共查询到20条相似文献,搜索用时 12 毫秒
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Yonghwi Kim Dr. Sunirban Das Saurav Bhattacharya Soonsang Hong Dr. Min Gyu Kim Dr. Minyoung Yoon Prof. Dr. Srinivasan Natarajan Prof. Dr. Kimoon Kim 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(52):16642-16648
A porous metal–organic framework, Mn(H3O)[(Mn4Cl)3(hmtt)8] (POST‐65), was prepared by the reaction of 5,5′,10,10′,15,15′‐hexamethyltruxene‐2,7,12‐tricarboxylic acid (H3hmtt) with MnCl2 under solvothermal conditions. POST‐65(Mn) was subjected to post‐synthetic modification with Fe, Co, Ni, and Cu according to an ion‐exchange method that resulted in the formation of three isomorphous frameworks, POST‐65(Co/Ni/Cu), as well as a new framework, POST‐65(Fe). The ion‐exchanged samples could not be prepared by regular solvothermal reactions. The complete exchange of the metal ions and retention of the framework structure were verified by inductively coupled plasma–atomic emission spectrometry (ICP‐AES), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) surface‐area analysis. Single‐crystal X‐ray diffractions studies revealed a single‐crystal‐to‐single‐crystal (SCSC)‐transformation nature of the ion‐exchange process. Hydrogen‐sorption and magnetization measurements showed metal‐specific properties of POST‐65. 相似文献
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Molecular Level Characterization of the Structure and Interactions in Peptide‐Functionalized Metal–Organic Frameworks
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Dr. Tanya K. Todorova Dr. Xavier Rozanska Dr. Christel Gervais Dr. Alexandre Legrand Dr. Linh N. Ho Pierrick Berruyer Dr. Anne Lesage Prof. Lyndon Emsley Dr. David Farrusseng Dr. Jérôme Canivet Dr. Caroline Mellot‐Draznieks 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(46):16531-16538
We use density functional theory, newly parameterized molecular dynamics simulations, and last generation 15N dynamic nuclear polarization surface enhanced solid‐state NMR spectroscopy (DNP SENS) to understand graft–host interactions and effects imposed by the metal–organic framework (MOF) host on peptide conformations in a peptide‐functionalized MOF. Focusing on two grafts typified by MIL‐68‐proline ( ‐Pro ) and MIL‐68‐glycine‐proline ( ‐Gly‐Pro ), we identified the most likely peptide conformations adopted in the functionalized hybrid frameworks. We found that hydrogen bond interactions between the graft and the surface hydroxyl groups of the MOF are essential in determining the peptides conformation(s). DNP SENS methodology shows unprecedented signal enhancements when applied to these peptide‐functionalized MOFs. The calculated chemical shifts of selected MIL‐68‐NH‐ Pro and MIL‐68‐NH‐ Gly‐Pro conformations are in a good agreement with the experimentally obtained 15N NMR signals. The study shows that the conformations of peptides when grafted in a MOF host are unlikely to be freely distributed, and conformational selection is directed by strong host–guest interactions. 相似文献
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Andrew D. Wiersum Estelle Soubeyrand‐Lenoir Dr. Qingyuan Yang Dr. Beatrice Moulin Vincent Guillerm Dr. Mouna Ben Yahia Dr. Sandrine Bourrelly Dr. Alexandre Vimont Dr. Stuart Miller Dr. Christelle Vagner Prof. Marco Daturi Dr. Guillaume Clet Dr. Christian Serre Dr. Guillaume Maurin Dr. Philip L. Llewellyn 《化学:亚洲杂志》2011,6(12):3270-3280
