub 2}O)){sub n} (1), ([Co(2,6-ndc)(aldrithiol)(H{sub 2}O){sub 2}]·2(H{sub 2}O)){sub n} (2), ([Cd{sub 2}(2,6-ndc){sub 2}(aldrithiol){sub 2}(H{sub 2}O){sub 2}]·(aldrithiol)·(EtOH)·3(H{sub 2}O)){sub n} (3), (2,6-ndc = 2,6-naphthalene dicarboxylic acid; aldrithiol = 4,4'-dipyridyl disulphide) have been synthesized and structurally characterized. Compounds 1 and 2 have 2D layered architectures with similar framework topology whereas 3 is a 2-fold interwoven three dimensional framework. Sorption studies reveal that compounds 1-3 selectively adsorbs CO{sub 2} over other gases and H{sub 2}O over other solvents. Proton conductivity study of compounds 1 and 2 show highest values of 6.73 x 10{sup -7} S.cm{sup -1}, 1.96 x 10{sup -5} S.cm{sup -1} at 318 K and 95% RH and these values are humidity dependent. Photoluminescent properties of compounds 1 and 3 show metal perturbed (π*–π and π*-n) intra ligand charge transfer transitions. Additionally, Compound 3 also displays reversible adsorption of molecular iodine. - Graphical abstarct: Three new 2D/3D interpenetrated MOFs are synthesized and their multifunctional material properties such as adsorption, proton conduction, iodine adsorption as well as luminscence have been explored. - Highlights: • We report multifunctional material properties in a series MOFs (Compounds 1-3) • All the compounds show selective adsorption of CO{sub 2} over other gases and H{sub 2}O over other solvents. • The proton conduction property studies of all the compounds reveal the humidity dependent conductivity. • Compound 2 shows reversible adsorption of molecular iodine in the framework. • Photoluminescent properties of compounds 1 and 2 show metal perturbed intra ligand charge transfer transitions.

  1. Post-synthetic metalation of metal-organic frameworks.

    PubMed

    Evans, Jack D; Sumby, Christopher J; Doonan, Christian J

    2014-08-21

    Post-synthetic metalation (PSMet) offers expansive scope for a targeted approach to tailoring the properties of MOFs. Numerous methods for carrying-out PSMet chemistry have been reported, however, these can be categorized into three general strategies: (a) addition to coordinating groups; (b) counter-ion exchange in charged frameworks; or, (c) host-guest encapsulation of metal-containing entities within the pores of the framework. PSMet has been applied to enhance the performance characteristics of parent MOFs for gas storage and separation, and catalysis. Notably, PSMet is a prominent strategy in the field of MOF catalysis as it offers a route to design size-selective catalysts, based on the premise of reticular chemistry in MOFs and the ability to incorporate a range of catalytically-active metal centres. Other applications for materials produced via or utilising PSMet strategies include enhancing gas storage or molecular separations, the triggered release of drugs, sensing and tunable light emission for luminescent materials. This review surveys seminal examples of PSMet to highlight the broad scope of this technique for enhancing the performance characteristics of MOFs and to demonstrate how the PSMet concept can be developed for future applications. PMID:24736674

  2. Interpenetrating metal-organic frameworks formed by self-assembly of tetrahedral and octahedral building blocks

    SciTech Connect

    Lu Yongming; Lan Yaqian; Xu Yanhong; Su Zhongmin; Li Shunli; Zang Hongying; Xu Guangjuan

    2009-11-15

    To investigate the relationship between topological types and molecular building blocks (MBBs), we have designed and synthesized a series of three-dimensional (3D) interpenetrating metal-organic frameworks based on different polygons or polyhedra under hydrothermal conditions, namely [Cd(bpib){sub 0.5}(L{sup 1})] (1), [Cd(bpib){sub 0.5}(L{sup 2})].H{sub 2}O (2), [Cd(bpib){sub 0.5}(L{sup 3})] (3) and [Cd(bib){sub 0.5}(L{sup 1})] (4), where bpib=1,4-bis(2-(pyridin-2-yl)-1H-imidazol-1-yl)butane, bib=1,4-bis(1H-imidazol-1-yl)butane, H{sub 2}L{sup 1}=4-(4-carboxybenzyloxy)benzoic acid, H{sub 2}L{sup 2}=4,4'-(ethane-1,2-diylbis(oxy))dibenzoic acid and H{sub 2}L{sup 3}=4,4'-(1,4-phenylenebis(methylene))bis(oxy)dibenzoic acid, respectively. Their structures have been determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1-3 display alpha-Po topological nets with different degrees of interpenetration based on the similar octahedral [Cd{sub 2}(-COO){sub 4}] building blocks. Compound 4 is a six-fold interpenetrating diamondoid net based on tetrahedral MBBs. By careful inspection of these structures, we find that various carboxylic ligands and N-donor ligands with different coordination modes and conformations, and metal centers with different geometries are important for the formation of the different MBBs. It is believed that different topological types lie on different MBBs with various polygons or polyhedra. Such as four- and six-connected topologies are formed by tetrahedral and octahedral building blocks. In addition, with the increase of carboxylic ligands' length, the degrees of interpenetration have been changed in the alpha-Po topological nets. And the luminescent properties of these compounds have been investigated in detail. - Graphical abstract: A series of three-dimensional interpenetrating metal-organic frameworks based on different polygons or polyhedra

  3. A lead-porphyrin metal-organic framework: gas adsorption properties and electrocatalytic activity for water oxidation.

    PubMed

    Dai, Fangna; Fan, Weidong; Bi, Jiahui; Jiang, Peng; Liu, Dandan; Zhang, Xirui; Lin, Huan; Gong, Chuanfang; Wang, Rongming; Zhang, Liangliang; Sun, Daofeng

    2016-01-01

    A 3D non-interpenetrating porous metal-organic framework [Pb2(H2TCPP)]·4DMF·H2O (Pb-TCPP) (H6TCPP = 5,10,15,20-tetra(carboxyphenyl)porphyrin) was synthesized by employment of a robust porphyrin ligand. Pb-TCPP exhibits a one-dimensional channel possessing fairly good capability of gas sorption for N2, H2, Ar, and CO2 gases, and also features selectivity for CO2 over CH4 at 298 K. Furthermore, Pb-TCPP shows electrocatalytic activity for water oxidation in alkaline solution. It is the first 3D porous Pb-MOF that exhibits both gas adsorption properties and electrocatalytic activity for an oxygen evolution reaction (OER). PMID:26606194

  4. Metal-organic frameworks with wine-rack motif: What determines their flexibility and elastic properties?

    NASA Astrophysics Data System (ADS)

    Ortiz, Aurélie U.; Boutin, A.; Fuchs, Alain H.; Coudert, François-Xavier

    2013-05-01

    We present here a framework for the analysis of the full tensors of second-order elastic constants of metal-organic frameworks, which can be obtained by ab initio calculations. We describe the various mechanical properties one can derive from such tensors: directional Young's modulus, shear modulus, Poisson ratio, and linear compressibility. We then apply this methodology to four different metal-organic frameworks displaying a wine-rack structure: MIL-53(Al), MIL-47, MIL-122(In), and MIL-140A. From these results, we shed some light into the link between mechanical properties, geometric shape, and compliance of the framework of these porous solids. We conclude by proposing a simple criterion to assess the framework compliance, based on the lowest eigenvalue of its second-order elastic tensor.

  5. High Methane Storage Capacity in Aluminum Metal-Organic Frameworks

    SciTech Connect

    Gándara, Felipe; Furukawa, Hiroyasu; Lee, Seungkyu; Yaghi, Omar M.

    2014-08-14

    The use of porous materials to store natural gas in vehicles requires large amounts of methane per unit of volume. Here we report the synthesis, crystal structure and methane adsorption properties of two new aluminum metal–organic frameworks, MOF-519 and MOF-520. Both materials exhibit permanent porosity and high methane volumetric storage capacity: MOF-519 has a volumetric capacity of 200 and 279 cm3 cm–3 at 298 K and 35 and 80 bar, respectively, and MOF-520 has a volumetric capacity of 162 and 231 cm3 cm–3 under the same conditions. Furthermore, MOF-519 exhibits an exceptional working capacity, being able to deliver a large amount of methane at pressures between 5 and 35 bar, 151 cm3 cm–3, and between 5 and 80 bar, 230 cm3 cm–3.

  6. Highly efficient electrochemiluminescence based on pyrazolecarboxylic metal organic framework.

    PubMed

    Feng, Chao; Ma, Yu-Heng; Zhang, Duo; Li, Xue-Jing; Zhao, Hong

    2016-03-15

    A series of transition metal complexes with the ligands 3-pyrazoledicarboxylic acid (H2L(1)) and ethyl 1-(2-ethoxy-2-oxoethyl)-1H-pyrazole-3-carboxylate (epzc) have been synthesized. The epzc generated 1-(carboxymethyl)-1H-pyrazole-3-carboxylic acid (H2L(2)) by an in situ hydrothermal hydrolysis reaction, using a one-pot method. Simple mononuclear [Co(HL(1))2(H2O)2] () and [Ni(L(2))(H2O)4] (), dinuclear [Ni2(L(1))2(H2O)6]·H2O () and [Cu2(L(2))2(H2O)4] () and 2D frameworks [Cu2(L(1))2]n (), [Co2(L(2))2(H2O)4]n () have been isolated. The structures have been established by single-crystal X-ray diffraction, and the complexes characterized by FT-IR, thermogravimetric analysis (TGA), PRXD, UV-Vis spectroscopy, and fluorescent spectroscopy. , , and were further assembled to form a supramolecular structure by hydrogen-bonding interactions and/or ππ stacking. and both possess a 2D network structure that is further interlinked via intermolecular hydrogen-bonding interactions. Most importantly, the complexes demonstrated highly intense electrochemiluminescence (ECL) in DMF solution. PMID:26883832

  7. Lithium-Ion-Battery Anode Materials with Improved Capacity from a Metal-Organic Framework.

    PubMed

    Lin, Xiao-Ming; Niu, Ji-Liang; Lin, Jia; Wei, Lei-Ming; Hu, Lei; Zhang, Gang; Cai, Yue-Peng

    2016-09-01

    We present a porous metal-organic framework (MOF) with remarkable thermal stability that exhibits a discharge capacity of 300 mAh g(-1) as an anode material for a lithium-ion battery. Pyrolysis of the obtained MOF gives an anode material with improved capacity (741 mAh g(-1)) and superior cyclic stability. PMID:27548622

  8. A visually detectable pH responsive zirconium metal-organic framework.

    PubMed

    Moon, Su-Young; Howarth, Ashlee J; Wang, Timothy; Vermeulen, Nicolaas A; Hupp, Joseph T; Farha, Omar K

    2016-02-16

    A halochromic Zr6-based metal-organic framework is synthesized using solvent-assisted linker incorporation (SALI) with NU-1000 as a platform and carboxylnaphthofluorescein as a pH sensitive ligand. The functionalized MOF can catalytically detoxify nerve agent simulants in addition to visually detecting the acidic byproduct produced during detoxification. PMID:26832648

  9. High-throughput synthesis and characterization of nanocrystalline porphyrinic zirconium metal-organic frameworks.

    PubMed

    Kelty, M L; Morris, W; Gallagher, A T; Anderson, J S; Brown, K A; Mirkin, C A; Harris, T D

    2016-06-14

    We describe and employ a high-throughput screening method to accelerate the synthesis and identification of pure-phase, nanocrystalline metal-organic frameworks (MOFs). We demonstrate the efficacy of this method through its application to a series of porphyrinic zirconium MOFs, resulting in the isolation of MOF-525, MOF-545, and PCN-223 on the nanoscale. PMID:27247981

  10. A Microporous Metal-Organic Framework for Gas Chromatographic Separation of Alkanes

    SciTech Connect

    Chen, Banglin; Liang, Chengdu; Yang, Jun; Contreras, Damacio; Clancy, Yvette; Lobkovsky, Emil B.; Yaghi, Omar; Dai, Sheng

    2006-01-01

    A zinc-based metal-organic framework (MOF) can be transformed reversibly from an open (a) to a dense (b) configuration. The microporous solid is the first example of a MOF that is highly selective in the gas-chromatographic separation of alkanes.

  11. A microporous metal-organic framework with polarized trifluoromethyl groups for high methane storage.

    PubMed

    Chang, Ganggang; Li, Bin; Wang, Hailong; Bao, Zongbi; Yildirim, Taner; Yao, Zizhu; Xiang, Shengchang; Zhou, Wei; Chen, Banglin

    2015-10-11

    A novel NbO-type metal-organic framework UTSA-88a with polarized trifluoromethyl groups exhibits a notably high methane storage capacity of 248 cm(3) (STP) cm(-3) (at room temperature and 65 bar) and a working capacity of 185 cm(3) (STP) cm(-3). PMID:26300179

  12. Chiral DHIP-Based Metal-Organic Frameworks for Enantioselective Recognition and Separation.

    PubMed

    Zhang, Jie; Li, Zijian; Gong, Wei; Han, Xing; Liu, Yan; Cui, Yong

    2016-08-01

    Two chiral porous 2,3-dihydroimidazo[1,2-a]pyridine (DHIP)-based metal-organic frameworks (MOFs) are assembled from an enantiopure dipyridyl-functionalized DHIP bridging ligand. The Zn-DHIP MOF shows a good enantioseparation performance toward aromatic sulfoxides, and the heterogeneous adsorbent can be readily recovered and reused without significant degradation of the separation performance. PMID:27227785

  13. A NbO-type metal-organic framework exhibiting high deliverable capacity for methane storage.

    PubMed

    Song, Chengling; Ling, Yajing; Feng, Yunlong; Zhou, Wei; Yildirim, Taner; He, Yabing

    2015-05-18

    A copper-based NbO-type metal-organic framework constructed from a tetracarboxylate incorporating phenylethyne as a spacer exhibited an exceptionally high methane working capacity of 184 cm(3) (STP) cm(-3) for methane storage. The value is among the highest reported for MOF materials. PMID:25892102

  14. Aqueous phase nitric oxide detection by an amine-decorated metal-organic framework.

    PubMed

    Desai, Aamod V; Samanta, Partha; Manna, Biplab; Ghosh, Sujit K

    2015-04-11

    Selective and sensitive aqueous phase nitric oxide (NO) detection has been demonstrated by implementing an unsophisticated approach of ligand modulation in a porous, robust metal-organic framework (MOF). The detection is achieved through deamination by NO in an amine-decorated luminescent MOF. This is the first report of employing a physiologically stable, functionalized MOF as a NO sensor. PMID:25744379

  15. Liquid exfoliation of alkyl-ether functionalised layered metal-organic frameworks to nanosheets.

    PubMed

    Foster, Jonathan A; Henke, Sebastian; Schneemann, Andreas; Fischer, Roland A; Cheetham, Anthony K

    2016-08-18

    We report the synthesis of a 2D-layered metal-organic framework incorporating weakly interacting chains designed to aid exfoliation of the layers into nanosheets. Dispersion of the nanosheets exposes labile metal-sites which are shown to exchange solvent molecules allowing the nanosheets to act as sensors in suspension. PMID:27452790

  16. Selective Bifunctional Modification of a Non-catenated Metal-Organic Framework Material via 'Click' Chemistry

    SciTech Connect

    Gadzikwa, Tendai; Farha, Omar K.; Malliakas, Christos D.; Kanatzidis, Mercouri G.; Hupp, Joseph T.; Nguyen, SonBinh T.; NWU

    2009-12-01

    A noncatenated, Zn-based metal-organic framework (MOF) material bearing silyl-protected acetylenes was constructed and postsynthetically modified using 'click' chemistry. Using a solvent-based, selective deprotection strategy, two different organic azides were 'clicked' onto the MOF crystals, resulting in a porous material whose internal and external surfaces are differently functionalized.

  17. A highly sensitive near-infrared luminescent metal-organic framework thermometer in the physiological range.

    PubMed

    Zhao, Dian; Zhang, Jun; Yue, Dan; Lian, Xiusheng; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2016-07-01

    A near-infrared luminescent metal-organic framework Nd0.866Yb0.134BTB was developed as a self-calibrated thermometer in the physiological range. Its features include high sensitivity and resolution, and good biocompatibility, making such a material useful for biomedical applications. PMID:27284589

  18. Synthesis of well dispersed polymer grafted metal-organic framework nanoparticles.

    PubMed

    Xie, K; Fu, Q; He, Y; Kim, J; Goh, S J; Nam, E; Qiao, G G; Webley, P A

    2015-11-01

    Novel polymer grafted metal-organic framework (MOF) nanoparticles were synthesized. The formed core/shell nanoparticles exhibit outstanding water dispersity and pH sensitivity, and show their catalytic effect for the reduction reaction of 4-nitrophenol (NP) to 4-aminophenol (AP) when loaded with Pd(0) catalyst. PMID:26355917

  19. Design of hydrophilic metal organic framework water adsorbents for heat reallocation.

    PubMed

    Cadiau, Amandine; Lee, Ji Sun; Damasceno Borges, Daiane; Fabry, Paul; Devic, Thomas; Wharmby, Michael T; Martineau, Charlotte; Foucher, Damien; Taulelle, Francis; Jun, Chul-Ho; Hwang, Young Kyu; Stock, Norbert; De Lange, Martijn F; Kapteijn, Freek; Gascon, Jorge; Maurin, Guillaume; Chang, Jong-San; Serre, Christian

    2015-08-26

    A new hydrothermally stable Al polycarboxylate metal-organic framework (MOF) based on a heteroatom bio-derived aromatic spacer is designed through a template-free green synthesis process. It appears that in some test conditions this MOF outperforms the heat reallocation performances of commercial SAPO-34. PMID:26193346

  20. Selective Catalysis in Nanoparticle Metal-Organic Framework Composites

    NASA Astrophysics Data System (ADS)

    Stephenson, Casey Justin

    The design of highly selective catalysts are becoming increasingly important, especially as chemical and pharmaceutical industries seek to improve atom economy and minimize energy intensive separations that are often required to separate side products from the desired product. Enzymes are among the most selective of all catalysts, generally operating through molecular recognition whereby an active site analogous to a lock and the substrate is analogous to a key. The assembly of a porous, crystalline material around a catalytically active metal particle could serve as an artificial enzyme. In this vein, we first synthesized the polyvinylpyrrolidone (PVP) coated nanoparticles of interest and then encapsulated them within zeolitic imidazolate framework 8 or ZIF-8. 2.8 nm Pt-PVP nanoparticles, which were encapsulated within ZIF-8 to form Pt ZIF-8 composite. Pt ZIF-8 was inactive for the hydrogenation of cyclic olefins such as cis-cyclooctene and cis-cyclohexene while the composite proved to be a highly selective catalyst for the hydrogenation of terminal olefins, hydrogenating trans-1,3-hexadiene to 3-hexene in 95% selectivity after 24 hours under 1 bar H2. We extended our encapsulation method to sub-2 nm Au nanoparticles to form Au ZIF-8. Au ZIF-8 served as a highly chemoselective catalyst for the hydrogenation of crotonaldehyde an alpha,beta-unsaturated aldehyde, to crotyl alcohol an alpha,beta-unsaturated alcohol, in 90-95% selectivity. In order to investigate nanoparticle size effects on selectivity, 6-10 nm Au nanoparticles were encapsulated within ZIF-8 to form Au6 ZIF-8. Control catalysts with nanoparticles supported on the surface of ZIF-8 were synthesized as well, Au/ZIF-8 and Au6/ZIF-8. Au6 ZIF-8 hydrogenated crotonaldehyde in 85% selectivity towards the unsaturated alcohol. Catalysts with nanoparticles supported on the exterior of ZIF-8 were far less selective towards the unsaturated alcohol. Post-catalysis transmission electron microscopy analysis of Au ZIF

  1. Metal-Organic Frameworks: Bimetallic Metal-Organic Frameworks: Probing the Lewis Acid Site for CO2 Conversion (Small 17/2016).

    PubMed

    Zou, Ruyi; Li, Pei-Zhou; Zeng, Yong-Fei; Liu, Jia; Zhao, Ruo; Duan, Hui; Luo, Zhong; Wang, Jin-Gui; Zou, Ruqiang; Zhao, Yanli

    2016-05-01

    On page 2334, R. Q. Zou, Y. L. Zhao, and co-workers present a porous metal-organic framework (MOF) that serves as a platform for studying the metal exchange effect on both CO2 adsorption and catalytic fixation. The effect is demonstrated by catalytic CO2 cycloaddition with propylene oxide to produce propylene carbonate. Molecular dynamic simulations are carried out to further confirm the catalytic performance of these MOFs on chemical fixation of CO2 to carbonates. This research sheds light on how metal exchange could influence the intrinsic properties of MOFs. PMID:27124007

  2. A homochiral 3D covalent framework assembled from vertical chiral layers with achiral bridging ligands

    NASA Astrophysics Data System (ADS)

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

    2005-02-01

    A novel metal-organic coordination polymer, [Cd(HPT) 2(4,4'-bpy)] n (PT=phthalate), has been hydrothermally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. Colorless crystals crystallized in the tetragonal system, space group I4 122, a=8.294(5), b=8.294(5), c=33.7535(17) Å, V=2321.8(18) Å 3, Z=4 and R=0.0207. The structure of the compound exhibiting a homochiral 3D covalent framework based on achiral bridging ligands has been constructed by an alternating assembly of vertical chiral layers consisting of homochiral helices.

  3. Visible-light-driven photocatalytic water oxidation catalysed by iron-based metal-organic frameworks.

    PubMed

    Horiuchi, Yu; Toyao, Takashi; Miyahara, Kenta; Zakary, Lionet; Van, Dang Do; Kamata, Yusuke; Kim, Tae-Ho; Lee, Soo Wohn; Matsuoka, Masaya

    2016-04-14

    An iron-based metal-organic framework, MIL-101(Fe), promotes photocatalytic water oxidation to produce oxygen from aqueous silver nitrate solution under visible-light irradiation. The finely dispersed iron-oxo clusters embedded as nodes of the porous framework would contribute importantly to the efficient promotion of the reaction as compared to bulk hematite (α-Fe2O3). PMID:26996996

  4. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    PubMed

    Cai, Weizhao; Katrusiak, Andrzej

    2014-01-01

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices. PMID:24993679

  5. A Nanoscale Multiresponsive Luminescent Sensor Based on a Terbium(III) Metal-Organic Framework.

    PubMed

    Dang, Song; Wang, Ting; Yi, Feiyan; Liu, Qinghui; Yang, Weiting; Sun, Zhong-Ming

    2015-08-01

    A nanoscale terbium-containing metal-organic framework (nTbL), with a layer-like structure and [H2 NMe2 ](+) cations located in the framework channels, was synthesized under hydrothermal conditions. The structure of the as-prepared sample was systematically confirmed by powder XRD and elemental analysis; the morphology was characterized by field-emission SEM and TEM. The photoluminescence studies revealed that rod-like nTbL exhibited bright-green emission, corresponding to (5)D4 →(7)FJ (J=6-3) transitions of the Tb(3+) ion under excitation. Further sensing measurements revealed that as-prepared nTbL could be utilized as a multiresponsive luminescent sensor, which showed significant and exclusive detection ability for Fe(3+) ions and phenylmethanol. These results highlight the practical applications of lanthanide-containing metal-organic frameworks as fluorescent probes. PMID:25965107

  6. Diamondoid Structure in a Metal-Organic Framework of Fe4 Single-Molecule Magnets.

    PubMed

    Rigamonti, Luca; Cotton, Carri; Nava, Andrea; Lang, Heinrich; Rüffer, Tobias; Perfetti, Mauro; Sorace, Lorenzo; Barra, Anne-Laure; Lan, Yanhua; Wernsdorfer, Wolfgang; Sessoli, Roberta; Cornia, Andrea

    2016-09-12

    A 3D metal-organic framework (MOF) having single-molecule magnet (SMM) linkers was prepared in crystalline form by using a tetrairon(III) complex functionalised with two divergent pyridyl groups, namely [Fe4 (pPy)2 (dpm)6 ] (1; H3 pPy=2-(hydroxymethyl)-2-(pyridin-4-yl)propane-1,3-diol, Hdpm=dipivaloylmethane). Reaction of 1 with silver(I) perchlorate afforded {[Fe4 (pPy)2 (dpm)6 ]2 Ag}ClO4 (2), which crystallises in a cubic face-centred lattice and exhibits two interlocked diamondoid networks. In 2, the SMMs act as linear ditopic synthons, and silver(I) ions as tetrahedral nodes coordinated by four pyridyl nitrogen atoms. The magnetic properties of 1 (S=5 and D≈-0.4 cm(-1) in the ground spin state) are largely preserved in 2, which shows slow magnetic relaxation with an anisotropy barrier of Ueff /kB =11.46(10) K in zero field and 14.25(8) K in an applied field of 1 kOe. However, crystal symmetry triggers highly noncollinear magnetic anisotropy contributions oriented at 109.47° from each other along the threefold axes of AgN4 tetrahedra, a unique scenario fully confirmed by a single-crystal cantilever torque magnetometry investigation. Magnetisation curves down to 0.03 K demonstrated the occurrence of a wide hysteresis loop when the magnetic field was swept along one of the four Ag-N bonds. By symmetry, the crystalline compound can then be persistently magnetised parallel or antiparallel to the four main diagonals of the unit cell, although the crystals have no overall second-order anisotropy. PMID:27356278

  7. Tuning the adsorption properties of isoreticular pyrazolate-based metal-organic frameworks through ligand modification.

    PubMed

    Colombo, Valentina; Montoro, Carmen; Maspero, Angelo; Palmisano, Giovanni; Masciocchi, Norberto; Galli, Simona; Barea, Elisa; Navarro, Jorge A R

    2012-08-01

    Two isoreticular series of pyrazolate-based 3D open metal-organic frameworks, MBDP_X, adopting the NiBDP and ZnBDP structure types [H(2)BDP = 1,4-bis(1H-pyrazol-4-yl)benzene], were synthesized with the new tagged organic linkers H(2)BDP_X (X = -NO(2), -NH(2), -OH). All of the MBDP_X materials have been characterized through a combination of techniques. IR spectroscopy proved the effective presence of tags, while X-ray powder diffraction (XRPD) witnessed their isoreticular nature. Simultaneous TG/DSC analyses (STA) demonstrated their remarkable thermal stability, while variable-temperature XRPD experiments highlighted their high degree of flexibility related to guest-induced fit processes of the solvent molecules included in the channels. A structural isomer of the parent NiBDP was obtained with a sulfonate tagged ligand, H(2)BDP_SO(3)H. Structure solution from powder diffraction data collected at three different temperatures (room temperature, 90, and 250 °C) allowed the determination of its structure and the comprehension of its solvent-related flexible behavior. Finally, the potential application of the tagged MOFs in selective adsorption processes for gas separation and purification purposes was investigated by conventional single component adsorption isotherms, as well as by advanced experiments of pulse gas chromatography and breakthrough curve measurements. Noteworthy, the results show that functionalization does not improve the adsorption selectivity (partition coefficients) for the resolution of gas mixtures characterized by similar high quadrupole moments (e.g., CO(2)/C(2)H(2)); however, the resolution of gas mixtures containing molecules with highly differentiated polarities (i.e., N(2)/CO(2) or CH(4)/CO(2)) is highly improved. PMID:22765315

  8. A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction.

    PubMed

    Bagheri, Habib; Javanmardi, Hasan; Abbasi, Alireza; Banihashemi, Solmaz

    2016-01-29

    A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the preliminary experiments showed that all of them, particularly the one containing MOF2, have higher extraction performances in compared with PANI. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some chlorobenzenes (CBs) from aqueous samples. Influencing parameters on the synthesize and extraction processes including the electrodeposition voltage and its duration time, the weight ratio of PANI and MOF, the ionic strength, desorption temperature and time, and extraction time and temperature were optimized. The developed method was validated by analyzing the spiked distilled water and gas chromatography-mass spectrometry (GC-MS). Under optimum condition, the relative standard deviation (RSD%) values for a double distilled water spiked with the selected CBs at 20ngL(-1) were 5-8% (n=3) and the detection limits were below 0.2ngL(-1). The linear dynamic range (LDR) of the method was in the concentration range of 0.5-1000ngL(-1) (R(2)>0.9994). The fiber-to-fiber reproducibility was found to be in the range of 4-7%. Eventually, various real-water samples were analyzed by the MOF/PANI-based HS-SPME and GC-MS and the relative recovery values were found to be in the range of 92-98%. PMID:26792446

  9. Three-dimensional Printed Acrylonitrile Butadiene Styrene Framework Coated with Cu-BTC Metal-organic Frameworks for the Removal of Methylene Blue

    NASA Astrophysics Data System (ADS)

    Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-Jun

    2014-08-01

    Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption.

  10. Three-dimensional Printed Acrylonitrile Butadiene Styrene Framework Coated with Cu-BTC Metal-organic Frameworks for the Removal of Methylene Blue

    PubMed Central

    Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-jun

    2014-01-01

    Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption. PMID:25089616

  11. Explosives: Metal-Organic Framework Templated Synthesis of Copper Azide as the Primary Explosive with Low Electrostatic Sensitivity and Excellent Initiation Ability (Adv. Mater. 28/2016).

    PubMed

    Wang, Qianyou; Feng, Xiao; Wang, Shan; Song, Naimeng; Chen, Yifa; Tong, Wenchao; Han, Yuzhen; Yang, Li; Wang, Bo

    2016-07-01

    On page 5837, L. Yang, B. Wang, and co-workers describe a metal-organic framework (MOF) templating method to synthesize copper azide uniformly anchored in a 3D interconnected carbon matrix and evenly spaced by the electron-conductive joints. This strategy sheds light on the preparation of powerful yet safe primary explosives and fulfills the need for controllable explosive systems. PMID:27442967

  12. Design of a humidity-stable metal-organic framework using a phosphonate monoester ligand.

    PubMed

    Gelfand, Benjamin S; Lin, Jian-Bin; Shimizu, George K H

    2015-02-16

    Phosphonate monoesters are atypical linkers for metal-organic frameworks, but they offer potentially added versatility. In this work, a bulky isopropyl ester is used to direct the topology of a copper(II) network from a dense to an open framework, CALF-30. CALF-30 shows no adsorption of N2 or CH4 however, using CO2 sorption, CALF-30 was found to have a Langmuir surface area of over 300 m(2)/g and to be stable to conditions of 90% relative humidity at 353 K owing to kinetic shielding of the framework by the phosphonate ester. PMID:25646642

  13. Fluorous Metal-Organic Frameworks with Enhanced Stability and High H2/CO2 Storage Capacities

    PubMed Central

    Zhang, Da-Shuai; Chang, Ze; Li, Yi-Fan; Jiang, Zhong-Yi; Xuan, Zhi-Hong; Zhang, Ying-Hui; Li, Jian-Rong; Chen, Qiang; Hu, Tong-Liang; Bu, Xian-He

    2013-01-01

    A new class of metal-organic frameworks (MOFs) has been synthesized by ligand-functionalization strategy. Systematic studies of their adsorption properties were performed at low and high pressure. Importantly, when fluorine was introduced into the framework via the functionalization, both the framework stabilities and adsorption capacities towards H2/CO2 were enhanced significantly. This consequence can be well interpreted by theoretical studies of these MOFs structures. In addition, one of these MOFs TKL-107 was used to fabricate mixed matrix membranes, which exhibit great potential for the application of CO2 separation. PMID:24264725

  14. Chromophore-Based Luminescent Metal-Organic Frameworks as Lighting Phosphors.

    PubMed

    Lustig, William P; Wang, Fangming; Teat, Simon J; Hu, Zhichao; Gong, Qihan; Li, Jing

    2016-08-01

    Energy-efficient solid-state-lighting (SSL) technologies are rapidly developing, but the lack of stable, high-performance rare-earth free phosphors may impede the growth of the SSL market. One possible alternative is organic phosphor materials, but these can suffer from lower quantum yields and thermal instability compared to rare-earth phosphors. However, if luminescent organic chromophores can be built into a rigid metal-organic framework, their quantum yields and thermal stability can be greatly improved. This Forum Article discusses the design of a group of such chromophore-based luminescent metal-organic frameworks with exceptionally high performance and rational control of the important parameters that influence their emission properties, including electronic structures of chromophore, coligands, metal ions, and guest molecules. PMID:27244591

  15. Application of metal-organic frameworks for purification of vegetable oils.

    PubMed

    Vlasova, E A; Yakimov, S A; Naidenko, E V; Kudrik, E V; Makarov, S V

    2016-01-01

    Reported here is the synthesis of aluminum-, zinc- and titanium-containing metal-organic frameworks based on terephthalic acid and an investigation on the possibility of using these compounds as adsorbents for the purification of unrefined vegetable oils. It is found that aluminum-, zinc- and titanium-containing metal-organic frameworks improve the physicochemical properties of unrefined vegetable oils (more pleasant taste and odor) due to the binding of free fatty acids and peroxide compounds. It is established that the synthesized materials are more effective in these respects as compared with traditional adsorbents. An adsorption mechanism of free fatty acids and peroxides is proposed. Last but not least, the used MOF can be easily recycled at least five times, via solvent washing. PMID:26212947

  16. Metal-organic frameworks: structure, properties, methods of synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Butova, V. V.; Soldatov, M. A.; Guda, A. A.; Lomachenko, K. A.; Lamberti, C.

    2016-03-01

    This review deals with key methods of synthesis and characterization of metal-organic frameworks (MOFs). The modular structure affords a wide variety of MOFs with different active metal sites and organic linkers. These compounds represent a new stage of development of porous materials in which the pore size and the active site structure can be modified within wide limits. The set of experimental methods considered in this review is sufficient for studying the short-range and long-range order of the MOF crystal structure, determining the morphology of samples and elucidating the processes that occur at the active metal site in the course of chemical reactions. The interest in metal-organic frameworks results, first of all, from their numerous possible applications, ranging from gas separation and storage to chemical reactions within the pores. The bibliography includes 362 references.

  17. Chemical pretreatment of olive oil mill wastewater using a metal-organic framework catalyst.

    PubMed

    De Rosa, Salvatore; Giordano, Girolamo; Granato, Teresa; Katovic, Andrea; Siciliano, Alessio; Tripicchio, Francesco

    2005-10-19

    Olive oil mill wastewaters (OOMW) are not suited for direct biological treatment because of their nonbiodegradable and phytotoxic compound (such as polyphenols) content. Advanced technologies for treatment of OOMW consider mainly the use of solid catalysts in processes that can be operated at room conditions. A system based on combined actions of catalytic oxidations and microbial technologies was studied. The wet hydrogen peroxide catalytic oxidation (WHPCO) process is one of the new emerging oxidation processes particularly attractive for the pretreatment of highly polluted OOMW containing polyphenols that are not suited for classical treatments. In this work, the biodegradability of OOMW was evaluated before and after treating the wastewater samples by the WHPCO process using a metal-organic framework (MOF) as a catalyst. This material, containing Cu and prepared with benzene-1,3,5-tricarboxylic acid (BTC), is a robust metal-organic polymer with a microporous structure that is reminiscent of the topology of zeolite frameworks. PMID:16218680

  18. Polydopamine tethered enzyme/metal-organic framework composites with high stability and reusability

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoling; Yang, Cheng; Ge, Jun; Liu, Zheng

    2015-11-01

    An enzyme/metal-organic framework (MOF) composite with both highly stable and easily reusable features was prepared via tethering enzyme/MOF nanocrystals with polydopamine (PDA). The micrometer-sized PDA tethered enzyme/MOF composite can be easily repeatedly used without obvious activity loss, promising for efficient enzymatic catalysis at low cost with long-term operational stability under harsh conditions.An enzyme/metal-organic framework (MOF) composite with both highly stable and easily reusable features was prepared via tethering enzyme/MOF nanocrystals with polydopamine (PDA). The micrometer-sized PDA tethered enzyme/MOF composite can be easily repeatedly used without obvious activity loss, promising for efficient enzymatic catalysis at low cost with long-term operational stability under harsh conditions. Electronic supplementary information (ESI) available: Synthesis of enzyme-MOF nanocrystals, SEM, TEM, CLSM characterization and measurements of enzymatic performances. See DOI: 10.1039/c5nr05190h

  19. Pd nanoparticles embedded into a metal-organic framework: synthesis, structural characteristics, and hydrogen sorption properties.

    PubMed

    Zlotea, Claudia; Campesi, Renato; Cuevas, Fermin; Leroy, Eric; Dibandjo, Philippe; Volkringer, Christophe; Loiseau, Thierry; Férey, Gérard; Latroche, Michel

    2010-03-10

    The metal-organic framework MIL-100(Al) has been used as a host to synthesize Pd nanoparticles (around 2.0 nm) embedded within the pores of the MIL, showing one of the highest metal contents (10 wt %) without degradation of the porous host. Textural properties of MIL-100(Al) are strongly modified by Pd insertion, leading to significant changes in gas sorption properties. The loss of excess hydrogen storage at low temperature can be correlated with the decrease of the specific surface area and pore volume after Pd impregnation. At room temperature, the hydrogen uptake in the composite MIL-100(Al)/Pd is almost twice that of the pristine material. This can be only partially accounted by Pd hydride formation, and a "spillover" mechanism is expected to take place promoting the dissociation of molecular hydrogen at the surface of the metal nanoparticles and the diffusion of monatomic hydrogen into the porosity of the host metal-organic framework. PMID:20155921

  20. Wavelength-Tunable Microlasers Based on the Encapsulation of Organic Dye in Metal-Organic Frameworks.

    PubMed

    Wei, Yanhui; Dong, Haiyun; Wei, Cong; Zhang, Wei; Yan, Yongli; Zhao, Yong Sheng

    2016-09-01

    A wavelength-tunable microlaser is realized based on the controlled intramolecular charge transfer (ICT) process in dye-encapsulated metal-organic framework (MOF) material. The confinement effect of the MOFs is beneficial for low-threshold lasing. By effectively controlling the polarity of the MOF pores, the population distribution between the locally excited and ICT states is continuously modulated, thus achieving broadband tunable MOF-based microlasers. PMID:27314453

  1. Metal-organic framework tethering PNIPAM for ON-OFF controlled release in solution.

    PubMed

    Nagata, Shunjiro; Kokado, Kenta; Sada, Kazuki

    2015-05-21

    A smart metal-organic framework (MOF) exhibiting controlled release was achieved by modification with a thermoresponsive polymer (PNIPAM) via a surface-selective post-synthetic modification technique. Simple temperature variation readily switches "open" (lower temperature) and "closed" (higher temperature) states of the polymer-modified MOF through conformational change of PNIPAM grafted onto the MOF, resulting in controlled release of the included guest molecules such as resorufin, caffeine, and procainamide. PMID:25896867

  2. Twelve-connected porous metal-organic frameworks with high H(2) adsorption.

    PubMed

    Jia, Junhua; Lin, Xiang; Wilson, Claire; Blake, Alexander J; Champness, Neil R; Hubberstey, Peter; Walker, Gavin; Cussen, Edmund J; Schröder, Martin

    2007-02-28

    The twelve-connected metal-organic frameworks {[Ni(3)(OH)(L)(3)].n(solv)}(infinity) and {[Fe(3)(O)(L)(3)].n(solv)}(infinity) [LH(2) = pyridine-3,5-bis(phenyl-4-carboxylic acid)] have been prepared and characterised: these materials can be desolvated to form porous materials that show adsorption of H(2) up to 4.15 wt% at 77 K. PMID:17308649

  3. Designing Higher Surface Area Metal-Organic Frameworks: Are Triple Bonds Better than Phenyls?

    SciTech Connect

    Farha, O. K.; Wilmer, C. E.; Eryazici, I.; Hauser, B. G.; Parilla, P. A.; Oneill, K.; Sarjeant, A. A.; Nguyen, S. T.; Snurr, R. Q.; Hupp, J. T.

    2012-06-20

    We have synthesized, characterized, and computationally validated the high Brunauer-Emmett-Teller surface area and hydrogen uptake of a new, noncatenating metal-organic framework (MOF) material, NU-111. Our results imply that replacing the phenyl spacers of organic linkers with triple-bond spacers is an effective strategy for boosting molecule-accessible gravimetric surface areas of MOFs and related high-porosity materials.

  4. Aldehyde-Tagged Zirconium Metal-Organic Frameworks: a Versatile Platform for Postsynthetic Modification.

    PubMed

    Xi, Fu-Gui; Liu, Hui; Yang, Ning-Ning; Gao, En-Qing

    2016-05-16

    Aldehyde-tagged UiO-67-type metal-organic frameworks (MOFs) have been synthesized via the direct solvothermal method or postsynthetic ligand exchange. Various functionalities have been introduced into the MOFs via postsynthetic modification (PSM) employing C-N and C-C coupling reactions of the aldehyde tag. Tandem PSM has also been demonstrated. An amino-functionalized MOF obtained by PSM is shown to be an efficient, heterogeneous, and recyclable catalyst for Knoevenagel condensation. PMID:27136395

  5. Metal-organic frameworks reactivate deceased diatoms to be efficient CO(2) absorbents.

    PubMed

    Liu, Dingxin; Gu, Jiajun; Liu, Qinglei; Tan, Yongwen; Li, Zhuo; Zhang, Wang; Su, Yishi; Li, Wuxia; Cui, Ajuan; Gu, Changzhi; Zhang, Di

    2014-02-26

    Diatomite combined with certain metal-organic frameworks (MOFs) is shown to be an effective CO2 absorbent, although diatomite alone is regarded as inert with respect to CO2 absorption. This finding opens the prospect of reactivating millions of tons of diatomite for CO2 absorption. It also shows for the first time that diatom frustules can act as CO2 buffers, an important link in a successive biological CO2 concentration mechanism chain that impacts on global warming. PMID:24285587

  6. Separation of polar compounds using a flexible metal-organic framework

    SciTech Connect

    Motkuri, Radha K.; Thallapally, Praveen K.; Annapureddy, Harsha V.; Dang, Liem X.; Krishna, Rajamani; Nune, Satish K.; Fernandez, Carlos A.; Liu, Jian; McGrail, B. Peter

    2015-01-01

    A flexible metal-organic framework constructed from a flexible linker is shown to possess the capability of separating mixtures of polar compounds by exploiting the differences in the saturation capacities of the constituents. The separation possibilities with the flexible MOF include mixtures of propanol isomers, and various azeotropes. Transient breakthrough simulations show that these sorption-based separations are in favor of the component with higher saturation capacity.

  7. Gas promotes the crystallization of nano-sized metal-organic frameworks in ionic liquid.

    PubMed

    Liu, Chengcheng; Zhang, Bingxing; Zhang, Jianling; Peng, Li; Kang, Xinchen; Han, Buxing; Wu, Tianbin; Sang, Xinxin; Ma, Xue

    2015-07-21

    Herein it was found that gas can be utilized as an activator to promote metal-organic framework (MOF) crystallization in IL at room temperature. The ultra-small MOF nanoparticles were obtained, and their size and porosity properties can be easily modulated by controlling gas pressure. The as-synthesized nano-sized Cu-MOF is an excellent candidate catalyst for the solvent-free oxidation of cyclohexene with oxygen. PMID:26087458

  8. Stabilization of a highly porous metal-organic framework utilizing a carborane-based linker.

    PubMed

    Clingerman, Daniel J; Morris, William; Mondloch, Joseph E; Kennedy, Robert D; Sarjeant, Amy A; Stern, Charlotte; Hupp, Joseph T; Farha, Omar K; Mirkin, Chad A

    2015-04-18

    The first tritopic carborane-based linker, H3BCA (C15B24O6H30), based on closo-1,10-C2B8H10, has been synthesized and incorporated into a metal-organic framework (MOF), NU-700 (Cu3(BCA)2). In contrast to the analogous MOF-143, NU-700 can be activated with retention of porosity, yielding a BET surface area of 1870 m(2) g(-1). PMID:25767827

  9. Removal of chlorine gas by an amine functionalized metal-organic framework via electrophilic aromatic substitution.

    PubMed

    DeCoste, Jared B; Browe, Matthew A; Wagner, George W; Rossin, Joseph A; Peterson, Gregory W

    2015-08-11

    Here we report the removal of chlorine gas from air via a reaction with an amine functionalized metal-organic framework (MOF). It is found that UiO-66-NH2 has the ability to remove 1.24 g of Cl2 per g of MOF via an electrophilic aromatic substitution reaction producing HCl, which is subsequently neutralized by the MOF. PMID:26146024

  10. A Naphthalenediimide-Based Metal-Organic Framework and Thin Film Exhibiting Photochromic and Electrochromic Properties.

    PubMed

    Xie, Yi-Xin; Zhao, Wen-Na; Li, Guo-Chang; Liu, Peng-Fei; Han, Lei

    2016-01-19

    A multifunctional metal-organic framework, NBU-3, has been explored as a 2D three-connected network based on a naphthalenediimide-based ligand. The NBU-3 crystals display photochromic properties, and NBU-3 thin films on FTO substrates exhibit electrochromic properties. NBU-3 is the first example of MOF materials containing both photochromic and electrochromic properties, which can be desirable for thin film devices. PMID:26713454

  11. High methane storage and working capacities in a NbO-type metal-organic framework.

    PubMed

    Song, Chengling; Liu, Huimin; Jiao, Jingjing; Bai, Dongjie; Zhou, Wei; Yildirim, Taner; He, Yabing

    2016-05-01

    To improve methane adsorption by pore structure optimization, we developed a new organic linker and used it to construct a NbO-type metal-organic framework ZJNU-53 that, after activation, exhibits exceptionally high methane storage and working capacities of 241 and 190 cm(3) (STP) cm(-3) at 298 K and 65 bar, respectively, if the packing loss is not considered, which are among the highest reported for MOF materials. PMID:27083013

  12. Metal-organic framework templated inorganic sorbents for rapid and efficient extraction of heavy metals.

    PubMed

    Abney, C W; Gilhula, J C; Lu, K; Lin, W

    2014-12-17

    An innovative wet-treatment with Na2 S transforms two indium metal-organic frameworks (MOFs) into a series of porous inorganic sorbents. These MOF-templated materials display remarkable affinity for heavy metals with saturation occurring in less than 1 h. The saturation capacity for Hg(II) exceeds 2 g g(-1) , more than doubling the best thiol-functionalized sorbents in the literature. PMID:25348588

  13. Metal-organic frameworks as cathode materials for Li-O2 batteries.

    PubMed

    Wu, Doufeng; Guo, Ziyang; Yin, Xinbo; Pang, Qingqing; Tu, Binbin; Zhang, Lijuan; Wang, Yong-Gang; Li, Qiaowei

    2014-05-28

    Metal-organic frameworks (MOFs) with open metal sites enrich the population of O2 in the pores significantly and assist the Li-O2 reaction when employed as a cell electrode material. A primary capacity of 9420 mA h g(-1) is achieved in a cell with Mn-MOF-74; more than four times higher than the value obtained in a cell without an MOF. PMID:24616022

  14. Ultraselective Gas Separation by Nanoporous Metal-Organic Frameworks Embedded in Gas-Barrier Nanocellulose Films.

    PubMed

    Matsumoto, Makoto; Kitaoka, Takuya

    2016-03-01

    Metal-organic frameworks (MOFs) are synthesized at carboxy groups on crystalline TEMPO-oxidized cellulose nanofibers (TOCNs). MOF-TOCN films coated on a paper filter have a hierarchical structure from the nano- to macroscale, and demonstrate a high CO2 /CH4 selectivity, over 120 for CO2 at a high gas flux, by the combination of the nanoporous MOFs and the gas-barrier TOCNs, which have strong affinity with each other. PMID:26669724

  15. Synthesis, structures, and properties of two three-dimensional metal-organic frameworks, based on concurrent ligand extension.

    PubMed

    Shi, Dabin; Ren, Yanwei; Jiang, Huanfeng; Cai, Bowei; Lu, Jiaxian

    2012-06-18

    A tritopic carboxylate ligand, tris(4'-carboxybiphenyl)amine (L-H(3)), has been synthesized and applied in the construction of microporous metal-organic frameworks (MOFs). Two novel metal-organic frameworks (MOFs), {[Zn(2)(L)(OH)]·2DMF·H(2)O}(∞) (1) and {[Cu(L-H)(DMA)]·DMA·2H(2)O}(∞) (2), have been constructed out of L-H(3), Zn(2+), and Cu(2+), respectively. 1 has a 2-fold interpenetrating three-dimensional framework formed by L connectors and the [Zn(2)(CO(2))(3)] secondary building units (SBUs). As for 1, it is worth pointing out that one μ(2)-OH group links two Zn atoms between two neighboring SBUs to produce interesting Zn-O-Zn zigzag chains in the structure. 2 has a two-dimensional grid sheet formed by L-H connectors and the typical paddle-wheel [Cu(2)(CO(2))(4)] SBUs. Two-dimensional (2D) sheets nest with each other, which finally forms a three-dimensional (3D) nested framework. Two MOFs are characterized by infrared (IR) spectroscopy, thermogravimetry, single-crystal and elemental analyses, and powder X-ray diffraction methods. Framework 1' exhibits high permanent porosity (Langmuir surface area = 848 m(2)/g), high thermal stability (up to 450 °C), highly active properties for Friedel-Crafts alkylation reaction, as well as the potential application for the CO(2) gas storage and luminescent material. The catalytic results reveal that 2' is indeed an efficient heterogeneous catalyst for olefin epoxidation reactions. PMID:22670898

  16. Experimental and theoretical investigations of the electronic band structure of metal-organic frameworks of HKUST-1 type

    NASA Astrophysics Data System (ADS)

    Gu, Zhi-Gang; Heinke, Lars; Wöll, Christof; Neumann, Tobias; Wenzel, Wolfgang; Li, Qiang; Fink, Karin; Gordan, Ovidiu D.; Zahn, Dietrich R. T.

    2015-11-01

    The electronic properties of metal-organic frameworks (MOFs) are increasingly attracting the attention due to potential applications in sensor techniques and (micro-) electronic engineering, for instance, as low-k-dielectric in semiconductor technology. Here, the band gap and the band structure of MOFs of type HKUST-1 are studied in detail by means of spectroscopic ellipsometry applied to thin surface-mounted MOF films and by means of quantum chemical calculations. The analysis of the density of states, the band structure, and the excitation spectrum reveal the importance of the empty Cu-3d orbitals for the electronic properties of HKUST-1. This study shows that, in contrast to common belief, even in the case of this fairly "simple" MOF, the excitation spectra cannot be explained by a superposition of "intra-unit" excitations within the individual building blocks. Instead, "inter-unit" excitations also have to be considered.

  17. Experimental and theoretical investigations of the electronic band structure of metal-organic frameworks of HKUST-1 type

    SciTech Connect

    Gu, Zhi-Gang; Heinke, Lars Wöll, Christof; Neumann, Tobias; Wenzel, Wolfgang; Li, Qiang; Fink, Karin; Gordan, Ovidiu D.; Zahn, Dietrich R. T.

    2015-11-02

    The electronic properties of metal-organic frameworks (MOFs) are increasingly attracting the attention due to potential applications in sensor techniques and (micro-) electronic engineering, for instance, as low-k-dielectric in semiconductor technology. Here, the band gap and the band structure of MOFs of type HKUST-1 are studied in detail by means of spectroscopic ellipsometry applied to thin surface-mounted MOF films and by means of quantum chemical calculations. The analysis of the density of states, the band structure, and the excitation spectrum reveal the importance of the empty Cu-3d orbitals for the electronic properties of HKUST-1. This study shows that, in contrast to common belief, even in the case of this fairly “simple” MOF, the excitation spectra cannot be explained by a superposition of “intra-unit” excitations within the individual building blocks. Instead, “inter-unit” excitations also have to be considered.

  18. Mesoporous Fluorinated Metal-Organic Frameworks with Exceptional Adsorption of Fluorocarbons and CFCs.

    PubMed

    Chen, Teng-Hao; Popov, Ilya; Kaveevivitchai, Watchareeya; Chuang, Yu-Chun; Chen, Yu-Sheng; Jacobson, Allan J; Miljanić, Ognjen Š

    2015-11-16

    Two mesoporous fluorinated metal-organic frameworks (MOFs) were synthesized from extensively fluorinated tritopic carboxylate- and tetrazolate-based ligands. The tetrazolate-based framework MOFF-5 has an accessible surface area of 2445 m(2) g(-1), the highest among fluorinated MOFs. Crystals of MOFF-5 adsorb hydrocarbons, fluorocarbons, and chlorofluorocarbons (CFCs)-the latter two being ozone-depleting substances and potent greenhouse species-with weight capacities of up to 225%. The material exhibits an apparent preference for the adsorption of non-spherical molecules, binding unusually low amounts of both tetrafluoromethane and sulfur hexafluoride. PMID:26423312

  19. Metal-organic frameworks for the storage and delivery of biologically active hydrogen sulfide

    SciTech Connect

    Allan, Phoebe K; Wheatley, Paul S; Aldous, David; Mohideen, M Infas; Tang, Chiu; Hriljac, Joseph A; Megson, Ian L; Chapman, Karena W; De Weireld, Guy; Vaesen, Sebastian; Morris, Russell E

    2012-04-02

    Hydrogen sulfide is an extremely toxic gas that is also of great interest for biological applications when delivered in the correct amount and at the desired rate. Here we show that the highly porous metal-organic frameworks with the CPO-27 structure can bind the hydrogen sulfide relatively strongly, allowing the storage of the gas for at least several months. Delivered gas is biologically active in preliminary vasodilation studies of porcine arteries, and the structure of the hydrogen sulfide molecules inside the framework has been elucidated using a combination of powder X-ray diffraction and pair distribution function analysis.

  20. Rationally designed micropores within a metal-organic framework for selective sorption of gas molecules.

    PubMed

    Chen, Banglin; Ma, Shengqian; Zapata, Fatima; Fronczek, Frank R; Lobkovsky, Emil B; Zhou, Hong-Cai

    2007-02-19

    A microporous metal-organic framework, MOF, Cu(FMA)(4,4'-Bpe)0.5 (3a, FMA = fumarate; 4,4'-Bpe = 4,4'-Bpe = trans-bis(4-pyridyl)ethylene) was rationally designed from a primitive cubic net whose pores are tuned by double framework interpenetration. With pore cavities of about 3.6 A, which are interconnected by pore windows of 2.0 x 3.2 A, 3a shows highly selective sorption behaviors of gas molecules. PMID:17291116

  1. Template-Free Synthesis of Hierarchical Porous Metal-Organic Frameworks

    SciTech Connect

    Yue, Yanfeng; Qiao, Zhen-an; Fulvio, Pasquale F; Dai, Sheng; Binder, Andrew J; Tian, Chengcheng; Nelson, Kimberly M; Zhu, Xiang

    2013-01-01

    A template-free synthesis of a hierarchical microporous-mesoporous metal-organic framework (MOF) of Zn(II)-2,5-dihydroxy-1,4-benzenedicarboxylate, namely Zn-MOF-74, is reported. The surface morphology and porosity of the bimodal materials can be modified by etching the pore walls with the synthesis solvent under different reaction times and different solvents. This template-free strategy allows for the preparation of stable frameworks with mesopores exceeding 15 nm, which was previously unattained by the synthesis of MOFs by ligand exten-sion method.

  2. Metal-Organic Framework Isomers with Diamondoid Networks Constructed of a Semi-Rigid Tetrahedral Linker

    SciTech Connect

    Tian, Jian; Motkuri, Radha K.; Thallapally, Praveen K.; McGrail, B. Peter

    2010-10-19

    Solvothermal assembly of a semi-rigid tetrahedral carboxylate ligand tetrakis[4-(carboxyphenyl)oxamethyl]methane acid (H4X) with Cd(II) ion in different solvent systems yields three novel metal-organic framework isomers (1-3) based on different secondary building units (SBUs). Although all three frameworks have the same dia (diamondoid) topology, complex 1 and 3 are chiral and complex 2 is achiral. One of the networks, 3 shows cross-linked three-fold interpenetration of the single dia net and exhibits permanent porosities, as confirmed by BET and selective CO2 adsorption.

  3. Ligand Functionalization in Metal-Organic Frameworks for Enhanced Carbon Dioxide Adsorption.

    PubMed

    Wang, Hao; Peng, Junjie; Li, Jing

    2016-06-01

    Ligand functionalization in metal-organic frameworks (MOFs) has been studied extensively and has been demonstrated to enhance gas adsorption and induce interesting gas adsorption phenomena. This account summarizes our recent study of three series of MOFs by ligand functionalization, as well as their carbon dioxide adsorption properties. While ligand functionalization does not change the overall structure of the frameworks, it can influence their gas adsorption behavior. In the first two series, we show how ligand functionalization influences the CO2 affinity and adsorption capacity of MOFs. We also show a special case in which subtle changes in ligand functionality alter the CO2 adsorption profile. PMID:27071491

  4. An all-atom force field developed for Zn₄O(RCO₂)₆ metal organic frameworks.

    PubMed

    Sun, Yingxin; Sun, Huai

    2014-03-01

    An all-atom force field is developed for metal organic frameworks Zn₄O(RCO₂)₆ by fitting to quantum mechanics data. Molecular simulations are conducted to validate the force field by calculating thermal expansion coefficients, crystal bulk and Young's moduli, power spectra, self-diffusion coefficients, and activation energies of self-diffusions for benzene and n-hexane. The calculated results are in good agreement with available experimental data. The proposed force field is suitable for simulations of adsorption or diffusion of organic molecules with flexible frameworks. PMID:24562858

  5. Computational studies of adsorption in metal organic frameworks and interaction of nanoparticles in condensed phases

    SciTech Connect

    Annapureddy, Harsha V.; Motkuri, Radha K.; Nguyen, Phuong T.; Truong, T. B.; Thallapally, Praveen K.; McGrail, B. Peter; Dang, Liem X.

    2014-01-08

    In this review, we describe recent efforts in which computer simulations were used to systematically study nano-structured metal organic frameworks, with particular emphasis on their application in heating and cooling processes. These materials also are known as metal organic heat carriers. We used both molecular dynamics and Grand Canonical Monte Carlo simulation techniques to gain a molecular-level understanding of the adsorption mechanism of gases in these porous materials. We investigated the uptake of various gases such as refrigerants R12 and R143a and also the elemental gases Xe and Rn by the metal organic framework (i.e., Ni2(dhtp)). We also evaluated the effects of temperature and pressure on the uptake mechanism. Our computed results compared reasonably well with available experimental measurements, thus validating our potential models and approaches. In addition, we also investigated the structural, diffusive, and adsorption properties of different hydrocarbons in Ni2(dhtp). To elucidate the mechanism of nanoparticle dispersion in condensed phases, we also studied the interactions among nanoparticles in various liquids, such as n-hexane, water and methanol. This work was performed at Pacific Northwest National Laboratory (PNNL) and was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy (DOE). PNNL is operated by Battelle for the DOE. The authors also gratefully acknowledge support received from the National Energy Technology Laboratory of DOE's Office of Fossil Energy.

  6. Barcoded materials based on photoluminescent hybrid system of lanthanide ions-doped metal organic framework and silica via ion exchange.

    PubMed

    Shen, Xiang; Yan, Bing

    2016-04-15

    A multicolored photoluminescent hybrid system based on lanthanide ions-doped metal organic frameworks/silica composite host has potential in display and barcode applications. By controlling the stoichiometry of the lanthanides via cation exchange, proportional various lanthanide ions are successfully introduced into metal organic frameworks, whose emission intensity is correspondingly proportional to its amount. The resulting luminescent barcodes depend on the lanthanide ions ratios and compositions. Subsequently, the lanthanide ions located in the channels of metal organic frameworks are protected from any interaction with the environment after the modification of silica on the surface. The optical and thermal stability of the hybrid materials are improved for technological application. PMID:26852345

  7. Computational studies of adsorption in metal organic frameworks and interaction of nanoparticles in condensed phases

    SciTech Connect

    Annapureddy, HVR; Motkuri, RK; Nguyen, PTM; Truong, TB; Thallapally, PK; McGrail, BP; Dang, LX

    2014-02-05

    In this review, we describe recent efforts to systematically study nano-structured metal organic frameworks (MOFs), also known as metal organic heat carriers, with particular emphasis on their application in heating and cooling processes. We used both molecular dynamics and grand canonical Monte Carlo simulation techniques to gain a molecular-level understanding of the adsorption mechanism of gases in these porous materials. We investigated the uptake of various gases such as refrigerants R12 and R143a. We also evaluated the effects of temperature and pressure on the uptake mechanism. Our computed results compared reasonably well with available measurements from experiments, thus validating our potential models and approaches. In addition, we investigated the structural, diffusive and adsorption properties of different hydrocarbons in Ni-2(dhtp). Finally, to elucidate the mechanism of nanoparticle dispersion in condensed phases, we studied the interactions among nanoparticles in various liquids, such as n-hexane, water and methanol.

  8. Doping of Metal-Organic Frameworks with Functional Guest Molecules and Nanoparticles

    NASA Astrophysics Data System (ADS)

    Schröder, Felicitas; Fischer, Roland A.

    Nanoparticle synthesis within metal-organic frameworks (MOFs) is performed by the adsorption of suitable precursor molecules for the metal component and subsequent decomposition to the composite materials nanoparticles@MOF. This chapter will review different approaches of loading MOFs with more complex organic molecules and metal-organic precursor molecules. The related reactions inside MOFs are discussed with a focus on stabilizing reactive intermediates in the corresponding cavities. The syntheses of metal and metal oxide nanoparticles inside MOFs are reviewed, and different synthetic routes compared. Emphasis is placed on the micro structural characterization of the materials nanoparticles@MOF with a particular focus on the location of embedded nanoparticles using TEM methods. Some first examples of applications of the doped MOFs in heterogeneous catalysis and hydrogen storage are described.

  9. Design and construction of porous metal-organic frameworks based on flexible BPH pillars

    SciTech Connect

    Hao, Xiang-Rong; Yang, Guang-sheng; Shao, Kui-Zhan; Su, Zhong-Min; Yuan, Gang; Wang, Xin-Long

    2013-02-15

    Three metal-organic frameworks (MOFs), [Co{sub 2}(BPDC){sub 2}(4-BPH){center_dot}3DMF]{sub n} (1), [Cd{sub 2}(BPDC){sub 2}(4-BPH){sub 2}{center_dot}2DMF]{sub n} (2) and [Ni{sub 2}(BDC){sub 2}(3-BPH){sub 2} (H{sub 2}O){center_dot}4DMF]{sub n} (3) (H{sub 2}BPDC=biphenyl-4,4 Prime -dicarboxylic acid, H{sub 2}BDC=terephthalic acid, BPH=bis(pyridinylethylidene)hydrazine and DMF=N,N Prime -dimethylformamide), have been solvothermally synthesized based on the insertion of heterogeneous BPH pillars. Framework 1 has 'single-pillared' MOF-5-like motif with inner cage diameters of up to 18.6 A. Framework 2 has 'double pillared' MOF-5-like motif with cage diameters of 19.2 A while 3 has 'double pillared' 8-connected framework with channel diameters of 11.0 A. Powder X-ray diffraction (PXRD) shows that 3 is a dynamic porous framework. - Graphical abstract: By insertion of flexible BPH pillars based on 'pillaring' strategy, three metal-organic frameworks are obtained showing that the porous frameworks can be constructed in a much greater variety. Highlights: Black-Right-Pointing-Pointer Frameworks 1 and 2 have MOF-5 like motif. Black-Right-Pointing-Pointer The cube-like cages in 1 and 2 are quite large, comparable to the IRMOF-10. Black-Right-Pointing-Pointer Framework 1 is 'single-pillared' mode while 2 is 'double-pillared' mode. Black-Right-Pointing-Pointer PXRD and gas adsorption analysis show that 3 is a dynamic porous framework.

  10. Five metal-organic frameworks from 3,4-dimethylphenyl substituted imidazole dicarboxylate: syntheses, structures and properties.

    PubMed

    Jia, Hongliang; Li, Yanlin; Xiong, Zhifang; Wang, Chengjie; Li, Gang

    2014-03-01

    Five metal-organic frameworks, namely, [Mn3(H2DMPhIDC)2(HDMPhIDC)2(bpp)]n (H3DMPhIDC = 2-(3,4-dimethylphenyl)-1H-imidazole-4,5-dicarboxylic acid, bpp = 1,3-di(4-pyridyl)propane) (), [Pb4(DMPhIDC)2(OH)2]n (), [Cd(HDMPhIDC)(en)]n (en = ethylenediamine) (), [Cu3(HDMPhIDC)3(Py)3]n (Py = pyridine) () and {[Zn2(HDMPhIDC)2(Phen)2]2·H2O}n (Phen = 1,10-phenanthroline) () have been hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental and thermal analyses and IR spectra. Polymer displays a 3D noninterpenetrated framework with 1D open channels. Polymer exhibits a stepped (4,4,4,4,6,6)-connect 2D topology. Polymer is a left-handed helix chain. Polymers and arrange the 3D supramolecular networks containing a 1D corrugated chain via ππ stacking or hydrogen bond interactions. In these MOFs, the imidazole dicarboxylate ligand shows various coordination modes and strong coordination ability. Furthermore, the solid-state luminescent properties of the polymers have also been discussed. PMID:24435588

  11. Stability and electronic properties of 3D covalent organic frameworks.

    PubMed

    Lukose, Binit; Kuc, Agnieszka; Heine, Thomas

    2013-05-01

    Covalent organic frameworks (COFs) are a class of covalently linked crystalline nanoporous materials, versatile for nanoelectronic and storage applications. 3D COFs, in particular, have very large pores and low mass densities. Extensive theoretical studies of their energetic and mechanical stability, as well as their electronic properties, have been carried out for all known 3D COFs. COFs are energetically stable and their bulk modulus ranges from 3 to 20 GPa. Electronically, all COFs are semiconductors with band gaps corresponding to the HOMO-LUMO gaps of the building units. PMID:23212235

  12. Synthesis, Structure Determination, and Hydrogen Sorption Studies of New Metal-Organic Frameworks Using Triazole and Naphthalenedicarboxylic Acid

    SciTech Connect

    Park,H.; Britten, J.; Mueller, U.; Lee, J.; Li, J.; Parise, J.

    2007-01-01

    Two new metal-organic framework compounds were synthesized under solvothermal conditions using Zn{sup 2+} ion, 1,2,4-triazole (TRZ), and 1,4- and 2,6-naphthalenedicarboxylic acids (NDC): Zn{sub 4}(TRZ){sub 4}(1,4-NDC){sub 2}-2DMF-2H{sub 2}O (1) and Zn{sub 4}(TRZ){sub 4}(2,6-NDC){sub 2}-2DMF-4H{sub 2}O (2). Their crystal structures were characterized by single-crystal X-ray diffraction. Structure 1 crystallizes in the P2{sub 1}/n space group with a = 13.609(2) {angstrom}, b = 27.181(5){angstrom}, c = 13.617(3) {angstrom}, {beta} = 92.46(1){sup o}, V = 5032.4(16) {angstrom}{sup 3}, and Z = 4. Structure 2 crystallizes in orthorhombic Pna2{sub 2} space group with a = 30.978(6) {angstrom}, b = 12.620(3) {angstrom}, c = 13.339(3) {angstrom}, V = 5215(2) {angstrom}{sup 3}, and Z = 4. Both structures are analogues of the previously reported Zn{sub 4}(TRZ){sub 4}(1,4-BDC){sub 2}-16H{sub 2}O where the layers of Zn-triazole moieties are pillared by aromatic dicarboxylates to create 3-D open frameworks. Nitrogen sorption studies revealed that these structures have Brunaer-Emmett-Teller (BET) surface areas of 362.1-584.1 m{sup 2}/g. Hydrogen sorption experiments showed they can store 0.84-1.09 wt % H{sub 2} at 77 K and 1 atm. Although they do not contain large pores or surface areas, they possess the hydrogen sorption capacities comparable to those of highly porous metal-organic frameworks.

  13. CFA-7: an interpenetrated metal-organic framework of the MFU-4 family.

    PubMed

    Schmieder, Phillip; Grzywa, Maciej; Denysenko, Dmytro; Hambach, Manuel; Volkmer, Dirk

    2015-08-01

    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). PMID:26103597

  14. Porous molybdenum carbide nano-octahedrons synthesized via confined carburization in metal-organic frameworks for efficient hydrogen production

    PubMed Central

    Wu, Hao Bin; Xia, Bao Yu; Yu, Le; Yu, Xin-Yao; Lou, Xiong Wen (David)

    2015-01-01

    Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and molybdenum-based polyoxometalates guest, mesoporous molybdenum carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts. PMID:25758159

  15. Porous molybdenum carbide nano-octahedrons synthesized via confined carburization in metal-organic frameworks for efficient hydrogen production

    NASA Astrophysics Data System (ADS)

    Wu, Hao Bin; Xia, Bao Yu; Yu, Le; Yu, Xin-Yao; Lou, Xiong Wen (David)

    2015-03-01

    Electrochemical water splitting has been considered as a promising approach to produce clean and sustainable hydrogen fuel. However, the lack of high-performance and low-cost electrocatalysts for hydrogen evolution reaction hinders the large-scale application. As a new class of porous materials with tunable structure and composition, metal-organic frameworks have been considered as promising candidates to synthesize various functional materials. Here we demonstrate a metal-organic frameworks-assisted strategy for synthesizing nanostructured transition metal carbides based on the confined carburization in metal-organic frameworks matrix. Starting from a compound consisting of copper-based metal-organic frameworks host and molybdenum-based polyoxometalates guest, mesoporous molybdenum carbide nano-octahedrons composed of ultrafine nanocrystallites are successfully prepared as a proof of concept, which exhibit remarkable electrocatalytic performance for hydrogen production from both acidic and basic solutions. The present study provides some guidelines for the design and synthesis of nanostructured electrocatalysts.

  16. Unique gas and hydrocarbon adsorption in a highly porous metal-organic framework made of extended aliphatic ligands.

    PubMed

    Li, Kunhao; Lee, Jeongyong; Olson, David H; Emge, Thomas J; Bi, Wenhua; Eibling, Matthew J; Li, Jing

    2008-12-14

    High and unique gas and hydrocarbon adsorption in a highly stable guest-free microporous metal-organic framework constructed on rigid aliphatic ligands, H(2)bodc and ted, is reported in this work. PMID:19082093

  17. The influence of the enantiomeric ratio of an organic ligand on the structure and chirality of Metal-Organic Frameworks

    PubMed Central

    Burneo, Iván; Stylianou, Kyriakos C.; Imaz, Inhar; Maspoch, Daniel

    2016-01-01

    We have prepared three distinct polyamino acid-based metal-organic frameworks (MOFs) with different chirality and porosity using the same chemistry, by simply modifying the enantiomeric ratio of the chiral organic ligand used. PMID:25253285

  18. Isoreticular zirconium-based metal-organic frameworks: discovering mechanical trends and elastic anomalies controlling chemical structure stability.

    PubMed

    Ryder, Matthew R; Civalleri, Bartolomeo; Tan, Jin-Chong

    2016-03-23

    Understanding the mechanical properties of metal-organic frameworks (MOFs) is crucial not only to yield robust practical applications, but also to advance fundamental research underpinning the flexibility of a myriad of open-framework chemical compounds. Herein we present one of the most comprehensive structural analyses yet on MOF-mechanics: elucidating the complex elastic response of an isoreticular series of topical Zr-based MOFs, explaining all the important mechanical properties, and identifying major trends arising from systematic organic linker exchange. Ab initio density functional theory (DFT) was employed to establish the single-crystal elastic constants of the nanoporous MIL-140(A-D) structures, generating a complete 3-D representation of the principal mechanical properties, encompassing the Young's modulus, shear modulus, linear compressibility and Poisson's ratio. Of particular interest, we discovered significantly high values of both positive and negative linear compressibility and Poisson's ratio, whose framework molecular mechanisms responsible for such elastic anomalies have been fully revealed. In addition to pinpointing large elastic anisotropy and unusual physical properties, we analyzed the bulk modulus of isoreticular Zr-MOF compounds to understand the framework structural resistance against the hydrostatic pressure, and determined the averaged mechanical behaviour of bulk (polycrystalline) MOF materials important for the design of emergent applications. PMID:26972778

  19. Efficient framework for deformable 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Fluck, Oliver; Aharon, Shmuel; Khamene, Ali

    2008-03-01

    Using 2D-3D registration it is possible to extract the body transformation between the coordinate systems of X-ray and volumetric CT images. Our initial motivation is the improvement of accuracy of external beam radiation therapy, an effective method for treating cancer, where CT data play a central role in radiation treatment planning. Rigid body transformation is used to compute the correct patient setup. The drawback of such approaches is that the rigidity assumption on the imaged object is not valid for most of the patient cases, mainly due to respiratory motion. In the present work, we address this limitation by proposing a flexible framework for deformable 2D-3D registration consisting of a learning phase incorporating 4D CT data sets and hardware accelerated free form DRR generation, 2D motion computation, and 2D-3D back projection.

  20. Exact matrix treatment of an osmotic ensemble model of adsorption and pressure induced structural transitions in metal organic frameworks.

    PubMed

    Dunne, Lawrence J; Manos, George

    2016-03-14

    Here we present an exactly treated quasi-one dimensional statistical mechanical osmotic ensemble model of pressure and adsorption induced breathing structural transformations of metal-organic frameworks (MOFs). The treatment uses a transfer matrix method. The model successfully reproduces the gas and pressure induced structural changes which are observed experimentally in MOFs. The model treatment presented here is a significant step towards analytical statistical mechanical treatments of flexible metal-organic frameworks. PMID:26514851

  1. Hybrid segmentation framework for 3D medical image analysis

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Metaxas, Dimitri N.

    2003-05-01

    Medical image segmentation is the process that defines the region of interest in the image volume. Classical segmentation methods such as region-based methods and boundary-based methods cannot make full use of the information provided by the image. In this paper we proposed a general hybrid framework for 3D medical image segmentation purposes. In our approach we combine the Gibbs Prior model, and the deformable model. First, Gibbs Prior models are applied onto each slice in a 3D medical image volume and the segmentation results are combined to a 3D binary masks of the object. Then we create a deformable mesh based on this 3D binary mask. The deformable model will be lead to the edge features in the volume with the help of image derived external forces. The deformable model segmentation result can be used to update the parameters for Gibbs Prior models. These methods will then work recursively to reach a global segmentation solution. The hybrid segmentation framework has been applied to images with the objective of lung, heart, colon, jaw, tumor, and brain. The experimental data includes MRI (T1, T2, PD), CT, X-ray, Ultra-Sound images. High quality results are achieved with relatively efficient time cost. We also did validation work using expert manual segmentation as the ground truth. The result shows that the hybrid segmentation may have further clinical use.

  2. A highly stable zeotype mesoporous zirconium metal-organic framework with ultralarge pores.

    SciTech Connect

    Feng, Dawei; Wang, Kecheng; Su, Jie; Liu, Tian-Fu; Park, Jihye; Wei, Zhangwen; Bosch, Mathieu; Yakovenko, Andrey; Zou, Xiaodong; Zhou, Hong-Cai

    2015-01-02

    Through topological rationalization, a zeotype mesoporous Zr-containing metal-organic framework (MOF), namely PCN-777, has been designed and synthesized. PCN-777 exhibits the largest cage size of 3.8nm and the highest pore volume of 2.8cm(3)g(-1) among reported Zr-MOFs. Moreover, PCN-777 shows excellent stability in aqueous environments, which makes it an ideal candidate as a support to incorporate different functional moieties. Through facile internal surface modification, the interaction between PCN-777 and different guests can be varied to realize efficient immobilization

  3. Highly porous metal-organic framework sustained with 12-connected nanoscopic octahedra.

    PubMed

    Lu, Weigang; Yuan, Daqiang; Makal, Trevor A; Wei, Zhangwen; Li, Jian-Rong; Zhou, Hong-Cai

    2013-02-01

    Two dicopper(II)-paddlewheel-based metal-organic frameworks (PCN-81 and -82) have been synthesized by using tetratopic ligands featuring 90°-carbazole-dicarboxylate moieties. Both adopt 12-connected tfb topology with nanoscopic octahedra as building units. The freeze-dried PCN-82 shows Brunauer-Emmett-Teller (BET) and Langmuir surface areas as high as 4488 and 4859 m(2) g(-1), respectively. It also exhibits high H(2)-adsorption capacity at low pressure (300 cm(3) g(-1) or 2.6 wt% at 77 K and 1 bar), which can be attributed to its high surface area, microporosity, and open metal sites. PMID:23160711

  4. Metal-organic framework with rationally tuned micropores for selective adsorption of water over methanol.

    PubMed

    Chen, Banglin; Ji, Yanyan; Xue, Ming; Fronczek, Frank R; Hurtado, Eric J; Mondal, Jalal U; Liang, Chengdu; Dai, Sheng

    2008-07-01

    A microporous metal-organic framework 1, Cu(R-GLA-Me)(4,4'-Bipy) 0.5.0.55H 2O (R-GLA-Me = R-2-methylglutarate, 4,4'-Bipy = 4,4'-bipyridine), with a primitive cubic net was synthesized and characterized. With pores of about 2.8 x 3.6 A, the activated 1a exhibits exclusive adsorption of water over methanol in a binary water-methanol (1:1) liquid mixture. PMID:18512902

  5. A triply interpenetrated microporous metal-organic framework for selective sorption of gas molecules.

    PubMed

    Chen, Banglin; Ma, Shengqian; Hurtado, Eric J; Lobkovsky, Emil B; Zhou, Hong-Cai

    2007-10-15

    A microporous metal-organic framework Zn(ADC)(4,4'-Bpe)(0.5).xG [1; ADC = 4,4'-azobenzenedicarboxylate, 4,4'-Bpe = trans-bis(4-pyridyl)ethylene, G = guest molecules] with a triply interpenetrative primitive cubic net was synthesized and characterized. With pores of about 3.4 x 3.4 A, the activated 1a exhibits highly selective sorption behavior toward H(2)/N(2), H(2)/CO, and CO(2)/CH(4). PMID:17854181

  6. Alcohol-Mediated Resistance-Switching Behavior in Metal-Organic Framework-Based Electronic Devices.

    PubMed

    Liu, Yaqing; Wang, Hong; Shi, Wenxiong; Zhang, Weina; Yu, Jiancan; Chandran, Bevita K; Cui, Chenlong; Zhu, Bowen; Liu, Zhiyuan; Li, Bin; Xu, Cai; Xu, Zhiling; Li, Shuzhou; Huang, Wei; Huo, Fengwei; Chen, Xiaodong

    2016-07-25

    Metal-organic frameworks (MOFs) have drawn increasing attentions as promising candidates for functional devices. Herein, we present MOF films in constructing memory devices with alcohol mediated resistance switching property, where the resistance state is controlled by applying alcohol vapors to achieve multilevel information storage. The ordered packing mode and the hydrogen bonding system of the guest molecules adsorbed in MOF crystals are shown to be the reason for the alcohol mediated electrical switching. This chemically mediated memory device can be a candidate in achieving environment-responsive devices and exhibits potential applications in wearable information storage systems. PMID:27311703

  7. Effective Detection of Mycotoxins by a Highly Luminescent Metal-Organic Framework.

    PubMed

    Hu, Zhichao; Lustig, William P; Zhang, Jingming; Zheng, Chong; Wang, Hao; Teat, Simon J; Gong, Qihan; Rudd, Nathan D; Li, Jing

    2015-12-30

    We designed and synthesized a new luminescent metal-organic framework (LMOF). LMOF-241 is highly porous and emits strong blue light with high efficiency. We demonstrate for the first time that very fast and extremely sensitive optical detection can be achieved, making use of the fluorescence quenching of an LMOF material. The compound is responsive to Aflatoxin B1 at parts per billion level, which makes it the best performing luminescence-based chemical sensor to date. We studied the electronic properties of LMOF-241 and selected mycotoxins, as well as the extent of mycotoxin-LMOF interactions, employing theoretical methods. Possible electron and energy transfer mechanisms are discussed. PMID:26654703

  8. Switching Kr/Xe Selectivity with Temperature in a Metal-Organic Framework

    SciTech Connect

    Fernandez, Carlos A.; Liu, Jian; Thallapally, Praveen K.; Strachan, Denis M.

    2012-05-16

    Krypton (Kr) and xenon (Xe) adsorption on two partially fluorinated metal-organic frameworks (FMOFCu and FMOFZn) with different cavity size and topologies were reported. FMOFCu shows an inversion in sorption selectivity toward Kr at temperatures below 0 C while FMOFZn does not. The 1D microtubes packed along the (101) direction connected through small bottleneck windows in FMOFCu appear to be the reason for this peculiar behavior. The FMOFCu shows an estimated Kr/Xe selectivity of 36 at 0.1 bar.

  9. Metal-Organic Frameworks for Removal of Xe and Kr from Nuclear Fuel Reprocessing Plants

    SciTech Connect

    Liu, Jian; Thallapally, Praveen K.; Strachan, Denis M.

    2012-08-07

    Removal of Xenon (Xe) and Krypton (Kr) from in parts per million (ppm) levels were demonstrated for the first time using two well known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC. Results of an activated carbon were also included for comparison. Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon. Moreover, results show that the Ni/DOBDC and HKUST-1 can selectively adsorb Xe and Kr from air even at 1000 ppm concentration. This shows a promising future for MOFs in a radioactive nuclides separation from spent fuel.

  10. Versatile, High Quality and Scalable Continuous Flow Production of Metal-Organic Frameworks

    PubMed Central

    Rubio-Martinez, Marta; Batten, Michael P.; Polyzos, Anastasios; Carey, Keri-Constanti; Mardel, James I.; Lim, Kok-Seng; Hill, Matthew R.

    2014-01-01

    Further deployment of Metal-Organic Frameworks in applied settings requires their ready preparation at scale. Expansion of typical batch processes can lead to unsuccessful or low quality synthesis for some systems. Here we report how continuous flow chemistry can be adapted as a versatile route to a range of MOFs, by emulating conditions of lab-scale batch synthesis. This delivers ready synthesis of three different MOFs, with surface areas that closely match theoretical maxima, with production rates of 60 g/h at extremely high space-time yields. PMID:24962145

  11. Photocatalytic CO2 reduction in metal-organic frameworks: A mini review

    NASA Astrophysics Data System (ADS)

    Wang, Chong-Chen; Zhang, Yan-Qiu; Li, Jin; Wang, Peng

    2015-03-01

    Photocatalytic reduction of CO2 for value-added chemicals is an attractive process to address both energy and environmental issues. This mini review paper presents two different conversion processes, namely conversion to organic chemicals (like CH4, CH3OH, HCOOH and so on) and being split into CO, in metal-organic frameworks (MOFs). The reported examples are collected and analyzed; and the reaction mechanism, the influence of various factors on the photocatalytic performance, the involved challenges, and the prospects are discussed and estimated. It is clear that MOFs have a bright prospect in the field of photocatalytic reduction of CO2.

  12. A Zn Metal-Organic Framework with High Stability and Sorption Selectivity for CO2.

    PubMed

    Wang, Rongming; Liu, Xiaobin; Qi, Dongdong; Xu, Yuwen; Zhang, Liangliang; Liu, Xiaoqing; Jiang, Jianzhuang; Dai, Fangna; Xiao, Xin; Sun, Daofeng

    2015-11-16

    A three-dimensional porous Zn metal-organic framework (UPC-12) with high thermal and chemical stability was isolated in high yield and purity from a hydrothermal reaction. UPC-12 exhibits high selectivity for CO2 due to the formation of hydrogen bonds between CO2 molecules and the -COOH groups exposed inside the channels and the effective π-π interactions between CO2 molecules and the pillared bipyridine moieties of the MOF. The adsorption-desorption process was studied, for the first time, by both (13)C CP-TOSS NMR spectroscopy and in situ DRIFTS. PMID:26503174

  13. Metal-organic framework biosensor with high stability and selectivity in a bio-mimic environment.

    PubMed

    Wu, Xiao-Qin; Ma, Jian-Gong; Li, Han; Chen, Di-Ming; Gu, Wen; Yang, Guang-Ming; Cheng, Peng

    2015-06-01

    A water-stable copper metal-organic framework (MOF), {[Cu2(HL)2(μ2-OH)2(H2O)5]·H2O}n (1, H2L = 2,5-dicarboxylic acid-3,4-ethylene dioxythiophene), was applied for the electrochemical detection of ascorbic acid (AA) without further post-modification. A glass carbon electrode covered with 1 was used as a biosensor for the simultaneous detection of AA and L-tryptophan (L-Trp) from both a single-component solution and a bio-mimic environment. PMID:25947336

  14. Diffusion of acetylene inside the Cu-BTC metal organic framework

    NASA Astrophysics Data System (ADS)

    Prabhudesai, S. A.; Sharma, V. K.; Mitra, S.; Mukhopadhyay, R.

    2012-06-01

    Dynamic of acetylene molecule adsorbed in Copper 1, 3, 5-benzenetricarboxylate metal-organic framework as studied using molecular dynamics simulation technique is reported here. The results showed that the translational motion of the guest molecule exist in two different time scales; faster one behave as free particle and other one is found to follow jump diffusion. Rotational motion of acetylene is found to be an order of magnitude faster than translational motion. Intermediate scattering functions corresponding to rotational motion show an unusual dip, which is described by the m-diffusion model.

  15. Transparent Metal-Organic Framework/Polymer Mixed Matrix Membranes as Water Vapor Barriers.

    PubMed

    Bae, Youn Jue; Cho, Eun Seon; Qiu, Fen; Sun, Daniel T; Williams, Teresa E; Urban, Jeffrey J; Queen, Wendy L

    2016-04-27

    Preventing the permeation of reactive molecules into electronic devices or photovoltaic modules is of great importance to ensure their life span and reliability. This work is focused on the formation of highly functioning barrier films based on nanocrystals (NCs) of a water-scavenging metal-organic framework (MOF) and a hydrophobic cyclic olefin copolymer (COC) to overcome the current limitations. Water vapor transmission rates (WVTR) of the films reveal a 10-fold enhancement in the WVTR compared to the substrate while maintaining outstanding transparency over most of the visible and solar spectrum, a necessary condition for integration with optoelectronic devices. PMID:27071544

  16. Recent advances in porous polyoxometalate-based metal-organic framework materials.

    PubMed

    Du, Dong-Ying; Qin, Jun-Sheng; Li, Shun-Li; Su, Zhong-Min; Lan, Ya-Qian

    2014-07-01

    Polyoxometalate (POM)-based metal-organic framework (MOF) materials contain POM units and generally generate MOF materials with open networks. POM-based MOF materials, which utilize the advantages of both POMs and MOFs, have received increasing attention, and much effort has been devoted to their preparation and relevant applications over the past few decades. They have good prospects in catalysis owing to the electronic and physical properties of POMs that are tunable by varying constituent elements. In this review, we present recent developments in porous POM-based MOF materials, including their classification, synthesis strategies, and applications, especially in the field of catalysis. PMID:24676127

  17. A porphyrin-based metal-organic framework as a pH-responsive drug carrier

    NASA Astrophysics Data System (ADS)

    Lin, Wenxin; Hu, Quan; Jiang, Ke; Yang, Yanyu; Yang, Yu; Cui, Yuanjing; Qian, Guodong

    2016-05-01

    A low cytotoxic porphyrin-based metal-organic framework (MOF) PCN-221, which exhibited high PC12 cell viability via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay, was selected as an oral drug carrier. Methotrexate (MTX) was chosen as the model drug molecule which was absorbed into inner pores and channels of MOFs by diffusion. PCN-221 showed high drug loading and sustained release behavior under physiological environment without "burst effect". The controlled pH-responsive release of drugs by PCN-221 revealed its promising application in oral drug delivery.