In addition to its high thermal stability, repetitive hydration/dehydration tests have revealed that the porous zirconium terephthalate UiO‐66 switches reversibly between its dehydroxylated and hydroxylated versions. The structure of its dehydroxylated form has thus been elucidated by coupling molecular simulations and X‐ray powder diffraction data. Infrared measurements have shown that relatively weak acid sites are available while microcalorimetry combined with Monte Carlo simulations emphasize moderate interactions between the UiO‐66 surface and a wide range of guest molecules including CH4, CO, and CO2. These properties, in conjunction with its significant adsorption capacity, make UiO‐66 of interest for its further evaluation for CO2 recovery in industrial applications. This global approach suggests a strategy for the evaluation of metal–organic frameworks for gas‐based applications. 相似文献
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Dr. Ya‐Qian Lan Dr. Shun‐Li Li Dr. Hai‐Long Jiang Prof. Dr. Qiang Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(26):8076-8083
In this work, we have demonstrated a family of diamondoid metal–organic frameworks (MOFs) based on functionalized molecular building blocks and length‐adjustable organic linkers by using a stepwise synthesis strategy. We have successfully achieved not only “design” and “control” to synthesize MOFs, but also the functionalization of both secondary building units (SBUs) and organic linkers in the same MOF for the first time. Furthermore, the results of N2 and H2 adsorption show that their surface areas and hydrogen uptake capacities are determined by the most optimal combination of functional groups from SBUs and organic linkers, interpenetration, and free volume in this system. A member of this series, DMOF‐6 exhibits the highest surface area and H2 adsorption capacity among this family of MOFs. 相似文献
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The electrochemical reduction of CO2 holds great promise for lowering the concentration of CO2 in the Earth′s atmosphere. However, several challenges have hindered the commercialization of this technology, including energy efficiency, the solubility of CO2 in the aqueous phase, and electrode stability. In this Minireview, we highlight and summarize the main advantages and limitations that metal–organic frameworks (MOFs) may offer in this field of research, either when used directly as electrocatalysts or when used as catalyst precursors. 相似文献
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Dr. Hui Liu Dr. Yonggang Zhao Zhijuan Zhang Nour Nijem Prof. Dr. Yves J. Chabal Prof. Dr. Xiangfang Peng Prof. Dr. Heping Zeng Prof. Dr. Jing Li 《化学:亚洲杂志》2013,8(4):778-785
We report two new 3D structures, [Zn3(bpdc)3(2,2′‐dmbpy)] (DMF)x(H2O)y ( 1 ) and [Zn3(bpdc)3(3,3′‐dmbpy)]?(DMF)4(H2O)0.5 ( 2 ), by methyl functionalization of the pillar ligand in [Zn3(bpdc)3(bpy)] (DMF)4?(H2O) ( 3 ) (bpdc=biphenyl‐4,4′‐dicarboxylic acid; z,z′‐dmbpy=z,z′‐dimethyl‐4,4′‐bipyridine; bpy=4,4′‐bipyridine). Single‐crystal X‐ray diffraction analysis indicates that 2 is isostructural to 3 , and the power X‐ray diffraction (PXRD) study shows a very similar framework of 1 to 2 and 3 . Both 1 and 2 are 3D porous structures made of Zn3(COO)6 secondary building units (SBUs) and 2,2′‐ or 3,3′‐dmbpy as pillar ligand. Thermogravimetric analysis (TGA) and PXRD studies reveal high thermal and water stability for both compounds. Gas‐adsorption studies show that the reduction of surface area and pore volume by introducing a methyl group to the bpy ligand leads to a decrease in H2 uptake for both compounds. However, CO2 adsorption experiments with 1′ (guest‐free 1 ) indicate significant enhancement in CO2 uptake, whereas for 2′ (guest‐free 2 ) the adsorbed amount is decreased. These results suggest that there are two opposing and competitive effects brought on by methyl functionalization: the enhancement due to increased isosteric heats of CO2 adsorption (Qst), and the detraction due to the reduction of surface area and pore volume. For 1′ , the enhancement effect dominates, which leads to a significantly higher uptake of CO2 than its parent compound 3′ (guest‐free 3 ). For 2′ , the detraction effect predominates, thereby resulting in reduced CO2 uptake relative to its parent structure 3′ . IR and Raman spectroscopic studies also present evidence for strong interaction between CO2 and methyl‐functionalized π moieties. Furthermore, all compounds exhibit high separation capability for CO2 over other small gases including CH4, CO, N2, and O2. 相似文献