  18. Efficient photocatalytic degradation of rhodamine 6G with a quantum dot-metal organic framework nanocomposite.

    PubMed

    Kaur, Rajnish; Vellingiri, Kowsalya; Kim, Ki-Hyun; Paul, A K; Deep, Akash

    2016-07-01

    The hybrid structures of metal organic frameworks (MOFs) and nanoparticles may offer the realization of effective photocatalytic materials due to combined benefits of the porous and molecular sieving properties of MOF matrix and the functional characteristics of encapsulated nanoparticles. In this study, cadmium telluride (CdTe) quantum dots (QD) are conjugated with a europium-MOF for the synthesis of a novel nanocomposite material with photocatalytic properties. Successful synthesis of a QD/Eu-MOF nanocomposite was characterized with various spectroscopic and microscopic techniques. This QD/Eu-MOF is found to be an effective catalyst to complete the degradation of Rhodamine 6G dye within 50 min. PMID:27101017

  19. Evaluation of Metal-Organic Frameworks and Porous Polymer Networks for CO2 -Capture Applications.

    PubMed

    Verdegaal, Wolfgang M; Wang, Kecheng; Sculley, Julian P; Wriedt, Mario; Zhou, Hong-Cai

    2016-03-21

    This manuscript presents experimental data for 20 adsorption materials (metal-organic frameworks, porous polymer networks, and Zeolite-5A), including CO2 and N2 isotherms and heat capacities. With input from only experimental data, working capacities per energy for each material were calculated. Furthermore, by running seven different carbon-capture scenarios in which the initial flue-gas composition and process temperature was systematically changed, we present a range of performances for each material and quantify how sensitive each is to these varying parameters. The presented calculations provide researchers with a tool to investigate promising carbon-capture materials more easily and completely. PMID:26840979

  20. Carbon dioxide capturing technologies: a review focusing on metal organic framework materials (MOFs).

    PubMed

    Sabouni, Rana; Kazemian, Hossein; Rohani, Sohrab

    2014-04-01

    In this study, a relevant literature has been reviewed focusing on the carbon dioxide capture technologies in general, such as amine-based absorption as conventional carbon dioxide capturing technology, aqueous ammonia-based absorption, membranes, and adsorption material (e.g., zeolites, and activated carbons). In more details, metal organic frameworks (MOFs) as new emerging technologies for carbon dioxide adsorption are discussed. The MOFs section is intended to provide a comprehensive overview of MOFs including material characteristics and synthesis, structural features, CO2 adsorption capacity, heat of adsorption and selectivity of CO2. PMID:24338107

  1. Review of Molecular Simulations of Methane Storage in Metal-Organic Frameworks.

    PubMed

    Lee, Seung-Joon; Bae, Youn-Sang

    2016-05-01

    Methane storage in porous materials is one of the hot issues because it can replace dangerous high-pressure compressed natural gas (CNG) tanks in natural gas vehicles. Among the diverse adsorbents, metal-organic frameworks (MOFs) are considered to be promising due to their extremely high surface areas and low crystal densities. Molecular simulation has been considered as an important tool for finding an appropriate MOF for methane storage. We review several important roles of molecular modeling for the studies of methane adsorption in MOFs. PMID:27483748

  2. Mechanical properties of metal-organic frameworks: An indentation study on epitaxial thin films

    NASA Astrophysics Data System (ADS)

    Bundschuh, S.; Kraft, O.; Arslan, H. K.; Gliemann, H.; Weidler, P. G.; Wöll, C.

    2012-09-01

    We have determined the hardness and Young's modulus of a highly porous metal-organic framework (MOF) using a standard nanoindentation technique. Despite the very low density of these films, 1.22 g cm-3, Young's modulus reaches values of almost 10 GPa for HKUST-1, demonstrating that this porous coordination polymer is substantially stiffer than normal polymers. This progress in characterizing mechanical properties of MOFs has been made possible by the use of high quality, oriented thin films grown using liquid phase epitaxy on modified Au substrates.

  3. Metal-organic framework derived hollow polyhedron metal oxide posited graphene oxide for energy storage applications.

    PubMed

    Ramaraju, Bendi; Li, Cheng-Hung; Prakash, Sengodu; Chen, Chia-Chun

    2016-01-18

    A composite made from hollow polyhedron copper oxide and graphene oxide was synthesized by sintering a Cu-based metal-organic framework (Cu-MOF) embedded with exfoliated graphene oxide. As a proof-of-concept application, the obtained Cu(ox)-rGO materials were used in a lithium-ion battery and a sodium-ion battery as anode materials. Overall, the Cu(ox)-rGO composite delivers excellent electrochemical properties with stable cycling when compared to pure CuO-rGO and Cu-MOF. PMID:26587567

  4. Synthesis and characterization of two dimensional metal organic framework of cerium with tetraaza macrocyclic

    SciTech Connect

    Bt Safiin, Nurul Atikah; Yarmo, Ambar; Yamin, Bohari M.

    2013-11-27

    A two dimensional metal organic framework containing cerium sufate layers and ethylenediaminium between layers was obtained by refluxing the mixture of cerium sulphate and 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-7, 14-diene bromide. The complex was characterized by infrared spectroscopy and microelemental analysis. X-ray study showed that the complex adopts eleven coordination environments about the central atom. Thermogravimetric study showed the removal of water molecules at about 70°C followed by a gradual mass loss until the whole structure collapsed at about 400°C.

  5. Unprecedented selectivity in molecular recognition of carbohydrates by a metal-organic framework.

    PubMed

    Yabushita, Mizuho; Li, Peng; Bernales, Varinia; Kobayashi, Hirokazu; Fukuoka, Atsushi; Gagliardi, Laura; Farha, Omar K; Katz, Alexander

    2016-06-01

    Metal-organic framework (MOF) material NU-1000 adsorbs dimers cellobiose and lactose from aqueous solution, in amounts exceeding 1250 mg gNU-1000(-1) while completely excluding the adsorption of the monomer glucose, even in a competitive mode with cellobiose. The MOF also discriminates between dimers consisting of α and β linkages, showing no adsorption of maltose. Electronic structure calculations demonstrate that key to this selective molecular recognition is the number of favorable CH-π interactions made by the sugar with pyrene units of the MOF. PMID:27184781

  6. Metal-organic frameworks constructed from crown ether-based 1,4-benzenedicarboxylic acid derivatives.

    PubMed

    Chen, Teng-Hao; Schneemann, Andreas; Fischer, Roland A; Cohen, Seth M

    2016-02-21

    A series of unprecedented crown ether- and thiacrown ether-derivatized benzene dicarboxylic acid (H2bdc) ligands has been synthesized and incorporated into the prototypical isoreticular metal-organic framework (IRMOF) and UiO-66 materials. In the case of UiO-66, only MOFs comprised from a mixed-ligand composition, requiring both unsubstituted bdc and crown ether containing ligands, could be prepared. These are among the few ligand derivatives, and resulting MOFs, that incorporate a macrocyclic group directly on the bdc ligand, providing a new, modular platform for exploring new supramolecular and coordination chemistry within MOFs. PMID:26765588

  7. Electrochemically addressable trisradical rotaxanes organized within a metal-organic framework.

    PubMed

    McGonigal, Paul R; Deria, Pravas; Hod, Idan; Moghadam, Peyman Z; Avestro, Alyssa-Jennifer; Horwitz, Noah E; Gibbs-Hall, Ian C; Blackburn, Anthea K; Chen, Dongyang; Botros, Youssry Y; Wasielewski, Michael R; Snurr, Randall Q; Hupp, Joseph T; Farha, Omar K; Stoddart, J Fraser

    2015-09-01

    The organization of trisradical rotaxanes within the channels of a Zr6-based metal-organic framework (NU-1000) has been achieved postsynthetically by solvent-assisted ligand incorporation. Robust Zr(IV)-carboxylate bonds are forged between the Zr clusters of NU-1000 and carboxylic acid groups of rotaxane precursors (semirotaxanes) as part of this building block replacement strategy. Ultraviolet-visible-near-infrared (UV-Vis-NIR), electron paramagnetic resonance (EPR), and 1H nuclear magnetic resonance (NMR) spectroscopies all confirm the capture of redox-active rotaxanes within the mesoscale hexagonal channels of NU-1000. Cyclic voltammetry measurements performed on electroactive thin films of the resulting material indicate that redox-active viologen subunits located on the rotaxane components can be accessed electrochemically in the solid state. In contradistinction to previous methods, this strategy for the incorporation of mechanically interlocked molecules within porous materials circumvents the need for de novo synthesis of a metal-organic framework, making it a particularly convenient approach for the design and creation of solid-state molecular switches and machines. The results presented here provide proof-of-concept for the application of postsynthetic transformations in the integration of dynamic molecular machines with robust porous frameworks. PMID:26283386

  8. Engineering chiral porous metal-organic frameworks for enantioselective adsorption and separation.

    PubMed

    Peng, Yongwu; Gong, Tengfei; Zhang, Kang; Lin, Xiaochao; Liu, Yan; Jiang, Jianwen; Cui, Yong

    2014-01-01

    The separation of racemic molecules is of substantial significance not only for basic science but also for technical applications, such as fine chemicals and drug development. Here we report two isostructural chiral metal-organic frameworks decorated with chiral dihydroxy or -methoxy auxiliares from enantiopure tetracarboxylate-bridging ligands of 1,1'-biphenol and a manganese carboxylate chain. The framework bearing dihydroxy groups functions as a solid-state host capable of adsorbing and separating mixtures of a range of chiral aromatic and aliphatic amines, with high enantioselectivity. The host material can be readily recycled and reused without any apparent loss of performance. The utility of the present adsorption separation is demonstrated in the large-scale resolution of racemic 1-phenylethylamine. Control experiments and molecular simulations suggest that the chiral recognition and separation are attributed to the different orientations and specific binding energies of the enantiomers in the microenvironment of the framework. PMID:25030529

  9. Engineering chiral porous metal-organic frameworks for enantioselective adsorption and separation

    NASA Astrophysics Data System (ADS)

    Peng, Yongwu; Gong, Tengfei; Zhang, Kang; Lin, Xiaochao; Liu, Yan; Jiang, Jianwen; Cui, Yong

    2014-07-01

    The separation of racemic molecules is of substantial significance not only for basic science but also for technical applications, such as fine chemicals and drug development. Here we report two isostructural chiral metal-organic frameworks decorated with chiral dihydroxy or -methoxy auxiliares from enantiopure tetracarboxylate-bridging ligands of 1,1‧-biphenol and a manganese carboxylate chain. The framework bearing dihydroxy groups functions as a solid-state host capable of adsorbing and separating mixtures of a range of chiral aromatic and aliphatic amines, with high enantioselectivity. The host material can be readily recycled and reused without any apparent loss of performance. The utility of the present adsorption separation is demonstrated in the large-scale resolution of racemic 1-phenylethylamine. Control experiments and molecular simulations suggest that the chiral recognition and separation are attributed to the different orientations and specific binding energies of the enantiomers in the microenvironment of the framework.

  10. A homochiral metal-organic framework as an effective asymmetric catalyst for cyanohydrin synthesis.

    PubMed

    Mo, Ke; Yang, Yuhua; Cui, Yong

    2014-02-01

    A homochiral metal-organic framework (MOF) of an enantiopure 2,2'-dihydroxy-1,1'-biphenyl ligand was constructed. After exchanging one proton of the dihydroxyl group for Li(I) ions, the framework is shown to be a highly efficient and recyclable heterogeneous catalyst for asymmetric cyanation of aldehydes with up to >99% ee. Compared with the homogeneous counterpart, the MOF catalyst exhibits significantly enhanced catalytic activity and enantioselectivity, especially at a low catalyst/substrate ratio, due to that the rigid framework could stabilize the catalytically active monolithium salt of biphenol against its free transformation to catalytically inactive and/or less active assemblies in reactions. The synthetic utility of the cyanation was demonstrated in the synthesis of (S)-bufuralol (a nonselective β-adrenoceptor blocking agent) with 98% ee. PMID:24447241

  11. Little Thermodynamic Penalty for the Synthesis of Ultraporous Metal Organic Frameworks.

    PubMed

    Akimbekov, Zamirbek; Navrotsky, Alexandra

    2016-02-16

    Many metal-organic frameworks (MOFs) of ultrahigh porosity (with molar volumes more than ten times greater than those of the corresponding dense phases) have been synthesized. However, the number of possible structures far exceeds those that have been made. It is logical to ask if there are energetic barriers to the stability of ultraporous MOFs or whether there is little thermodynamic penalty to their formation. Herein, we show that although the molar volumes of MOF-177 and UMCM-1 reach ultrahigh values, their energetic metastability is in the same range (of 7-36 kJ mol(-1)) as that seen previously for other porous materials. These findings suggest that there is little thermodynamic penalty for the synthesis of structures with varying porosity, and hence, ultraporous frameworks are energetically accessible. Therefore, innovative synthesis methods have the possibility to overcome the drawbacks of conventional approaches and greatly extend the number, porosity, and properties of new framework materials. PMID:26670808

  12. Water adsorption and proton conduction in metal-organic frameworks: Insights from molecular simulations

    NASA Astrophysics Data System (ADS)

    Paesani, Francesco

    2014-03-01

    Metal-organic frameworks (MOFs) are a relatively new class of porous materials that hold great potential for a wide range of applications in chemistry, materials science, and nanoengineering. Compared to other porous materials such as zeolites, MOF properties are highly tunable. In particular, it has been shown that both size and shape of the MOF pores can be rationally designed for specific applications. For example, the ability to modify the framework properties with respect to hydrophilicity/hydrophobicity and acidity/basicity can enable the direct control of proton conduction through carrier molecules adsorbed inside the pores. Here, I report on our current efforts aimed at providing a molecular-level characterization of water-mediated proton conduction through the MOF pores. Particular emphasis will be put on correlation between proton conduction and both structural and chemical properties of the frameworks as well as on the dynamical behavior of water confined in the MOF pores. NSF award number: DMR-130510

  13. Transformation of metal-organic framework to polymer gel by cross-linking the organic ligands preorganized in metal-organic framework.

    PubMed

    Ishiwata, Takumi; Furukawa, Yuki; Sugikawa, Kouta; Kokado, Kenta; Sada, Kazuki

    2013-04-10

    Until now, seamless fusion of metal-organic frameworks (MOFs) and covalently cross-linked polymer gels (PG) at molecular level has been extremely rare, since these two matters have been regarded as opposite, that is, hard versus soft. In this report, we demonstrate transformation of cubic MOF crystals to PG via inner cross-linking of the organic linkers in the void space of MOF, followed by decomposition of the metal coordination. The obtained PG behaved as a polyelectrolyte gel, indicating the high content of ionic groups inside. Metal ions were well adsorbed in the PG due to its densely packed carboxylate groups. A chimera-type hybrid material consisting of MOF and PG was obtained by partial hydrolysis of resulting cross-linked MOF. The shape of resulting PG network well reflected the crystal structure of MOF employed as a template. Our results will connect the two different network materials that have been ever studied in the two different fields to provide new soft and hard hybrid materials, and the unique copolymerization in the large void space of the MOF will open a new horizon toward "ideal network polymers" never prepared before now. PMID:23472763

  14. Facile method to disperse nonporous metal organic frameworks: composite formation with a porous metal organic framework and application in adsorptive desulfurization.

    PubMed

    Hasan, Zubair; Jhung, Sung Hwa

    2015-05-20

    It is generally not easy to utilize nonporous metal organic frameworks (MOFs) with a large crystal size (especially for catalysis or adsorption) because their surface area is low and the majority of the active sites exist inside the MOFs. Composing with porous materials may be one way to disperse the nonporous materials. In this study, a nonporous/nonsoluble MOF (in which the particle size was much larger than the cavity size of the porous MOFs) containing Cu(I) ((Cu2(pyz)2(SO4)(H2O)2)n, denoted as CP) was composed with typical porous MOFs such as MIL100(Fe) (iron-benzenetricarboxylate) and CuBTC (cupper-benzenetricarboxylate). The Cu(I) species of the nonporous MOF was effectively utilized for the adsorptive desulfurization (ADS) of model fuel. Even though the porosities of the composed MOFs decreased as the content of CP increased, the adsorption capacity increased as the content of CP increased (up to a certain content). Considering the negligible capacity of CP for ADS, the enhanced adsorption capacity may be a result of the well-dispersed Cu(I), which is known to be beneficial for ADS via π-complexation. The dispersed CP was also observed by transmission electron microscopy mapping. Therefore, composing a nonporous MOF with porous MOF is a new and facile way to disperse/utilize the active sites of a nonporous MOF. PMID:25912936

  15. Metal organic framework derived magnetically separable 3-dimensional hierarchical Ni@C nanocomposites: Synthesis and adsorption properties

    NASA Astrophysics Data System (ADS)

    Song, Yixuan; Qiang, Tingting; Ye, Ming; Ma, Qiuyang; Fang, Zhen

    2015-12-01

    Design an effective absorbent that has high surface area, and perfect recyclable is imperative for pollution elimination. Herein, we report a facile two-step strategy to fabricate magnetically separable 3-dimensional (3D) hierarchical carbon-coated nickel (Ni@C) nanocomposites by calcinating nickel based metal organic framework (Ni3(OH)2(C8H4O4)2(H2O)4). SEM and TEM images illuminate that the nanocomposites were constructed by 8 nm nickel nanoparticle encapsulated in 3D flake like carbon. The specific surface area of the obtained nanocomposites is up to 120.38 m2 g-1. Room temperature magnetic measurement indicates the nanocomposites show soft magnetism property, which endows the nanocomposites with an ideal fast magnetic separable property. The maximum adsorption capacity of the nanocomposites for rhodamine B is 84.5 mg g-1. Furthermore, the nanocomposites also exhibit a high adsorption capacity for heavy metal ions. The adsorbent can be very easily separated from the solution by using a common magnet without exterior energy. The as-prepared Ni@C nanocomposites can apply in waste water treatment on a large-scale as a new adsorbent with high efficiency and excellent recyclability.

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

    PubMed

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

    2016-08-26

    A new lanthanide metal-organic frameworks NKU-1 have successfully incorporated into poly (BMA-co-EDMA) monolith and evaluated by capillary electrochromatography (CEC). Lanthanide metal-organic frameworks [Eu2(ABTC)1.5(H2O)3(DMA)] (NKU-1) were synthesized by self-assembly of Eu(III) ions and 3,3',5,5'-azo benzene tetracarboxylic acid ligands have been fabricated into poly(BMA-co-EDMA) monoliths. 1-Butyl-3-methylimidazolium tetrafluoroborate and N,N-dimethylformamide were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column. The successful incorporation of NKU-1 into poly(BMA-co-EDMA) was confirmed and characterized by FT-IR spectra, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer area scanning, and transmission electron microscopy. Separation ability of the NKU-1-poly (BMA-co-EDMA) monoliths was demonstrated by separating four groups of analytes in CEC, including alkylbenzenes, polycyclic aromatic hydrocarbon, aniline series and naphthyl substitutes. Compared with bare monolithic (column efficiency of 100,000plates/m), the NKU-1-poly (BMA-co-EDMA) monoliths have displayed greater column efficiency (maximum 210,000plates/m) and higher permeability, as well as less peak tailing. The results showed that the NKU-1-poly (BMA-co-EDMA) monoliths are promising stationary phases for CEC separations. PMID:27432788

  17. Adsorption of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates

    SciTech Connect

    Ma Fengji; Liu Shuxia; Liang Dadong; Ren Guojian; Wei Feng; Chen Yaguang; Su Zhongmin

    2011-11-15

    The functionalization of porous metal-organic frameworks (Cu{sub 3}(BTC){sub 2}) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N{sub 2} and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius-Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs. - Graphical Abstract: The adsorption behavior of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates has been systematically evaluated. Highlights: > Functionalization of MOFs was achieved by incorporating Keggin-type POMs. > Introduction of POMs improved the thermal stability and adsorption capacity. > Alkali metal ion-exchange modified the inclusion state and also enhanced the adsorption. > Adsorption enthalpies were estimated to study the impact of POMs and alkali metal cations.

  18. Isolation of Renewable Phenolics by Adsorption on Ultrastable Hydrophobic MIL-140 Metal-Organic Frameworks.

    PubMed

    Van de Voorde, Ben; Damasceno Borges, Daiane; Vermoortele, Frederik; Wouters, Robin; Bozbiyik, Belgin; Denayer, Joeri; Taulelle, Francis; Martineau, Charlotte; Serre, Christian; Maurin, Guillaume; De Vos, Dirk

    2015-09-21

    The isolation and separation of phenolic compounds from aqueous backgrounds is challenging and will gain in importance as we become more dependent on phenolics from lignocellulose-derived bio-oil to meet our needs for aromatic compounds. Herein, we show that highly stable and hydrophobic Zr metal-organic frameworks of the MIL-140 type are effective adsorbent materials for the separation of different phenolics and far outperform other classes of porous solids (silica, zeolites, carbons). The mechanism of the hydroquinone-catechol separation on MIL-140C was studied in detail by combining experimental results with computational techniques. Although the differences in adsorption enthalpy between catechol and hydroquinone are negligible, the selective uptake of catechol in MIL-140C is explained by its dense π-π stacking in the pores. The interplay of enthalpic and entropic effects allowed separation of a complex, five-compound phenol mixture through breakthrough over a MIL-140C column. Unlike many other metal-organic frameworks, MIL-140C is remarkably stable and maintained structure, porosity and performance after five adsorption-desorption cycles. PMID:26373364

  19. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    PubMed Central

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-01-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials. PMID:24964404

  20. Fabrication of carbon nanorods and graphene nanoribbons from a metal-organic framework.

    PubMed

    Pachfule, Pradip; Shinde, Dhanraj; Majumder, Mainak; Xu, Qiang

    2016-07-01

    One- and two-dimensional carbon nanomaterials are attracting considerable attention because of their extraordinary electrical, mechanical and thermal properties, which could lead to a range of important potential applications. Synthetic processes associated with making these materials can be quite complex and also consume large amounts of energy, so a major challenge is to develop simple and efficient methods to produce them. Here, we present a self-templated, catalyst-free strategy for the synthesis of one-dimensional carbon nanorods by morphology-preserved thermal transformation of rod-shaped metal-organic frameworks. The as-synthesized non-hollow (solid) carbon nanorods can be transformed into two- to six-layered graphene nanoribbons through sonochemical treatment followed by chemical activation. The performance of these metal-organic framework-derived carbon nanorods and graphene nanoribbons in supercapacitor electrodes demonstrates that this synthetic approach can produce functionally useful materials. Moreover, this approach is readily scalable and could be used to produce carbon nanorods and graphene nanoribbons on industrial levels. PMID:27325100

  1. Bi2O3 nanoparticles encapsulated in surface mounted metal-organic framework thin films

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Chen, Zhi; Yang, Chengwu; Neumann, Tobias; Kübel, Christian; Wenzel, Wolfgang; Welle, Alexander; Pfleging, Wilhelm; Shekhah, Osama; Wöll, Christof; Redel, Engelbert

    2016-03-01

    We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye.We describe a novel procedure to fabricate a recyclable hybrid-photocatalyst based on Bi2O3@HKUST-1 MOF porous thin films. Bi2O3 nanoparticles (NPs) were synthesized within HKUST-1 (or Cu3(BTC)2) surface-mounted metal-organic frame-works (SURMOFs) and characterized using X-ray diffraction (XRD), a quartz crystal microbalance (QCM) and transmission electron microscopy (TEM). The Bi2O3 semiconductor NPs (diameter 1-3 nm)/SURMOF heterostructures exhibit superior photo-efficiencies compared to NPs synthesized using conventional routes, as demonstrated via the photodegradation of the nuclear fast red (NFR) dye. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00532b

  2. Metal-organic framework with optimally selective xenon adsorption and separation.

    PubMed

    Banerjee, Debasis; Simon, Cory M; Plonka, Anna M; Motkuri, Radha K; Liu, Jian; Chen, Xianyin; Smit, Berend; Parise, John B; Haranczyk, Maciej; Thallapally, Praveen K

    2016-01-01

    Nuclear energy is among the most viable alternatives to our current fossil fuel-based energy economy. The mass deployment of nuclear energy as a low-emissions source requires the reprocessing of used nuclear fuel to recover fissile materials and mitigate radioactive waste. A major concern with reprocessing used nuclear fuel is the release of volatile radionuclides such as xenon and krypton that evolve into reprocessing facility off-gas in parts per million concentrations. The existing technology to remove these radioactive noble gases is a costly cryogenic distillation; alternatively, porous materials such as metal-organic frameworks have demonstrated the ability to selectively adsorb xenon and krypton at ambient conditions. Here we carry out a high-throughput computational screening of large databases of metal-organic frameworks and identify SBMOF-1 as the most selective for xenon. We affirm this prediction and report that SBMOF-1 exhibits by far the highest reported xenon adsorption capacity and a remarkable Xe/Kr selectivity under conditions pertinent to nuclear fuel reprocessing. PMID:27291101

  3. Gold nanoparticles immobilized on metal-organic frameworks with enhanced catalytic performance for DNA detection.

    PubMed

    Liu, Ya Li; Fu, Wen Liang; Li, Chun Mei; Huang, Cheng Zhi; Li, Yuan Fang

    2015-02-25

    In this work, gold nanoparticles (AuNPs) assembled on the surface of iron based metal-organic frameworks (MOFs), Fe-MIL-88, are facilely prepared through electrostatic interactions using polyethyleneimine (PEI) molecules as linker. The resulting hybrid materials possess synergetic peroxidase-like activity. Because iron based metal-organic frameworks, Fe-MIL-88, exhibits highly peroxidase-like activity, and AuNPs has the distinct adsorption property to single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The peroxidase-like activity of Au@Fe-MIL-88 exhibit excellent switchable in response to specific DNA, ssDNA is easily adsorbed on the surface of the Au@Fe-MIL-88 hybrids, resulting in the reduce of the peroxidase-like activity of the hybrids. While it is recovered by the addition of target DNA, and the recovery degree is proportional to the target DNA concentration over the range of 30-150 nM with a detection limit of 11.4 nM. Based on these unique properties, we develop a label-free colorimetric method for DNA hybridization detection. In control experiment, base-mismatched DNA cannot induce recovery of the peroxidase-like activity. This detection method is simple, cheap, rapid and colorimetric. PMID:25702274

  4. Percolative metal-organic framework/carbon composites for hydrogen storage

    NASA Astrophysics Data System (ADS)

    Xie, Shuqian; Hwang, Jiann-Yang; Sun, Xiang; Shi, Shangzhao; Zhang, Zheng; Peng, Zhiwei; Zhai, Yuchun

    2014-05-01

    Percolative Metal-organic framework/Carbon (MOFAC) composites are synthesized by IRMOF8 (isoreticular metal-organic frameworks) directly depositing on activated carbon via heterogeneous nucleation. Carbon content is calculated by TGA (Thermogravimetric analysis) tests. XRD (X-ray diffraction) and FESEM (Field emission-scanning electron microscope) are carried out to characterize the structures of the samples. BET surface areas and the pore size distribution are measured. The dielectric constant is measured with impedance analyzer and a specially designed sample holder. The dielectric constants of the MOFAC composites rise with increasing the carbon content, and the composites possess the insulator-conductor transition as the carbon content increases from 17.77 wt% to 22.2 wt%. The composites are further tested for hydrogen storage capability under assist of the PMN-PT (single crystal lead magnesium niobate-lead titanate) generated electric field. With help from the PMN-PT, the hydrogen uptake capability is increased about 31.5% over the MOFAC3 (MOF-Carbon composite with 22.2 wt% of carbon) without PMN-PT, which is elucidated by the charge distribution mechanisms. The improved storage is due to a stronger electrostatic interaction between IRMOF8 and hydrogen molecule caused by field polarization. Meanwhile, rapid adsorption/desorption kinetics and total reversibility on the samples are observed in the present or absence of external electric field.

  5. Made-to-order metal-organic frameworks for trace carbon dioxide removal and air capture

    NASA Astrophysics Data System (ADS)

    Shekhah, Osama; Belmabkhout, Youssef; Chen, Zhijie; Guillerm, Vincent; Cairns, Amy; Adil, Karim; Eddaoudi, Mohamed

    2014-06-01

    Direct air capture is regarded as a plausible alternate approach that, if economically practical, can mitigate the increasing carbon dioxide emissions associated with two of the main carbon polluting sources, namely stationary power plants and transportation. Here we show that metal-organic framework crystal chemistry permits the construction of an isostructural metal-organic framework (SIFSIX-3-Cu) based on pyrazine/copper(II) two-dimensional periodic 44 square grids pillared by silicon hexafluoride anions and thus allows further contraction of the pore system to 3.5 versus 3.84 Å for the parent zinc(II) derivative. This enhances the adsorption energetics and subsequently displays carbon dioxide uptake and selectivity at very low partial pressures relevant to air capture and trace carbon dioxide removal. The resultant SIFSIX-3-Cu exhibits uniformly distributed adsorption energetics and offers enhanced carbon dioxide physical adsorption properties, uptake and selectivity in highly diluted gas streams, a performance, to the best of our knowledge, unachievable with other classes of porous materials.

  6. Post Modification of Metal-Organic Framework and Their Application In Cancer Theranostics

    NASA Astrophysics Data System (ADS)

    Lakkakula, Hima bindu

    The research proposal aims to demonstrate that Metal-Organic Frameworks (MOFs) are mainly used for cancer theranostics which is the combination of both diagnostic and therapeutic functions. The research will emphasis on synthesis of Fe- MOFs by solvothermal nucleation, crystallization, characterization by microscopy and spectroscopy and evaluation with different lattice parameters and its morphology. Nowadays MOFs are used for the novel drug delivery purposes. The current published Fe- MOFs research focus is on the cancer theranostics by Indian medicines which will be impregnated into the MOFs and which will evaluate bioavailability and the chemotherapeutic activity of the drug. Nanotechnology provides the target specificity without affecting the healthy tissues. Other research problems to be addressed are the relationship between metal connectivity and ligand-based luminescence, MOF stability in an aqueous environment and activating it at increased temperature serves as a crucial role. The merits of this research are to increase the surface area and pore size of the drug so that the therapeutic efficacy can be improved. Moreover, the stabilization of metal-organic frameworks can also be enhanced with high surface area.

  7. Ultrastable Polymolybdate-Based Metal-Organic Frameworks as Highly Active Electrocatalysts for Hydrogen Generation from Water.

    PubMed

    Qin, Jun-Sheng; Du, Dong-Ying; Guan, Wei; Bo, Xiang-Jie; Li, Ya-Fei; Guo, Li-Ping; Su, Zhong-Min; Wang, Yuan-Yuan; Lan, Ya-Qian; Zhou, Hong-Cai

    2015-06-10

    Two novel polyoxometalate (POM)-based metal-organic frameworks (MOFs), [TBA]3[ε-PMo(V)8Mo(VI)4O36(OH)4Zn4][BTB]4/3·xGuest (NENU-500, BTB = benzene tribenzoate, TBA(+) = tetrabutylammonium ion) and [TBA]3[ε-PMo(V)8Mo(VI)4O37(OH)3Zn4][BPT] (NENU-501, BPT = [1,1'-biphenyl]-3,4',5-tricarboxylate), were isolated. In these compounds, the POM fragments serving as nodes were directly connected with organic ligands giving rise to three-dimensional (3D) open frameworks. The two anionic frameworks were balanced by TBA(+) ions residing inside the open channels. They exhibit not only good stability in air but also tolerance to acidic and basic media. Furthermore, they were employed as electrocatalysts for the hydrogen evolution reaction (HER) owing to the combination of the redox activity of a POM unit and the porosity of a MOF. Meanwhile, the HER activities of ε(trim)(4/3), NENU-5, and HKUST-1 were also studied for comparison. Remarkably, as a 3D hydrogen-evolving cathode operating in acidic electrolytes, NENU-500 exhibits the highest activity among all MOF materials. It shows an onset overpotential of 180 mV and a Tafel slope of 96 mV·dec(-1), and the catalytic current density can approach 10 mA·cm(-2) at an overpotential of 237 mV. Moreover, NENU-500 and NENU-501 maintain their electrocatalytic activities after 2000 cycles. PMID:25933041

  8. Mechanical tunability via hydrogen bonding in metal-organic frameworks with the perovskite architecture.

    PubMed

    Li, Wei; Thirumurugan, A; Barton, Phillip T; Lin, Zheshuai; Henke, Sebastian; Yeung, Hamish H-M; Wharmby, Michael T; Bithell, Erica G; Howard, Christopher J; Cheetham, Anthony K

    2014-06-01

    Two analogous metal-organic frameworks (MOFs) with the perovskite architecture, [C(NH2)3][Mn(HCOO)3] (1) and [(CH2)3NH2][Mn(HCOO)3] (2), exhibit significantly different mechanical properties. The marked difference is attributed to their distinct modes of hydrogen bonding between the A-site amine cation and the anionic framework. The stronger cross-linking hydrogen bonding in 1 gives rise to Young's moduli and hardnesses that are up to twice those in 2, while the thermal expansion is substantially smaller. This study presents clear evidence that the mechanical properties of MOF materials can be substantially tuned via hydrogen-bonding interactions. PMID:24815319

  9. Selective Gas Adsorption within a Five-Connected Porous Metal-Organic Framework

    SciTech Connect

    Xue, Ming; Zhang, Zhangjing; Xiang, Shengchang; Zhao, Jin; Liang, Chengdu; Guang-Shan, Zhu; Qiu, Shi-Lun; Chen, Banglin

    2010-01-01

    A metal-organic framework, Zn3(OH)( BDC-2,5-Cl2)2.5(DMF)3(H2O) 1 (BDC-2,5-Cl2 = 1,4-benzenedicarboxylate-2,5-dichloro and DMF = N,N -dimethylformamide) of rare five-connected (44)(66) topology was synthesized and structurally characterized. The framework is thermally stable up to 350 C, thus activation of this new MOF material at different temperature of 150 and 300 C under high vacuum formed two microporous materials 1a and 1b, respectively, exhibiting selective gas adsorption behavior with respect to H2/N2 and O2/N2, and CO2/CH4 and CO2/N2.

  10. Rational design of metal-organic frameworks with anticipated porosities and functionalities

    SciTech Connect

    Zhang, MW; Bosch, M; Gentle, T; Zhou, HC

    2014-01-01

    Metal-organic frameworks have emerged as a new category of porous materials that have intriguing structures and diverse applications. Even though the early discovery of new MOFs appears to be serendipitous, much effort has been made to reveal their structure-property relationships for the purpose of rationally designing novel frameworks with expected properties. Until now, much progress has been made to rationalize the design and synthesis of MOFs. This highlight review will outline the recent advances on this topic from both our and other groups and provide a systematic overview of different methods for the rational design of MOFs with desired porosities and functionalities. In this review, we will categorize the recent efforts for rational MOF design into two different approaches: a structural approach and a functional approach.

  11. Tetrazole-Viologen-based Flexible Microporous Metal-Organic Framework with High CO2 Selective Uptake.

    PubMed

    Zhao, Ya-Ping; Li, Yan; Cui, Cai-Yan; Xiao, Yu; Li, Rong; Wang, Shuai-Hua; Zheng, Fa-Kun; Guo, Guo-Cong

    2016-08-01

    A flexible metal-organic framework (FMOF) with functionalized pores was hydrothermally synthesized to improve CO2 affinity and selectivity. The obtained FMOF exhibits a reversible shrinking and swelling framework transformation, which is triggered by the adsorption of CO2 rather than by the adsorption of N2 and CH4. At ambient temperature and an atmospheric pressure, this FMOF shows not only a high CO2 uptake (98 cm(3) g(-1), 19.3 wt %) but also a good calculated adsorption selectivity for CO2 over both CH4 and N2 (CO2/CH4 50:50 v/v: 28.6:1, CO2/N2 15:85 v/v: 210.4:1 calculated by ideal adsorbed solution theory), indicating potential applications in the purification of natural gas and industrial flue gas. PMID:27400274

  12. Defining the Proton Topology of the Zr6-Based Metal-Organic Framework NU-1000.

    PubMed

    Planas, Nora; Mondloch, Joseph E; Tussupbayev, Samat; Borycz, Joshua; Gagliardi, Laura; Hupp, Joseph T; Farha, Omar K; Cramer, Christopher J

    2014-11-01

    Metal-organic frameworks (MOFs) constructed from Zr6-based nodes have recently received considerable attention given their exceptional thermal, chemical, and mechanical stability. Because of this, the structural diversity of Zr6-based MOFs has expanded considerably and in turn given rise to difficulty in their precise characterization. In particular it has been difficult to assign where protons (needed for charge balance) reside on some Zr6-based nodes. Elucidating the precise proton topologies in Zr6-based MOFs will have wide ranging implications in defining their chemical reactivity, acid/base characteristics, conductivity, and chemical catalysis. Here we have used a combined quantum mechanical and experimental approach to elucidate the precise proton topology of the Zr6-based framework NU-1000. Our data indicate that a mixed node topology, [Zr6(μ3-O)4(μ3-OH)4(OH)4 (OH2)4](8+), is preferred and simultaneously rule out five alternative node topologies. PMID:26278741

  13. Carbonization and oxidation of metal-organic frameworks based on 1,4-naphthalene dicarboxylates

    NASA Astrophysics Data System (ADS)

    Chen, Jiun-Jen; Chen, Ya-Ting; Senthil Raja, Duraisamy; Kang, Yu-Hao; Tseng, Pen-Chang; Lin, Chia-Her

    2015-10-01

    Three new isostructural metal-organic frameworks (MOFs), [V(OH)(NDC)] (1), [Cr(OH)(NDC)] (2), and [Ga(OH)(NDC)] (3) have been synthesized hydrothermally using 1,4-naphthalene dicarboxylate (NDC) as the linker. These MOFs (1, 2 and 3) have been used as a template for the synthesis of metal-oxide-inserted nanoporous carbon materials. The newly synthesized MOFs and the resulting porous carbon hybrid functional materials have been characterized using powder x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopic analysis. Results show that compounds 2 and 3 form their respective metal oxide nanoparticles on the surface of the carbon materials during carbonization at 800 °C. The gas sorption properties of the new MOFs and their corresponding carbon frameworks have been reported.

  14. Luminescent zinc metal-organic framework (ZIF-90) for sensing metal ions, anions and small molecules.

    PubMed

    Liu, Chang; Yan, Bing

    2015-09-26

    We synthesize a zinc zeolite-type metal-organic framework, the zeolitic imidazolate framework (ZIF-90), which exhibits an intense blue luminescence excited under visible light. Luminescent studies indicate that ZIF-90 could be an efficient multifunctional fluorescence material for high sensitivity metal ions, anions and organic small molecules, especially for Cd(2+), Cu(2+), CrO4(2-) and acetone. The luminescence intensity of ZIF-90 increases with the concentration of Cd(2+) and decreases proportionally with the concentration of Cu(2+), while the same quenched experimental phenomena appear in the sensing of CrO4(2-). With the increase of the amount of acetone, the luminescence intensity decreases gradually in the emulsions of ZIF-90. The mechanism of the sensing properties is studied in detail as well. This study shows that ZIF-90 could be a useful luminescent sensor for metal ions, anions and organic small molecules. PMID:26123790

  15. Heterogeneity within a Mesoporous Metal-Organic Framework with Three Distinct Metal-Containing Building Units.

    PubMed

    Tu, Binbin; Pang, Qingqing; Ning, Erlong; Yan, Wenqing; Qi, Yi; Wu, Doufeng; Li, Qiaowei

    2015-10-28

    Materials built from multiple constituents have revealed emerging properties that are beyond linear integration of those from single components. We report a mesoporous metal-organic framework made from three geometrically distinct metal-containing secondary building units (SBUs) as a result of topological induction. The combinations of the Cu-based triangular, Zn-based octahedral, and Zn-based square pyramidal SBUs have created four types of cages in the network, despite that only one organic linker pyrazolecarboxylate was used. The longest distance for molecules maneuvering inside the largest cage is 5.2 nm. Furthermore, the complex and diversified pore environments allow the installation of various new functionalities in the framework as well as the expedited Ag nanoparticle formation in the pores. As presented in the molecule movement diagram, the crystal has provided specific arrangements of cages and apertures with distinct chemical features for guests transporting between the pores. PMID:26335899

  16. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals.

    PubMed

    Bachman, Jonathan E; Smith, Zachary P; Li, Tao; Xu, Ting; Long, Jeffrey R

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes. PMID:27064528

  17. Lithium inclusion in indium metal-organic frameworks showing increased surface area and hydrogen adsorption

    SciTech Connect

    Bosch, Mathieu; Zhang, Muwei; Feng, Dawei; Yuan, Shuai; Wang, Xuan; Chen, Ying-Pin; Zhou, Hong-Cai

    2014-12-01

    Investigation of counterion exchange in two anionic In-Metal-Organic Frameworks (In-MOFs) showed that partial replacement of disordered ammonium cations was achieved through the pre-synthetic addition of LiOH to the reaction mixture. This resulted in a surface area increase of over 1600% in (Li [In(1,3 − BDC){sub 2}]){sub n} and enhancement of the H{sub 2} uptake of approximately 275% at 80 000 Pa at 77 K. This method resulted in frameworks with permanent lithium content after repeated solvent exchange as confirmed by inductively coupled plasma mass spectrometry. Lithium counterion replacement appears to increase porosity after activation through replacement of bulkier, softer counterions and demonstrates tuning of pore size and properties in MOFs.

  18. Enhanced ethylene separation and plasticization resistance in polymer membranes incorporating metal-organic framework nanocrystals

    NASA Astrophysics Data System (ADS)

    Bachman, Jonathan E.; Smith, Zachary P.; Li, Tao; Xu, Ting; Long, Jeffrey R.

    2016-08-01

    The implementation of membrane-based separations in the petrochemical industry has the potential to reduce energy consumption significantly relative to conventional separation processes. Achieving this goal, however, requires the development of new membrane materials with greater selectivity, permeability and stability than available at present. Here, we report composite materials consisting of nanocrystals of metal-organic frameworks dispersed within a high-performance polyimide, which can exhibit enhanced selectivity for ethylene over ethane, greater ethylene permeability and improved membrane stability. Our results suggest that framework-polymer interactions reduce chain mobility of the polymer while simultaneously boosting membrane separation performance. The increased stability, or plasticization resistance, is expected to improve membrane utility under real process conditions for petrochemical separations and natural gas purification. Furthermore, this approach can be broadly applied to numerous polymers that encounter aggressive environments, potentially making gas separations possible that were previously inaccessible to membranes.

  19. Quasi-3D Multi-scale Modeling Framework Development

    NASA Astrophysics Data System (ADS)

    Arakawa, A.; Jung, J.

    2008-12-01

    When models are truncated in or near an energetically active range of the spectrum, model physics must be changed as the resolution changes. The model physics of GCMs and that of CRMs are, however, quite different from each other and at present there is no unified formulation of model physics that automatically provides transition between these model physics. The Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is an attempt to bridge this gap. Like the recently proposed Heterogeneous Multiscale Method (HMM) (E and Engquist 2003), MMF combines a macroscopic model, GCM, and a microscopic model, CRM. Unlike the traditional multiscale methods such as the multi-grid and adapted mesh refinement techniques, HMM and MMF are for solving multi-physics problems. They share the common objective "to design combined macroscopic-microscopic computational methods that are much more efficient than solving the full microscopic model and at the same time give the information we need" (E et al. 2008). The question is then how to meet this objective in practice, which can be highly problem dependent. In HHM, the efficiency is gained typically by localization of the microscale problem. Following the pioneering work by Grabowski and Smolarkiewicz (1999) and Grabowski (2001), MMF takes advantage of the fact that 2D CRMs are reasonably successful in simulating deep clouds. In this approach, the efficiency is gained by sacrificing the three-dimensionality of cloud-scale motion. It also "localizes" the algorithm through embedding a CRM in each GCM grid box using cyclic boundary condition. The Q3D MMF is an attempt to reduce the expense due to these constraints by partially including the cloud-scale 3D effects and extending the CRM beyond individual GCM grid boxes. As currently formulated, the Q3D MMF is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic cloud-resolving vector vorticity equation model (VVM) applied to a network of horizontal grids. The network

  20. Metal-organic frameworks with functional pores for recognition of small molecules.

    PubMed

    Chen, Banglin; Xiang, Shengchang; Qian, Guodong

    2010-08-17

    Molecular recognition, an important process in biological and chemical systems, governs the diverse functions of a variety of enzymes and unique properties of some synthetic receptors. Because molecular recognition is based on weak interactions between receptors and substrates, the design and assembly of synthetic receptors to mimic biological systems and the development of novel materials to discriminate different substrates for selective recognition of specific molecules has proved challenging. The extensive research on synthetic receptors for molecular recognition, particularly on noncovalent complexes self-assembled by hydrogen bonding and metal-organic coordination, has revealed some underlying principles. In particular, these studies have demonstrated that the shapes of the supramolecular receptors play significant roles in their specific and selective recognition of substrates: receptors can offer concave surfaces that complement their convex targets. This Account describes our research to develop a synthetic molecular recognition platform using porous metal-organic frameworks (MOFs). These materials contain functional pores to direct their specific and unique recognition of small molecules through several types of interactions: van der Waals interactions of the framework surface with the substrate, metal-substrate interactions, and hydrogen bonding of the framework surface with the substrate. These materials have potential applications for gas storage, separation, and sensing. We demonstrate a simple strategy to construct a primitive cubic net of interpenetrated microporous MOFs from the self-assembly of the paddle-wheel clusters M(2)(CO(2))(4) (M = Cu(2+), Zn(2+), and Co(2+)) with two types of organic dicarboxylic acid and pillar bidentate linkers. This efficient method allows us to rationally tune the micropores to size-exclusively sort different small gas molecules, leading to the highly selective separation and purification of gases. By optimizing the

  1. Tetrazine chromophore-based metal-organic frameworks with unusual configurations: synthetic, structural, theoretical, fluorescent, and nonlinear optical studies.

    PubMed

    Li, Jianghua; Jia, Ding; Meng, Suci; Zhang, Jinfang; Cifuentes, Marie P; Humphrey, Mark G; Zhang, Chi

    2015-05-18

    Three unusual three-dimensional (3D) tetrazine chromophore-based metal-organic frameworks (MOFs) {(Et4 N)[WS4 Cu3 (CN)2 (4,4'-pytz)0.5 ]}n (1), {[MoS4 Cu4 (CN)2 (4,4'-pytz)2 ]⋅CH2 Cl2 }n (2), and {[WS4 Cu3 (4,4'-pytz)3 ]⋅[N(CN)2 ]}n (3; 4,4'-pytz=3,6-bis(4-pyridyl)tetrazine) have been synthesized and characterized by using FTIR and UV/Vis spectroscopy, elemental analysis, powder X-ray diffraction, gel permeation chromatography, steady-state fluorescence, and thermogravimetric analysis; their identities were confirmed by single-crystal X-ray diffraction studies. MOF 1 possesses the first five-connected M/S/Cu (M=Mo, W) framework with an unusual 3D (4(4) ⋅6(6) ) topology constructed from T-shaped [WS4 Cu3 ](+) clusters as nodes and single CN(-) /4,4'-pytz bridges as linkers. MOF 2 features a novel 3D MOF structure with (4(20) ⋅6(8) ) topology, in which the bridging 4,4'-pytz ligands exhibit unique distorted arch structures. MOF 3 displays the first 3D MOF structure based on flywheel-shaped [WS4 Cu3 ](+) clusters with a non-interpenetrating honeycomb-like framework and a heavily distorted "ACS" topology. Steady-state fluorescence studies of 1-3 reveal significant fluorescence emissions. The nonlinear optical (NLO) properties of 1-3 were investigated by using a Z-scan technique with 5 ns pulses at λ=532 nm. The Z-scan experimental results show that the π-delocalizable tetrazine-based 4,4'-pytz ligands contribute to the strong third-order NLO properties exhibited by 1-3. Time-dependent density functional theory studies afforded insight into the electronic transitions and spectral characterization of these functionalized NLO molecular materials. PMID:25877804

  2. 3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK

    SciTech Connect

    Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D

    2006-08-24

    3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.

  3. Reversible and selective solvent adsorption in layered metal-organic frameworks by coordination control.

    PubMed

    Yin, Xinbo; Chen, Haohong; Song, Yuna; Wang, Yang; Li, Qiaowei; Zhang, Lijuan

    2014-01-01

    With various functionalities in the framework and high thermal stability, metal-organic frameworks (MOFs) have been extensively studied for the applications in adsorption and separation. In last decade, synthesizing new MOFs with desired structures and improved chemical stability to meet these applications has drawn great attention. In this report, by using an organic ligand with azolate moiety, benzo-bis(imidazole) (H2BBI), we synthesized two new 2D layered MOF structures with distinct topologies. Framework 1 {[Zn2Cl2(BBI)(MSM)2]n, MSM=methylsulfonylmethane}, constructed from tetrahedral Zn(II) and BBI, maintains its structure in organic solvents, such as methanol and benzene, and even in water. Meanwhile, framework 2 {[Cd2Cl2(BBI)(DMSO)2]n, DMSO=dimethyl sulfoxide} differs from framework 1, and is assembled from trigonal bipyramidal Cd(II) and square planar BBI. By removing the DMSO molecules coordinated to Cd(II) (25 weight% of the structure), 2 could transform to 3 {[Cd2Cl2(BBI)]n}, which was further characterized by high-resolution powder X-ray diffraction. The solvent-free 3 retains the original connectivity within each layer, and is capable of reversible and selective adsorption of DMSO molecules. The bistable four- and five-coordinated geometry exchange of Cd(II) is the origin of this adsorption with improved selectivity and capacity. PMID:24183447

  4. A novel type of matrix for surface-assisted laser desorption-ionization mass spectrometric detection of biomolecules using metal-organic frameworks.

    PubMed

    Fu, Chien-Ping; Lirio, Stephen; Liu, Wan-Ling; Lin, Chia-Her; Huang, Hsi-Ya

    2015-08-12

    A 3D metal-organic framework (MOF) nanomaterial as matrix for surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) and tandem mass spectrometry (MS/MS) was developed for the analysis of complex biomolecules. Unlike other nanoparticle matrices, this MOF nanomaterial does not need chemical modification prior to use. An exceptional signal reproducibility as well as very low background interferences in analyzing mono-/di-saccharides, peptides and complex starch digests demonstrate its high potential for biomolecule assays, especially for small molecules. PMID:26320964

  5. Screening for high-spin metal organic frameworks (MOFs): density functional theory study on DUT-8(M1,M2) (with Mi = V,…,Cu).

    PubMed

    Schwalbe, Sebastian; Trepte, Kai; Seifert, Gotthard; Kortus, Jens

    2016-03-01

    We present a first principles study of low-spin (LS)/high-spin (HS) screening for 3d metal centers in the metal organic framework (MOF) DUT-8(Ni). Various density functional theory (DFT) codes have been used to evaluate numerical and DFT related errors. We compare highly accurate all-electron implementations with the widely used plane wave approach. We present electronically and magnetically stable DUT-8(Ni) HS secondary building units (SBUs). In this work we show how to tune the magnetic and electronic properties of the original SBU only by changing the metal centers. PMID:26922864

  6. Triangular framework mesh generation of 3D geological structure

    NASA Astrophysics Data System (ADS)

    Meng, Xianhai; Zhou, Kun; Li, Jigang; Yang, Qin

    2013-03-01

    The dynamic simulation of oil migration and accumulation is an important issue on the research of petroleum exploration, and it is a numerical simulation process with special requirement on the framework mesh of 3D geological models, which means that the mesh should have same geometry and topology relation near the intersected part of geological surfaces. In this paper, basing on the conforming Delaunay triangulation algorithm to construct mesh of individual geological stratum or fault, a novel link-Delaunay-triangulation method is presented to achieve the geometric and topological consistency in the intersected line between two surfaces, also with the analysis of termination of our algorithm. Finally, some examples of the geological framework mesh are provided and the experimental result proved that the algorithm's effectiveness in engineering practice.

  7. A Molecular Artisans Guide to Supramolecular Coordination Complexes and Metal Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Wu, Xialu; Young, David J.; Hor, T. S. Andy

    2015-10-01

    As molecular synthesis advances, we are beginning to learn control of not only the chemical reactivity (and function) of molecules, but also of their interactions with other molecules. It is this basic idea that has led to the current explosion of supramolecular science and engineering. Parallel to this development, chemists have been actively pursuing the design of very large molecules using basic molecular building blocks. Herein, we review the general development of supramolecular chemistry and particularly of two new branches: supramolecular coordination complexes (SCCs) and metal organic frameworks (MOFs). These two fields are discussed in detail with typical examples to illustrate what is now possible and what challenges lie ahead for tomorrow's molecular artisans.

  8. Cobalt-Based Layered Metal-Organic Framework as an Ultrahigh Capacity Supercapacitor Electrode Material.

    PubMed

    Liu, Xiuxiu; Shi, Changdong; Zhai, Changwei; Cheng, Meiling; Liu, Qi; Wang, Guoxiu

    2016-02-24

    Metal-organic frameworks (MOFs) have recently received increasing interest due to their potential application in the energy storage and conversion field. Herein, cobalt-based layered MOF ({[Co(Hmt)(tfbdc)(H2O)2]·(H2O)2}n, Co-LMOF; Hmt = hexamethylenetetramine; H2tfbdc = 2,3,5,6-tetrafluoroterephthalic acid) has been evaluated as an electrode material for supercapacitors. The Co-LMOF electrode exhibits a high specific capacitance and excellent cycling stability. Its maximum specific capacitance is 2474 F g(-1) at a current density of 1 A g(-1), and the specific capacitance retention is about 94.3% after 2000 cycles. The excellent electrochemical property may be ascribed to the intrinsic nature of Co-LMOF, enough space available for the storage and diffusion of the electrolyte, and the particles of nanoscale size. PMID:26829547

  9. Fabrication of the microchannel by metal-organic framework, copper benzenetricarboxylate.

    PubMed

    Lim, Mikyung; Seo, You-Kyong; Park, Hyoun Hyang; Kim, Jin-Ha; Chang, Jong-San; Hwang, Young Kyu; Lee, Seung S

    2013-04-01

    We successfully fabricated the metal-organic framework (MOF), copper benzenetricarboxylate on a microchannel system, which was able to solve the problems created by increased heat dissipation in small electronic equipment. The microchannel system was designed to make an entrance part that can control the reaction temperature, which was predicted through a heat transfer analysis and the finite element method with COMSOL Multiphysics. Synthetic conditions, synthesis time, temperature and microchannel size were systematically tuned for the selective fabrication of copper benzenetricarboxylate on a microchannel surface. Scanning electron microscope (SEM) images, selected area electron diffraction (SAED) pattern and Fourier transform infrared (FT-IR) data clearly demonstrated that copper benzenetricarboxylate was strongly adhered to the bottom surfaces of the microchannels. Moreover, the synthesis of MOF in the microchannel system provided a much faster growth rate and better crystallinity compared to a conventional synthesis method. PMID:23763149

  10. Computational Design of Metal-Organic Frameworks with High Methane Deliverable Capacity

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Martin, Richard; Simon, Cory; Haranczyk, Maciej; Smit, Berend; Deem, Michael; Deem Team; Haranczyk Team; Smit Team

    Metal-organic frameworks (MOFs) are a rapidly emerging class of nanoporous materials with largely tunable chemistry and diverse applications in gas storage, gas purification, catalysis, etc. Intensive efforts are being made to develop new MOFs with desirable properties both experimentally and computationally in the past decades. To guide experimental synthesis with limited throughput, we develop a computational methodology to explore MOFs with high methane deliverable capacity. This de novo design procedure applies known chemical reactions, considers synthesizability and geometric requirements of organic linkers, and evolves a population of MOFs with desirable property efficiently. We identify about 500 MOFs with higher deliverable capacity than MOF-5 in 10 networks. We also investigate the relationship between deliverable capacity and internal surface area of MOFs. This methodology can be extended to MOFs with multiple types of linkers and multiple SBUs. DE-FG02- 12ER16362.

  11. A metal-organic framework-based splitter for separating propylene from propane.

    PubMed

    Cadiau, A; Adil, K; Bhatt, P M; Belmabkhout, Y; Eddaoudi, M

    2016-07-01

    The chemical industry is dependent on the olefin/paraffin separation, which is mainly accomplished by using energy-intensive processes. We report the use of reticular chemistry for the fabrication of a chemically stable fluorinated metal-organic framework (MOF) material (NbOFFIVE-1-Ni, also referred to as KAUST-7). The bridging of Ni(II)-pyrazine square-grid layers with (NbOF5)(2-) pillars afforded the construction of a three-dimensional MOF, enclosing a periodic array of fluoride anions in contracted square-shaped channels. The judiciously selected bulkier (NbOF5)(2-) caused the looked-for hindrance of the previously free-rotating pyrazine moieties, delimiting the pore system and dictating the pore aperture size and its maximum opening. The restricted MOF window resulted in the selective molecular exclusion of propane from propylene at atmospheric pressure, as evidenced through multiple cyclic mixed-gas adsorption and calorimetric studies. PMID:27387945

  12. Size-selective crystallization of homochiral camphorate metal-organic frameworks for lanthanide separation.

    PubMed

    Zhao, Xiang; Wong, Matthew; Mao, Chengyu; Trieu, Thuong Xinh; Zhang, Jian; Feng, Pingyun; Bu, Xianhui

    2014-09-10

    Lanthanides (Ln) are a group of important elements usually found in nature as mixtures. Their separation is essential for technological applications but is made challenging by their subtly different properties. Here we report that crystallization of homochiral camphorate metal-organic frameworks (MOFs) is highly sensitive to ionic radii of lanthanides and can be used to selectively crystallize a lanthanide element into predesigned MOFs. Two series of camphorate MOFs were synthesized with acetate (Type 1 with early lanthanides La-Dy) or formate (Type 2 with late lanthanides Tb-Lu and Y) as the auxiliary ligand, respectively. The Ln coordination environment in each type exhibits selectivity for Ln(3+) of different sizes, which could form the basis for a new cost-effective method for Ln separation. PMID:25164942

  13. Adsorption of silver nanoparticles from aqueous solution on copper-based metal organic frameworks (HKUST-1).

    PubMed

    Conde-González, J E; Peña-Méndez, E M; Rybáková, S; Pasán, J; Ruiz-Pérez, C; Havel, J

    2016-05-01

    Silver nanoparticles (AgNP) are emerging pollutants. The use of novel materials such as Cu-(benzene 1,3,5-tricarboxylate, BTC) Metal-Organic Framework (MOFs), for AgNP adsorption and their removal from aqueous solutions has been studied. The effect of different parameters was followed and isotherm model was suggested. MOFs adsorbed fast and efficiently AgNP in the range C0 < 10 mg L(-1), being Freundlich isotherm (R = 0.993) these data fitted to. Among studied parameters a remarkable effect of chloride on sorption was found, thus their possible interactions were considered. The high adsorption efficiency of AgNP was achieved and it was found to be very fast. The feasibility of adsorption on Cu-(BTC) was proved in spiked waters. The results showed the potential interest of new material as adsorbent for removing AgNP from environment. PMID:26879292

  14. Detection of Volatile Organic Compounds by Weight-Detectable Sensors coated with Metal-Organic Frameworks

    PubMed Central

    Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi

    2014-01-01

    Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs. PMID:25175808

  15. A Solvent-Free Hot-Pressing Method for Preparing Metal-Organic-Framework Coatings.

    PubMed

    Chen, Yifa; Li, Siqing; Pei, Xiaokun; Zhou, Junwen; Feng, Xiao; Zhang, Shenghan; Cheng, Yuanyuan; Li, Haiwei; Han, Ruodan; Wang, Bo

    2016-03-01

    Metal-organic frameworks (MOFs), with their well-defined pores and rich structural diversity and functionality, have drawn a great deal of attention from across the scientific community. However, industrial applications are hampered by their intrinsic fragility and poor processability. Stable and resilient MOF devices with tunable flexibility are highly desirable. Herein, we present a solvent- and binder-free approach for producing stable MOF coatings by a unique hot-pressing (HoP) method, in which temperature and pressure are applied simultaneously to facilitate the rapid growth of MOF nanocrystals onto desired substrates. This strategy was proven to be applicable to carboxylate-based, imidazolate-based, and mixed-metal MOFs. We further successfully obtained superhydrophobic and "Janus" MOF films through layer-by-layer pressing. This HoP method can be scaled up in the form of roll-to-roll production and may push MOFs into unexplored industrial applications. PMID:26847472

  16. Platinum nanoparticles encapsulated metal-organic frameworks for the electrochemical detection of telomerase activity.

    PubMed

    Ling, Pinghua; Lei, Jianping; Jia, Li; Ju, Huangxian

    2016-01-21

    A simple and rapid electrochemical sensor is constructed for the detection of telomerase activity based on the electrocatalysis of platinum nanoparticle (Pt NP) encapsulated metal-organic frameworks (MOFs), which are synthesized by one-pot encapsulation of Pt NPs into prototypal MOFs, UiO-66-NH2. Integrating with the efficient electrocatalysis of Pt@MOFs towards NaBH4 oxidation, this biosensor shows the wide dynamic correlation of telomerase activity from 5 × 10(2) to 10(7) HeLa cells mL(-1) and the telomerase activity in a single HeLa cell was calculated to be 2.0 × 10(-11) IU, providing a powerful platform for detecting telomerase activity. PMID:26612011

  17. Iron-Based Metal-Organic Frameworks as Catalysts for Visible Light-Driven Water Oxidation.

    PubMed

    Chi, Le; Xu, Qian; Liang, Xiaoyu; Wang, Jide; Su, Xintai

    2016-03-01

    The development of earth-abundant, active, and stable catalysts is important for solar energy conversion. Metal-organic frameworks (MOFs) have been viewed as a promising class of porous materials, which may have innovative application in photocatalysis. In this paper, three types of Fe-based MOFs and their aminofunctionalized derivatives have been fabricated and systematically studied as water oxidation catalysts (WOCs) for oxygen evolution under visible light irradiation. MIL-101(Fe) possesses a higher current density and earlier onset potential and exhibits excellent visible light-driven oxygen evolution activity than the other Fe-based catalysts. It speeds up the oxygen evolution reaction rate with the higher initial turnover frequencies value of 0.10 s(-1) . Our study demonstrates that Fe-based MOFs as efficient WOCs are promising candidates for photocatalytic water oxidation process. PMID:26756919

  18. Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nanoporous Carbons

    PubMed Central

    Tang, Jing; Salunkhe, Rahul R.; Zhang, Huabin; Malgras, Victor; Ahamad, Tansir; Alshehri, Saad M.; Kobayashi, Naoya; Tominaka, Satoshi; Ide, Yusuke; Kim, Jung Ho; Yamauchi, Yusuke

    2016-01-01

    Single metal-organic frameworks (MOFs), constructed from the coordination between one-fold metal ions and organic linkers, show limited functionalities when used as precursors for nanoporous carbon materials. Herein, we propose to merge the advantages of zinc and cobalt metals ions into one single MOF crystal (i.e., bimetallic MOFs). The organic linkers that coordinate with cobalt ions tend to yield graphitic carbons after carbonization, unlike those bridging with zinc ions, due to the controlled catalytic graphitization by the cobalt nanoparticles. In this work, we demonstrate a feasible method to achieve nanoporous carbon materials with tailored properties, including specific surface area, pore size distribution, degree of graphitization, and content of heteroatoms. The bimetallic-MOF-derived nanoporous carbon are systematically characterized, highlighting the importance of precisely controlling the properties of the carbon materials. This can be done by finely tuning the components in the bimetallic MOF precursors, and thus designing optimal carbon materials for specific applications. PMID:27471193

  19. Interactive Thermal Effects on Metal-Organic Framework Polymer Composite Membranes.

    PubMed

    Cacho-Bailo, Fernando; Téllez, Carlos; Coronas, Joaquín

    2016-07-01

    Polymeric membranes are important tools for intensifying separation processes in chemical industries, concerning strategic tasks such as CO2 sequestration, H2 production, and water supply and disposal. Mixed-matrix and supported membranes have been widely developed; recently many of them have been based on metal-organic frameworks (MOFs). However, most of the impacts MOFs have within the polymer matrix have yet to be determined. The effects related to thermal behavior arising from the combination of MOF ZIF-8 and polysulfone have now been quantified. The catalyzed oxidation of the polymer is strongly affected by the MOF crystal size and distribution inside the membrane. A 16 wt % 140 nm-sized ZIF-8 loading causes a 40 % decrease in the observed activation energy of the polysulfone oxidation that takes place at a temperature (545 °C) 80 °C lower than in the raw polymer (625 °C). PMID:27156113

  20. Heterometallic Metal-Organic Frameworks That Catalyze Two Different Reactions Sequentially.

    PubMed

    Saha, Debraj; Hazra, Dipak K; Maity, Tanmoy; Koner, Subratanath

    2016-06-20

    A series of copper- and alkaline-earth-metal-based multidimensional metal-organic frameworks, {[CuMg(pdc)2(H2O)4]·2H2O}n (1), [CuCa(pdc)2]n (2), [CuSr(pdc)2(H2O)3]n (3), and {[CuBa(pdc)2(H2O)5]·H2O}n (4), where H2Pdc = pyridine-2,5-dicarboxylic acid, were hydrothermally synthesized and characterized. Two different metals act as the active center to catalyze two kinds of reactions, viz., olefin to its epoxide followed by epoxide ring opening to afford the corresponding vicinal diol in a sequential manner. PMID:27232433

  1. Entropy prediction for H2 adsorption in metal-organic frameworks.

    PubMed

    Liu, Yu; Guo, Fangyuan; Hu, Jun; Zhao, Shuangliang; Liu, Honglai; Hu, Ying

    2016-09-14

    Entropy is an important thermodynamic property and serves as a bridge connecting equilibrium and non-equilibrium systems, which provides a basic understanding of various practical phenomena. In this study, classical density functional theory was introduced to efficiently predict entropy. The theory was applied to a high-throughput prediction of entropy and excess entropy for H2 adsorption in metal-organic frameworks. It seems that the entropy screening and uptake screening are generally equivalent at high temperature. Based on the entropy screening, the best hydrogen storage materials have been identified. The correlations between entropy and thermodynamic properties, such as uptake, isosteric heat and adsorption degree, were examined and are explained. The results imply that among the tested thermodynamic properties, the correlation between entropy and isosteric heat is the strongest. PMID:27523720

  2. Metal-Organic Frameworks Modulated by Doping Er(3+) for Up-Conversion Luminescence.

    PubMed

    Zhang, Xindan; Li, Bin; Ma, Heping; Zhang, Liming; Zhao, Haifeng

    2016-07-13

    Here we present metal-organic frameworks prepared by a one-step synthesis method, possessing both architectural properties of MOF building and up-conversion luminescence of rare earth Er(3+) (hereafter denoted as Up-MOFs). Up-MOFs have characteristic up-conversion emissions at 520, 540, and 651 nm under the excitation of 980 nm owing to the multiple photon absorption. The up-conversion mechanism of these Up-MOFs has been discussed, and it can be attributed to the excited state absorption process. The design and synthesis of Up-MOF materials possessing near-infrared region excitation and up-conversion luminescence are fully expected to be candidates for the advancement of applications in bioimaging, sensors, optoelectronics, and energy conversion/storage devices. PMID:27315339

  3. Aromatic Substituent Effects on the Flexibility of Metal-Organic Frameworks.

    PubMed

    Hahm, Hyungwoo; Yoo, Kwangho; Ha, Hyeonbin; Kim, Min

    2016-08-01

    The flexibility (or breathing behavior) of zinc-based metal-organic frameworks (MOFs) has been manipulated by regioisomeric and positional control of organic functionalities. Ten new regioisomeric BDC (ortho- or para-disubstituted benzene-1,4-dicarboxylic acid) ligands have been synthesized and applied to a DMOF (dabco MOF) system, which has a zinc(II) paddle-wheel SBU (secondary building unit). Among the new regioisomeric MOFs, the NH2-OMe combination showed significant flexibility (breathing behavior) changes by simply altering the functional group positions (from 2,3 to 2,5). The electronic density of the benzene ring was considered to be a major factor in the flexibility changes in the regioisomeric MOF system. PMID:27414764

  4. Functionalization and Isoreticulation in a Series of Metal-Organic Frameworks Derived from Pyridinecarboxylates.

    PubMed

    Pachfule, Pradip; Garai, Bikash; Banerjee, Rahul

    2016-08-01

    The partially fluorinated metal-organic frameworks (F-MOFs) have been constructed from 3-fluoro-4-pyridinecarboxylic acid and trans-3-fluoro-4-pyridineacrylic acid linkers using Mn(2+), Co(2+), and Cd(2+) metals via the solvothermal method, which show isostructural isomerism with their nonfluorinated counterparts synthesized using 4-pyridinecarboxylic acid and trans-4-pyridineacrylic acid, respectively. The simultaneous effect of partial fluorination and isoreticulation on structure and H2 adsorption has been studied systematically in isostructural nonfluorinated and partially fluorinated MOFs, which shows that the increment in the hydrogen uptake properties in F-MOFs is not a universal phenomenon but is rather system-specific and changes from one system to another. PMID:27164435

  5. Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nanoporous Carbons

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Salunkhe, Rahul R.; Zhang, Huabin; Malgras, Victor; Ahamad, Tansir; Alshehri, Saad M.; Kobayashi, Naoya; Tominaka, Satoshi; Ide, Yusuke; Kim, Jung Ho; Yamauchi, Yusuke

    2016-07-01

    Single metal-organic frameworks (MOFs), constructed from the coordination between one-fold metal ions and organic linkers, show limited functionalities when used as precursors for nanoporous carbon materials. Herein, we propose to merge the advantages of zinc and cobalt metals ions into one single MOF crystal (i.e., bimetallic MOFs). The organic linkers that coordinate with cobalt ions tend to yield graphitic carbons after carbonization, unlike those bridging with zinc ions, due to the controlled catalytic graphitization by the cobalt nanoparticles. In this work, we demonstrate a feasible method to achieve nanoporous carbon materials with tailored properties, including specific surface area, pore size distribution, degree of graphitization, and content of heteroatoms. The bimetallic-MOF-derived nanoporous carbon are systematically characterized, highlighting the importance of precisely controlling the properties of the carbon materials. This can be done by finely tuning the components in the bimetallic MOF precursors, and thus designing optimal carbon materials for specific applications.

  6. Metal organic framework-mediated synthesis of highly active and stable Fischer-Tropsch catalysts.

    PubMed

    Santos, Vera P; Wezendonk, Tim A; Jaén, Juan José Delgado; Dugulan, A Iulian; Nasalevich, Maxim A; Islam, Husn-Ubayda; Chojecki, Adam; Sartipi, Sina; Sun, Xiaohui; Hakeem, Abrar A; Koeken, Ard C J; Ruitenbeek, Matthijs; Davidian, Thomas; Meima, Garry R; Sankar, Gopinathan; Kapteijn, Freek; Makkee, Michiel; Gascon, Jorge

    2015-01-01

    Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging. Here we present a strategy to produce highly dispersed iron carbides embedded in a matrix of porous carbon. Very high iron loadings (>40 wt %) are achieved while maintaining an optimal dispersion of the active iron carbide phase when a metal organic framework is used as catalyst precursor. The unique iron spatial confinement and the absence of large iron particles in the obtained solids minimize catalyst deactivation, resulting in high active and stable operation. PMID:25740709

  7. Metal organic framework-mediated synthesis of highly active and stable Fischer-Tropsch catalysts

    NASA Astrophysics Data System (ADS)

    Santos, Vera P.; Wezendonk, Tim A.; Jaén, Juan José Delgado; Dugulan, A. Iulian; Nasalevich, Maxim A.; Islam, Husn-Ubayda; Chojecki, Adam; Sartipi, Sina; Sun, Xiaohui; Hakeem, Abrar A.; Koeken, Ard C. J.; Ruitenbeek, Matthijs; Davidian, Thomas; Meima, Garry R.; Sankar, Gopinathan; Kapteijn, Freek; Makkee, Michiel; Gascon, Jorge

    2015-03-01

    Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging. Here we present a strategy to produce highly dispersed iron carbides embedded in a matrix of porous carbon. Very high iron loadings (>40 wt %) are achieved while maintaining an optimal dispersion of the active iron carbide phase when a metal organic framework is used as catalyst precursor. The unique iron spatial confinement and the absence of large iron particles in the obtained solids minimize catalyst deactivation, resulting in high active and stable operation.

  8. Remarkable Lattice Shrinkage in Highly Oriented Crystalline Three-Dimensional Metal-Organic Framework Thin Films.

    PubMed

    Haraguchi, Tomoyuki; Otsubo, Kazuya; Sakata, Osami; Fujiwara, Akihiko; Kitagawa, Hiroshi

    2015-12-21

    Highly oriented crystalline thin films of metal-organic frameworks (MOFs) have promising practical applications, such as in gas separation, catalysis, and sensing. We report on the successful fabrication of highly oriented crystalline thin films of three-dimensional porous MOFs, Fe(pz)[M(CN)4] (M = Ni, Pd; pz = pyrazine). Synchrotron X-ray diffraction studies reveal not only the highly oriented crystalline nature but also the remarkable shrunken structure of the thin films (∼3-7% volume shrinkage) compared with bulk samples. Furthermore, because of lattice shrinkage, these films exhibit large lattice expansions upon guest adsorption, in marked contrast to the almost unchanged lattice in the bulk samples. PMID:26641131

  9. Metal-organic framework based highly selective fluorescence turn-on probe for hydrogen sulphide

    PubMed Central

    Nagarkar, Sanjog S.; Saha, Tanmoy; Desai, Aamod V.; Talukdar, Pinaki; Ghosh, Sujit K.

    2014-01-01

    Hydrogen sulphide (H2S) is known to play a vital role in human physiology and pathology which stimulated interest in understanding complex behaviour of H2S. Discerning the pathways of H2S production and its mode of action is still a challenge owing to its volatile and reactive nature. Herein we report azide functionalized metal-organic framework (MOF) as a selective turn-on fluorescent probe for H2S detection. The MOF shows highly selective and fast response towards H2S even in presence of other relevant biomolecules. Low cytotoxicity and H2S detection in live cells, demonstrate the potential of MOF towards monitoring H2S chemistry in biological system. To the best of our knowledge this is the first example of MOF that exhibit fast and highly selective fluorescence turn-on response towards H2S under physiological conditions. PMID:25394493

  10. Mechanized azobenzene-functionalized zirconium metal-organic framework for on-command cargo release.

    PubMed

    Meng, Xiangshi; Gui, Bo; Yuan, Daqiang; Zeller, Matthias; Wang, Cheng

    2016-08-01

    Stimuli-responsive metal-organic frameworks (MOFs) have gained increasing attention recently for their potential applications in many areas. We report the design and synthesis of a water-stable zirconium MOF (Zr-MOF) that bears photoresponsive azobenzene groups. This particular MOF can be used as a reservoir for storage of cargo in water, and the cargo-loaded MOF can be further capped to construct a mechanized MOF through the binding of β-cyclodextrin with the azobenzene stalks on the MOF surface. The resulting mechanized MOF has shown on-command cargo release triggered by ultraviolet irradiation or addition of competitive agents without premature release. This study represents a simple approach to the construction of stimuli-responsive mechanized MOFs, and considering mechanized UiO-68-azo made from biocompatible components, this smart system may provide a unique MOF platform for on-command drug delivery in the future. PMID:27493996

  11. Metal-organic frameworks with high capacity and selectivity for harmful gases

    PubMed Central

    Britt, David; Tranchemontagne, David; Yaghi, Omar M.

    2008-01-01

    Benchmarks have been established for the performance of six metal-organic frameworks (MOFs) and isoreticular MOFs (IRMOFs, which have the same underlying topology as MOF-5), MOF-5, IRMOF-3, MOF-74, MOF-177, MOF-199, and IRMOF-62, as selective adsorbents for eight harmful gases: sulfur dioxide, ammonia, chlorine, tetrahydrothiophene, benzene, dichloromethane, ethylene oxide, and carbon monoxide. Kinetic breakthrough measurements are used to determine the calculated dynamic adsorption capacity of each “benchmark” MOF for each gas. The capacity of each MOF is compared to that of a sample of Calgon BPL activated carbon. We find that pore functionality plays a dominant role in determining the dynamic adsorption performance of MOFs. MOFs featuring reactive functionality outperform BPL carbon in all but one case and exhibit high dynamic adsorption capacities up to 35% by weight. PMID:18711128

  12. Metal-Organic Framework (MOF) Compounds: Photocatalysts for Redox Reactions and Solar Fuel Production.

    PubMed

    Dhakshinamoorthy, Amarajothi; Asiri, Abdullah M; García, Hermenegildo

    2016-04-25

    Metal-organic frameworks (MOFs) are crystalline porous materials formed from bi- or multipodal organic linkers and transition-metal nodes. Some MOFs have high structural stability, combined with large flexibility in design and post-synthetic modification. MOFs can be photoresponsive through light absorption by the organic linker or the metal oxide nodes. Photoexcitation of the light absorbing units in MOFs often generates a ligand-to-metal charge-separation state that can result in photocatalytic activity. In this Review we discuss the advantages and uniqueness that MOFs offer in photocatalysis. We present the best practices to determine photocatalytic activity in MOFs and for the deposition of co-catalysts. In particular we give examples showing the photocatalytic activity of MOFs in H2 evolution, CO2 reduction, photooxygenation, and photoreduction. PMID:26970539

  13. High proton conduction in a chiral ferromagnetic metal-organic quartz-like framework.

    PubMed

    Pardo, Emilio; Train, Cyrille; Gontard, Geoffrey; Boubekeur, Kamal; Fabelo, Oscar; Liu, Hongbo; Dkhil, Brahim; Lloret, Francesc; Nakagawa, Kosuke; Tokoro, Hiroko; Ohkoshi, Shin-ichi; Verdaguer, Michel

    2011-10-01

    A complex-as-ligand strategy to get a multifunctional molecular material led to a metal-organic framework with the formula (NH(4))(4)[MnCr(2)(ox)(6)]·4H(2)O. Single-crystal X-ray diffraction revealed that the anionic bimetallic coordination network adopts a chiral three-dimensional quartz-like architecture. It hosts ammonium cations and water molecules in functionalized channels. In addition to ferromagnetic ordering below T(C) = 3.0 K related to the host network, the material exhibits a very high proton conductivity of 1.1 × 10(-3) S cm(-1) at room temperature due to the guest molecules. PMID:21913689

  14. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    PubMed Central

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes. PMID:26796523

  15. Metal-organic Frameworks as A Tunable Platform for Designing Functional Molecular Materials

    PubMed Central

    Wang, Cheng; Liu, Demin

    2013-01-01

    Metal-organic frameworks (MOFs), also known as coordination polymers, represent an interesting class of crystalline molecular materials that are synthesized by combining metal-connecting points and bridging ligands. The modular nature of and mild conditions for MOF synthesis have permitted the rational structural design of numerous MOFs and the incorporation of various functionalities via constituent building blocks. The resulting designer MOFs have shown promise for applications in a number of areas, including gas storage/separation, nonlinear optics/ferroelectricity, catalysis, energy conversion/storage, chemical sensing, biomedical imaging, and drug delivery. The structure-property relationships of MOFs can also be readily established by taking advantage of the knowledge of their detailed atomic structures, which enables fine-tuning of their functionalities for desired applications. Through the combination of molecular synthesis and crystal engineering MOFs thus present an unprecedented opportunity for the rational and precise design of functional materials. PMID:23944646

  16. A novel hybrid metal-organic framework-polymeric monolith for solid-phase microextraction.

    PubMed

    Lin, Chen-Lan; Lirio, Stephen; Chen, Ya-Ting; Lin, Chia-Her; Huang, Hsi-Ya

    2014-03-17

    This study describes the fabrication of a novel hybrid metal-organic framework- organic polymer (MOF-polymer) for use as a stationary phase in fritless solid-phase microextraction (SPME) for validating analytical methods. The MOF-polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium-based ionic liquid as porogenic solvent followed by microwave-assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF-polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF-organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63-96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min. PMID:24615770

  17. Bimetallic Metal-Organic Frameworks for Controlled Catalytic Graphitization of Nanoporous Carbons.

    PubMed

    Tang, Jing; Salunkhe, Rahul R; Zhang, Huabin; Malgras, Victor; Ahamad, Tansir; Alshehri, Saad M; Kobayashi, Naoya; Tominaka, Satoshi; Ide, Yusuke; Kim, Jung Ho; Yamauchi, Yusuke

    2016-01-01

    Single metal-organic frameworks (MOFs), constructed from the coordination between one-fold metal ions and organic linkers, show limited functionalities when used as precursors for nanoporous carbon materials. Herein, we propose to merge the advantages of zinc and cobalt metals ions into one single MOF crystal (i.e., bimetallic MOFs). The organic linkers that coordinate with cobalt ions tend to yield graphitic carbons after carbonization, unlike those bridging with zinc ions, due to the controlled catalytic graphitization by the cobalt nanoparticles. In this work, we demonstrate a feasible method to achieve nanoporous carbon materials with tailored properties, including specific surface area, pore size distribution, degree of graphitization, and content of heteroatoms. The bimetallic-MOF-derived nanoporous carbon are systematically characterized, highlighting the importance of precisely controlling the properties of the carbon materials. This can be done by finely tuning the components in the bimetallic MOF precursors, and thus designing optimal carbon materials for specific applications. PMID:27471193

  18. A new method to position and functionalize metal-organic framework crystals

    PubMed Central

    Falcaro, Paolo; Hill, Anita J.; Nairn, Kate M.; Jasieniak, Jacek; Mardel, James I.; Bastow, Timothy J.; Mayo, Sheridan C.; Gimona, Michele; Gomez, Daniel; Whitfield, Harold J.; Riccò, Raffaele; Patelli, Alessandro; Marmiroli, Benedetta; Amenitsch, Heinz; Colson, Tobias; Villanova, Laura; Buso, Dario

    2011-01-01

    With controlled nanometre-sized pores and surface areas of thousands of square metres per gram, metal-organic frameworks (MOFs) may have an integral role in future catalysis, filtration and sensing applications. In general, for MOF-based device fabrication, well-organized or patterned MOF growth is required, and thus conventional synthetic routes are not suitable. Moreover, to expand their applicability, the introduction of additional functionality into MOFs is desirable. Here, we explore the use of nanostructured poly-hydrate zinc phosphate (α-hopeite) microparticles as nucleation seeds for MOFs that simultaneously address all these issues. Affording spatial control of nucleation and significantly accelerating MOF growth, these α-hopeite microparticles are found to act as nucleation agents both in solution and on solid surfaces. In addition, the introduction of functional nanoparticles (metallic, semiconducting, polymeric) into these nucleating seeds translates directly to the fabrication of functional MOFs suitable for molecular size-selective applications. PMID:21407203

  19. Separation of C2 Hydrocarbons by Porous Materials: Metal Organic Frameworks as Platform

    SciTech Connect

    Banerjee, Debasis; Liu, Jun; Thallapally, Praveen K.

    2014-12-22

    The effective separation of small hydrocarbon molecules (C1 – C4) is an important process for petroleum industry, determining the end price of many essential commodities in our daily lives. Current technologies for separation of these molecules rely on energy intensive fractional distillation processes at cryogenic temperature, which is particularly difficult because of their similar volatility. In retrospect, adsorptive separation using solid state adsorbents might be a cost effective alternative. Several types of solid state adsorbents (e.g. zeolite molecular sieves) were tested for separation of small hydrocarbon molecules as a function of pressure, temperature or vacuum. Among different types of plausible adsorbents, metal organic frameworks (MOFs), a class of porous, crystalline, inorganic-organic hybrid materials, is particularly promising. In this brief comment article, we discuss the separation properties of different types of solid state adsorbents, with a particular emphasis on MOF based adsorbents for separation of C2 hydrocarbon molecules.

  20. A scalable synthesis of a mesoporous metal-organic framework called NU-1000.

    SciTech Connect

    Wang, Timothy C.; Vermeulen, Nicolaas A.; Kim, In Soo; Martinson, Alex B. F.; Stoddart, J. Fraser; Hupp, Joseph T.; Farha, Omar K.

    2016-01-01

    The synthesis of NU-1000, a mesoporous metal-organic framework (MOF), can be conducted efficiently on a multigram scale from inexpensive starting materials. NU-1000 has been reported as an excellent candidate for gas separation and catalysis. In particular, it is ideal for the catalytic deactivation of nerve agents and shows great promise as a new generic platform for a wide range of applications. Multiple post-synthetic modification protocols have been developed using NU-1000 as the parent material, making it a potentially useful scaffold for several catalytic applications. The procedure for the preparation of NU-1000 can be scaled up reliably and is suitable for the production of 50 grams of the requisite organic linker and ?? grams of NU-1000. The entire synthesis is performed without purification by column chromatography and can be completed within 10 days.

  1. Observation of Resonant Quantum Magnetoelectric Effect in a Multiferroic Metal-Organic Framework.

    PubMed

    Tian, Ying; Shen, Shipeng; Cong, Junzhuang; Yan, Liqin; Wang, Shouguo; Sun, Young

    2016-01-27

    A resonant quantum magnetoelectric coupling effect has been demonstrated in the multiferroic metal-organic framework of [(CH3)2NH2]Fe(HCOO)3. This material shows a coexistence of a spin-canted antiferromagnetic order and ferroelectricity as well as clear magnetoelectric coupling below TN ≈ 19 K. In addition, a component of single-ion quantum magnets develops below ∼ 8 K because of an intrinsic magnetic phase separation. The stair-shaped magnetic hysteresis loop at 2 K signals resonant quantum tunneling of magnetization. Meanwhile, the magnetic field dependence of dielectric permittivity exhibits sharp peaks just at the critical tunneling fields, evidencing the occurrence of resonant quantum magnetoelectric coupling effect. This resonant effect enables a simple electrical detection of quantum tunneling of magnetization. PMID:26743039

  2. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Kim, Hyunho; Cho, H. Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M.; Wang, Evelyn N.

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes.

  3. Modulation by Amino Acids: Toward Superior Control in the Synthesis of Zirconium Metal-Organic Frameworks.

    PubMed

    Gutov, Oleksii V; Molina, Sonia; Escudero-Adán, Eduardo C; Shafir, Alexandr

    2016-09-12

    The synthesis of zirconium metal-organic frameworks (Zr MOFs) modulated by various amino acids, including l-proline, glycine, and l-phenylalanine, is shown to be a straightforward approach toward functional-group incorporation and particle-size control. High yields in Zr-MOF synthesis are achieved by employing 5 equivalents of the modulator at 120 °C. At lower temperatures, the method provides a series of Zr MOFs with increased particle size, including many suitable for single-crystal X-ray diffraction studies. Furthermore, amino acid modulators can be incorporated at defect sites in Zr MOFs with an amino acid/ligand ratio of up to 1:1, depending on the ligand structure and reaction conditions. The MOFs obtained through amino acid modulation exhibit an improved CO2 -capture capacity relative to nonfunctionalized materials. PMID:27482849

  4. Metal-organic frameworks for electronics: emerging second order nonlinear optical and dielectric materials

    NASA Astrophysics Data System (ADS)

    Mendiratta, Shruti; Lee, Cheng-Hua; Usman, Muhammad; Lu, Kuang-Lieh

    2015-10-01

    Metal-organic frameworks (MOFs) have been intensively studied over the past decade because they represent a new category of hybrid inorganic-organic materials with extensive surface areas, ultrahigh porosity, along with the extraordinary tailorability of structure, shape and dimensions. In this highlight, we summarize the current state of MOF research and report on structure-property relationships for nonlinear optical (NLO) and dielectric applications. We focus on the design principles and structural elements needed to develop potential NLO and low dielectric (low-κ) MOFs with an emphasis on enhancing material performance. In addition, we highlight experimental evidence for the design of devices for low-dielectric applications. These results motivate us to develop better low-dielectric and NLO materials and to perform in-depth studies related to deposition techniques, patterning and the mechanical performance of these materials in the future.

  5. Mechanisms of Heat Transfer in Porous Crystals Containing Adsorbed Gases: Applications to Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Babaei, Hasan; Wilmer, Christopher E.