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Multiscale Computational Study on the Adsorption and Separation of CO2/CH4 and CO2/H2 on Li+‐Doped Mixed‐Ligand Metal–Organic Framework Zn2(NDC)2(diPyNI)
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The quantum mechanics (QM) method and grand canonical Monte Carlo (GCMC) simulations are used to study the effect of lithium cation doping on the adsorption and separation of CO2, CH4, and H2 on a twofold interwoven metal–organic framework (MOF), Zn2(NDC)2(diPyNI) (NDC=2,6‐naphthalenedicarboxylate; diPyNI=N,N′‐di‐(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide). Second‐order Moller–Plesset (MP2) calculations on the (Li+–diPyNI) cluster model show that the energetically most favorable lithium binding site is above the pyridine ring side at a distance of 1.817 Å from the oxygen atom. The results reveal that the adsorption capacity of Zn2(NDC)2(diPyNI) for carbon dioxide is higher than those of hydrogen and methane at room temperature. Furthermore, GCMC simulations on the structures obtained from QM calculations predict that the Li+‐doped MOF has higher adsorption capacities than the nondoped MOF, especially at low pressures. In addition, the probability density distribution plots reveal that CO2, CH4, and H2 molecules accumulate close to the Li cation site. The selectivity results indicate that CO2/H2 selectivity values in Zn2(NDC)2(diPyNI) are higher than those of CO2/CH4. The selectivity of CO2 over CH4 on Li+‐doped Zn2(NDC)2(diPyNI) is improved relative to the nondoped MOF. 相似文献
9.
Tetrazine Chromophore‐Based Metal–Organic Frameworks with Unusual Configurations: Synthetic,Structural, Theoretical,Fluorescent, and Nonlinear Optical Studies
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Dr. Jianghua Li Ding Jia Dr. Suci Meng Dr. Jinfang Zhang Dr. Marie P. Cifuentes Prof. Dr. Mark G. Humphrey Prof. Dr. Chi Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7914-7926
Three unusual three‐dimensional (3D) tetrazine chromophore‐based metal–organic frameworks (MOFs) {(Et4N)[WS4Cu3(CN)2(4,4′‐pytz)0.5]}n ( 1 ), {[MoS4Cu4(CN)2(4,4′‐pytz)2] ? CH2Cl2}n ( 2 ), and {[WS4Cu3(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 (44?66) topology constructed from T‐shaped [WS4Cu3]+ clusters as nodes and single CN?/4,4′‐pytz bridges as linkers. MOF 2 features a novel 3D MOF structure with (420?68) 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 [WS4Cu3]+ 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. 相似文献
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Hye Jeong Park Young Eun Cheon Prof. Myunghyun Paik Suh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(38):11662-11669
The porous metal–organic framework (MOF) {[Zn2(TCPBDA)(H2O)2]?30 DMF?6 H2O}n ( SNU‐30 ; DMF=N,N‐dimethylformamide) has been prepared by the solvothermal reaction of N,N,N′,N′‐tetrakis(4‐carboxyphenyl)biphenyl‐4,4′‐diamine (H4TCPBDA) and Zn(NO3)2?6 H2O in DMF/tBuOH. The post‐synthetic modification of SNU‐30 by the insertion of 3,6‐di(4‐pyridyl)‐1,2,4,5‐tetrazine (bpta) affords single‐crystalline {[Zn2(TCPBDA)(bpta)]?23 DMF?4 H2O}n ( SNU‐31 SC ), in which channels are divided by the bpta linkers. Interestingly, unlike its pristine form, the bridging bpta ligand in the MOF is bent due to steric constraints. SNU‐31 can be also prepared through