    2016-01-01

    We have studied the mechanisms of heat transfer in a porous crystal-gas mixture system, motivated by the not insignificant challenge of quickly dissipating heat generated in metal-organic frameworks (MOFs) due to gas adsorption. Our study reveals that the thermal conductance of the system (crystal and gas) is dominated by lattice thermal conductivity in the crystal, and that conductance is reduced as the concentration of gas in the pores increases. This mechanism was observed from classical molecular simulations of a monatomic gas in an idealized porous crystal structure. We show that the decreased conductivity associated with increased gas concentration is due to phonon scattering in the crystal due to interactions with gas molecules. Calculations of scattering rates for two phonon modes reveal that scattering of the lowest frequency mode scales linearly with gas density. This result suggests that the probability of a phonon-gas collision is simply proportional to the number of gas molecules in the pore.

  6. Metal-organic frameworks: mechanisms of antibacterial action and potential applications.

    PubMed

    Wyszogrodzka, Gabriela; Marszałek, Bartosz; Gil, Barbara; Dorożyński, Przemysław

    2016-06-01

    The growing resistance of pathogens to conventional antibiotics has become a public health problem and raises the need to seek new effective solutions. Metal-organic frameworks (MOFs) are porous, hybrid materials comprising metal ions linked by organic binding ligands. The possibility of using a variety of chemical building components in MOFs enables the formation of structures with desired properties. They can act as a reservoir of metal ions, providing their gradual release and resulting in a sustained antibacterial action analogous to that proposed for metal/metal oxide nanoparticles (NPs) but different to that of antibiotics. These features make MOFs promising candidates for pharmaceutical and biomedical applications, as illustrated by examples discussed in this review. PMID:27091434

  7. Surfactant-thermal method to prepare two new cobalt metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Yu, Xianglin; Toh, Yong Siang; Zhao, Jun; Nie, Lina; Ye, Kaiqi; Wang, Yue; Li, Dongsheng; Zhang, Qichun

    2015-12-01

    Employing surfactants as reaction media, two new metal-organic frameworks (MOFs):(HTEA)3[Co3(BTC)3] (NTU-Z33) and (HTEA)[Co3(HBTC)2(BTC)] (NTU-Z34) (H3BTC=1,3,5-benzenetricarboxylic acid, TEA=trimethylamine, and NTU=Nanyang Technological University), have been successfully synthesized and fully characterized. Note that NTU-Z33 has an unusual trimeric [Co3(COO)9] secondary building unit (SBU). Magnetic characterization suggests that both compounds have weak antiferromagnetic behaviors. Our success in preparing new crystalline Co-BTC based MOFs under different surfactant media could provide a new road to prepare new diverse MOFs through various combinations of surfactants.

  8. Lithium ion battery application of porous composite oxide microcubes prepared via metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Yang, Xia; Tang, Yong-Bing; Huang, Xing; Xue, Hong Tao; Kang, Wen Pei; Li, Wen Yue; Ng, Tsz-Wai; Lee, Chun-Sing

    2015-06-01

    Prussian Blue (PB, Fe4[Fe(CN)6]3) is utilized to synthesize bimetallic metal-organic frameworks (MOFs) (Fe4[Fe(CN)6]3/Mx[Fe(CN)6], M = Cu, Ni, Co, etc.) by cation exchange, driven by differences in solubility product constant (Ksp) of monometallic MOFs. Upon decomposition, the bimetallic MOFs convert to porous composite metal oxides (Fe2O3/MOx, M = Cu, Ni, Co, etc.) while keeping the original cubic morphology. This study demonstrates a general approach for preparing bimetallic MOFs and porous composite oxides. We also demonstrate the good electrochemical performance (specific capacity of 774 mAh g-1 after 120 cycles at 500 mA g-1) of the synthesized porous Fe2O3-CuO composite as an anode material for lithium ion batteries. And according to references, this composite exhibit better or comparable rate capability and cycle stability compared with other hybrid transition metal oxides.

  9. Computational design of metal-organic frameworks with paddlewheel-type secondary building units

    NASA Astrophysics Data System (ADS)

    Schwingenschlogl, Udo; Peskov, Maxim V.; Masghouni, Nejib

    We employ the TOPOS package to study 697 coordination polymers containing paddlewheel-type secondary building units. The underlying nets are analyzed and 3 novel nets are chosen as potential topologies for paddlewheel-type metal organic frameworks (MOFs). Dicarboxylate linkers are used to build basic structures for novel isoreticular MOF series, aiming at relatively compact structures with a low number of atoms per unit cell. The structures are optimized using density functional theory. Afterwards the Grand Canonical Monte Carlo approach is employed to generate adsorption isotherms for CO2, CO, and CH4 molecules. We utilize the universal forcefield for simulating the interaction between the molecules and hosting MOF. The diffusion behavior of the molecules inside the MOFs is analyzed by molecular dynamics simulations.

  10. High-pressure, ambient temperature hydrogen storage in metal-organic frameworks and porous carbon

    NASA Astrophysics Data System (ADS)

    Beckner, Matthew; Dailly, Anne

    2014-03-01

    We investigated hydrogen storage in micro-porous adsorbents at ambient temperature and pressures up to 320 bar. We measured three benchmark adsorbents: two metal-organic frameworks, Cu3(1,3,5-benzenetricarboxylate)2 [Cu3(btc)2; HKUST-1] and Zn4O(1,3,5-benzenetribenzoate)2 [Zn4O(btb)2; MOF-177], and the activated carbon MSC-30. In this talk, we focus on adsorption enthalpy calculations using a single adsorption isotherm. We use the differential form of the Claussius-Clapeyron equation applied to the Dubinin-Astakhov adsorption model to calculate adsorption enthalpies. Calculation of the adsorption enthalpy in this way gives a temperature independent enthalpy of 5-7 kJ/mol at the lowest coverage for the three materials investigated. Additionally, we discuss the assumptions and corrections that must be made when calculating adsorption isotherms at high-pressure and adsorption enthalpies.

  11. Hydrogen storage in Pd nanocrystals covered with a metal-organic framework.

    PubMed

    Li, Guangqin; Kobayashi, Hirokazu; Taylor, Jared M; Ikeda, Ryuichi; Kubota, Yoshiki; Kato, Kenichi; Takata, Masaki; Yamamoto, Tomokazu; Toh, Shoichi; Matsumura, Syo; Kitagawa, Hiroshi

    2014-08-01

    Hydrogen is an essential component in many industrial processes. As a result of the recent increase in the development of shale gas, steam reforming of shale gas has received considerable attention as a major source of H2, and the more efficient use of hydrogen is strongly demanded. Palladium is well known as a hydrogen-storage metal and an effective catalyst for reactions related to hydrogen in a variety of industrial processes. Here, we present remarkably enhanced capacity and speed of hydrogen storage in Pd nanocrystals covered with the metal-organic framework (MOF) HKUST-1 (copper(II) 1,3,5-benzenetricarboxylate). The Pd nanocrystals covered with the MOF have twice the storage capacity of the bare Pd nanocrystals. The significantly enhanced hydrogen storage capacity was confirmed by hydrogen pressure-composition isotherms and solid-state deuterium nuclear magnetic resonance measurements. The speed of hydrogen absorption in the Pd nanocrystals is also enhanced by the MOF coating. PMID:25017188

  12. Cu₃(hexaiminotriphenylene)₂: an electrically conductive 2D metal-organic framework for chemiresistive sensing.

    PubMed

    Campbell, Michael G; Sheberla, Dennis; Liu, Sophie F; Swager, Timothy M; Dincă, Mircea

    2015-03-27

    The utility of metal-organic frameworks (MOFs) as functional materials in electronic devices has been limited to date by a lack of MOFs that display high electrical conductivity. Here, we report the synthesis of a new electrically conductive 2D MOF, Cu3(HITP)2 (HITP=2,3,6,7,10,11-hexaiminotriphenylene), which displays a bulk conductivity of 0.2 S cm(-1) (pellet, two-point-probe). Devices synthesized by simple drop casting of Cu3(HITP)2 dispersions function as reversible chemiresistive sensors, capable of detecting sub-ppm levels of ammonia vapor. Comparison with the isostructural 2D MOF Ni3(HITP)2 shows that the copper sites are critical for ammonia sensing, indicating that rational design/synthesis can be used to tune the functional properties of conductive MOFs. PMID:25678397

  13. A novel series of isoreticular metal organic frameworks: realizing metastable structures by liquid phase epitaxy

    NASA Astrophysics Data System (ADS)

    Liu, Jinxuan; Lukose, Binit; Shekhah, Osama; Arslan, Hasan Kemal; Weidler, Peter; Gliemann, Hartmut; Bräse, Stefan; Grosjean, Sylvain; Godt, Adelheid; Feng, Xinliang; Müllen, Klaus; Magdau, Ioan-Bogdan; Heine, Thomas; Wöll, Christof

    2012-12-01

    A novel class of metal organic frameworks (MOFs) has been synthesized from Cu-acetate and dicarboxylic acids using liquid phase epitaxy. The SURMOF-2 isoreticular series exhibits P4 symmetry, for the longest linker a channel-size of 3 × 3 nm2 is obtained, one of the largest values reported for any MOF so far. High quality, ab-initio electronic structure calculations confirm the stability of a regular packing of (Cu++)2- carboxylate paddle-wheel planes with P4 symmetry and reveal, that the SURMOF-2 structures are in fact metastable, with a fairly large activation barrier for the transition to the bulk MOF-2 structures exhibiting a lower, twofold (P2 or C2) symmetry. The theoretical calculations also allow identifying the mechanism for the low-temperature epitaxial growth process and to explain, why a synthesis of this highly interesting, new class of high-symmetry, metastable MOFs is not possible using the conventional solvothermal process.

  14. A microporous metal-organic framework with butynelene functionality for selective gas sorption

    NASA Astrophysics Data System (ADS)

    Wang, Lifeng; Zhai, Lu; Ren, Xiaoming; Zhang, Wenwei

    2013-08-01

    A porous metal-organic framework {[Cu2(BBTC)(H2O)2]·2DMSO·4H2O}n (Cu-BBTC, BBTC=1, 1‧-butadiynebenzene -3,3‧,5,5‧-tetracarboxylate; DMSO=dimethyl sulfoxide) was solvothermally synthesized from a tetracarboxylate ligand with butynelene functionality and structurally characterized. Cu-BBTC features a three-dimensional fof network with two types of cages, a small cage is about 14 Å in diameter and a large shows an ellipsoidal pore with about 14.2×22.6 Å in axes. The activated sample of Cu-BBTC, with Langmuir surface area of 1569 m2 g-1, exhibits selective gas adsorption behavior with respect to C2H2/CH4 and CO2/CH4 at room temperature.

  15. Metal-Organic Framework/PVDF Composite Membranes with High H2 Permselectivity Synthesized by Ammoniation.

    PubMed

    Li, Wanbin; Meng, Qin; Zhang, Congyang; Zhang, Guoliang

    2015-05-01

    Herein we report a new ammoniation-based chemical modification strategy for synthesis of continuous and uniform metal-organic framework (MOF)/polyvinylidene fluoride (PVDF) membranes with attractive performance. Ammoniation can promote the support PVDF membrane to produce amino groups, form a nanoparticle structure, and be well cross-linked; therefore, the high-density heterogeneous nucleation sites for MOFs growth were provided and the thermal stability and chemical resistance of composite membranes can be greatly improved. The high-quality layers of representative Cu-BTC and ZIF-8 were synthesized on the chemically modified PVDF membranes. By ammoniation, ZIF-7 can even be grown under harsh synthetic conditions such as in DMF precursor solutions at 403 K. The fabricated MOF/PVDF composite membranes with excellent hollow fiber structures and enhanced structural stability exhibited high H2 permselectivities for H2 /CO2 and H2 /N2 . PMID:25810142

  16. Theoretical and experimental analysis of H2 binding in a prototype metal organic framework material

    SciTech Connect

    Kong, Dr. Lingzhu; Cooper, Valentino R; Nijem, Nour; Li, Kunhao; Li, Jing; Chabal, Yves J.; Langreth, David C.

    2009-01-01

    Hydrogen adsorption by the metal organic framework (MOF) structure Zn2(BDC)2(TED) is investigated using a combination of experimental and theoretical methods. By use of the nonempirical van der Waals density-functional (vdW-DF) approach, it is found that the locus of deepest H2 binding positions lies within two types of narrow channel. The energies of the most stable binding sites, as well as the number of such binding sites, are consistent with the values obtained from experimental adsorption isotherms and heat of adsorption data. Calculations of the shift of the H H stretch frequency when adsorbed in the MOF give a value of approximately −30 cm−1 at the strongest binding point in each of the two channels. Ambient temperature infrared absorption spectroscopy measurements give a hydrogen peak centered at 4120 cm−1, implying a shift consistent with the theoretical calculations.

  17. Postsynthetic modification of metal-organic framework for hydrogen sulfide detection

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Zhang, Jianmin; Hu, Quan; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-11-01

    Hydrogen sulfide (H2S) has recently been identified as the third biological gaseous messenger (gasotransmitter) that is involved in regulating many important physiological processes. The detection of H2S is thus essential for its roles but remain challenging in living systems. We report herein a novel turn-on fluorescent probe for H2S detection based on azide functionalized metal-organic framework (MOF). The MOF probe displayed high sensitivity (detection limit, 28.3 μM), excellent selectivity, and fast response (<2 min) toward H2S over other biologically relevant species. We envisage that this MOF probe can be employed as a useful tool to further elucidate the biological roles of H2S.

  18. A Chlorin-Based Nanoscale Metal-Organic Framework for Photodynamic Therapy of Colon Cancers.

    PubMed

    Lu, Kuangda; He, Chunbai; Lin, Wenbin

    2015-06-24

    We report here the rational design of the first chlorin-based nanoscale metal-organic framework (NMOF), DBC-UiO, with much improved photophysical properties over the previously reported porphyrin-based NMOF, DBP-UiO. Reduction of the DBP ligands in DBP-UiO to the DBC ligands in DBC-UiO led to a 13 nm red shift and an 11-fold increase in the extinction coefficient of the lowest-energy Q band. While inheriting the crystallinity, stability, porosity, and nanoplate morphology of DBP-UiO, DBC-UiO sensitizes more efficient (1)O2 generation and exhibits significantly enhanced photodynamic therapy (PDT) efficacy on two colon cancer mouse models as a result of its improved photophysical properties. Both apoptosis and immunogenic cell death contributed to killing of cancer cells in DBC-UiO-induced PDT. PMID:26068094

  19. In Silico Discovery of High Deliverable Capacity Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Martin, Richard; Simon, Cory; Haranczyk, Maciej; Smit, Berend; Deem, Michael; Michael W. Deem Team; Maciej Haranczyk Team; Berend Smit Team

    2015-03-01

    Metal organic frameworks (MOFs) are actively being explored as potential adsorbed natural gas storage materials for small vehicles. Experimental exploration of potential materials is limited by the throughput of synthetic chemistry. We here describe a computational methodology to complement and guide these experimental efforts. The method uses known chemical transformations in silico to identify MOFs with high methane deliverable capacity. The procedure explicitly considers synthesizability with geometric requirements on organic linkers. We efficiently search the composition and conformation space of organic linkers for nine MOF networks, finding 48 materials with higher predicted deliverable capacity (at 65 bar storage, 5.8 bar depletion, and 298 K) than MOF-5 in four of the nine networks. The best material has a predicted deliverable capacity 8% higher than that of MOF-5. US Department of Energy.

  20. Hydrogen storage in Pd nanocrystals covered with a metal-organic framework

    NASA Astrophysics Data System (ADS)

    Li, Guangqin; Kobayashi, Hirokazu; Taylor, Jared M.; Ikeda, Ryuichi; Kubota, Yoshiki; Kato, Kenichi; Takata, Masaki; Yamamoto, Tomokazu; Toh, Shoichi; Matsumura, Syo; Kitagawa, Hiroshi

    2014-08-01

    Hydrogen is an essential component in many industrial processes. As a result of the recent increase in the development of shale gas, steam reforming of shale gas has received considerable attention as a major source of H2, and the more efficient use of hydrogen is strongly demanded. Palladium is well known as a hydrogen-storage metal and an effective catalyst for reactions related to hydrogen in a variety of industrial processes. Here, we present remarkably enhanced capacity and speed of hydrogen storage in Pd nanocrystals covered with the metal-organic framework (MOF) HKUST-1 (copper(II) 1,3,5-benzenetricarboxylate). The Pd nanocrystals covered with the MOF have twice the storage capacity of the bare Pd nanocrystals. The significantly enhanced hydrogen storage capacity was confirmed by hydrogen pressure-composition isotherms and solid-state deuterium nuclear magnetic resonance measurements. The speed of hydrogen absorption in the Pd nanocrystals is also enhanced by the MOF coating.

  1. Application of Two Cobalt-Based Metal-Organic Frameworks as Oxidative Desulfurization Catalysts.

    PubMed

    Masoomi, Mohammad Yaser; Bagheri, Minoo; Morsali, Ali

    2015-12-01

    Two new porous cobalt-based metal-organic frameworks, [Co6(oba)5(OH)2(H2O)2(DMF)4]n · 5DMF (TMU-10) and [Co3(oba)3(O) (Py)0.5] n · 4DMF · Py (TMU-12) have been synthesized by solvothermal method using a nonlinear dicarboxylate ligand. Under mild reaction conditions, these compounds exhibited good catalytic activity and reusability in oxidative desulfurization (ODS) reaction of model oil which was prepared by dissolving dibenzothiophene (DBT) in n-hexane. FT-IR and Mass analysis showed that the main product of DBT oxidation is its corresponding sulfone, which was adsorbed on the surfaces of catalysts. The activation energy was obtained as 13.4 kJ/mol. PMID:26571113

  2. Generic postfunctionalization route from amino-derived metal-organic frameworks.

    PubMed

    Savonnet, Marie; Bazer-Bachi, Delphine; Bats, Nicolas; Perez-Pellitero, Javier; Jeanneau, Erwann; Lecocq, Vincent; Pinel, Catherine; Farrusseng, David

    2010-04-01

    This study deals with the development of a soft, generic, one-pot postfunctionalization method for metal-organic frameworks (MOFs) starting from compounds with an amino group on the linker. The first step consists of transforming the amino group into azide (N(3)) by an unconventional route using tBuONO and TMSN(3). In the same vessel, the desired functionalized MOF then is obtained by the Huisgen 1,3-dipolar cycloaddition of azides to alkynes, otherwise known as the "click" reaction. The method was applied to DMOF-NH(2) and MIL-68(In)-NH(2), which represent two distinct and important classes of MOF. For both, the functionalization was complete (>90% grafting) and the crystallinity was maintained. Thanks to the large diversity and availability of cyano- and acetylene-based chemicals, this method opens the door to tailor-made functionalized MOFs. PMID:20232865

  3. Anisotropic elastic properties of flexible metal-organic frameworks: how soft are soft porous crystals?

    PubMed

    Ortiz, Aurélie U; Boutin, Anne; Fuchs, Alain H; Coudert, François-Xavier

    2012-11-01

    We performed ab initio calculations of the elastic constants of five flexible metal-organic frameworks (MOFs): MIL-53(Al), MIL-53(Ga), MIL-47, and the square and lozenge structures of DMOF-1. Tensorial analysis of the elastic constants reveals a highly anisotropic elastic behavior, some deformation directions exhibiting very low Young's modulus and shear modulus. This anisotropy can reach a 400:1 ratio between the most rigid and weakest directions, in stark contrast to the case of nonflexible MOFs such as MOF-5 and ZIF-8. In addition, we show that flexible MOFs can display extremely large negative linear compressibility. These results uncover the microscopic roots of stimuli-induced structural transitions in flexible MOFs, by linking the local elastic behavior of the material and its multistability. PMID:23215398

  4. Metal-Organic Framework Thin Films as Stationary Phases in Microfabricated Gas-Chromatography Columns.

    SciTech Connect

    Read, Douglas; Sillerud, Colin Halliday

    2016-01-01

    The overarching goal of this project is to integrate Sandia's microfabricated gas-chromatography ( GC) columns with a stationary phase material that is capable of retaining high-volatility chemicals and permanent gases. The successful integration of such a material with GCs would dramatically expand the repertoire of detectable compounds for Sandia's various microanalysis systems. One such promising class of candidate materials is metal-organic frameworks (MOFs). In this report we detail our methods for controlled deposition of HKUST-1 MOF stationary phases within GC columns. We demonstrate: the chromatographic separation of natural gas; a method for determining MOF film thickness from chromatography alone; and the first-reported GC x GC separation of natural gas -- in general -- let alone for two disparate MOF stationary phases. In addition we determine the fundamental thermodynamic constant for mass sorption, the partition coefficient, for HKUST-1 and several light hydrocarbons and select toxic industrial chemicals.

  5. Active and Durable Hydrogen Evolution Reaction Catalyst Derived from Pd-Doped Metal-Organic Frameworks.

    PubMed

    Chen, Jitang; Xia, Guoliang; Jiang, Peng; Yang, Yang; Li, Ren; Shi, Ruohong; Su, Jianwei; Chen, Qianwang

    2016-06-01

    The water electrolysis is of critical importance for sustainable hydrogen production. In this work, a highly efficient and stable PdCo alloy catalyst (PdCo@CN) was synthesized by direct annealing of Pd-doped metal-organic frameworks (MOFs) under N2 atmosphere. In 0.5 M H2SO4 solution, PdCo@CN displays remarkable electrocatalytic performance with overpotential of 80 mV, a Tafel slope of 31 mV dec(-1), and excellent stability of 10 000 cycles. Our studies reveal that noble metal doped MOFs are ideal precursors for preparing highly active alloy electrocatalysts with low content of noble metal. PMID:27112733

  6. Direct X-ray observation of trapped CO₂ in a predesigned porphyrinic metal-organic framework.

    PubMed

    Johnson, Jacob A; Chen, Shuang; Reeson, Tyler C; Chen, Yu-Sheng; Zeng, Xiao Cheng; Zhang, Jian

    2014-06-16

    Metal-organic frameworks (MOFs) are emerging microporous materials that are promising for capture and sequestration of CO2 due to their tailorable binding properties. However, it remains a grand challenge to pre-design a MOF with a precise, multivalent binding environment at the molecular level to enhance CO2 capture. Here, we report the design, synthesis, and direct X-ray crystallographic observation of a porphyrinic MOF, UNLPF-2, that contains CO2-specific single molecular traps. Assembled from an octatopic porphyrin ligand with [Co2(COO)4] paddlewheel clusters, UNLPF-2 provides an appropriate distance between the coordinatively unsaturated metal centers, which serve as the ideal binding sites for in situ generated CO2. The coordination of Co(II) in the porphyrin macrocycle is crucial and responsible for the formation of the required topology to trap CO2. By repeatedly releasing and recapturing CO2, UNLPL-2 also exhibits recyclability. PMID:24861568

  7. Cross coupling between electric and magnetic orders in a multiferroic metal-organic framework.

    PubMed

    Tian, Ying; Stroppa, Alessandro; Chai, Yisheng; Yan, Liqin; Wang, Shouguo; Barone, Paolo; Picozzi, Silvia; Sun, Young

    2014-01-01

    The coexistence of both electric and magnetic orders in some metal-organic frameworks (MOFs) has yielded a new class of multiferroics beyond inorganic materials. However, the coupling between two orders in multiferroic MOFs has not been convincingly verified yet. Here we present clear experimental evidences of cross coupling between electric and magnetic orders in a multiferroic MOF [(CH3)2NH2]Fe(HCOO)3 with a perovskite structure. The dielelectric constant exhibit a hump just at the magnetic ordering temperature TN. Moreover, both the direct (magnetic field control of dielectric properties) and converse (electric field control of magnetization) magnetoelectric effects have been observed in the multiferroic state. This work opens up new insights on the origin of ferroelectricity in MOFs and highlights their promise as magnetoelectric multiferroics. PMID:25317819

  8. Fluorous Metal Organic Frameworks as Superhydrophobic Adsorbents for Oil Spill Cleanup and Hydrocarbons Storage

    SciTech Connect

    Yang, Chi; Mather, Qian; Wang, Xiaoping; Kaipa, Ushasree; Nesterov, Vladimir; Venero, Augustin; Omary, Mohammad A

    2011-01-01

    We demonstrate that fluorous metal-organic frameworks (FMOFs) are highly hydrophobic porous materials with a high capacity and affinity to C{sub 6}-C{sub 8} hydrocarbons of oil components. FMOF-1 exhibits reversible adsorption with a high capacity for n-hexane, cyclohexane, benzene, toluene, and p-xylene, with no detectable water adsorption even at near 100% relative humidity, drastically outperforming activated carbon and zeolite porous materials. FMOF-2, obtained from annealing FMOF-1, shows enlarged cages and channels with double toluene adsorption vs FMOF-1 based on crystal structures. The results suggest great promise for FMOFs in applications such as removal of organic pollutants from oil spills or ambient humid air, hydrocarbon storage and transportation, water purification, etc. under practical working conditions.

  9. A Water-Stable Cationic Metal-Organic Framework as a Dual Adsorbent of Oxoanion Pollutants.

    PubMed

    Desai, Aamod V; Manna, Biplab; Karmakar, Avishek; Sahu, Amit; Ghosh, Sujit K

    2016-06-27

    A three-dimensional water-stable cationic metal-organic framework (MOF) pillared by a neutral ligand and with Ni(II)  metal nodes has been synthesized employing a rational design approach. Owing to the ordered arrangement of the uncoordinated tetrahedral sulfate (SO4 (2-) ) ions in the channels, the compound has been employed for aqueous-phase ion-exchange applications. The compound exhibits rapid and colorimetric aqueous-phase capture of environmentally toxic oxoanions (with similar geometries) in a selective manner. This system is the first example of a MOF-based system which absorbs both dichromate (Cr2 O7 (2-) ) and permanganate (MnO4 (-) ) ions, with the latter acting as a model for the radioactive contaminant pertechnetate (TcO4 (-) ). PMID:26855323

  10. Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks.

    PubMed

    Kim, Hyunho; Cho, H Jeremy; Narayanan, Shankar; Yang, Sungwoo; Furukawa, Hiroyasu; Schiffres, Scott; Li, Xiansen; Zhang, Yue-Biao; Jiang, Juncong; Yaghi, Omar M; Wang, Evelyn N

    2016-01-01

    Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes. PMID:26796523

  11. System and method for generating and/or screening potential metal-organic frameworks

    DOEpatents

    Wilmer, Christopher E; Leaf, Michael; Snurr, Randall Q; Farha, Omar K; Hupp, Joseph T

    2015-04-21

    A system and method for systematically generating potential metal-organic framework (MOFs) structures given an input library of building blocks is provided herein. One or more material properties of the potential MOFs are evaluated using computational simulations. A range of material properties (surface area, pore volume, pore size distribution, powder x-ray diffraction pattern, methane adsorption capability, and the like) can be estimated, and in doing so, illuminate unidentified structure-property relationships that may only have been recognized by taking a global view of MOF structures. In addition to identifying structure-property relationships, this systematic approach to identify the MOFs of interest is used to identify one or more MOFs that may be useful for high pressure methane storage.

  12. System and method for generating and/or screening potential metal-organic frameworks

    DOEpatents

    Wilmer, Christopher E; Leaf, Michael; Snurr, Randall Q; Farha, Omar K; Hupp, Joseph T

    2014-12-02

    A system and method for systematically generating potential metal-organic framework (MOFs) structures given an input library of building blocks is provided herein. One or more material properties of the potential MOFs are evaluated using computational simulations. A range of material properties (surface area, pore volume, pore size distribution, powder x-ray diffraction pattern, methane adsorption capability, and the like) can be estimated, and in doing so, illuminate unidentified structure-property relationships that may only have been recognized by taking a global view of MOF structures. In addition to identifying structure-property relationships, this systematic approach to identify the MOFs of interest is used to identify one or more MOFs that may be useful for high pressure methane storage.

  13. A Luminescent Metal-Organic Framework Thermometer with Intrinsic Dual Emission from Organic Lumophores.

    PubMed

    Zhang, Hao; Lin, Chensheng; Sheng, Tianlu; Hu, Shengmin; Zhuo, Chao; Fu, Ruibiao; Wen, Yuehong; Li, Haoran; Su, Shaodong; Wu, Xintao

    2016-03-18

    A new mixed-ligand metal-organic framework (MOF), ZnATZ-BTB, has been constructed as a luminescent ratiometric thermometer by making use of the intrinsic dual emission at cryogenic temperatures. Its twofold interpenetrated network promotes the Dexter energy transfer (DET) between the mixed organic lumophores. The temperature-dependent luminescent behavior arises from the thermal equilibrium between two separated excited states coupled by DET, which is confirmed by Boltzmann distribution fitting. The small excited-state energy gap allows ZnATZ-BTB to measure and visualize cryogenic temperatures (30-130 K) with significantly high relative sensitivity (up to 5.29 % K(-1) at 30 K). Moreover, it is the first example of a ratiometric MOF thermometer the dual emitting sources of which are widely applicable mixed organic ligands, opening up new opportunities for designing such devices. PMID:26864609

  14. Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation

    NASA Astrophysics Data System (ADS)

    Feng, Dawei; Liu, Tian-Fu; Su, Jie; Bosch, Mathieu; Wei, Zhangwen; Wan, Wei; Yuan, Daqiang; Chen, Ying-Pin; Wang, Xuan; Wang, Kecheng; Lian, Xizhen; Gu, Zhi-Yuan; Park, Jihye; Zou, Xiaodong; Zhou, Hong-Cai

    2015-01-01

    Enzymatic catalytic processes possess great potential in chemical manufacturing, including pharmaceuticals, fuel production and food processing. However, the engineering of enzymes is severely hampered due to their low operational stability and difficulty of reuse. Here, we develop a series of stable metal-organic frameworks with rationally designed ultra-large mesoporous cages as single-molecule traps (SMTs) for enzyme encapsulation. With a high concentration of mesoporous cages as SMTs, PCN-333(Al) encapsulates three enzymes with record-high loadings and recyclability. Immobilized enzymes that most likely undergo single-enzyme encapsulation (SEE) show smaller Km than free enzymes while maintaining comparable catalytic efficiency. Under harsh conditions, the enzyme in SEE exhibits better performance than free enzyme, showing the effectiveness of SEE in preventing enzyme aggregation or denaturation. With extraordinarily large pore size and excellent chemical stability, PCN-333 may be of interest not only for enzyme encapsulation, but also for entrapment of other nanoscaled functional moieties.

  15. Highly efficient enrichment of phosphopeptides by a magnetic lanthanide metal-organic framework.

    PubMed

    Xie, Yiqin; Deng, Chunhui

    2016-10-01

    Highly efficient enrichment of phosphopeptides from complex biological samples is crucial prior to mass spectrometry analysis due to the low abundance and ion suppression effects. In this study, a facile route was designed for preparation of a magnetic erbium(Er)-based metal-organic framework (denoted as Fe3O4@PDA@Er(btc)), which was synthesized with 1,3,5-benzenetricarboxylic acid(H3btc) as ligand and grafted on the polydopamine (PDA) - coated Fe3O4. The as-prepared material exhibited ultra-high sensitivity (detection limit of 20amol/μL) and selectivity at a low mass ratio of β-Casein/BSA (1:500). Moreover, it was also investigated for enrichment of phosphopeptides from human serum, which provided a promising technique for highly efficient enrichment of low-abundance phosphorylated peptides in the practical application. PMID:27474271

  16. High photoluminescent metal-organic frameworks as optical markers for the identification of gunshot residues.

    PubMed

    Weber, Ingrid Távora; de Melo, Adenaule James Geber; Lucena, Marcella Auxiliadora de Melo; Rodrigues, Marcelo Oliveira; Alves, Severino

    2011-06-15

    Gunshot residue (GSR) are solid particles produced when a firearm is discharged, and its detection is important evidence in forensic investigations. Currently, scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS) is the standard technique adopted for the analysis and identification of GSR; however, this methodology is inefficient for lead-free ammunition. Herein, we report the inclusion of high photoluminescent metal-organic frameworks in ammunition to allow for the visual detection of GSR. The tests indicated that marked GSR is easily visible in proportions above 5.0 wt %. A total of 1 g of marker suffices to tag 100 0.38 mm bullets or 62 0.40 mm bullets. PMID:21585195

  17. Synthesis and structure of new carbohydrate metal-organic frameworks and inclusion complexes

    NASA Astrophysics Data System (ADS)

    Sha, Jing-Quan; Wu, Lian-He; Li, Shu-Xian; Yang, Xiao-Ning; Zhang, Yu; Zhang, Qian-Nan; Zhu, Pei-Pei

    2015-12-01

    Two new metal-organic framework compounds based on natural β-cyclodextrin molecules (β-CD) and alkali metals (Na+/K+) were synthesized and characterized by elemental analyses, IR, XPRD and 1HNMR. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 possess the bowl-like pore and the "8" type double channels configuration. Due to the [blow + channel] double configuration, 5-Fluorouracil (5-FU) and Quercetin inclusion complexes of compound 1 are studied, and the results show that the two kinds of drug with different structure and size can be included into the compound at the same time, which is expected to become a new type of multi-functional green crystalline solid material.

  18. Dubinin-Astakhov model for acetylene adsorption on metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Cheng, Peifu; Hu, Yun Hang

    2016-07-01

    Acetylene (C2H2) is explosive at a pressure above 29 psi, causing a safety issue for its storage and applications. C2H2 adsorption on metal-organic frameworks (MOFs) has been explored to solve the issue. However, a suitable isotherm equation for C2H2 adsorption on various MOFs has not been found. In this paper, it was demonstrated that Dubinin-Astakhov equation can be exploited as a general isotherm model to depict C2H2 adsorption on MOF-5, ZIF-8, HKUST-1, and MIL-53. In contrast, commonly used Langmuir and BET models exhibited their inapplicability for C2H2 adsorption on those MOFs.

  19. Mechanized azobenzene-functionalized zirconium metal-organic framework for on-command cargo release

    PubMed Central

    Meng, Xiangshi; Gui, Bo; Yuan, Daqiang; Zeller, Matthias; Wang, Cheng

    2016-01-01

    Stimuli-responsive metal-organic frameworks (MOFs) have gained increasing attention recently for their potential applications in many areas. We report the design and synthesis of a water-stable zirconium MOF (Zr-MOF) that bears photoresponsive azobenzene groups. This particular MOF can be used as a reservoir for storage of cargo in water, and the cargo-loaded MOF can be further capped to construct a mechanized MOF through the binding of β-cyclodextrin with the azobenzene stalks on the MOF surface. The resulting mechanized MOF has shown on-command cargo release triggered by ultraviolet irradiation or addition of competitive agents without premature release. This study represents a simple approach to the construction of stimuli-responsive mechanized MOFs, and considering mechanized UiO-68-azo made from biocompatible components, this smart system may provide a unique MOF platform for on-command drug delivery in the future. PMID:27493996

  20. Electronic and magnetic properties of a conductive metal-organic framework from first principles

    NASA Astrophysics Data System (ADS)

    Hamed, Samia M.; Reyes-Lillo, Sebastian E.; Neaton, Jeffrey B.

    Motivated by the recent synthesis of a mixed-valence metal-organic framework (MOF) displaying high electron mobilities upon reduction, we undertake a computational study of its electronic, structural, and magnetic properties, utilizing ab initio density functional theory. We model the reduced system through charge doping, and the local ligand environment through finite cluster calculations. Molecular orbitals near the Fermi level are found to display mixtures of localized iron d and delocalized ligand p states suggesting strong charge carrier delocalization. Furthermore, we extend our study to one dimensional and three dimensional periodic systems and discuss possible transport mechanisms. Finally, the static correlation effects due to the presence of partially filled iron d orbitals requires an especially careful choice of exchange correlation functional, and the consequence of this choice is demonstrated.

  1. Nucleation and Early Stages of Layer-by-Layer Growth of Metal Organic Frameworks on Surfaces

    PubMed Central

    2015-01-01

    High resolution atomic force microscopy (AFM) is used to resolve the evolution of crystallites of a metal organic framework (HKUST-1) grown on Au(111) using a liquid-phase layer-by-layer methodology. The nucleation and faceting of individual crystallites is followed by repeatedly imaging the same submicron region after each cycle of growth and we find that the growing surface is terminated by {111} facets leading to the formation of pyramidal nanostructures for [100] oriented crystallites, and triangular [111] islands with typical lateral dimensions of tens of nanometres. AFM images reveal that crystallites can grow by 5–10 layers in each cycle. The growth rate depends on crystallographic orientation and the morphology of the gold substrate, and we demonstrate that under these conditions the growth is nanocrystalline with a morphology determined by the minimum energy surface. PMID:26709359

  2. NMR relaxation and exchange in metal-organic frameworks for surface area screening

    SciTech Connect

    Chen, JJ; Mason, JA; Bloch, ED; Gygi, D; Long, JR; Reimer, JA

    2015-03-15

    We describe a robust screening technique that correlates the surface area of metal organic frameworks to the proton T-2 relaxation behavior of imbibed solvent at low field (13 MHz). In frameworks with small pore sizes (<1 nm) or strong solvent-framework interactions, diffusional exchange between the pore-confined and inter-particle solvent populations remains slow compared to the T-2 of the pore-confined solvent, allowing for a direct porosity analysis of the T-2 spectrum obtained from Laplace inversions. Increases in framework pore-size (>1 nm) lead to corresponding increases in the rate of solvent exchange, as confirmed by T-2 relaxation exchange (REXSY) experiments; increases in the pore size also increases the T-2 of the pore-confined solvent. The combination of these two effects results in comparable rates of relaxation and exchange, which precludes the direct analysis of Laplace inversions. Thus, two- and three-site kinetics models were applied to extract porosity from relaxation decays, thereby improving the utility of the porosity screening tool. (C) 2014 Elsevier Inc. All rights reserved.

  3. Functionalization of Metal-Organic Frameworks for Enhanced Stability under Humid Carbon Dioxide Capture Conditions.

    PubMed

    Andirova, Dinara; Lei, Yu; Zhao, Xiaodan; Choi, Sunho

    2015-10-26

    Metal-organic frameworks (MOFs) have been highlighted recently as promising materials for CO2 capture. However, in practical CO2 capture processes, such as capture from flue gas or ambient air, the adsorption properties of MOFs tend to be harmed by the presence of moisture possibly because of the hydrophilic nature of the coordinatively unsaturated sites (CUSs) within their framework. In this work, the CUSs of the MOF framework are functionalized with amine-containing molecules to prevent structural degradation in a humid environment. Specifically, the framework of the magnesium dioxybenzenedicarboxylate (Mg/DOBDC) MOF was functionalized with ethylenediamine (ED) molecules to make the overall structure less hydrophilic. Structural analysis after exposure to high-temperature steam showed that the ED-functionalized Mg/DOBDC (ED-Mg/DOBDC) is more stable under humid conditions, than Mg/DOBDC, which underwent drastic structural changes. ED-Mg/DOBDC recovered its CO2 adsorption capacity and initial adsorption rate quite well as opposed to the original Mg/DOBDC, which revealed a significant reduction in its capture capacity and kinetics. These results suggest that the amine-functionalization of the CUSs is an effective way to enhance the structural stability of MOFs as well as their capture of humid CO2 . PMID:26367016

  4. Imparting functionality to a metal-organic framework material by controlled nanoparticle encapsulation.

    PubMed

    Lu, Guang; Li, Shaozhou; Guo, Zhen; Farha, Omar K; Hauser, Brad G; Qi, Xiaoying; Wang, Yi; Wang, Xin; Han, Sanyang; Liu, Xiaogang; DuChene, Joseph S; Zhang, Hua; Zhang, Qichun; Chen, Xiaodong; Ma, Jan; Loo, Say Chye Joachim; Wei, Wei D; Yang, Yanhui; Hupp, Joseph T; Huo, Fengwei

    2012-04-01

    Microporous metal-organic frameworks (MOFs) that display permanent porosity show great promise for a myriad of purposes. The potential applications of MOFs can be developed further and extended by encapsulating various functional species (for example, nanoparticles) within the frameworks. However, despite increasing numbers of reports of nanoparticle/MOF composites, simultaneously to control the size, composition, dispersed nature, spatial distribution and confinement of the incorporated nanoparticles within MOF matrices remains a significant challenge. Here, we report a controlled encapsulation strategy that enables surfactant-capped nanostructured objects of various sizes, shapes and compositions to be enshrouded by a zeolitic imidazolate framework (ZIF-8). The incorporated nanoparticles are well dispersed and fully confined within the ZIF-8 crystals. This strategy also allows the controlled incorporation of multiple nanoparticles within each ZIF-8 crystallite. The as-prepared nanoparticle/ZIF-8 composites exhibit active (catalytic, magnetic and optical) properties that derive from the nanoparticles as well as molecular sieving and orientation effects that originate from the framework material. PMID:22437717

  5. A multifunctional metal-organic framework based tumor targeting drug delivery system for cancer therapy

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Gang; Dong, Zhi-Yue; Cheng, Hong; Wan, Shuang-Shuang; Chen, Wei-Hai; Zou, Mei-Zhen; Huo, Jia-Wei; Deng, He-Xiang; Zhang, Xian-Zheng

    2015-09-01

    Drug delivery systems (DDSs) with biocompatibility and precise drug delivery are eagerly needed to overcome the paradox in chemotherapy that high drug doses are required to compensate for the poor biodistribution of drugs with frequent dose-related side effects. In this work, we reported a metal-organic framework (MOF) based tumor targeting DDS developed by a one-pot, and organic solvent-free ``green'' post-synthetic surface modification procedure, starting from the nanoscale MOF MIL-101. Owing to the multifunctional surface coating, premature drug release from this DDS was prevented. Due to the pH responsive benzoic imine bond and the redox responsive disulfide bond at the modified surface, this DDS exhibited tumor acid environment enhanced cellular uptake and intracellular reducing environment triggered drug release. In vitro and in vivo results showed that DOX loaded into this DDS exhibited effective cancer cell inhibition with much reduced side effects.Drug delivery systems (DDSs) with biocompatibility and precise drug delivery are eagerly needed to overcome the paradox in chemotherapy that high drug doses are required to compensate for the poor biodistribution of drugs with frequent dose-related side effects. In this work, we reported a metal-organic framework (MOF) based tumor targeting DDS developed by a one-pot, and organic solvent-free ``green'' post-synthetic surface modification procedure, starting from the nanoscale MOF MIL-101. Owing to the multifunctional surface coating, premature drug release from this DDS was prevented. Due to the pH responsive benzoic imine bond and the redox responsive disulfide bond at the modified surface, this DDS exhibited tumor acid environment enhanced cellular uptake and intracellular reducing environment triggered drug release. In vitro and in vivo results showed that DOX loaded into this DDS exhibited effective cancer cell inhibition with much reduced side effects. Electronic supplementary information (ESI) available

  6. Formation mechanism of the secondary building unit in a chromium terephthalate metal-organic framework

    SciTech Connect

    Cantu Cantu, David; McGrail, B. Peter; Glezakou, Vassiliki Alexandra

    2014-09-18

    Based on density functional theory calculations and simulation, a detailed mechanism is presented on the formation of the secondary building unit (SBU) of MIL-101, a chromium terephthalate metal-organic framework (MOF). SBU formation is key to MOF nucleation, the rate-limiting step in the formation process of many MOFs. A series of reactions that lead to the formation of the SBU of MIL-101 is proposed in this work. Initial rate-limiting reactions form the metal cluster with three chromium (III) atoms linked to a central bridging oxygen. Terephthalate linkers play a key role as chromium (III) atoms are joined to linker carboxylate groups prior to the placement of the central bridging oxygen. Multiple linker addition reactions, which follow in different paths due to structural isomers, are limited by the removal of water molecules in the first chromium coordination shell. The least energy path is identified were all linkers on one face of the metal center plane are added first. A simple kinetic model based on transition state theory shows the rate of secondary building unit formation similar to the rate metal-organic framework nucleation. The authors are thankful to Dr. R. Rousseau for a critical reading of the manuscript. This research would not have been possible without the support of the Office of Fossil Energy, U.S. Department of Energy. This research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and the PNNL Institutional Computing (PIC) program located at Pacific Northwest National Laboratory.

  7. Methane storage in flexible metal-organic frameworks with intrinsic thermal management.

    PubMed

    Mason, Jarad A; Oktawiec, Julia; Taylor, Mercedes K; Hudson, Matthew R; Rodriguez, Julien; Bachman, Jonathan E; Gonzalez, Miguel I; Cervellino, Antonio; Guagliardi, Antonietta; Brown, Craig M; Llewellyn, Philip L; Masciocchi, Norberto; Long, Jeffrey R

    2015-11-19

    As a cleaner, cheaper, and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage. Adsorbed natural gas systems have the potential to store high densities of methane (CH4, the principal component of natural gas) within a porous material at ambient temperature and moderate pressures. Although activated carbons, zeolites, and metal-organic frameworks have been investigated extensively for CH4 storage, there are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from the adsorbent. Here, we use a reversible phase transition in a metal-organic framework to maximize the deliverable capacity of CH4 while also providing internal heat management during adsorption and desorption. In particular, the flexible compounds Fe(bdp) and Co(bdp) (bdp(2-) = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp 'step'. Such behaviour enables greater storage capacities than have been achieved for classical adsorbents, while also reducing the amount of heat released during adsorption and the impact of cooling during desorption. The pressure and energy associated with the phase transition can be tuned either chemically or by application of mechanical pressure. PMID:26503057

  8. Methane storage in flexible metal-organic frameworks with intrinsic thermal management

    NASA Astrophysics Data System (ADS)

    Mason, Jarad A.; Oktawiec, Julia; Taylor, Mercedes K.; Hudson, Matthew R.; Rodriguez, Julien; Bachman, Jonathan E.; Gonzalez, Miguel I.; Cervellino, Antonio; Guagliardi, Antonietta; Brown, Craig M.; Llewellyn, Philip L.; Masciocchi, Norberto; Long, Jeffrey R.

    2015-11-01

    As a cleaner, cheaper, and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage. Adsorbed natural gas systems have the potential to store high densities of methane (CH4, the principal component of natural gas) within a porous material at ambient temperature and moderate pressures. Although activated carbons, zeolites, and metal-organic frameworks have been investigated extensively for CH4 storage, there are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from the adsorbent. Here, we use a reversible phase transition in a metal-organic framework to maximize the deliverable capacity of CH4 while also providing internal heat management during adsorption and desorption. In particular, the flexible compounds Fe(bdp) and Co(bdp) (bdp2- = 1,4-benzenedipyrazolate) are shown to undergo a structural phase transition in response to specific CH4 pressures, resulting in adsorption and desorption isotherms that feature a sharp ‘step’. Such behaviour enables greater storage capacities than have been achieved for classical adsorbents, while also reducing the amount of heat released during adsorption and the impact of cooling during desorption. The pressure and energy associated with the phase transition can be tuned either chemically or by application of mechanical pressure.

  9. Anion Binding in Metal-Organic Frameworks Functionalized with Urea Hydrogen-Bonding Groups

    SciTech Connect

    Custelcean, Radu; Moyer, Bruce A; Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2006-01-01

    A series of metal-organic frameworks (MOFs) functionalized with urea hydrogen-bonding groups has been synthesized and structurally analyzed by single-crystal X-ray diffraction to evaluate the efficacy of anion coordination by urea within the structural constraints of the MOFs. We found that urea-based functionalities may be used for anion binding within metal-organic frameworks when the tendency for urea{hor_ellipsis}urea self-association is decreased by strengthening the intramolecular CH{hor_ellipsis}O hydrogen bonding of N-phenyl substituents to the carbonyl oxygen atom. Theoretical calculations indicate that N,N'-bis(m-pyridyl)urea (BPU) and N,N'-bis(m-cyanophenyl)urea (BCPU) should have enhanced hydrogen-bonding donor abilities toward anions and decreased tendencies to self-associate into hydrogen-bonded tapes compared to other disubstituted ureas. Accordingly, BPU and BCPU were incorporated in MOFs as linkers through coordination of various Zn, Cu, and Ag transition metal salts, including Zn(ClO{sub 4}){sub 2}, ZnSO{sub 4}, Cu(NO{sub 3}){sub 2}, Cu(CF{sub 3}SO{sub 3}){sub 2}, AgNO{sub 3}, and AgSO{sub 3}CH{sub 3}. Structural analysis by single-crystal X-ray diffraction showed that these linkers are versatile anion binders, capable of chelate hydrogen bonding to all of the oxoanions explored. Anion coordination by the urea functionalities was found to successfully compete with urea self-association in all cases except for that of charge-diffuse perchlorate.

  10. Embedding Knowledge in 3D Data Frameworks in Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Coughenour, C. M.; Vincent, M. L.; de Kramer, M.; Senecal, S.; Fritsch, D.; Flores Gutirrez, M.; Lopez-Menchero Bendicho, V. M.; Ioannides, M.

    2015-08-01

    At present, where 3D modeling and visualisation in cultural heritage are concerned, an object's documentation lacks its interconnected memory provided by multidisciplinary examination and linked data. As the layers of paint, wood, and brick recount a structure's physical properties, the intangible, such as the forms of worship through song, dance, burning incense, and oral traditions, contributes to the greater story of its cultural heritage import. Furthermore, as an object or structure evolves through time, external political, religious, or environmental forces can affect it as well. As tangible and intangible entities associated with the structure transform, its narrative becomes dynamic and difficult to easily record. The Initial Training Network for Digital Cultural Heritage (ITN-DCH), a Marie Curie Actions project under the EU 7th Framework Programme, seeks to challenge this complexity by developing a novel methodology capable of offering such a holistic framework. With the integration of digitisation, conservation, linked data, and retrieval systems for DCH, the nature of investigation and dissemination will be augmented significantly. Examples of utilisating and evaluating this framework will range from a UNESCOWorld Heritage site, the Byzantine church of Panagia Forviotissa Asinou in the Troodos Mountains of Cyprus, to various religious icons and a monument located at the Monastery of Saint Neophytos. The application of this effort to the Asinou church, representing the first case study of the ITN-DCH project, is used as a template example in order to assess the technical challenges involved in the creation of such a framework.

  11. Guest-dependent high pressure phenomena in a nanoporous metal-organic framework material.

    PubMed

    Chapman, Karena W; Halder, Gregory J; Chupas, Peter J

    2008-08-13

    The nanoporous metal-organic framework material Cu3(1,3,5-benzenetricarboxylate)2(H2O)3.{guest} exhibits anomalous compression under applied pressure that is associated with the hyper-filling of the pore network. This behavior involves a dramatic transition between a "hard" regime (bulk modulus, Khard approximately 118 GPa), where the pressure-transmitting fluid penetrates the framework cavities, and a "soft" regime (Ksoft approximately 30 GPa), where the guest-framework system compresses concertedly. Not only is the duality in compressibility triggered by the availability of potential guests but the size/penetrability of the guest molecules determines the pressure at which the hard-soft transition occurs. Specifically, the observed compression behavior depends on the size of the pressure-transmitting fluid molecules, the sample particle size (i.e., the extent of the pore network), and the rate at which the pressure is increased. The unprecedented pressure-induced phenomena documented here, illustrates the exotic high-pressure behaviors possible in this versatile class of advanced functional materials with broad implications for their structure-function relationships and accordingly their practical application. PMID:18636710

  12. Microscopic Mechanism of Chiral Induction in a Metal-Organic Framework.

    PubMed

    Evans, Jack D; Coudert, François-Xavier

    2016-05-18

    The recently reported process of chiral induction in a metal-organic framework (MOF) by nonchiral guest adsorption, demonstrated on the prototypical MOF-5, may revolutionize the production of MOFs for enantioselective separation and catalysis. Herein, we describe an investigation employing multiscale molecular simulation to discover the microscopic mechanism of chiral induction and investigate the stability of the resulting framework. Our results explain how the molecular size and chemical nature of N-methyl-2-pyrrolidone (NMP) give rise to the chiral transformation in MOF-5, whereas it cannot occur for other guest molecules, such as N,N-dimethylformamide (DMF). Moreover, we show that the guest-free CMOF-5 structure is energetically unstable, with either the achiral conventional structure or a closed pore structure preferred, demonstrating that chirality will not be retained upon activation of CMOF-5. While this limits the usability of chiral induction in MOFs, our study opens new avenues for the use of other guest molecules and provides microscopic insight into this unexpected outcome of guest-framework interactions in a soft porous crystal. PMID:27146908

  13. Structural Effects in Visible-Light-Responsive Metal-Organic Frameworks Incorporating ortho-Fluoroazobenzenes.

    PubMed

    Castellanos, Sonia; Goulet-Hanssens, Alexis; Zhao, Fangli; Dikhtiarenko, Alla; Pustovarenko, Alexey; Hecht, Stefan; Gascon, Jorge; Kapteijn, Freek; Bléger, David

    2016-01-11

    The ability to control the interplay of materials with low-energy photons is important as visible light offers several appealing features compared to ultraviolet radiation (less damaging, more selective, predominant in the solar spectrum, possibility to increase the penetration depth). Two different metal-organic frameworks (MOFs) were synthesized from the same linker bearing all-visible ortho-fluoroazobenzene photoswitches as pendant groups. The MOFs exhibit different architectures that strongly influence the ability of the azobenzenes to isomerize inside the voids. The framework built with Al-based nodes has congested 1D channels that preclude efficient isomerization. As a result, local light-heat conversion can be used to alter the CO2 adsorption capacity of the material on exposure to green light. The second framework, built with Zr nodes, provides enough room for the photoswitches to isomerize, which leads to a unique bistable photochromic MOF that readily responds to blue and green light. The superiority of green over UV irradiation was additionally demonstrated by reflectance spectroscopy and analysis of digested samples. This material offers promising perspectives for liquid-phase applications such as light-controlled catalysis and adsorptive separation. PMID:26617393

  14. Metallacarborane-Based Metal-Organic Framework with a Complex Topology

    SciTech Connect

    Kennedy, RD; Clingerman, DJ; Morris, W; Wilmer, CE; Sarjeant, AA; Stern, CL; O'Keeffe, M; Snurr, RQ; Hupp, JT; Farha, OK; Mirkin, CA

    2014-03-01

    The long, linear cobalt(III) bis(dicarbollide)-based bis(isophthalic acid) anion was synthesized as a tetraphenylphosphonium salt in five steps from 8-iodo-closo-1,2-C2B10H11. The solvothermal reaction between the anionic bis(isophthalic acid) linker and copper(II) nitrate in acidified DMF yielded single crystals. Despite the tendency for copper(II) and analogous linear tetraacids to form members of an isoreticular family of metal-organic frameworks (MOFs) with the fof topology, single-crystal X-ray diffraction analysis revealed the growth of three different frameworks. These MOFs, NU-150, NU-151, and NU-152, have three distinct topologies: fof, sty, and hbk, respectively. NU-152 has a novel quadrinodal topology in which cuboctahedral coordination polyhedra are each connected to 10 neighboring polyhedra via the cobalt bis(dicarbollide) portions of the linkers. The formation of these frameworks illustrates the limitations of structure prediction in MOP chemistry and the possibility of using flexible linkers to generate unexpected topologies. Furthermore, this work represents the first example of the incorporation of an anionic bis(dicarbollide) unit into a MOF.

  15. Research Update: Mechanical properties of metal-organic frameworks - Influence of structure and chemical bonding

    NASA Astrophysics Data System (ADS)

    Li, Wei; Henke, Sebastian; Cheetham, Anthony K.

    2014-12-01

    Metal-organic frameworks (MOFs), a young family of functional materials, have been attracting considerable attention from the chemistry, materials science, and physics communities. In the light of their potential applications in industry and technology, the fundamental mechanical properties of MOFs, which are of critical importance for manufacturing, processing, and performance, need to be addressed and understood. It has been widely accepted that the framework topology, which describes the overall connectivity pattern of the MOF building units, is of vital importance for the mechanical properties. However, recent advances in the area of MOF mechanics reveal that chemistry plays a major role as well. From the viewpoint of materials science, a deep understanding of the influence of chemical effects on MOF mechanics is not only highly desirable for the development of novel functional materials with targeted mechanical response, but also for a better understanding of important properties such as structural flexibility and framework breathing. The present work discusses the intrinsic connection between chemical effects and the mechanical behavior of MOFs through a number of prototypical examples.

  16. Guest-dependent high-pressure phenomena in a nanoporous metal-organic framework material.

    SciTech Connect

    Chapman, K.; Halder, G. J.; Chupas, P. J.

    2008-08-13

    The nanoporous metal?organic framework material Cu{sub 3}(1,3,5-benzenetricarboxylate){sub 2}(H{sub 2}O){sub 3} {center_dot} (guest) exhibits anomalous compression under applied pressure that is associated with the hyper-filling of the pore network. This behavior involves a dramatic transition between a 'hard' regime (bulk modulus, K{sub hard} {approx} 118 GPa), where the pressure-transmitting fluid penetrates the framework cavities, and a 'soft' regime (K{sub soft} {approx} 30 GPa), where the guest-framework system compresses concertedly. Not only is the duality in compressibility triggered by the availability of potential guests but the size/penetrability of the guest molecules determines the pressure at which the hard-soft transition occurs. Specifically, the observed compression behavior depends on the size of the pressure-transmitting fluid molecules, the sample particle size (i.e., the extent of the pore network), and the rate at which the pressure is increased. The unprecedented pressure-induced phenomena documented here, illustrates the exotic high-pressure behaviors possible in this versatile class of advanced functional materials with broad implications for their structure-function relationships and accordingly their practical application.

  17. Postsynthetic modifications of iron-carboxylate nanoscale metal-organic frameworks for imaging and drug delivery.

    PubMed

    Taylor-Pashow, Kathryn M L; Della Rocca, Joseph; Xie, Zhigang; Tran, Sylvie; Lin, Wenbin

    2009-10-14

    Fe(III)-carboxylate nanoscale metal-organic frameworks (NMOFs) with the MIL-101 structure were synthesized using a solvothermal technique with microwave heating. The approximately 200 nm particles were characterized using a variety of methods, including SEM, PXRD, nitrogen adsorption measurements, TGA, and EDX. By replacing a percentage of the bridging ligand (terephthalic acid) with 2-amino terephthalic acid, amine groups were incorporated into the framework to provide sites for covalent attachment of biologically relevant cargoes while still maintaining the MIL-101 structure. In proof-of-concept experiments, an optical contrast agent (a BODIPY dye) and an ethoxysuccinato-cisplatin anticancer prodrug were successfully incorporated into the Fe(III)-carboxylate NMOFs via postsynthetic modifications of the as-synthesized particles. These cargoes are released upon the degradation of the NMOF frameworks, and the rate of cargo release was controlled by coating the NMOF particles with a silica shell. Potential utility of the new NMOF-based nanodelivery vehicles for optical imaging and anticancer therapy was demonstrated in vitro using HT-29 human colon adenocarcinoma cells. PMID:19807179

  18. Tunable Two-color Luminescence and Host-guest Energy Transfer of Fluorescent Chromophores Encapsulated in Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Yan, Dongpeng; Tang, Yanqun; Lin, Heyang; Wang, Dan

    2014-03-01

    Co-assembly of chromophore guests with host matrices can afford materials which have photofunctionalities different from those of individual components. Compared with clay and zeolite materials, the use of metal-organic frameworks (MOFs) as a host structure for fabricating luminescent host-guest materials is still at an early stage. Herein, we report the incorporation of a laser dye, 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), into stilbene-based and naphthalene-based MOF systems. The resulting materials exhibit blue/red two-color emission, and the intensity ratio of blue to red fluorescence varies in different planes within the MOF crystal as detected by 3D confocal fluorescence microscopy. The observed changes in ratiometric fluorescence suggest the occurrence of energy transfer from MOF host to DCM molecules, which can be further confirmed by periodic density functional theoretical (DFT) calculations. Moreover, selective changes in luminescence behavior are observed on treating the guest@MOF samples with volatile organic compounds (methanol, acetone and toluene), indicating that these host-guest systems have potential applications as fluorescence sensors. It can be expected that by rational selection of MOF hosts and guest chromophores with suitable emissive colors and energy levels, a wide variety of multi-color luminescent and energy-transfer systems can readily be prepared in a similar manner.

  19. Postsynthetic Improvement of the Physical Properties in a Metal-Organic Framework through a Single Crystal to Single Crystal Transmetallation.

    PubMed

    Grancha, Thais; Ferrando-Soria, Jesús; Zhou, Hong-Cai; Gascon, Jorge; Seoane, Beatriz; Pasán, Jorge; Fabelo, Oscar; Julve, Miguel; Pardo, Emilio

    2015-05-26

    A single crystal to single crystal transmetallation process takes place in the three-dimensional (3D) metal-organic framework (MOF) of formula Mg(II) 2 {Mg(II) 4 [Cu(II) 2 (Me3 mpba)2 ]3 }⋅45 H2 O (1; Me3 mpba(4-) =N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)). After complete replacement of the Mg(II) ions within the coordination network and those hosted in the channels by either Co(II) or Ni(II) ions, 1 is transmetallated to yield two novel MOFs of formulae Co2 (II) {Co(II) 4 [Cu(II) 2 (Me3 mpba)2 ]3 }⋅56 H2 O (2) and Ni2 (II) {Ni(II) 4 [Cu(II) 2 (Me3 mpba)2 ]3 }⋅ 54 H2 O (3). This unique postsynthetic metal substitution affords materials with higher structural stability leading to enhanced gas sorption and magnetic properties. PMID:25873186

  20. Three novel metal-organic frameworks based on flexible porphyrin tetracarboxylic acids as highly effective catalysts

    NASA Astrophysics Data System (ADS)

    Zhang, Zengqi; Su, Xiaoqin; Yu, Fan; Li, Jun

    2016-06-01

    Targeted synthesis of metalloporphyrinic frameworks (MPFs) with Cu(II) (1), Ni(II) (2, 3) 5, 10, 15, 20-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (Cu(TCMOPP) and Ni(TCMOPP)) as building blocks afforded three new extended coordination polymers inter-linked by Zn(II) (1) and K(I) (2, 3). 1 shows 2D frameworks while 2, 3 are 3D frameworks. The open channel are 7-17 Å wide and accessible to guest/solvent molecules. Besides, the thermogravimetric analyses (TGA) indicate that the framework structures of the three compounds are stable until 300 °C. In addition, the catalytic activities of 1-3 to the alkylbenzenes oxidation are examined, and the results indicate that 1 exhibit high catalytic activity to oxidation of ethylbenzene and 1,2,3,4-tetrahydronaphthalene with conversion of 64.1% and 80.3% respectively.

  1. Metal-Ion Metathesis and Properties of Triarylboron-Functionalized Metal-Organic Frameworks.

    PubMed

    Wang, Xiaoqing; Zhang, Liangliang; Yang, Jie; Dai, Fangna; Wang, Rongming; Sun, Daofeng

    2015-07-01

    An anionic metal-organic framework, H3[(Mn4Cl)3L8]⋅30H2O⋅2.5 DMF⋅5 Diox (UPC-15), was successfully prepared by the reaction of MnCl2 with tris(p-carboxylic acid)tridurylborane (H3 L) under solvothermal conditions. UPC-15 with wide-open pores (∼18.8 Å) is constructed by packing of octahedral and cuboctahedral cages, and exhibits high gas-sorption capabilities. Notably, UPC-15 shows selective adsorption of cationic dyes due to the anion framework. Moreover, the catalytic and magnetic properties were investigated, and UPC-15 can highly catalyze the cyanosilylation of aromatic aldehydes. UPC-15 exhibits the exchange of metal ions from Mn to Cu in a single-crystal-to-single-crystal manner to generate UPC-16, which could not be obtained by the direct solvothermal reaction of CuCl2 and H3L. UPC-16 exhibits similar properties for gas sorption, dye separation, and catalytic activity. However, the magnetic behaviors for UPC-15 and UPC-16 are distinct due to the metal-specific properties. Below 47 K, UPC-15 exhibits a ferromagnetic coupling but UPC-16 shows a dominant antiferromagnetic behavior. PMID:25929722

  2. Zirconium-Based Metal-Organic Framework for Removal of Perrhenate from Water.

    PubMed

    Banerjee, Debasis; Xu, Wenqian; Nie, Zimin; Johnson, Lewis E V; Coghlan, Campbell; Sushko, Maria L; Kim, Dongsang; Schweiger, Michael J; Kruger, Albert A; Doonan, Christian J; Thallapally, Praveen K

    2016-09-01

    The efficient removal of pertechnetate (TcO4(-)) anions from liquid waste or melter off-gas solution for an alternative treatment is one of the promising options to manage (99)Tc in legacy nuclear waste. Safe immobilization of (99)Tc is of major importance because of its long half-life (t1/2 = 2.13 × 10(5) yrs) and environmental mobility. Different types of inorganic and solid-state ion-exchange materials have been shown to absorb TcO4(-) anions from water. However, both high capacity and selectivity have yet to be achieved in a single material. Herein, we show that a protonated version of an ultrastable zirconium-based metal-organic framework can adsorb perrhenate (ReO4(-)) anions, a nonradioactive surrogate for TcO4(-), from water even in the presence of other common anions. Synchrotron-based powder X-ray diffraction and molecular simulations were used to identify the position of the adsorbed ReO4(-) (surrogate for TcO4(-)) molecule within the framework. PMID:27494264

  3. Highly selective water adsorption in a lanthanum metal-organic framework.

    PubMed

    Plessius, Raoul; Kromhout, Rosa; Ramos, André Luis Dantas; Ferbinteanu, Marilena; Mittelmeijer-Hazeleger, Marjo C; Krishna, Rajamani; Rothenberg, Gadi; Tanase, Stefania

    2014-06-23

    We present a new metal-organic framework (MOF) built from lanthanum and pyrazine-2,5-dicarboxylate (pyzdc) ions. This MOF, [La(pyzdc)1.5(H2O)2]⋅2 H2O, is microporous, with 1D channels that easily accommodate water molecules. Its framework is highly robust to dehydration/hydration cycles. Unusually for a MOF, it also features a high hydrothermal stability. This makes it an ideal candidate for air drying as well as for separating water/alcohol mixtures. The ability of the activated MOF to adsorb water selectively was evaluated by means of thermogravimetric analysis, powder and single-crystal X-ray diffraction and adsorption studies, indicating a maximum uptake of 1.2 mmol g(-1) MOF. These results are in agreement with the microporous structure, which permits only water molecules to enter the channels (alcohols, including methanol, are simply too large). Transient breakthrough simulations using water/methanol mixtures confirm that such mixtures can be separated cleanly using this new MOF. PMID:24867871

  4. Structuralization of Ca(2+)-Based Metal-Organic Frameworks Prepared via Coordination Replication of Calcium Carbonate.

    PubMed

    Sumida, Kenji; Hu, Ming; Furukawa, Shuhei; Kitagawa, Susumu

    2016-04-01

    The emergence of metal-organic frameworks (MOFs) as potential candidates to supplant existing adsorbent types in real-world applications has led to an explosive growth in the number of compounds available to researchers, as well as in the diversity of the metal salts and organic linkers from which they are derived. In this context, the use of carbonate-based precursors as metal sources is of interest due to their abundance in mineral deposits and their reaction chemistry with acids, resulting in just water and carbon dioxide as side products. Here, we have explored the use of calcium carbonate as a metal source and demonstrate its versatility as a precursor to several known frameworks, as well as a new flexible compound based on the 2,5-dihydroxybenzoquinone (H2dhbq) linker, Ca(dhbq)(H2O)2. Furthermore, inspired by the ubiquity and unique structures of biomineralized forms of calcium carbonate, we also present examples of the preparation of superstructures of Ca-based MOFs via the coordination replication technique. In all, the results confirm the suitability of carbonate-based metal sources for the preparation of MOFs and further expand upon the growing scope of coordination replication as a convenient strategy for the preparation of structuralized materials. PMID:27002690

  5. Sulfation of metal-organic framework: Opportunities for acid catalysis and proton conductivity

    SciTech Connect

    Goesten, M.G.; Stavitski, E.; Juan-Alcaniz, J.; Ramos-Fernandez, E.V.; Sai Sankar Gupta, K.B.; van Bekkum, H.; Gascon, J. and Kapteijn, F.

    2011-05-24

    A new post-functionalization method for metal-organic frameworks (MOFs) has been developed to introduce acidity for catalysis. Upon treatment with a mixture of triflic anhydride and sulfuric acid, chemically stable MOF structures MIL-101(Cr) and MIL-53(Al) can be sulfated, resulting in a Broensted sulfoxy acid group attached to up to 50% of the aromatic terephthalate linkers of the structure. The sulfated samples have been extensively characterized by solid-state NMR, XANES, and FTIR spectroscopy. The functionalized acidic frameworks show catalytic activity similar to that of acidic polymers like Nafion{reg_sign} display in the esterification of n-butanol with acetic acid (TOF {approx} 1 min{sup -1} {at} 343 K). Water adsorbs strongly up to 4 molecules per sulfoxy acid group, and an additional 2 molecules are taken up at lower temperatures in the 1-D pore channels of S-MIL-53(Al). The high water content and Broensted acidity provide the structure S-MIL-53(Al) a high proton conductivity up to moderate temperatures.

  6. Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

    PubMed Central

    Wang, Chenghong; Liu, Xinlei; Chen, J. Paul; Li, Kang

    2015-01-01

    In this study, water stable zirconium metal-organic framework (UiO-66) has been synthesized and for the first time applied as an adsorbent to remove aquatic arsenic contamination. The as-synthesized UiO-66 adsorbent functions excellently across a broad pH range of 1 to 10, and achieves a remarkable arsenate uptake capacity of 303 mg/g at the optimal pH, i.e., pH = 2. To the best of our knowledge, this is the highest arsenate As(V) adsorption capacity ever reported, much higher than that of currently available adsorbents (5–280 mg/g, generally less than 100 mg/g). The superior arsenic uptake performance of UiO-66 adsorbent could be attributed to the highly porous crystalline structure containing zirconium oxide clusters, which provides a large contact area and plenty of active sites in unit space. Two binding sites within the adsorbent framework are proposed for arsenic species, i.e., hydroxyl group and benzenedicarboxylate ligand. At equilibrium, seven equivalent arsenic species can be captured by one Zr6 cluster through the formation of Zr-O-As coordination bonds. PMID:26559001

  7. Cooperative insertion of CO2 in diamine-appended metal-organic frameworks.

    PubMed

    McDonald, Thomas M; Mason, Jarad A; Kong, Xueqian; Bloch, Eric D; Gygi, David; Dani, Alessandro; Crocellà, Valentina; Giordanino, Filippo; Odoh, Samuel O; Drisdell, Walter S; Vlaisavljevich, Bess; Dzubak, Allison L; Poloni, Roberta; Schnell, Sondre K; Planas, Nora; Lee, Kyuho; Pascal, Tod; Wan, Liwen F; Prendergast, David; Neaton, Jeffrey B; Smit, Berend; Kortright, Jeffrey B; Gagliardi, Laura; Bordiga, Silvia; Reimer, Jeffrey A; Long, Jeffrey R

    2015-03-19

    The process of carbon capture and sequestration has been proposed as a method of mitigating the build-up of greenhouse gases in the atmosphere. If implemented, the cost of electricity generated by a fossil fuel-burning power plant would rise substantially, owing to the expense of removing CO2 from the effluent stream. There is therefore an urgent need for more efficient gas separation technologies, such as those potentially offered by advanced solid adsorbents. Here we show that diamine-appended metal-organic frameworks can behave as 'phase-change' adsorbents, with unusual step-shaped CO2 adsorption isotherms that shift markedly with temperature. Results from spectroscopic, diffraction and computational studies show that the origin of the sharp adsorption step is an unprecedented cooperative process in which, above a metal-dependent threshold pressure, CO2 molecules insert into metal-amine bonds, inducing a reorganization of the amines into well-ordered chains of ammonium carbamate. As a consequence, large CO2 separation capacities can be achieved with small temperature swings, and regeneration energies appreciably lower than achievable with state-of-the-art aqueous amine solutions become feasible. The results provide a mechanistic framework for designing highly efficient adsorbents for removing CO2 from various gas mixtures, and yield insights into the conservation of Mg(2+) within the ribulose-1,5-bisphosphate carboxylase/oxygenase family of enzymes. PMID:25762144

  8. Metal-Organic Frameworks: Literature Survey and Recommendation of Potential Sorbent Materials

    SciTech Connect

    Baumann, T F

    2010-04-29

    Metal-organic frameworks (MOFs) are a special type of porous material with a number of unique properties, including exceptionally high surface areas, large internal pore volumes (void space) and tunable pore sizes. These materials are prepared through the assembly of molecular building blocks into ordered three-dimensional structures. The bulk properties of the MOF are determined by the nature of the building blocks and, as such, these materials can be designed with special characteristics that cannot be realized in other sorbent materials, like activated carbons. For example, MOFs can be constructed with binding sites or pockets that can exhibit selectivity for specific analytes. Alternatively, the framework can be engineered to undergo reversible dimensional changes (or 'breathing') upon interaction with an analyte, effectively trapping the molecule of interest in the lattice structure. In this report, we have surveyed the 4000 different MOF structures reported in the open literature and provided recommendations for specific MOF materials that should be investigated as sorbents for this project.

  9. Cooperative insertion of CO2 in diamine-appended metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    McDonald, Thomas M.; Mason, Jarad A.; Kong, Xueqian; Bloch, Eric D.; Gygi, David; Dani, Alessandro; Crocellà, Valentina; Giordanino, Filippo; Odoh, Samuel O.; Drisdell, Walter S.; Vlaisavljevich, Bess; Dzubak, Allison L.; Poloni, Roberta; Schnell, Sondre K.; Planas, Nora; Lee, Kyuho; Pascal, Tod; Wan, Liwen F.; Prendergast, David; Neaton, Jeffrey B.; Smit, Berend; Kortright, Jeffrey B.; Gagliardi, Laura; Bordiga, Silvia; Reimer, Jeffrey A.; Long, Jeffrey R.

    2015-03-01

    The process of carbon capture and sequestration has been proposed as a method of mitigating the build-up of greenhouse gases in the atmosphere. If implemented, the cost of electricity generated by a fossil fuel-burning power plant would rise substantially, owing to the expense of removing CO2 from the effluent stream. There is therefore an urgent need for more efficient gas separation technologies, such as those potentially offered by advanced solid adsorbents. Here we show that diamine-appended metal-organic frameworks can behave as `phase-change' adsorbents, with unusual step-shaped CO2 adsorption isotherms that shift markedly with temperature. Results from spectroscopic, diffraction and computational studies show that the origin of the sharp adsorption step is an unprecedented cooperative process in which, above a metal-dependent threshold pressure, CO2 molecules insert into metal-amine bonds, inducing a reorganization of the amines into well-ordered chains of ammonium carbamate. As a consequence, large CO2 separation capacities can be achieved with small temperature swings, and regeneration energies appreciably lower than achievable with state-of-the-art aqueous amine solutions become feasible. The results provide a mechanistic framework for designing highly efficient adsorbents for removing CO2 from various gas mixtures, and yield insights into the conservation of Mg2+ within the ribulose-1,5-bisphosphate carboxylase/oxygenase family of enzymes.

  10. Electronic and optical excitations in building blocks of the metal organic framework MOF-5

    NASA Astrophysics Data System (ADS)

    Shi, Bin; Hung, Linda; Yildirim, Taner; Ogut, Serdar

    Metal organic frameworks (MOFs) are a relatively new class of materials which are made of metal-oxide clusters linked by organic bridging ligands. In recent years, MOFs have received considerable attention due to their widely tunable structural, chemical and physical properties. We investigate one of the well characterized MOFs, MOF-5, whose framework consists of tetrahedral [Zn40]6+ units linked by rigid arylcarboxylate ligands. We use many-body perturbation (GW +BSE) and time-dependent DFT methods in real space to examine the electronic and optical excitations in the building blocks of MOF-5, such as Zn4O(COOH)6, basic zinc acetate [Zn4O(CH3COO)6], and tetranuclear zinc benzoate [Zn4O(C6H5COO)6]. The calculated spectra are compared with available experimental measurements and existing calculations to shed light on the controversy regarding the nature (metal-ligand versus ligand-ligand) of low-energy electronic and optical excitations in MOF-5. Supported by DOE Grant No. DE-SC0001853.

  11. Bimetallic Metal-Organic Frameworks: Probing the Lewis Acid Site for CO2 Conversion.

    PubMed

    Zou, Ruyi; Li, Pei-Zhou; Zeng, Yong-Fei; Liu, Jia; Zhao, Ruo; Duan, Hui; Luo, Zhong; Wang, Jin-Gui; Zou, Ruqiang; Zhao, Yanli

    2016-05-01

    A highly porous metal-organic framework (MOF) incorporating two kinds of second building units (SBUs), i.e., dimeric paddlewheel (Zn2 (COO)4 ) and tetrameric (Zn4 (O)(CO2 )6 ), is successfully assembled by the reaction of a tricarboxylate ligand with Zn(II) ion. Subsequently, single-crystal-to-single-crystal metal cation exchange using the constructed MOF is investigated, and the results show that Cu(II) and Co(II) ions can selectively be introduced into the MOF without compromising the crystallinity of the pristine framework. This metal cation-exchangeable MOF provides a useful platform for studying the metal effect on both gas adsorption and catalytic activity of the resulted MOFs. While the gas adsorption experiments reveal that Cu(II) and Co(II) exchanged samples exhibit comparable CO2 adsorption capability to the pristine Zn(II) -based MOF under the same conditions, catalytic investigations for the cycloaddition reaction of CO2 with epoxides into related carbonates demonstrate that Zn(II) -based MOF affords the highest catalytic activity as compared with Cu(II) and Co(II) exchanged ones. Molecular dynamic simulations are carried out to further confirm the catalytic performance of these constructed MOFs on chemical fixation of CO2 to carbonates. This research sheds light on how metal exchange can influence intrinsic properties of MOFs. PMID:26900671

  12. Understanding Small-Molecule Interactions in Metal-Organic Frameworks: Coupling Experiment with Theory.

    PubMed

    Lee, Jason S; Vlaisavljevich, Bess; Britt, David K; Brown, Craig M; Haranczyk, Maciej; Neaton, Jeffrey B; Smit, Berend; Long, Jeffrey R; Queen, Wendy L

    2015-10-14

    Metal-organic frameworks (MOFs) have gained much attention as next-generation porous media for various applications, especially gas separation/storage, and catalysis. New MOFs are regularly reported; however, to develop better materials in a timely manner for specific applications, the interactions between guest molecules and the internal surface of the framework must first be understood. A combined experimental and theoretical approach is presented, which proves essential for the elucidation of small-molecule interactions in a model MOF system known as M2 (dobdc) (dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate; M = Mg, Mn, Fe, Co, Ni, Cu, or Zn), a material whose adsorption properties can be readily tuned via chemical substitution. It is additionally shown that the study of extensive families like this one can provide a platform to test the efficacy and accuracy of developing computational methodologies in slightly varying chemical environments, a task that is necessary for their evolution into viable, robust tools for screening large numbers of materials. PMID:26033176

  13. A partially interpenetrated metal-organic framework for selective hysteretic sorption of carbon dioxide

    NASA Astrophysics Data System (ADS)

    Yang, Sihai; Lin, Xiang; Lewis, William; Suyetin, Mikhail; Bichoutskaia, Elena; Parker, Julia E.; Tang, Chiu C.; Allan, David R.; Rizkallah, Pierre J.; Hubberstey, Peter; Champness, Neil R.; Mark Thomas, K.; Blake, Alexander J.; Schröder, Martin

    2012-08-01

    The selective capture of carbon dioxide in porous materials has potential for the storage and purification of fuel and flue gases. However, adsorption capacities under dynamic conditions are often insufficient for practical applications, and strategies to enhance CO2-host selectivity are required. The unique partially interpenetrated metal-organic framework NOTT-202 represents a new class of dynamic material that undergoes pronounced framework phase transition on desolvation. We report temperature-dependent adsorption/desorption hysteresis in desolvated NOTT-202a that responds selectively to CO2. The CO2 isotherm shows three steps in the adsorption profile at 195 K, and stepwise filling of pores generated within the observed partially interpenetrated structure has been modelled by grand canonical Monte Carlo simulations. Adsorption of N2, CH4, O2, Ar and H2 exhibits reversible isotherms without hysteresis under the same conditions, and this allows capture of gases at high pressure, but selectively leaves CO2 trapped in the nanopores at low pressure.

  14. A partially interpenetrated metal-organic framework for selective hysteretic sorption of carbon dioxide.

    PubMed

    Yang, Sihai; Lin, Xiang; Lewis, William; Suyetin, Mikhail; Bichoutskaia, Elena; Parker, Julia E; Tang, Chiu C; Allan, David R; Rizkallah, Pierre J; Hubberstey, Peter; Champness, Neil R; Thomas, K Mark; Blake, Alexander J; Schröder, Martin

    2012-08-01

    The selective capture of carbon dioxide in porous materials has potential for the storage and purification of fuel and flue gases. However, adsorption capacities under dynamic conditions are often insufficient for practical applications, and strategies to enhance CO(2)-host selectivity are required. The unique partially interpenetrated metal-organic framework NOTT-202 represents a new class of dynamic material that undergoes pronounced framework phase transition on desolvation. We report temperature-dependent adsorption/desorption hysteresis in desolvated NOTT-202a that responds selectively to CO(2). The CO(2) isotherm shows three steps in the adsorption profile at 195 K, and stepwise filling of pores generated within the observed partially interpenetrated structure has been modelled by grand canonical Monte Carlo simulations. Adsorption of N(2), CH(4), O(2), Ar and H(2) exhibits reversible isotherms without hysteresis under the same conditions, and this allows capture of gases at high pressure, but selectively leaves CO(2) trapped in the nanopores at low pressure. PMID:22660661

  15. Charge Transfer-Induced Molecular Hole Doping into Thin Film of Metal-Organic Frameworks.

    PubMed

    Lee, Deok Yeon; Kim, Eun-Kyung; Shrestha, Nabeen K; Boukhvalov, Danil W; Lee, Joong Kee; Han, Sung-Hwan

    2015-08-26

    Despite the highly porous nature with significantly large surface area, metal-organic frameworks (MOFs) can be hardly used in electronic and optoelectronic devices due to their extremely poor electrical conductivity. Therefore, the study of MOF thin films that require electron transport or conductivity in combination with the everlasting porosity is highly desirable. In the present work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity are synthesized using layer-by-layer and doctor blade coating techniques followed by iodine doping. The as-prepared and doped films are characterized using FE-SEM, EDX, UV/visible spectroscopy, XPS, current-voltage measurement, photoluminescence spectroscopy, cyclic voltammetry, and incident photon to current efficiency measurements. In addition, the electronic and semiconductor properties of the MOF films are characterized using Hall Effect measurement, which reveals that, in contrast to the insulator behavior of the as-prepared MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by charge transfer-induced hole doping into the frameworks. The observed charge transfer-induced hole doping phenomenon is also confirmed by calculating the densities of states of the as-prepared and iodine doped MOFs based on density functional theory. Photoluminescence spectroscopy demonstrates an efficient interfacial charge transfer between TiO2 and iodine doped MOFs, which can be applied to harvest solar radiations. PMID:26226050

  16. Pore size dynamics in interpenetrated metal organic frameworks for selective sensing of aromatic compounds.

    PubMed

    Myers, Matthew; Podolska, Anna; Heath, Charles; Baker, Murray V; Pejcic, Bobby

    2014-03-28

    The two-fold interpenetrated metal-organic framework, [Zn2(bdc)2(dpNDI)]n (bdc=1,4-benzenedicarboxylate, dpNDI=N'N'-di(4-pyridyl)-1,4,5,8-naphthalenediimide) can undergo structural re-arrangement upon adsorption of chemical species changing its pore structure. For a competitive binding process with multiple analytes of different sizes and geometries, the interpenetrated framework will adopt a conformation to maximize the overall binding interactions. In this study, we show for binary mixtures that there is a high selectivity for the larger methylated aromatic compounds, toluene and p-xylene, over the small non-methylated benzene. The dpNDI moiety within [Zn2(bdc)2(dpNDI)]n forms an exciplex with these aromatic compounds. The emission wavelength is dependent on the strength of the host-guest CT interaction allowing these compounds to be distinguished. We show that the sorption selectivity characteristics can have a significant impact on the fluorescence sensor response of [Zn2(bdc)2(dpNDI)]n towards environmentally important hydrocarbons based contaminants (i.e., BTEX, PAH). PMID:24636414

  17. Structures and Gas Storage Performance of Metal-organic Framework Materials at High Pressures

    NASA Astrophysics Data System (ADS)

    Song, Yang; Hu, Yue; Huang, Yining

    2013-06-01

    Metal Organic Frameworks (MOFs), are crystalline nanoporous materials comprised of small metal clusters connected three-dimensionally by polyfunctional organic ligands. MOFs have been widely studied due to their high porosity, surface area and thermal stability, which make them promising candidates for gas capture and storage. In the MOF family, Zeolitic Imidazolate Frameworks (ZIFs) have attracted much attention because of their promising applications for CO2 storage. In contrast to the extensive studies under ambient conditions, most ZIFs have only been studied under pressure in a very limited range. It is known that pressure can provide an effective driving force to achieve structural modification which includes changes in pore size, opening and geometry, channel shape and internal surface area. Subsequently, these pressure-induced changes will affect the sorption selectivity, capacity and access to the binding sites of the porous materials. Here, we report the first in situ high-pressure investigation of several ZIFs by FTIR spectroscopy. We observed rich pressure-induced transformations upon compression in different pressure ranges. Furthermore, the reversibilities of these transformations upon decompression were also examined. Finally, the performance of CO2 storage of selected ZIFs at high pressures will be addressed. Our observation and analyses contribute to the understanding of chemical and mechanical properties of ZIFs under high-pressure conditions and provide new insight into their storage applications.

  18. Computational screening of large molecule adsorption by metal-organic frameworks.

    SciTech Connect

    Allendorf, Mark D.; Greathouse, Jeffery A.

    2010-04-01

    Grand canonical Monte Carlo simulations were performed to investigate trends in low-pressure adsorption of a broad range of organic molecules by a set of metal-organic frameworks (MOFs). The organic analytes considered here are relevant to applications in chemical detection: small aromatics (o-, m-, and p-xylene), polycyclic aromatic hydrocarbons (naphthalene, anthracene, phenanthrene), explosives (TNT and RDX), and chemical warfare agents (GA and VM). The framework materials included several Zn-MOFs (IRMOFs 1-3, 7, 8), a Cr-MOF (CrMIL-53lp), and a Cu-MOF (HKUST-1). Many of the larger organics were significantly adsorbed by the target MOFs at low pressure, which is consistent with the exceptionally high isosteric heats of adsorption (25 kcal/mol - 60 kcal/mol) for this range of analyte. At a higher loading pressure of 101 kPa, the Zn-MOFs show a much higher volumetric uptake than either CrMIL-53-lp or HKUST-1 for all types of analyte. Within the Zn-MOF series, analyte loading is proportional to free volume, and loading decreases with increasing analyte size due to molecular packing effects. CrMIL-53lp showed the highest adsorption energy for all analytes, suggesting that this material may be suitable for low-level detection of organics.

  19. Assembly of a Metal-Organic Framework into 3 D Hierarchical Porous Monoliths Using a Pickering High Internal Phase Emulsion Template.