a one‐pot solvothermal synthesis from ZnII, TCPBDA4?, and bpta. The bpta linker can be liberated from this MOF by immersion in N,N‐diethylformamide (DEF) to afford the single‐crystalline SNU‐30 SC , which is structurally similar to SNU‐30 . This phenomenon of reversible insertion and removal of the bridging ligand while preserving the single crystallinity is unprecedented in MOFs. Desolvated solid SNU‐30′ adsorbs N2, O2, H2, CO2, and CH4 gases, whereas desolvated SNU‐31′ exhibits selective adsorption of CO2 over N2, O2, H2, and CH4, thus demonstrating that the gas adsorption properties of MOF can be modified by post‐synthetic insertion/removal of a bridging ligand. 相似文献
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Dr. Nerina Armata Dr. Remedios Cortese Prof. Dario Duca Prof. Roberto Triolo 《Chemphyschem》2013,14(1):220-226
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 η2 coordination mode are more favored. 相似文献
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Effect of Functionalized Groups on Gas‐Adsorption Properties: Syntheses of Functionalized Microporous Metal–Organic Frameworks and Their High Gas‐Storage Capacity
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Yanlong Wang Chunhong Tan Zhihao Sun Zhenzhen Xue Dr. Qilong Zhu Dr. Chaojun Shen Dr. Yuehong Wen Dr. Shengmin Hu Yong Wang Prof. Tianlu Sheng Prof. Xintao Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1341-1348
The microporous metal–organic framework (MMOF) Zn4O(L1)2 ? 9 DMF ? 9 H2O ( 1‐H ) and its functionalized derivatives Zn4O(L1‐CH3)2 ? 9 DMF ? 9 H2O ( 2‐CH3 ) and Zn4O(L1‐Cl)2 ? 9 DMF ? 9 H2O ( 3‐Cl ) have been synthesized and characterized (H3L1=4‐[N,N‐bis(4‐methylbenzoic acid)amino]benzoic acid, H3L1‐CH3=4‐[N,N‐bis(4‐methylbenzoic acid)amino]‐2‐methylbenzoic acid, H3L1‐Cl=4‐[N,N‐bis(4‐methylbenzoic acid)amino]‐2‐chlorobenzoic acid). Single‐crystal X‐ray diffraction analyses confirmed that the two functionalized MMOFs are isostructural to their parent MMOF, and are twofold interpenetrated three‐dimensional (3D) microporous frameworks. All of the samples possess enduring porosity with Langmuir surface areas over 1950 cm2 g?1. Their pore volumes and surface areas decrease in the order 1‐H > 2‐CH3 > 3‐Cl . Gas‐adsorption studies show that the H2 uptakes of these samples are among the highest of the MMOFs (2.37 wt % for 3‐Cl at 77 K and 1 bar), although their structures are interpenetrating. Furthermore, this work reveals that the adsorbate–adsorbent interaction plays a more important role in the gas‐adsorption properties of these samples at low pressure, whereas the effects of the pore volumes and surface areas dominate the gas‐adsorption properties at high pressure. 相似文献
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Prof. Dr. Danil N. Dybtsev Maxim P. Yutkin Dr. Denis G. Samsonenko Prof. Dr. Vladimir P. Fedin Dr. Alexey L. Nuzhdin Andrey A. Bezrukov Prof. Konstantin P. Bryliakov Prof. Evgeniy P. Talsi Prof. Rodion V. Belosludov Prof. Hiroshi Mizuseki Prof. Yoshiyuki Kawazoe Dr. Oleg S. Subbotin Vladimir R. Belosludov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(34):10348-10356
Two new, homochiral, porous metal–organic coordination polymers [Zn2(ndc){(R)‐man}(dmf)]?3DMF and [Zn2(bpdc){(R)‐man}(dmf)]?2DMF (ndc=2,6‐naphthalenedicarboxylate; bpdc=4,4′‐biphenyldicarboxylate; man=mandelate; dmf=N,N′‐dimethylformamide) have been synthesized by heating ZnII nitrate, H2ndc or H2bpdc and chiral (R)‐mandelic acid (H2man) in DMF. The colorless crystals were obtained and their structures were established by single‐crystal X‐ray diffraction. These isoreticular structures share the same topological features as the previously reported zinc(II) terephthalate lactate [Zn2(bdc){(S)‐lac}(dmf)]?DMF framework, but have larger pores