    PubMed

    Zhu, He; Zhang, Qi; Zhu, Shiping

    2016-06-20

    3D Hierarchical porous metal-organic framework (MOF) monoliths are prepared by using Pickering high internal phase emulsion (HIPE) template. Pickering HIPEs were stabilized solely by UiO-66 MOF particles with internal phase up to 90 % of the volume. The effects of internal phase type and volume, as well as MOF particle concentration on the stability of resulting Pickering HIPEs were investigated. Furthermore, by adding small amount of polyvinyl alcohol (PVA) as binder or polymerization in the continuous aqueous phase, followed by freeze-drying, two types of MOF-based 3D hierarchical porous monoliths with ultralow density (as low as 12 mg cm(-3) ) were successfully prepared. This Pickering HIPE template approach provides a facile and practical way for assembling of MOFs into complex structures. PMID:27123547

  20. Hollow silica-copper-carbon anodes using copper metal-organic frameworks as skeletons

    NASA Astrophysics Data System (ADS)

    Sun, Zixu; Xin, Fengxia; Cao, Can; Zhao, Chongchong; Shen, Cai; Han, Wei-Qiang

    2015-12-01

    Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and cushion the volume change. In consequence, the resulting material as an anode for lithium-ion batteries (LIBs) delivers a reversible capacity of 495 mA h g-1 after 400 cycles at a current density of 500 mA g-1. The synthetic method presented in this paper provides a facile and low-cost strategy for the large-scale production of hollow silica/copper/carbon nanocomposites as an anode in LIBs.Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and

  1. Ab initio investigation on hydrogen adsorption capability in Zn and Cu-based metal organic frameworks

    NASA Astrophysics Data System (ADS)

    Tanuwijaya, V. V.; Hidayat, N. N.; Agusta, M. K.; Dipojono, H. K.

    2015-09-01

    One of the biggest challenge in material technology for hydrogen storage application is to increase hydrogen uptake in room temperature and pressure. As a class of highly porous material, Metal-Organic Frameworks (MOF) holds great potential with its tunable structure. However, little is known about the effect of metal cluster to its hydrogen storage capability. Investigation on this matter has been carried out carefully on small cluster of Zn and Cu-based MOF using first principles method. The calculation of two distinct building units of MOFs, namely octahedral and paddle-wheel models, have been done with B3LYP density functional method using 6-31G(d,p) and LANL2DZ basis sets. From geometry optimization of Zn-based MOF linked by benzene-dicarboxylate (MOF-5), it is found that hydrogen tends to keep distance from metal cluster group and stays above benzene ring. In the other hand, hydrogen molecule prefers to stay atop of the exposed Cu atom in Cu-based MOF system linked by the same linker group (Cu-bdc). Calculated hydrogen binding enthalpies for Zn and Cu octahedral cages at ZnO3 sites are 1.64kJ/mol and 2.73kJ/mol respectively, while hydrogen binding enthalpies for Zn and Cu paddle-wheel cages calculated on top of metal atoms are found to be at 6.05kJ/mol and 6.10kJ/mol respectively. Major difference between Zn-MOF-5 and Cu-bdc hydrogen uptake performance might be caused by unsaturated metal sites present in Cu-bdc system and the influence of their geometric structures, although a small difference on binding energy in the type of transition metal used is also observed. The comparison between Zn and Cu-based MOF may contribute to a comprehensive understanding of metal clusters and the importance of selecting best transition metal for design and synthesis of metal-organic frameworks.

  2. Ab initio investigation on hydrogen adsorption capability in Zn and Cu-based metal organic frameworks

    SciTech Connect

    Tanuwijaya, V. V.; Hidayat, N. N. Agusta, M. K. Dipojono, H. K.

    2015-09-30

    One of the biggest challenge in material technology for hydrogen storage application is to increase hydrogen uptake in room temperature and pressure. As a class of highly porous material, Metal-Organic Frameworks (MOF) holds great potential with its tunable structure. However, little is known about the effect of metal cluster to its hydrogen storage capability. Investigation on this matter has been carried out carefully on small cluster of Zn and Cu-based MOF using first principles method. The calculation of two distinct building units of MOFs, namely octahedral and paddle-wheel models, have been done with B3LYP density functional method using 6-31G(d,p) and LANL2DZ basis sets. From geometry optimization of Zn-based MOF linked by benzene-dicarboxylate (MOF-5), it is found that hydrogen tends to keep distance from metal cluster group and stays above benzene ring. In the other hand, hydrogen molecule prefers to stay atop of the exposed Cu atom in Cu-based MOF system linked by the same linker group (Cu-bdc). Calculated hydrogen binding enthalpies for Zn and Cu octahedral cages at ZnO{sub 3} sites are 1.64kJ/mol and 2.73kJ/mol respectively, while hydrogen binding enthalpies for Zn and Cu paddle-wheel cages calculated on top of metal atoms are found to be at 6.05kJ/mol and 6.10kJ/mol respectively. Major difference between Zn-MOF-5 and Cu-bdc hydrogen uptake performance might be caused by unsaturated metal sites present in Cu-bdc system and the influence of their geometric structures, although a small difference on binding energy in the type of transition metal used is also observed. The comparison between Zn and Cu-based MOF may contribute to a comprehensive understanding of metal clusters and the importance of selecting best transition metal for design and synthesis of metal-organic frameworks.

  3. Anion Coordination in Metal-Organic Frameworks Functionalized with Urea Hydrogen-Bonding Groups

    SciTech Connect

    Custelcean, Radu; Moyer, Bruce A.; Bryantsev, Vyacheslav; Hay, Benjamin P.

    2005-12-15

    A series of metal-organic frameworks (MOFs) functionalized with urea hydrogen-bonding groups have been designed, synthesized, and structurally analyzed by single crystal X-ray diffraction to evaluate the efficacy of anion binding within the structural constraints of the MOFs. We found that urea-based functionalities may be used for anion binding within metal-organic frameworks when the tendency for urea???urea self-association is decreased by strengthening the intramolelcular CH???O hydrogen bonding of N-phenyl substituents to the carbonyl oxygen atom. Theoretical calculations indicate that N,N?-bis(m-pyridyl)urea (BPU) and N,N?-bis(m-cyanophenyl)urea (BCPU) should have enhanced hydrogen-bonding donor abilities toward anions and decreased tendencies to self-associate into hydrogen-bonded chains compared to other disubstituted ureas. Accordingly, BPU and BCPU were incorporated in MOFs as linkers through coordination of various Zn, Cu, and Ag transition metal salts, including Zn(ClO4)2, ZnSO4, Cu(NO3)2, Cu(CF3SO3)2, AgNO3 and AgSO3CH3. Structural analysis by single-crystal X-ray diffraction showed that these linkers are versatile anion binders, capable of chelate hydrogen bonding to all of the oxoanions explored. Anion binding by the urea functionalities was found to successfully compete with urea self-association in all cases except for that of charge-diffuse perchlorate. This research was sponsored by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy, under contract number DE-AC05-00OR22725 with Oak Ridge National Laboratory (managed by UT-Battelle, LLC), and performed at Oak Ridge National laboratory and Pacific Northwest National Laboratory (managed by Battelle for the U.S. Department of Energy under contract DE-AC05-76RL01830). This research was performed in part using the Molecular Science Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences laboratory

  4. A high-performance "sweeper" for toxic cationic herbicides: an anionic metal-organic framework with a tetrapodal cage.

    PubMed

    Jia, Yan-Yuan; Zhang, Ying-Hui; Xu, Jian; Feng, Rui; Zhang, Ming-Shi; Bu, Xian-He

    2015-12-21

    This communication reports a novel metal-organic framework exhibiting an excellent performance in adsorbing small toxic cationic herbicides, i.e. methyl viologen and diquat, with large adsorption capacities and ultratrace residue levels. To the best of our knowledge, this is the first example of high-performance MOFs trapping toxic cationic herbicides. PMID:26468513

  5. High acetylene/ethylene separation in a microporous zinc(II) metal-organic framework with low binding energy.

    PubMed

    Wen, Hui-Min; Li, Bin; Wang, Hailong; Krishna, Rajamani; Chen, Banglin

    2016-01-21

    A novel zinc(II) metal-organic framework UTSA-67a with narrow one-dimensional (1D) pore channels and inner cages of moderate size has been developed for highly selective separation of C2H2/C2H4 mixtures at room temperature. PMID:26597048

  6. Enantioselective ring-opening of meso-epoxides by aromatic amines catalyzed by a homochiral metal-organic framework.

    PubMed

    Regati, Sridhar; He, Yabing; Thimmaiah, Muralidhara; Li, Peng; Xiang, Shengchang; Chen, Banglin; Zhao, John Cong-Gui

    2013-10-28

    The enantioselective ring-opening of meso-epoxides by aromatic amines was achieved by using a new chiral metal-organic framework . The corresponding α-hydroxyamines were obtained with good yields and ee values (up to 89% ee). PMID:24030658

  7. Fast detection of oxygen by the naked eye using a stable metal-organic framework containing methyl viologen cations.

    PubMed

    Gong, Yun-Nan; Lu, Tong-Bu

    2013-09-11

    A stable porous metal-organic framework (MOF) containing methyl viologen cations exhibits reversible photochromic, thermochromic and fluorescence changes via host-guest interactions, and can be used for fast and selective detection of oxygen by naked eye recognition of color change within five seconds. PMID:23877538

  8. A homochiral porous metal-organic framework for enantioselective adsorption of mandelates and photocyclizaton of tropolone ethers.

    PubMed

    Peng, Yongwu; Gong, Tengfei; Cui, Yong

    2013-09-25

    A chiral porous metal-organic framework of an axially C2-symmetric 1,1'-biphenol ligand is constructed and can be used as a solid-state host to enanioselectively adsorb mandelates with up to 93.1% ee and to entrap achiral tropolone ethers and induce their asymmetric photocyclization with up to 98.5% ee. PMID:23926598

  9. A three-dimensional porous metal-organic framework constructed from two-dimensional sheets via interdigitation exhibiting dynamic features.

    SciTech Connect

    Ma, S.; Sun, D.; Forster, P. M.; Yuan, D.; Zhuang, W.; Chen, Y. S.; Parise, J. B.; Zhou, H. C.

    2009-04-23

    A three-dimensional porous metal-organic framework (PCN-18) was constructed through interdigitating two-dimensional grid sheets composed of 4,4{prime}-(anthracene-9,10-diyl)dibenzoate and copper paddlewheel secondary building units, and its dynamic features were evidenced by gas sorption isotherms.

  10. Atomic/molecular layer deposition: a direct gas-phase route to crystalline metal-organic framework thin films.

    PubMed

    Ahvenniemi, E; Karppinen, M

    2016-01-21

    Atomic/molecular layer deposition offers us an elegant way of fabricating crystalline copper(ii)terephthalate metal-organic framework (MOF) thin films on various substrate surfaces. The films are grown from two gaseous precursors with a digital atomic/molecular level control for the film thickness under relatively mild conditions in a simple and fast one-step process. PMID:26612265

  11. A metal-organic framework constructed using a flexible tripodal ligand and tetranuclear copper cluster for sensing small molecules.

    PubMed

    Hou, Chaoyi; Bai, Yue-Ling; Bao, XiaoLi; Xu, Liangzhen; Lin, Rong-Guang; Zhu, Shourong; Fang, Jianhui; Xu, Jiaqiang

    2015-05-01

    A new porous metal-organic framework (MOF) {[Cu4(OH)2(tci)2(bpy)2]·11H2O} (1) based on a tetranuclear copper cluster with intracluster antiferromagnetic interactions was synthesized. Quartz crystal microbalance (QCM) sensor studies reveal sensitive and selective sensing for small molecules. PMID:25857286

  12. A microporous anionic metal-organic framework for a highly selective and sensitive electrochemical sensor of Cu(2+) ions.

    PubMed

    Jin, Jun-Cheng; Wu, Ju; Yang, Guo-Ping; Wu, Yun-Long; Wang, Yao-Yu

    2016-06-28

    We first reported an anionic metal-organic framework for electrode material for the electrochemical detection of Cu(2+). The modified electrode shows an excellent selectivity, high stability and sensitivity, wide linear range and lower detection limit. This strategy for generating new electrode materials will be useful for preparing new sensors and reporters for biological systems. PMID:27315447

  13. Enhanced adsorptive desulfurization with flexible metal-organic frameworks in the presence of diethyl ether and water.

    PubMed

    Khan, Nazmul Abedin; Yoon, Ji Woong; Chang, Jong-San; Jhung, Sung Hwa

    2016-07-01

    Several metal-organic frameworks (MOFs) were employed in adsorptive desulfurization in the presence of oxygen-containing compounds (OCCs). Unlike conventional MOFs and activated carbon, flexible MOFs with a MIL-53 topology showed remarkable performances for the desulfurization in the presence of OCCs. PMID:27284597

  14. Facile stabilization of cyclodextrin metal-organic frameworks under aqueous conditions via the incorporation of C60 in their matrices.

    PubMed

    Li, Haiqing; Hill, Matthew R; Huang, Runhong; Doblin, Christian; Lim, Seng; Hill, Anita J; Babarao, Ravichandar; Falcaro, Paolo

    2016-05-21

    A facile method to improve the stability of γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) in an aqueous environment has been developed through the incorporation of hydrophobic C60 in their matrices, and the resulting hybrid materials were exploited for drug delivery applications. PMID:27055670

  15. A facilely synthesized amino-functionalized metal-organic framework for highly specific and efficient enrichment of glycopeptides.

    PubMed

    Zhang, Yi-Wei; Li, Ze; Zhao, Qiang; Zhou, Ying-Lin; Liu, Hu-Wei; Zhang, Xin-Xiang

    2014-10-01

    A facilely synthesized amino-functionalized metal-organic framework (MOF) MIL-101(Cr)-NH2 was first applied for highly specific glycopeptide enrichment based on the hydrophilic interactions. With the special characteristics of the MOF, the material performed well in selectivity and sensitivity for both standard glycoprotein samples and complex biological samples. PMID:25131456

  16. Facile xenon capture and release at room temperature using a metal-organic framework: a comparison with activated charcoal

    SciTech Connect

    Thallapally, Praveen K.; Grate, Jay W.; Motkuri, Radha K.

    2012-01-11

    Two well known Metal organic frameworks (MOF-5, NiDOBDC) were synthesized and studied for facile xenon capture and separation. Our results indicate the NiDOBDC adsorbs significantly more xenon than MOF-5, releases it more readily than activated carbon, and is more selective for Xe over Kr than activated carbon.

  17. A metal-organic framework with immobilized Ag(i) for highly efficient desulfurization of liquid fuels.

    PubMed

    Huang, Minhui; Chang, Ganggang; Su, Ye; Xing, Huabin; Zhang, Zhiguo; Yang, Yiwen; Ren, Qilong; Bao, Zongbi; Chen, Banglin

    2015-08-01

    A metal-organic framework immobilized with Ag(i) sites, namely, (Cr)-MIL-101-SO3Ag, was successfully developed as a highly efficient desulfurization adsorbent because of the strong binding of these Ag(i) sites for thiophene derivatives. PMID:26136210

  18. Palladium nanoparticles supported on a nickel pyrazolate metal organic framework as a catalyst for Suzuki and carbonylative Suzuki couplings.

    PubMed

    Augustyniak, A W; Zawartka, W; Navarro, J A R; Trzeciak, A M

    2016-09-14

    Methanolic reduction of [PdCl2(CH3CN)2] on a [Ni(2,5-di(1H-pyrazol-4-yl)benzenesulfonate)2] metal organic framework gives rise to Pd(2+)/Pd(0) nanocomposites with Suzuki and carbonylative Suzuki heterogeneous catalytic activities. PMID:27506244

  19. Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry

    ERIC Educational Resources Information Center

    Sumida, Kenji; Arnold, John

    2011-01-01

    Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…

  20. Magnetic metal-organic frameworks for selective enrichment and exclusion of proteins for MALDI-TOF MS analysis.

    PubMed

    Wan, Wei; Liang, Qionglin; Zhang, Xiaoqiong; Yan, Min; Ding, Mingyu

    2016-08-01

    We firstly report magnetic metal-organic frameworks for selective enrichment and exclusion of proteins for MALDI-TOF MS analysis. Fe3O4@MIL-100(Fe) nanoparticles were achieved by step-by-step assembly on poly(acrylic acid) modified Fe3O4. PMID:27350019

  1. Patterned deposition of metal-organic frameworks onto plastic, paper, and textile substrates by inkjet printing of a precursor solution.

    PubMed

    Zhuang, Jin-Liang; Ar, Deniz; Yu, Xiu-Jun; Liu, Jin-Xuan; Terfort, Andreas

    2013-09-01

    Flexible in many aspects: inkjet printing of metal-organic frameworks permits their larger area, high-resolution deposition in any desired pattern, even in the form of gradients or shades. When flexible substrates are used, many applications can be envisioned, such as sensing and capture of hazardous gases for personal safety measures. PMID:23813674

  2. Using functional nano- and microparticles for the preparation of metal-organic framework composites with novel properties.

    PubMed

    Doherty, Cara M; Buso, Dario; Hill, Anita J; Furukawa, Shuhei; Kitagawa, Susumu; Falcaro, Paolo

    2014-02-18

    A critical materials challenge over the next quarter century is the sustainable use and management of the world's natural resources, particularly the scarcest of them. Chemistry's ability to get more from less is epitomized by porous coordination polymers, also known as metal-organic frameworks (MOFs), which use a minimum amount of material to build maximum surface areas with fine control over pore size. Their large specific surface area and tunable porosity make MOFs useful for applications including small-molecule sensing, separation, catalysis, and storage and release of molecules of interest. Proof-of-concept projects have demonstrated their potential for environmental applications such as carbon separation and capture, water purification, carcinogen sequestration, byproduct separation, and resource recovery. To translate these from the laboratory into devices for actual use, however, will require synthesis of MOFs with new functionality and structure. This Account summarizes recent progress in the use of nano- and microparticles to control the function, location, and 3D structure of MOFs during MOF self-assembly, creating novel, hybrid, multifunctional, ultraporous materials as a first step towards creating MOF-based devices. The use of preformed ceramic, metallic, semiconductive, or polymeric particles allows the particle preparation process to be completely independent of the MOF synthesis, incorporating nucleating, luminescent, magnetic, catalytic, or templating particles into the MOF structure. We discuss success in combining functional nanoparticles and porous crystals for applications including molecular sieve detectors, repositionable and highly sensitive sensors, pollutant-sequestering materials, microfluidic microcarriers, drug-delivery materials, separators, and size-selective catalysts. In sections within the Account, we describe how functional particles can be used for (1) heterogeneous nucleation (seeding) of MOFs, (2) preparation of framework

  3. Synthesis, crystal structures and luminescent properties of zinc(II) metal-organic frameworks constructed from terpyridyl derivative ligand

    NASA Astrophysics Data System (ADS)

    Yang, Xiao-Le; Shangguan, Yi-Qing; Hu, Huai-Ming; Xu, Bing; Wang, Bao-Cheng; Xie, Juan; Yuan, Fei; Yang, Meng-Lin; Dong, Fa-Xin; Xue, Gang-Lin

    2014-08-01

    Five zinc(II) metal-organic frameworks, [Zn3(344-pytpy)2Cl6]n·n(H2O) (1), [Zn(344-pytpy)(ox)]n (2), [Zn2(344-pytpy)(bdc)2]n·1.5n(H2O) (3), [Zn2(344-pytpy)2 (sfdb)2]n·1.5n(H2O) (4) and [Zn3(344-pytpy)2(btc)2]n·2n(H2O) (5), (344-pytpy=4‧-(3-pyridyl)-4,2‧:6‧,4″-terpyridine, H2ox=oxalic acid, H2bdc=1,4-benzenedi-carboxylic acid, H2sfdb=4,4‧-sulfonyldibenzoic acid and H3btc=1,3,5-benzene-tricarboxylic acid) have been prepared by hydrothermal reactions. Compound 1 is a 1D chain structure, in which 344-pytpy ligand links three ZnII centers through three of terminal N-donors. Compound 2 is a 4-connected 3D framework with the dia topological net and the Schläfli symbol of 66. Compound 3 displays a unusual 3-fold interpenetrating 3D coordination network which exhibits a new intriguing (3,3,4)-connected topological net with the Schläfli symbol of (4.82)(4.85)(83). Compound 4 features a two-fold interpenetrating 4-connected 2D framework with the sql topological net and the Schläfli symbol of (44.62). Compound 5 is a new self-interpenetrating (3,3,4,4)-connected topological net with the Schläfli symbol of (6.82)2(62.82.10.12)(62.83.10)2(62.8)2. The luminescence properties of 1-5 have been investigated by emission spectra and they possess great thermal stabilities which can be stable up to around 400 °C.

  4. Flexible sorption and transformation behavior in a microporous metal-organic framework.

    PubMed

    Cussen, Edmund J; Claridge, John B; Rosseinsky, Matthew J; Kepert, Cameron J

    2002-08-14

    Crystals of the metal-organic framework material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4) (A) have been grown by reaction of Ni(NO(3))(2).6H(2)O and 4,4'-bipyridine in methanol solution. Single-crystal X-ray diffraction experiments show that the ladder structure of the framework is maintained after desolvation of the material, resulting in the production of a porous solid stable to 215(4) degrees C. Powder X-ray diffraction has been employed to confirm the bulk purity and temperature stability of this material. The crystal structure indicates that the pore window has an area of 12.3 A(2). However, sorption experiments show these windows will admit toluene, which has a minimum cross-sectional area of 26.6 A(2), with no significant change in the structure. Monte Carlo docking calculations show that toluene can be accommodated within the large pores of the structure. Exposure of the related microporous material Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH (B) to methanol vapor causes a guest-driven solid-state transformation to A which is observed using powder X-ray diffraction. This structural rearrangement proceeds directly from crystalline B to crystalline A and is complete in less than 1 day. Mechanisms for the transformation are proposed which require breaking of at least one in six of the covalent bonds that confer rigidity on the framework. PMID:12167052

  5. Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) for highly selective separations

    SciTech Connect

    Yaghi, Omar M

    2012-09-17

    Metal-organic and zeolite imidazolate frameworks (MOFs and ZIFs) have been investigated for the realization as separation media with high selectivity. These structures are held together with strong bonds, making them architecturally, chemically, and thermally stable. Therefore, employing well designed building units, it is possible to discover promising materials for gas and vapor separation. This grant was focused on the study of MOFs and ZIFs with these specific objectives: (i) to develop a strategy for producing MOFs and ZIFs that combine high surface areas with active sites for their use in gas adsorption and separation of small organic compounds, (ii) to introduce active sites in the framework by a post-synthetic modification and metalation of MOFs and ZIFs, and (iii) to design and synthesize MOFs with extremely high surface areas and large pore volumes to accommodate large amounts of guest molecules. By the systematic study, this effort demonstrated how to introduce active functional groups in the frameworks, and this is also the origin of a new strategy, which is termed isoreticular functionalization and metalation. However, a large pore volume is still a prerequisite feature. One of the solutions to overcome this challenge is an isoreticular expansion of a MOF's structure. With triangular organic linker and square building units, we demonstrated that MOF-399 has a unit cell volume 17 times larger than that of the first reported material isoreticular to it, and it has the highest porosity (94%) and lowest density (0.126 g cm-3) of any MOF reported to date. MOFs are not just low density materials; the guest-free form of MOF-210 demonstrates an ultrahigh porosity, whose BET surface area was estimated to be 6240 m2 g-1 by N2 adsorption measurements.

  6. Chemoselective single-site Earth-abundant metal catalysts at metal-organic framework nodes.

    PubMed

    Manna, Kuntal; Ji, Pengfei; Lin, Zekai; Greene, Francis X; Urban, Ania; Thacker, Nathan C; Lin, Wenbin

    2016-01-01

    Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones. Our structural, spectroscopic and kinetic studies suggest that chemoselective organic transformations occur on site-isolated, electron-deficient and coordinatively unsaturated metal centres at the SBUs via σ-bond metathesis pathways and as a result of the steric environment around the catalytic site. MOFs thus provide a novel platform for the development of highly active and affordable base metal catalysts for the sustainable synthesis of fine chemicals. PMID:27574182

  7. Porous metal-organic-framework nanoscale carriers as a potential platform for drug delivery and imaging.

    PubMed

    Horcajada, Patricia; Chalati, Tamim; Serre, Christian; Gillet, Brigitte; Sebrie, Catherine; Baati, Tarek; Eubank, Jarrod F; Heurtaux, Daniela; Clayette, Pascal; Kreuz, Christine; Chang, Jong-San; Hwang, Young Kyu; Marsaud, Veronique; Bories, Phuong-Nhi; Cynober, Luc; Gil, Sophie; Férey, Gérard; Couvreur, Patrick; Gref, Ruxandra

    2010-02-01

    In the domain of health, one important challenge is the efficient delivery of drugs in the body using non-toxic nanocarriers. Most of the existing carrier materials show poor drug loading (usually less than 5 wt% of the transported drug versus the carrier material) and/or rapid release of the proportion of the drug that is simply adsorbed (or anchored) at the external surface of the nanocarrier. In this context, porous hybrid solids, with the ability to tune their structures and porosities for better drug interactions and high loadings, are well suited to serve as nanocarriers for delivery and imaging applications. Here we show that specific non-toxic porous iron(III)-based metal-organic frameworks with engineered cores and surfaces, as well as imaging properties, function as superior nanocarriers for efficient controlled delivery of challenging antitumoural and retroviral drugs (that is, busulfan, azidothymidine triphosphate, doxorubicin or cidofovir) against cancer and AIDS. In addition to their high loadings, they also potentially associate therapeutics and diagnostics, thus opening the way for theranostics, or personalized patient treatments. PMID:20010827

  8. Porous metal-organic-framework nanoscale carriers as a potential platform for drug delivery and imaging

    NASA Astrophysics Data System (ADS)

    Horcajada, Patricia; Chalati, Tamim; Serre, Christian; Gillet, Brigitte; Sebrie, Catherine; Baati, Tarek; Eubank, Jarrod F.; Heurtaux, Daniela; Clayette, Pascal; Kreuz, Christine; Chang, Jong-San; Hwang, Young Kyu; Marsaud, Veronique; Bories, Phuong-Nhi; Cynober, Luc; Gil, Sophie; Férey, Gérard; Couvreur, Patrick; Gref, Ruxandra

    2010-02-01

    In the domain of health, one important challenge is the efficient delivery of drugs in the body using non-toxic nanocarriers. Most of the existing carrier materials show poor drug loading (usually less than 5wt% of the transported drug versus the carrier material) and/or rapid release of the proportion of the drug that is simply adsorbed (or anchored) at the external surface of the nanocarrier. In this context, porous hybrid solids, with the ability to tune their structures and porosities for better drug interactions and high loadings, are well suited to serve as nanocarriers for delivery and imaging applications. Here we show that specific non-toxic porous iron(III)-based metal-organic frameworks with engineered cores and surfaces, as well as imaging properties, function as superior nanocarriers for efficient controlled delivery of challenging antitumoural and retroviral drugs (that is, busulfan, azidothymidine triphosphate, doxorubicin or cidofovir) against cancer and AIDS. In addition to their high loadings, they also potentially associate therapeutics and diagnostics, thus opening the way for theranostics, or personalized patient treatments.

  9. In situ synthesis of homochiral metal-organic framework in capillary column for capillary electrochromatography enantioseparation.

    PubMed

    Pan, Congjie; Wang, Weifeng; Zhang, Huige; Xu, Laifang; Chen, Xingguo

    2015-04-01

    Homochiral metal-organic frameworks (MOFs) are promising as porous stationary phase for open-tubular capillary electrochromatography (OT-CEC) enantioseparation owing to their fine-tuned pore sizes and large surface areas. In this work, the homochiral MOF AlaZnCl was successfully coated on the inner wall of fused silica capillary by an in situ, layer-by-layer self-assembly approach at room temperature. The results of scanning electron microscopy (SEM), X-ray diffraction (XRD), streaming potential (SP) and Fourier-transform infrared spectroscopy (FT-IR) indicated that the homochiral MOF AlaZnCl was successfully coated on the capillary inner wall. To evaluate the performance of the homochiral MOF AlaZnCl coated capillary column, the enantioseparation was carried out by using six amine drugs and monoamine neurotransmitters as model analytes and excellent enantioseparation efficiency was achieved. Run-to-run, day-to-day, and column-to-column relative standard deviations (RSDs) were all less than 5%. Moreover, the separation efficiency of the homochiral MOF AlaZnCl coated capillary column did not decrease obviously over 100 runs. PMID:25725957

  10. Understanding the electromagnetic interaction of metal organic framework reactants in aqueous solution at microwave frequencies.

    PubMed

    Laybourn, Andrea; Katrib, Juliano; Palade, Paula A; Easun, Timothy L; Champness, Neil R; Schröder, Martin; Kingman, Samuel W

    2016-02-21

    Preparation of metal organic frameworks (MOFs) via microwave heating is becoming increasingly popular due to reduced reaction times and enhanced control of MOF particle size. However, there is little understanding about the detailed interaction of the electric field portion of the wave with reactants during the synthesis of MOFs. In order to overcome this lack of fundamental understanding, information about the dielectric properties of the reactants is required. In this work the dielectric constants (ε') and loss factors (ε'') of benzene-1,4-dicarboxylic acid (H2BDC; also known as terephthalic acid) and a number of M(III) (M = metal) salts dissolved in deionized water were measured as a function of frequency, temperature and concentration and with varying anions and cations. Dielectric data confirm the aqueous M(III) salts to be strong microwave absorbers, particularly at 915 MHz. M(III) salts with mono-anionic ligands (for example chlorides and nitrates) exhibit higher losses than di-anionic salts (sulfates) demonstrating that the former are heated more effectively in an applied microwave field. Of the M(III) salts containing either singly- or doubly-charged anions, those containing Fe(III) have the highest loss indicating that they will heat more efficiently than other M(III) salts such as Cr(III) and Al(III). Interestingly, H2BDC exhibits little interaction with the electric field at microwave frequencies. PMID:26822947

  11. Efficient purification of ethene by an ethane-trapping metal-organic framework

    PubMed Central

    Liao, Pei-Qin; Zhang, Wei-Xiong; Zhang, Jie-Peng; Chen, Xiao-Ming

    2015-01-01

    Separating ethene (C2H4) from ethane (C2H6) is of paramount importance and difficulty. Here we show that C2H4 can be efficiently purified by trapping the inert C2H6 in a judiciously designed metal-organic framework. Under ambient conditions, passing a typical cracked gas mixture (15:1 C2H4/C2H6) through 1 litre of this C2H6 selective adsorbent directly produces 56 litres of C2H4 with 99.95%+ purity (required by the C2H4 polymerization reactor) at the outlet, with a single breakthrough operation, while other C2H6 selective materials can only produce ca. ⩽ litre, and conventional C2H4 selective adsorbents require at least four adsorption–desorption cycles to achieve the same C2H4 purity. Single-crystal X-ray diffraction and computational simulation studies showed that the exceptional C2H6 selectivity arises from the proper positioning of multiple electronegative and electropositive functional groups on the ultramicroporous pore surface, which form multiple C–H···N hydrogen bonds with C2H6 instead of the more polar competitor C2H4. PMID:26510376

  12. Metal-Organic Frameworks (MOFs) as Sandwich Coating Cushion for Silicon Anode in Lithium Ion Batteries.

    PubMed

    Han, Yuzhen; Qi, Pengfei; Zhou, Junwen; Feng, Xiao; Li, Siwu; Fu, Xiaotao; Zhao, Jingshu; Yu, Danni; Wang, Bo

    2015-12-01

    A novel metal-organic framework (MOF) sandwich coating method (denoted as MOF-SC) is developed for hybrid Li ion battery electrode preparation, in which the MOF films are casted on the surface of a silicon layer and sandwiched between the active silicon and the separator. The obtained electrodes show improved cycling performance. The areal capacity of the cheap and readily available microsized Si treated with MOF-SC can reach 1700 μAh cm(-2) at 265 μA cm(-2) and maintain at 850 μAh cm(-2) after 50 cycles. Beyond the above, the commercial nanosized Si treated by MOF-SC also shows greatly enhanced areal capacity and outstanding cycle stability, 600 μAh cm(-2) for 100 cycles without any apparent fading. By virtue of the novel structure prepared by the MOFs, this new MOF-SC structure serves as an efficient protection cushion for the drastic volume change of silicon during charge/discharge cycles. Furthermore, this MOF layer, with large pore volume and high surface area, can adsorb electrolyte and allow faster diffusion of Li(+) as evidenced by decreased impedance and improved rate performance. PMID:26569374

  13. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution.

    PubMed

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E; Kung, Chung-Wei; So, Monica; Sampson, Matthew D; Peters, Aaron W; Kubiak, Cliff P; Farha, Omar K; Hupp, Joseph T

    2015-01-01

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm(-2). Although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst. PMID:26365764

  14. Extension of the Universal Force Field to Metal-Organic Frameworks.

    PubMed

    Addicoat, Matthew A; Vankova, Nina; Akter, Ismot Farjana; Heine, Thomas

    2014-02-11

    The Universal Force Field (UFF) (Rappé et al., J. Am. Chem. Soc. 1992) provides a general approach to molecular mechanics for molecules and materials composed of elements throughout the periodic table. Though the method is tunable by the specification of bond orders and the introduction of effective charges, the presently available list of atom types is insufficient to treat various systems containing transition metals, including metal-organic frameworks (MOFs). As MOFs are composite materials built of a combination of individually stable building blocks, a plethora of MOF structures are possible, and the prediction of their structure with a low-cost method is important. We have extended the UFF parameter set to include transition metal elements Zn, Cu, Ni, Co, Fe, Mn, Cr, V, Ti, Sc, and Al, as they occur in MOFs, and have proposed additional O parameters that provide reliable structures of the metal oxide clusters of the connectors. We have benchmarked the performance of the MOF extension to UFF (UFF4MOF) with respect to experimentally available data and to DFT calculations. The parameters are available in various well-spread programs, including GULP, deMonNano, and ADF, and all information is provided to include them in other molecular mechanics codes. PMID:26580059

  15. Emerging adsorptive removal of azo dye by metal-organic frameworks.

    PubMed

    Ayati, Ali; Shahrak, Mahdi Niknam; Tanhaei, Bahareh; Sillanpää, Mika

    2016-10-01

    Adsorptive removal of toxic compounds using advanced porous materials is one of the most attractive approaches. In recent years, the metal-organic frameworks (MOFs), a subset of advanced porous nano-structured materials, due to their unique characteristics are showing great promise for better adsorption/separation of various water contaminants. Given the importance of azo dye removal, as an important class of pollutants, this paper aims to review and summarize the recently published research on the effectiveness of various MOFs adsorbents under different physico-chemical process parameters in dyes adsorption. The effect of pH, the adsorption mechanism and the applicability of various adsorption kinetic and thermodynamic models are briefly discussed. Most of the results observed showed that the adsorption kinetic and isotherm of azo dyes onto the MOFs mostly followed the pseudo-second order and Langmuir models respectively. Also, the optimum pH value for the removal of majority of azo dyes by MOFs was observed to be in the range of ∼5-7. PMID:27355417

  16. Elucidating the mechanism responsible for anomalous thermal expansion in a metal-organic framework.

    PubMed

    van Heerden, Dewald P; Esterhuysen, Catharine; Barbour, Leonard J

    2016-03-14

    The previously reported anisotropic thermal expansion of a three-dimensional metal-organic framework (MOF) is examined by means of theoretical calculations. Inspection of the 100, 190, 280 and 370 K single crystal X-ray diffraction (SCD) structures indicated a concerted change in the coordination sphere of the zinc centre leading to elongation of the coordination helix in the crystallographic c direction (the Zn-O(H)-Zn angle expands), while the largely unaltered ligands (the ZnLZn distance remains constant) are pulled closer together in the ab plane. This study develops and evaluates a mechanistic model at the DFT level of theory that reproduces the convergent expansion of the coordination helix of the material. The linear increase in energy calculated for extension of a model consisting of six zinc centres and truncated ligands compares favourably with results obtained from a periodic DFT evaluation of the SCD structures. It was also found that the anisotropic thermal expansion trend could be reproduced qualitatively by Molecular Dynamics (MD) simulations in the NPT ensemble. PMID:26171815

  17. Molecular modeling of zinc paddlewheel molecular complexes and the pores of a flexible metal organic framework.

    PubMed

    Alzahrani, Khalid A H; Deeth, Robert J

    2016-04-01

    A new all-atom first-principles force field (FF) is constructed for the bimetallic, four-bladed zinc paddlewheel (ZPW) motif. Zinc-ligand interactions are described via Morse functions and the angular geometry at the metal centers is modeled with a pure ligand-ligand repulsion term. The ZPW-FF is principally based on 15 DFT-optimized model systems of general formula ZnPR.nL, where ZnP is the base Zn2(O2CR)4 unit, R = H, CH3 or CF3, L = NH3 or pyridine, and n = 0, 1 or 2. It correctly generates the distorted tetrahedral coordination of the uncapped [Zn2(O2CR)4] species in their ground states as well as giving reasonable structures and energies for the higher symmetry D4h transition state conformations. The zinc-ligand Morse function reference distance, r 0 , is further refined against 30 complexes located in the Cambridge Structural Database and this FF is applied to pore models of the flexible metal-organic framework (MOF) [Zn(bdc)2(dabco)]n (bdc = 1,4-benzendicarboxylate; dabco = 1,4-diazabicyclo(2.2.2)octane). A single pore model reproduces the unit cell of the evacuated MOF system while a 3×3 grid model is necessary to provide good agreement with the observed pronounced structural changes upon adsorption of either dimethylformamide or benzene. PMID:26979608

  18. Stress-induced chemical detection using flexible metal-organic frameworks.

    PubMed

    Allendorf, Mark D; Houk, Ronald J T; Andruszkiewicz, Leanne; Talin, A Alec; Pikarsky, Joel; Choudhury, Arnab; Gall, Kenneth A; Hesketh, Peter J

    2008-11-01

    In this work we demonstrate the concept of stress-induced chemical detection using metal-organic frameworks (MOFs) by integrating a thin film of the MOF HKUST-1 with a microcantilever surface. The results show that the energy of molecular adsorption, which causes slight distortions in the MOF crystal structure, can be converted to mechanical energy to create a highly responsive, reversible, and selective sensor. This sensor responds to water, methanol, and ethanol vapors, but yields no response to either N2 or O2. The magnitude of the signal, which is measured by a built-in piezoresistor, is correlated with the concentration and can be fitted to a Langmuir isotherm. Furthermore, we show that the hydration state of the MOF layer can be used to impart selectivity to CO2. Finally, we report the first use of surface-enhanced Raman spectroscopy to characterize the structure of a MOF film. We conclude that the synthetic versatility of these nanoporous materials holds great promise for creating recognition chemistries to enable selective detection of a wide range of analytes. PMID:18841964

  19. Preparation of Nanofibrous Metal-Organic Framework Filters for Efficient Air Pollution Control.

    PubMed

    Zhang, Yuanyuan; Yuan, Shuai; Feng, Xiao; Li, Haiwei; Zhou, Junwen; Wang, Bo

    2016-05-11

    Environmental challenges especially air pollution (particulate matter (PM) and toxic gases) pose serious threats to public health globally. Metal-organic frameworks (MOFs) are crystalline materials with high porosity, tunable pore size, and rich functionalities, holding the promise for poisonous pollutants capture. Here, nanocrystals of four unique MOF structures are processed into nanofibrous filters (noted as MOFilter) with high MOF loadings (up to 60 wt %). The MOFilters show high PM removal efficiencies up to 88.33 ± 1.52% and 89.67 ± 1.33% for PM2.5 and PM10, respectively, in the hazy environment, and the performance remains largely unchanged over 48 h of continuous filtration. For the first time, the interactions between such porous crystalline material and particulate pollutants were explored. These thin MOFilters can further selectively capture and retain SO2 when exposed to a stream of SO2/N2 mixture, and their hierarchical nanostructures can easily permeate fresh air at high gas flow rate with the pressure drop <20 Pa. PMID:27090776

  20. Peptide-Metal Organic Framework Swimmers that Direct the Motion toward Chemical Targets.

    PubMed

    Ikezoe, Yasuhiro; Fang, Justin; Wasik, Tomasz L; Shi, Menglu; Uemura, Takashi; Kitagawa, Susumu; Matsui, Hiroshi

    2015-06-10

    Highly efficient and robust chemical motors are expected for the application in microbots that can selectively swim toward targets and accomplish their tasks in sensing, labeling, and delivering. However, one of major issues for such development is that current artificial swimmers have difficulty controlling their directional motion toward targets like bacterial chemotaxis. To program synthetic motors with sensing capability for the target-directed motion, we need to develop swimmers whose motions are sensitive to chemical gradients in environments. Here we create a new intelligent biochemical swimmer by integrating metal organic frameworks (MOFs) and peptides that can sense toxic heavy metals in solution and swim toward the targets. With the aid of Pb-binding enzymes, the peptide-MOF motor can directionally swim toward PbSe quantum dots (QD) by sensing pH gradient and eventually complete the motion as the swimmer reaches the highest gradient point at the target position in solution. This type of technology could be evolved to miniaturize chemical robotic systems that sense target chemicals and swim toward target locations. PMID:26010172

  1. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    SciTech Connect

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; Hupp, Joseph T.

    2015-09-14

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm−2. In conclusion, although the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.

  2. A porous proton-relaying metal-organic framework material that accelerates electrochemical hydrogen evolution

    DOE PAGESBeta

    Hod, Idan; Deria, Pravas; Bury, Wojciech; Mondloch, Joseph E.; Kung, Chung-Wei; So, Monica; Sampson, Matthew D.; Peters, Aaron W.; Kubiak, Cliff P.; Farha, Omar K.; et al

    2015-09-14

    The availability of efficient hydrogen evolution reaction (HER) catalysts is of high importance for solar fuel technologies aimed at reducing future carbon emissions. Even though Pt electrodes are excellent HER electrocatalysts, commercialization of large-scale hydrogen production technology requires finding an equally efficient, low-cost, earth-abundant alternative. Here, high porosity, metal-organic framework (MOF) films have been used as scaffolds for the deposition of a Ni-S electrocatalyst. Compared with an MOF-free Ni-S, the resulting hybrid materials exhibit significantly enhanced performance for HER from aqueous acid, decreasing the kinetic overpotential by more than 200 mV at a benchmark current density of 10 mA cm−2. In conclusion, althoughmore » the initial aim was to improve electrocatalytic activity by greatly boosting the active area of the Ni-S catalyst, the performance enhancements instead were found to arise primarily from the ability of the proton-conductive MOF to favourably modify the immediate chemical environment of the sulfide-based catalyst.« less

  3. Formation of a new archetypal Metal-Organic Framework from a simple monatomic liquid

    NASA Astrophysics Data System (ADS)

    Metere, Alfredo; Oleynikov, Peter; Dzugutov, Mikhail; O'Keeffe, Michael

    2014-12-01

    We report a molecular-dynamics simulation of a single-component system of particles interacting via a spherically symmetric potential that is found to form, upon cooling from a liquid state, a low-density porous crystalline phase. Its structure analysis demonstrates that the crystal can be described by a net with a topology that belongs to the class of topologies characteristic of the Metal-Organic Frameworks (MOFs). The observed net is new, and it is now included in the Reticular Chemistry Structure Resource database. The observation that a net topology characteristic of MOF crystals, which are known to be formed by a coordination-driven self-assembly process, can be reproduced by a thermodynamically stable configuration of a simple single-component system of particles opens a possibility of using these models in studies of MOF nets. It also indicates that structures with MOF topology, as well as other low-density porous crystalline structures can possibly be produced in colloidal systems of spherical particles, with an appropriate tuning of interparticle interaction.

  4. Porous, rigid metal(III)-carboxylate metal-organic frameworks for the delivery of nitric oxide

    NASA Astrophysics Data System (ADS)

    Eubank, Jarrod F.; Wheatley, Paul S.; Lebars, Gaëlle; McKinlay, Alistair C.; Leclerc, Hervé; Horcajada, Patricia; Daturi, Marco; Vimont, Alexandre; Morris, Russell E.; Serre, Christian

    2014-12-01

    The room temperature sorption properties of the biological gas nitric oxide (NO) have been investigated on the highly porous and rigid iron or chromium carboxylate based metal-organic frameworks Material Institut Lavoisier (MIL)-100(Fe or Cr) and MIL-127(Fe). In all cases, a significant amount of NO is chemisorbed at 298 K with a loading capacity that depends both on the nature of the metal cation, the structure and the presence of additional iron(II) Lewis acid sites. In a second step, the release of NO triggered by wet nitrogen gas has been studied by chemiluminescence and indicates that only a partial release of NO occurs as well as a prolonged delivery at the biological level. Finally, an in situ infrared spectroscopy study confirms not only the coordination of NO over the Lewis acid sites and the stronger binding of NO on the additional iron(II) sites, providing further insights over the partial release of NO only in the presence of water at room temperature.

  5. Tuning the luminescence of metal-organic frameworks for detection of energetic heterocyclic compounds.

    PubMed

    Guo, Yuexin; Feng, Xiao; Han, Tianyu; Wang, Shan; Lin, Zhengguo; Dong, Yuping; Wang, Bo

    2014-11-01

    Herein we report three metal-organic frameworks (MOFs), TABD-MOF-1, -2, and -3, constructed from Mg(2+), Ni(2+), and Co(2+), respectively, and deprotonated 4,4'-((Z,Z)-1,4-diphenylbuta-1,3-diene-1,4-diyl)dibenzoic acid (TABD-COOH). The fluorescence of these three MOFs is tuned from highly emissive to completely nonemissive via ligand-to-metal charge transfer by rational alteration of the metal ion. Through competitive coordination substitution, the organic linkers in the TABD-MOFs are released and subsequently reassemble to form emissive aggregates due to aggregation-induced emission. This enables highly sensitive and selective detection of explosives such as five-membered-ring energetic heterocyclic compounds in a few seconds with low detection limits through emission shift and/or turn-on. Remarkably, the cobalt-based MOF can selectively sense the powerful explosive 5-nitro-2,4-dihydro-3H-1,2,4-triazole-3-one with high sensitivity discernible by the naked eye (detection limit = 6.5 ng on a 1 cm(2) testing strip) and parts per billion-scale sensitivity by spectroscopy via pronounced fluorescence emission. PMID:25325884

  6. Hydrogen adsorption in metal-organic frameworks: The role of nuclear quantum effects

    SciTech Connect

    Wahiduzzaman, Mohammad; Walther, Christian F. J.; Heine, Thomas

    2014-08-14

    The role of nuclear quantum effects on the adsorption of molecular hydrogen in metal-organic frameworks (MOFs) has been investigated on grounds of Grand-Canonical Quantized Liquid Density-Functional Theory (GC-QLDFT) calculations. For this purpose, we have carefully validated classical H{sub 2}-host interaction potentials that are obtained by fitting Born-Oppenheimer ab initio reference data. The hydrogen adsorption has first been assessed classically using Liquid Density-Functional Theory and the Grand-Canonical Monte Carlo methods. The results have been compared against the semi-classical treatment of quantum effects by applying the Feynman-Hibbs correction to the Born-Oppenheimer-derived potentials, and by explicit treatment within the GC-QLDFT. The results are compared with experimental data and indicate pronounced quantum and possibly many-particle effects. After validation calculations have been carried out for IRMOF-1 (MOF-5), GC-QLDFT is applied to study the adsorption of H{sub 2} in a series of MOFs, including IRMOF-4, -6, -8, -9, -10, -12, -14, -16, -18, and MOF-177. Finally, we discuss the evolution of the H{sub 2} quantum fluid with increasing pressure and lowering temperature.

  7. Progress in Adsorption-Based CO2 Capture by Metal-Organic Frameworks

    SciTech Connect

    Liu, Jian; Thallapally, Praveen K.; McGrail, B. Peter; Brown, Daryl R.; Liu, Jun

    2012-01-01

    Metal-organic frameworks (MOFs) have recently attracted intense research interest because of their permanent porous structures, large surface areas, and potential applications as novel adsorbents. The recent progress in adsorption-based CO2 capture by MOFs is reviewed and summarized in this paper. CO2 adsorption in MOFs has been divided into two sections, adsorption at high pressures and selective adsorption at approximate atmospheric pressures. Keys to CO2 adsorption in MOFs at high pressures and low pressures are summarized to be pore volumes of MOFs, and heats of adsorption, respectively. Many MOFs have high CO2 selectivities over N2 and CH4. Water effects on CO2 adsorption in MOFs are presented and compared with benchmark zeolites. In addition, strategies appeared in the literature to enhance CO2 adsorption capacities and/or selectivities in MOFs have been summarized into three main categories, catenation and interpenetration, chemical bonding enhancement, and electrostatic force involvement. Besides the advantages, two main challenges for using MOFs in CO2 capture, the cost of synthesis and the stability toward water vapor, have been analyzed and possible solutions and path-forward have been proposed to address the two challenges as well.

  8. A porous metal-organic framework with ultrahigh acetylene uptake capacity under ambient conditions.

    PubMed

    Pang, Jiandong; Jiang, Feilong; Wu, Mingyan; Liu, Caiping; Su, Kongzhao; Lu, Weigang; Yuan, Daqiang; Hong, Maochun

    2015-01-01

    Acetylene, an important petrochemical raw material, is very difficult to store safely under compression because of its highly explosive nature. Here we present a porous metal-organic framework named FJI-H8, with both suitable pore space and rich open metal sites, for efficient storage of acetylene under ambient conditions. Compared with existing reports, FJI-H8 shows a record-high gravimetric acetylene uptake of 224 cm(3) (STP) g(-1) and the second-highest volumetric uptake of 196 cm(3) (STP) cm(-3) at 295 K and 1 atm. Increasing the storage temperature to 308 K has only a small effect on its acetylene storage capacity (∼200 cm(3) (STP) g(-1)). Furthermore, FJI-H8 exhibits an excellent repeatability with only 3.8% loss of its acetylene storage capacity after five cycles of adsorption-desorption tests. Grand canonical Monte Carlo simulation reveals that not only open metal sites but also the suitable pore space and geometry play key roles in its remarkable acetylene uptake. PMID:26123775

  9. Aluminium fumarate metal-organic framework: A super adsorbent for fluoride from water.

    PubMed

    Karmakar, Sankha; Dechnik, Janina; Janiak, Christoph; De, Sirshendu

    2016-02-13

    Potential of aluminium fumarate metal organic framework (MOF) for fluoride removal from groundwater has been explored in this work. The laboratory produced MOF exhibited characteristics similar to the commercial version. MOF was found to be micro-porous with surface area of 1156 m(2)/g and average pore size 17Å. Scanning electron micrograph of the AlFu MOF showed minute pores and texture was completely different from either of the parent materials. Change in the composition of AlFu MOF after fluoride adsorption was evident from powder X-ray diffraction analysis. Thermal stability of the AlFu MOF up to 700K was established by thermo-gravimetric analysis. Incorporation of fluoride phase after adsorption was confirmed by X-ray fluorescence analysis. As observed from FTIR study, hydroxyl ions in AlFu MOF were substituted by fluoride. 0.75 g/l AlFu MOF was good enough for complete removal of 30 mg/l fluoride concentration in feed solution. The maximum adsorption capacity for fluoride was 600, 550, 504 and 431 mg/g, respectively, at 293, 303, 313 and 333K. PMID:26513559

  10. A porous metal-organic framework with ultrahigh acetylene uptake capacity under ambient conditions

    PubMed Central

    Pang, Jiandong; Jiang, Feilong; Wu, Mingyan; Liu, Caiping; Su, Kongzhao; Lu, Weigang; Yuan, Daqiang; Hong, Maochun

    2015-01-01

    Acetylene, an important petrochemical raw material, is very difficult to store safely under compression because of its highly explosive nature. Here we present a porous metal-organic framework named FJI-H8, with both suitable pore space and rich open metal sites, for efficient storage of acetylene under ambient conditions. Compared with existing reports, FJI-H8 shows a record-high gravimetric acetylene uptake of 224 cm3 (STP) g−1 and the second-highest volumetric uptake of 196 cm3 (STP) cm−3 at 295 K and 1 atm. Increasing the storage temperature to 308 K has only a small effect on its acetylene storage capacity (∼200 cm3 (STP) g−1). Furthermore, FJI-H8 exhibits an excellent repeatability with only 3.8% loss of its acetylene storage capacity after five cycles of adsorption–desorption tests. Grand canonical Monte Carlo simulation reveals that not only open metal sites but also the suitable pore space and geometry play key roles in its remarkable acetylene uptake. PMID:26123775

  11. Comparative study of metal-organic frameworks for carbon capture applications

    NASA Astrophysics Data System (ADS)

    Simmons, Jason; Zhou, Wei; Wu, Hui; Yildirim, Taner

    2010-03-01

    With the current prevalence of hydrocarbon-based energy sources, carbon capture and sequestration are essential technologies for minimizing the emission of carbon dioxide and the resulting increased atmospheric concentration of CO2. Current technologies based on absorption require high temperature regeneration of the solvent, ultimately leading to significantly decreased efficiency and increased cost. Development of an adsorption-based technology, based on physical adsorption in optimized porous media, would greatly reduce the regeneration costs. Here we discuss the carbon capture performance of a range of metal-organic frameworks (MOFs), including both high surface area materials as well as those with sites that have been engineered to have enhanced binding. In particular, we demonstrate that MOFs can capture significant amounts of CO2 and that the CO2 can be readily removed from the MOF using standard pressure/vacuum swing techniques, yielding cyclic capture capacities in excess of 5 mmol/g. Further, we discuss the role of pore geometry and surface chemistry in the capacity of CO2 that can be removed in order to best optimize these materials. Lastly, we will address the effect of flue gas impurities on the carbon capture performance of these MOFs.

  12. Constructing Free Standing Metal Organic Framework MIL-53 Membrane Based on Anodized Aluminum Oxide Precursor

    PubMed Central

    Zhang, Yunlu; Gao, Qiuming; Lin, Zhi; Zhang, Tao; Xu, Jiandong; Tan, Yanli; Tian, Weiqian; Jiang, Lei

    2014-01-01

    Metal organic framework (MOF) materials have attracted great attention due to their well-ordered and controllable pores possessing of prominent potentials for gas molecule sorption and separation performances. Organizing the MOF crystals to a continuous membrane with a certain scale will better exhibit their prominent potentials. Reports in recent years concentrate on well grown MOF membranes on specific substrates. Free standing MOF membranes could have more important applications since they are independent from the substrates. However, the method to prepare such a membrane has been a great challenge because good mechanical properties and stabilities are highly required. Here, we demonstrate a novel and facile technique for preparing the free standing membrane with a size as large as centimeter scale. The substrate we use proved itself not only a good skeleton but also an excellent precursor to fulfill the reaction. This kind of membrane owns a strong mechanical strength, based on the fact that it is much thinner than the composite membranes grown on substrates and it could exhibit good property of gas separation. PMID:24821299

  13. Carbonized nanoscale metal-organic frameworks as high performance electrocatalyst for oxygen reduction reaction.

    PubMed

    Zhao, Shenlong; Yin, Huajie; Du, Lei; He, Liangcan; Zhao, Kun; Chang, Lin; Yin, Geping; Zhao, Huijun; Liu, Shaoqin; Tang, Zhiyong

    2014-12-23

    The oxygen reduction reaction (ORR) is one of the key steps in clean and efficient energy conversion techniques such as in fuel cells and metal-air batteries; however, several disadvantages of current ORRs including the kinetically sluggish process and expensive catalysts hinder mass production of these devices. Herein, we develop carbonized nanoparticles, which are derived from monodisperse nanoscale metal organic frameworks (MIL-88B-NH3), as the high performance ORR catalysts. The onset potential and the half-wave potential for the ORR at these carbonized nanoparticles is up to 1.03 and 0.92 V (vs RHE) in 0.1 M KOH solution, respectively, which represents the best ORR activity of all the non-noble metal catalysts reported so far. Furthermore, when used as the cathode of the alkaline direct fuel cell, the power density obtained with the carbonized nanoparticles reaches 22.7 mW/cm2, 1.7 times higher than the commercial Pt/C catalysts. PMID:25426850

  14. Synthesis of metal-organic framework films by pore diffusion method

    NASA Astrophysics Data System (ADS)

    Murayama, Naohiro; Nishimura, Yuki; Kajiro, Hiroshi; Kishida, Satoru; Kinoshita, Kentaro; Tottori Univ Team; Nippon Steel; Sumitomo Metal Co. Collaboration; Tottori Integrated Frontier Resaerch Center (Tifrec) Collaboration; Tottori University Electronic Display Resaerch Center (Tedrec) Collaboration

    Metal-organic frameworks (MOFs) presents high controllability in designing the nano-scale pore, and this enable molecular storages, catalysts, gas sensors, gas separation membranes, and electronic devices for next-generation. Therefore, a simple method for film synthesis of MOFs compared with conventional methods [1] is strongly required. In this paper, we provide pore diffusion method, in which a substrate containing constituent metals of MOF is inserted in solution that includes only linker molecules of MOF. As a result, 2D growth of MOF was effectively enhanced, and the formation of flat and dense MOF films was attained. The growth time, t, dependence of film thickness, d, can be expressed by the relation of d = Aln(t + 1) + B, where A and B are constants. It means that ionized coppers diffuse through the pores of MOFs and the synthesis reaction proceeds at the MOF/solvent interface. We demonstrated the fabrication of a HKUST-1/Cu-TPA hetero structure by synthesizing a Cu-TPA film continuously after the growth of a HKUST-1 film on the CuOx substrate.

  15. Photoreactivity of Metal-Organic Frameworks in Aqueous Solutions: Metal Dependence of Reactive Oxygen Species Production.

    PubMed

    Liu, Kai; Gao, Yanxin; Liu, Jing; Wen, Yifan; Zhao, Yingcan; Zhang, Kunyang; Yu, Gang

    2016-04-01

    Promising applications of metal-organic frameworks (MOFs) in various fields have raised concern over their environmental fate and safety upon inevitable discharge into aqueous environments. Currently, no information regarding the transformation processes of MOFs is available. Due to the presence of repetitive π-bond structure and semiconductive property, photochemical transformations are an important fate process that affects the performance of MOFs in practical applications. In the current study, the generation of reactive oxygen species (ROS) in isoreticular MIL-53s was studied. Scavengers were employed to probe the production of (1)O2, O2(•-), and •OH, respectively. In general, MIL-53(Cr) and MIL-53(Fe) are dominated by type I and II photosensitization reactions, respectively, and MIL-53(Al) appears to be less photoreactive. The generation of ROS in MIL-53(Fe) may be underestimated due to dismutation. Further investigation of MIL-53(Fe) encapsulated diclofenac transformation revealed that diclofenac can be easily transformed by MIL-53(Fe) generated ROS. However, the cytotoxicity results implied that the ROS generated from MIL-53s have little effect on the viability of the human hepatocyte (HepG2) cell line. These results suggest that the photogeneration of ROS by MOFs may be metal-node dependent, and the application of MIL-53s as drug carriers needs to be carefully considered due to their high photoreactivity. PMID:26942867

  16. Design and Synthesis of Novel Porous Metal-Organic Frameworks (MOFs) Toward High Hydrogen Storage Capacity

    SciTech Connect

    Mohamed, Eddaoudi; Zaworotko, Michael; Space, Brian; Eckert, Juergen

    2013-05-08

    Statement of Objectives: 1. Synthesize viable porous MOFs for high H2 storage at ambient conditions to be assessed by measuring H2 uptake. 2. Develop a better understanding of the operative interactions of the sorbed H2 with the organic and inorganic constituents of the sorbent MOF by means of inelastic neutron scattering (INS, to characterize the H2-MOF interactions) and computational studies (to interpret the data and predict novel materials suitable for high H2 uptake at moderate temperatures and relatively low pressures). 3. Synergistically combine the outcomes of objectives 1 and 2 to construct a made-to-order inexpensive MOF that is suitable for super H2 storage and meets the DOE targets - 6% H2 per weight (2kWh/kg) by 2010 and 9% H2 per weight (3kWh/kg) by 2015. The ongoing research is a collaborative experimental and computational effort focused on assessing H2 storage and interactions with pre-selected metal-organic frameworks (MOFs) and zeolite-like MOFs (ZMOFs), with the eventual goal of synthesizing made-to-order high H2 storage materials to achieve the DOE targets for mobile applications. We proposed in this funded research to increase the amount of H2 uptake, as well as tune the interactions (i.e. isosteric heats of adsorption), by targeting readily tunable MOFs:

  17. Chromophore-immobilized luminescent metal-organic frameworks as potential lighting phosphors and chemical sensors.

    PubMed

    Wang, Fangming; Liu, Wei; Teat, Simon J; Xu, Feng; Wang, Hao; Wang, Xinlong; An, Litao; Li, Jing

    2016-08-11

    An organic chromophore H4tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn2(tcbpe-F)(4,4'-bpy)·xDMA] (1) and [Zn2(tcbpe-F)(bpee)·xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of ∼51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor. PMID:27465685

  18. Evaluation of heterogeneous metal-organic framework organocatalysts prepared by postsynthetic modification.

    PubMed

    Garibay, Sergio J; Wang, Zhenqiang; Cohen, Seth M

    2010-09-01

    A metal-organic framework (MOF) containing 2-amino-1,4-benzenedicarboxylate (NH(2)-BDC) as a building block is shown to undergo chemical modification with a set of cyclic anhydrides. The modification of the aluminum-based MOF known as MIL-53(Al)-NH(2) (MIL = Material Institut Lavoisier) by these reagents is demonstrated by using a variety of methods, including NMR and electrospray ionization mass spectrometry (ESI-MS), and the structural integrity of the modified MOFs has been confirmed by thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD). Reaction with these cyclic anhydrides produces MOFs that display carboxylic acid functional groups within their pores. Furthermore, it is shown that maleic acid functionalized MIL-53(Al)-AMMal can act as a Brønsted acid catalyst and facilitate the methanolysis of several small epoxides. Experiments show that MIL-53(Al)-AMMal acts in a heterogeneous manner and is recyclable with consistent activity over at least three catalytic cycles. The findings presented here demonstrate several important features of covalent postsynthetic modification (PSM) on MOFs, including (1) facile introduction of catalytic functionality using simple organic reagents (e.g., anhydrides); (2) the ability to utilize and recycle organocatalytic MOFs; (3) control of catalytic activity through choice of functional group. The findings clearly illustrate that covalent postsynthetic modification represents a powerful means to access new MOF compounds that serve as organocatalytic materials. PMID:20698561

  19. Metal-organic framework nanosheets in polymer composite materials for gas separation

    PubMed Central

    Seoane, Beatriz; Miro, Hozanna; Corma, Avelino; Kapteijn, Freek; Llabrés i Xamena, Francesc X.; Gascon, Jorge

    2014-01-01

    Composites incorporating two-dimensional nanostructures within polymeric matrices hold potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic-frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of free standing nanosheets has proven challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometer lateral dimensions and nanometer thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increment in the separation selectivity with pressure. As revealed by tomographic focused-ion-beam scanning-electron-microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared to isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications. PMID:25362353

  20. Promotion of low-humidity proton conduction by controlling hydrophilicity in layered metal-organic frameworks.

    PubMed

    Sadakiyo, Masaaki; Okawa, Hisashi; Shigematsu, Akihito; Ohba, Masaaki; Yamada, Teppei; Kitagawa, Hiroshi

    2012-03-28

    We controlled the hydrophilicity of metal-organic frameworks (MOFs) to achieve high proton conductivity and high adsorption of water under low humidity conditions, by employing novel class of MOFs, {NR(3)(CH(2)COOH)}[MCr(ox)(3)]·nH(2)O (abbreviated as R-MCr, where R = Me (methyl), Et (ethyl), or Bu (n-butyl), and M = Mn or Fe): Me-FeCr, Et-MnCr, Bu-MnCr, and Bu-FeCr. The cationic components have a carboxyl group that functions as the proton carrier. The hydrophilicity of the cationic ions was tuned by the NR(3) residue to decrease with increasing bulkiness of the residue: {NMe(3)(CH(2)COOH)}(+) > {NEt(3)(CH(2)COOH)}(+) > {NBu(3)(CH(2)COOH)}(+). The proton conduction of the MOFs increased with increasing hydrophilicity of the cationic ions. The most hydrophilic sample, Me-FeCr, adsorbed a large number of water molecules and showed a high proton conductivity of ~10(-4) S cm(-1), even at a low humidity of 65% relative humidity (RH), at ambient temperature. Notably, this is the highest conductivity among the previously reported proton-conducting MOFs that operate under low RH conditions. PMID:22409393

  1. Specific oriented metal-organic framework membranes and their facet-tuned separation performance.

    PubMed

    Mao, Yiyin; Su, Binbin; Cao, Wei; Li, Junwei; Ying, Yulong; Ying, Wen; Hou, Yajun; Sun, Luwei; Peng, Xinsheng

    2014-09-24

    Modulating the crystal morphology, or the exposed crystal facets, of metal-organic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO2 from 0.55 nm SF6 was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling. PMID:25184955

  2. Metal-organic frameworks as templates for nanoscale NaAlH4.

    PubMed

    Bhakta, Raghunandan K; Herberg, Julie L; Jacobs, Benjamin; Highley, Aaron; Behrens, Richard; Ockwig, Nathan W; Greathouse, Jeffery A; Allendorf, Mark D

    2009-09-23

    Metal-organic frameworks (MOFs) offer an attractive alternative to traditional hard and soft templates for nanocluster synthesis because their ordered crystalline lattice provides a highly controlled and inherently understandable environment. We demonstrate that MOFs are stable hosts for metal hydrides proposed for hydrogen storage and their reactive precursors, providing platform to test recent theoretical predictions that some of these materials can be destabilized with respect to hydrogen desorption by reducing their critical dimension to the nanoscale. With the MOF HKUST-1 as template, we show that NaAlH(4) nanoclusters as small as eight formula units can be synthesized. The confinement of these clusters within the MOF pores dramatically accelerates the desorption kinetics, causing decomposition to occur at approximately 100 degrees C lower than bulk NaAlH(4). However, using simultaneous thermogravimetric modulated beam mass spectrometry, we also show that the thermal decomposition mechanism of NaAlH(4) is complex and may involve processes such as nucleation and growth in addition to the normally assumed two-step chemical decomposition reactions. PMID:19719170

  3. Hybrid glasses from strong and fragile metal-organic framework liquids

    PubMed Central

    Bennett, Thomas D.; Tan, Jin-Chong; Yue, Yuanzheng; Baxter, Emma; Ducati, Caterina; Terrill, Nick J.; Yeung, Hamish H. -M.; Zhou, Zhongfu; Chen, Wenlin; Henke, Sebastian; Cheetham, Anthony K.; Greaves, G. Neville

    2015-01-01

    Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density ‘perfect' glass, similar to those formed in ice, silicon and disaccharides. This order–order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order–disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of ‘melt-casting' MOF glasses. PMID:26314784

  4. Hybrid glasses from strong and fragile metal-organic framework liquids.

    PubMed

    Bennett, Thomas D; Tan, Jin-Chong; Yue, Yuanzheng; Baxter, Emma; Ducati, Caterina; Terrill, Nick J; Yeung, Hamish H-M; Zhou, Zhongfu; Chen, Wenlin; Henke, Sebastian; Cheetham, Anthony K; Greaves, G Neville

    2015-01-01

    Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density 'perfect' glass, similar to those formed in ice, silicon and disaccharides. This order-order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order-disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of 'melt-casting' MOF glasses. PMID:26314784

  5. Synthesis of magnetic metal-organic framework (MOF) for efficient removal of organic dyes from water

    PubMed Central

    Zhao, Xiaoli; Liu, Shuangliu; Tang, Zhi; Niu, Hongyun; Cai, Yaqi; Meng, Wei; Wu, Fengchang; Giesy, John P.

    2015-01-01

    A novel, simple and efficient strategy for fabricating a magnetic metal-organic framework (MOF) as sorbent to remove organic compounds from simulated water samples is presented and tested for removal of methylene blue (MB) as an example. The novel adsorbents combine advantages of MOFs and magnetic nanoparticles and possess large capacity, low cost, rapid removal and easy separation of the solid phase, which makes it an excellent sorbent for treatment of wastewaters. The resulting magnetic MOFs composites (also known as MFCs) have large surface areas (79.52 m2 g−1), excellent magnetic response (14.89 emu g−1), and large mesopore volume (0.09 cm3 g−1), as well as good chemical inertness and mechanical stability. Adsorption was not drastically affected by pH, suggesting π–π stacking interaction and/or hydrophobic interactions between MB and MFCs. Kinetic parameters followed pseudo-second-order kinetics and adsorption was described by the Freundlich isotherm. Adsorption capacity was 84 mg MB g−1 at an initial MB concentration of 30 mg L−1, which increased to 245 mg g−1 when the initial MB concentration was 300 mg L−1. This capacity was much greater than most other adsorbents reported in the literature. In addition, MFC adsorbents possess excellent reusability, being effective after at least five consecutive cycles. PMID:26149818

  6. High Methane Storage Working Capacity in Metal-Organic Frameworks with Acrylate Links.

    PubMed

    Jiang, Juncong; Furukawa, Hiroyasu; Zhang, Yue-Biao; Yaghi, Omar M

    2016-08-17

    High methane storage capacity in porous materials is important for the design and manufacture of vehicles powered by natural gas. Here, we report the synthesis, crystal structures and methane adsorption properties of five new zinc metal-organic frameworks (MOFs), MOF-905, MOF-905-Me2, MOF-905-Naph, MOF-905-NO2, and MOF-950. All these MOFs consist of the Zn4O(-CO2)6 secondary building units (SBUs) and benzene-1,3,5-tri-β-acrylate, BTAC. The permanent porosity of all five materials was confirmed, and their methane adsorption measured up to 80 bar to reveal that MOF-905 is among the best performing methane storage materials with a volumetric working capacity (desorption at 5 bar) of 203 cm(3) cm(-3) at 80 bar and 298 K, a value rivaling that of HKUST-1 (200 cm(3) cm(-3)), the benchmark compound for methane storage in MOFs. This study expands the scope of MOF materials with ultrahigh working capacity to include linkers having the common acrylate connectivity. PMID:27442620

  7. Capturing snapshots of post-synthetic metallation chemistry in metal-organic frameworks

    NASA Astrophysics Data System (ADS)

    Bloch, Witold M.; Burgun, Alexandre; Coghlan, Campbell J.; Lee, Richmond; Coote, Michelle L.; Doonan, Christian J.; Sumby, Christopher J.

    2014-10-01

    Post-synthetic metallation is employed strategically to imbue metal-organic frameworks (MOFs) with enhanced performance characteristics. However, obtaining precise structural information for metal-centred reactions that take place within the pores of these materials has remained an elusive goal, because of issues with high symmetry in certain MOFs, lower initial crystallinity for some chemically robust MOFs, and the reduction in crystallinity that can result from carrying out post-synthetic reactions on parent crystals. Here, we report a new three-dimensional MOF possessing pore cavities that are lined with vacant di-pyrazole groups poised for post-synthetic metallation. These metallations occur quantitatively without appreciable loss of crystallinity, thereby enabling examination of the products by single-crystal X-ray diffraction. To illustrate the potential of this platform to garner fundamental insight into metal-catalysed reactions in porous solids we use single-crystal X-ray diffraction studies to structurally elucidate the reaction products of consecutive oxidative addition and methyl migration steps that occur within the pores of the Rh-metallated MOF, 1·[Rh(CO)2][Rh(CO)2Cl2].

  8. Covalent bonding of homochiral metal-organic framework in capillaries for stereoisomer separation by capillary electrochromatography.

    PubMed

    Ma, Jichao; Ye, Nengsheng; Li, Jian

    2016-02-01

    In this work, a [Cu(mal)(bpy)]⋅H2O (mal, L-(-)-malic acid; bpy, 4,4'-bipyridyl) homochiral metal-organic frameworks (MOFs) was synthesized and used for modifying the inner walls of capillary columns by utilizing amido bonds to form covalent links between the MOFs particles and capillary inner wall. The synthesized [Cu(mal)(bpy)]⋅H2 O and MOFs-modified capillary column were characterized by X-ray diffraction, thermogravimetric analysis, particle size distribution analysis, nitrogen absorption characterization, FTIR spectroscopy, SEM, and energy-dispersive X-ray spectroscopy (EDX). The MOFs-modified capillary column was used for the stereoisomer separation of some drugs. The LODs and LOQs of six analytes were 0.1 and 0.25 μg/mL, respectively. The linear range was 0.25-250 μg/mL for ephedrine, 0.25-250 μg/mL for pseudoephedrine, 0.25-180 μg/mL for D-penicillamine, 0.25-120 μg/mL for L-penicillamine, 0.25-180 μg/mL for D-phenylalanine, and 0.25-160 μg/mL for L-phenylalanine, all with R(2) > 0.999. Finally, the MOFs-modified capillary column was applied for the analysis of active ingredients in a real sample of the traditional Chinese medicine ephedra. PMID:26542186

  9. Sintering-Resistant Single-Site Nickel Catalyst Supported by Metal-Organic Framework.

    PubMed

    Li, Zhanyong; Schweitzer, Neil M; League, Aaron B; Bernales, Varinia; Peters, Aaron W; Getsoian, Andrew Bean; Wang, Timothy C; Miller, Jeffrey T; Vjunov, Aleksei; Fulton, John L; Lercher, Johannes A; Cramer, Christopher J; Gagliardi, Laura; Hupp, Joseph T; Farha, Omar K

    2016-02-17

    Developing supported single-site catalysts is an important goal in heterogeneous catalysis since the well-defined active sites afford opportunities for detailed mechanistic studies, thereby facilitating the design of improved catalysts. We present herein a method for installing Ni ions uniformly and precisely on the node of a Zr-based metal-organic framework (MOF), NU-1000, in high density and large quantity (denoted as Ni-AIM) using atomic layer deposition (ALD) in a MOF (AIM). Ni-AIM is demonstrated to be an efficient gas-phase hydrogenation catalyst upon activation. The structure of the active sites in Ni-AIM is proposed, revealing its single-site nature. More importantly, due to the organic linker used to construct the MOF support, the Ni ions stay isolated throughout the hydrogenation catalysis, in accord with its long-term stability. A quantum chemical characterization of the catalyst and the catalytic process complements the experimental results. With validation of computational modeling protocols, we further targeted ethylene oligomerization catalysis by Ni-AIM guided by theoretical prediction. Given the generality of the AIM methodology, this emerging class of materials should prove ripe for the discovery of new catalysts for the transformation of volatile substrates. PMID:26836273

  10. Enhanced gas sorption and breathing properties of the new sulfone functionalized COMOC-2 metal organic framework.

    PubMed

    Wang, Guangbo; Leus, Karen; Couck, Sarah; Tack, Pieter; Depauw, Hannes; Liu, Ying-Ya; Vincze, Laszlo; Denayer, Joeri F M; Van Der Voort, Pascal

    2016-06-21

    A new sulfone functionalized vanadium metal-organic framework (MOF), denoted as SO2-COMOC-2, has been synthesized solvothermally. Its structural and gas sorption properties towards CO2 and CH4 have been evaluated and compared to those of the pristine COMOC-2 material. The SO2-COMOC-2 shows a remarkable increase in CO2 capacity at ambient pressure (2.13 mmol g(-1) at 273 K vs. 1.23 mmol g(-1) for the pristine COMOC-2). Additionally, the high pressure CO2 sorption isotherm shows a distinctive two-step sorption behavior with a final capacity of 12.45 mmol g(-1) for SO2-COMOC-2 at 303 K, while for CH4 a typical Type I isotherm was obtained with a capacity of 4.13 mmol g(-1). In situ synchrotron X-ray powder diffraction measurements have been carried out to characterize the structural flexibility of the materials, showing both the presence of large pore and narrow pore form. Furthermore, synchrotron XANES and a variety of spectroscopic techniques have been utilized to verify the presence of hydroxyl groups and the existence of the mixed vanadium oxidation states in the titled MOF structure. PMID:27192612

  11. Electronic origins of photocatalytic activity in d0 metal organic frameworks

    PubMed Central

    Nasalevich, Maxim A.; Hendon, Christopher H.; Santaclara, Jara G.; Svane, Katrine; van der Linden, Bart; Veber, Sergey L.; Fedin, Matvey V.; Houtepen, Arjan J.; van der Veen, Monique A.; Kapteijn, Freek; Walsh, Aron; Gascon, Jorge

    2016-01-01

    Metal-organic frameworks (MOFs) containing d0 metals such as NH2-MIL-125(Ti), NH2-UiO-66(Zr) and NH2-UiO-66(Hf) are among the most studied MOFs for photocatalytic applications. Despite structural similarities, we demonstrate that the electronic properties of these MOFs are markedly different. As revealed by quantum chemistry, EPR measurements and transient absorption spectroscopy, the highest occupied and lowest unoccupied orbitals of NH2-MIL-125(Ti) promote a long lived ligand-to-metal charge transfer upon photoexcitation, making this material suitable for photocatalytic applications. In contrast, in case of UiO materials, the d-orbitals of Zr and Hf, are too low in binding energy and thus cannot overlap with the π* orbital of the ligand, making both frontier orbitals localized at the organic linker. This electronic reconfiguration results in short exciton lifetimes and diminishes photocatalytic performance. These results highlight the importance of orbital contributions at the band edges and delineate future directions in the development of photo-active hybrid solids. PMID:27020767

  12. Metal-organic frameworks supported surface-imprinted nanoparticles for the sensitive detection of metolcarb.

    PubMed

    Qian, Kun; Deng, Qiliang; Fang, Guozhen; Wang, Junping; Pan, Mingfei; Wang, Shuo; Pu, Yuehong

    2016-05-15

    A novel approach to synthesize molecularly imprinted polymer (MIP) nanoparticles using a MIL-101 support (a type of metal-organic framework) is reported herein for the first time; the sample is referred as MIL@MIP. The nanoparticles were well distributed within the polymer film, and exhibit an octahedral shape, satisfied thermal stability, and a high specific surface area (SSA) of 1579.43 m(2)g(-1). The adsorption behavior of MIL@MIP toward metolcarb in aqueous solution was subsequently examined. The synthesized MIL@MIP displayed satisfactory high transfer mass rates and a high selective adsorption affinity for metolcarb. Based on these results, a quartz crystal microbalance (QCM) sensor based on MIL@MIP was subsequently constructed and examined for the sensitive detection of metolcarb. Under optimal conditions, the detection limit of the system assessed in pear juice was 0.0689 mg L(-1) within a linear concentration range of 0.1-0.9 mg L(-1). MIL@MIP-QCM system combines the advantages of MIL-101 and molecularly imprinted technology (MIT), thereby achieving high detection sensitivity and selectivity. The current findings suggest the potential of MIL@MIP for detecting trace level pesticides and veterinary drugs for food safety and environmental control. PMID:26735869

  13. Hybrid glasses from strong and fragile metal-organic framework liquids

    NASA Astrophysics Data System (ADS)

    Bennett, Thomas D.; Tan, Jin-Chong; Yue, Yuanzheng; Baxter, Emma; Ducati, Caterina; Terrill, Nick J.; Yeung, Hamish H.-M.; Zhou, Zhongfu; Chen, Wenlin; Henke, Sebastian; Cheetham, Anthony K.; Greaves, G. Neville

    2015-08-01

    Hybrid glasses connect the emerging field of metal-organic frameworks (MOFs) with the glass formation, amorphization and melting processes of these chemically versatile systems. Though inorganic zeolites collapse around the glass transition and melt at higher temperatures, the relationship between amorphization and melting has so far not been investigated. Here we show how heating MOFs of zeolitic topology first results in a low density `perfect' glass, similar to those formed in ice, silicon and disaccharides. This order-order transition leads to a super-strong liquid of low fragility that dynamically controls collapse, before a subsequent order-disorder transition, which creates a more fragile high-density liquid. After crystallization to a dense phase, which can be remelted, subsequent quenching results in a bulk glass, virtually identical to the high-density phase. We provide evidence that the wide-ranging melting temperatures of zeolitic MOFs are related to their network topologies and opens up the possibility of `melt-casting' MOF glasses.

  14. Electronic origins of photocatalytic activity in d0 metal organic frameworks

    NASA Astrophysics Data System (ADS)

    Nasalevich, Maxim A.; Hendon, Christopher H.; Santaclara, Jara G.; Svane, Katrine; van der Linden, Bart; Veber, Sergey L.; Fedin, Matvey V.; Houtepen, Arjan J.; van der Veen, Monique A.; Kapteijn, Freek; Walsh, Aron; Gascon, Jorge

    2016-03-01

    Metal-organic frameworks (MOFs) containing d0 metals such as NH2-MIL-125(Ti), NH2-UiO-66(Zr) and NH2-UiO-66(Hf) are among the most studied MOFs for photocatalytic applications. Despite structural similarities, we demonstrate that the electronic properties of these MOFs are markedly different. As revealed by quantum chemistry, EPR measurements and transient absorption spectroscopy, the highest occupied and lowest unoccupied orbitals of NH2-MIL-125(Ti) promote a long lived ligand-to-metal charge transfer upon photoexcitation, making this material suitable for photocatalytic applications. In contrast, in case of UiO materials, the d-orbitals of Zr and Hf, are too low in binding energy and thus cannot overlap with the π* orbital of the ligand, making both frontier orbitals localized at the organic linker. This electronic reconfiguration results in short exciton lifetimes and diminishes photocatalytic performance. These results highlight the importance of orbital contributions at the band edges and delineate future directions in the development of photo-active hybrid solids.

  15. Lanthanide metal-organic frameworks as selective microporous materials for adsorption of heavy metal ions.

    PubMed

    Jamali, Abbas; Tehrani, Alireza Azhdari; Shemirani, Farzaneh; Morsali, Ali

    2016-06-14

    Four microporous lanthanide metal-organic frameworks (MOFs), namely Ln(BTC)(H2O)(DMF)1.1 (Ln = Tb, Dy, Er and Yb, DMF = dimethylformamide, H3BTC = benzene-1,3,5-tricarboxylic acid), have been used for selective adsorption of Pb(ii) and Cu(ii). Among these MOFs, the Dy-based MOF shows better adsorption property and selectivity toward Pb(ii) and Cu(ii) ions. Adsorption isotherms indicate that sorption of Pb(ii) and Cu(ii) on MOFs is via monolayer coverage. Preconcentration is based on solid-phase extraction in which MOFs were rapidly injected into water samples and adsorption of metal ions was rapid because of good contact with analyte; then adsorbed Pb(ii) and Cu(ii) ions were analyzed by FAAS. The optimized methodology represents good linearity between 1 and 120 μg L(-1) and detection limit of 0.4 and 0.26 μg L(-1) for Pb(ii) and Cu(ii), respectively. Subsequently the method was evaluated for preconcentration of target metal ions in some environmental water samples. PMID:27171975

  16. Synthesis of magnetic metal-organic framework (MOF) for efficient removal of organic dyes from water

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoli; Liu, Shuangliu; Tang, Zhi; Niu, Hongyun; Cai, Yaqi; Meng, Wei; Wu, Fengchang; Giesy, John P.

    2015-07-01

    A novel, simple and efficient strategy for fabricating a magnetic metal-organic framework (MOF) as sorbent to remove organic compounds from simulated water samples is presented and tested for removal of methylene blue (MB) as an example. The novel adsorbents combine advantages of MOFs and magnetic nanoparticles and possess large capacity, low cost, rapid removal and easy separation of the solid phase, which makes it an excellent sorbent for treatment of wastewaters. The resulting magnetic MOFs composites (also known as MFCs) have large surface areas (79.52 m2 g-1), excellent magnetic response (14.89 emu g-1), and large mesopore volume (0.09 cm3 g-1), as well as good chemical inertness and mechanical stability. Adsorption was not drastically affected by pH, suggesting π-π stacking interaction and/or hydrophobic interactions between MB and MFCs. Kinetic parameters followed pseudo-second-order kinetics and adsorption was described by the Freundlich isotherm. Adsorption capacity was 84 mg MB g-1 at an initial MB concentration of 30 mg L-1, which increased to 245 mg g-1 when the initial MB concentration was 300 mg L-1. This capacity was much greater than most other adsorbents reported in the literature. In addition, MFC adsorbents possess excellent reusability, being effective after at least five consecutive cycles.

  17. Metal-organic framework nanosheets in polymer composite materials for gas separation

    NASA Astrophysics Data System (ADS)

    Rodenas, Tania; Luz, Ignacio; Prieto, Gonzalo; Seoane, Beatriz; Miro, Hozanna; Corma, Avelino; Kapteijn, Freek; Llabrés I Xamena, Francesc X.; Gascon, Jorge

    2015-01-01

    Composites incorporating two-dimensional nanostructures within polymeric matrices have potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of freestanding nanosheets has proved challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometre lateral dimensions and nanometre thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increase in the separation selectivity with pressure. As revealed by tomographic focused ion beam scanning electron microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared with isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications.

  18. Adsorption of carbon dioxide, methane and nitrogen on an ultramicroporous copper metal-organic framework.

    PubMed

    Wu, Xiaofei; Yuan, Bin; Bao, Zongbi; Deng, Shuguang

    2014-09-15

    An ultramicroporous copper metal-organic framework (Cu-MOF), Cu(hfipbb)(H2hfipbb)0.5 [H2hfipbb=4,4'-(hexafluoro-isopropylidene) bis(benzoic acid)] was successfully synthesized by a microwave-assisted method (1) with a shorter reaction time and higher MOFs yield. The obtained Cu-MOF sample was characterized with scanning electron microscopy for crystal structure, powder X-ray diffraction for phase structure, and carbon dioxide adsorption at 273 K for pore textural properties. Single-component adsorption (adsorption equilibrium and kinetics) of CO2, CH4, and N2 on 1 was measured using a Micromeritics ASAP 2020 adsorption porosimeter at 278, 298 and 318 K, and pressures up to 1 bar. Isosteric heats of adsorption, Henry's constants, and diffusion time constants were calculated and carefully analyzed. Adsorption equilibrium selectivity (α), adsorbent selection parameter for pressure swing adsorption processes (S), kinetic selectivity and combined separation selectivity (β) for CO2/CH4, CO2/N2 and CH4/N2 binary mixtures were estimated based on the single-component adsorption data. The relative high values of the adsorption selectivities suggest that Cu-MOF is a promising adsorbent for separating CO2/CH4, CO2/N2 and CH4/N2 gas pairs. PMID:24998057

  19. Mechanically Interlocked Linkers inside Metal-Organic Frameworks: Effect of Ring Size on Rotational Dynamics.

    PubMed

    Vukotic, V Nicholas; O'Keefe, Christopher A; Zhu, Kelong; Harris, Kristopher J; To, Christine; Schurko, Robert W; Loeb, Stephen J

    2015-08-01

    A series of metal-organic framework (MOF) materials has been prepared, each containing a mechanically interlocked molecule (MIM) as the linker and a copper(II) paddlewheel as the secondary building unit (SBU). The MIM linkers are [2]rotaxanes with varying sizes of crown ether macrocycles ([22]crown-6, 22C6; [24]crown-6, 24C6; [26]crown-6, 26C6; benzo[24]crown-6, B24C6) and an anilinium-based axle containing four carboxylate donor groups. Herein, the X-ray structures of MOFs UWCM-1 (no crown) and UWDM-1(22) are compared and demonstrate the effect of including a macrocycle around the axle of the linker. The rotaxane linkers are linear and result in nbo-type MOFs with void space that allows for motion of the interlocked macrocycle inside the MOF pores, while the macrocycle-free linker is bent and yields a MOF with a novel 12-connected bcc structure. Variable temperature (2)H solid-state nuclear magnetic resonance showed that the macrocycles in UWDM-1(22), UWDM-1(24), and UWDM-1(B24) undergo different degrees and rates of rotation depending on the size and shape of the macrocycle. PMID:26175343

  20. Metal-organic framework nanosheets in polymer composite materials for gas separation.

    PubMed

    Rodenas, Tania; Luz, Ignacio; Prieto, Gonzalo; Seoane, Beatriz; Miro, Hozanna; Corma, Avelino; Kapteijn, Freek; Llabrés i Xamena, Francesc X; Gascon, Jorge

    2015-01-01

    Composites incorporating two-dimensional nanostructures within polymeric matrices have potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of freestanding nanosheets has proved challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometre lateral dimensions and nanometre thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increase in the separation selectivity with pressure. As revealed by tomographic focused ion beam scanning electron microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared with isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications. PMID:25362353