and opposite absolute configuration of the chiral centers. The enhanced pores size results in differing stereoselective sorption properties: the new metal–organic frameworks effectively and stereoselectively (ee up to 62 %) accommodate bulkier guest molecules (alkyl aryl sulfoxides) than the parent [Zn2(bdc){(S)‐lac}(dmf)]?DMF, while the latter demonstrates decent enantioselectivity toward precursor of chiral anticancer drug sulforaphane, CH3SO(CH2)4OH. The new homochiral porous metal–organic coordination polymers are capable of catalyzing a highly selective oxidation of bulkier sulfides (2‐NaphSMe (2‐C10H7SMe) and PhSCH2Ph) that could not be achieved by the smaller‐pore [Zn2(bdc){(S)‐lac}(dmf)]?DMF. The sorption of different guest molecules (both R and S isomers) into the chiral pores of [Zn2(bdc){(S)‐lac}(dmf)]?DMF was modeled by using ab initio calculations that provided a qualitative explanation for the observed sorption enantioselectivity. The high stereo‐preference is accounted for by the presence of coordinated inner‐pore DMF molecule that forms a weak C? H???O bond between the DMF methyl group and the (S)‐PhSOCH3 sulfinyl group. 相似文献
15.
Javier Pérez‐Pellitero Dr. Hedi Amrouche Flor R. Siperstein Dr. Gerhard Pirngruber Dr. Carlos Nieto‐Draghi Dr. Gérald Chaplais Dr. Angélique Simon‐Masseron Dr. Delphine Bazer‐Bachi Dr. David Peralta Nicolas Bats Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(5):1560-1571
Experimental measurements and molecular simulations were conducted for two zeolitic imidazolate frameworks, ZIF‐8 and ZIF‐76. The transferability of the force field was tested by comparing molecular simulation results of gas adsorption with experimental data available in the literature for other ZIF materials (ZIF‐69). Owing to the good agreement observed between simulation and experimental data, the simulation results can be used to identify preferential adsorption sites, which are located close to the organic linkers. Topological mapping of the potential‐energy surfaces makes it possible to relate the preferential adsorption sites, Henry constant, and isosteric heats of adsorption at zero coverage to the nature of the host–guest interactions and the chemical nature of the organic linker. The role played by the topology of the solid and the organic linkers, instead of the metal sites, upon gas adsorption on zeolite‐like metal–organic frameworks is discussed. 相似文献
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Dr. Pascal Roy Andreas Schaate Prof. Dr. Peter Behrens Prof. Dr. Adelheid Godt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(22):6979-6985
Cycloaddition reactions are highly attractive for post‐synthetic modification of metal–organic frameworks (MOFs). We report herein on cycloaddition reactions with PIZOF(R1,R2)s, which are porous interpenetrated Zr‐based MOFs with Zr6O4(OH)4(CO2)12 as the nodes and the dicarboxylates ?O2C[PE‐P(R1,R2)‐EP]CO2? (P: phenylene, E: ethynylene; R1, R2: side chains at the central phenylene unit) as the linkers. 1,3‐Dipolar cycloaddition between the pendant ethyne moieties of PIZOF(OMe,OCH2C?CH) and 4‐methylbenzyl azide resulted in 98 % conversion of the ethyne groups. Reactions of PIZOF(OMe,O(CH2)3furan) with maleimide, N‐methylmaleimide, and N‐phenylmaleimide converted 98, 99, and 89 % of the furan moieties into the Diels–Alder adducts. However, no reaction occurred with maleic anhydride. High‐resolution 1H NMR spectra were crucial in determining the conversion and identifying the reaction products. Of all the reagents (NaOD/D2O, D2SO4, Bu4NF, CsF, CsF/DCl, and KHF2) tested for the disassembly of the PIZOFs in [D6]DMSO, the combination of CsF and DCl was found to be the best. The disassembly at room temperature was fast (5–15 min), and after the addition of K2CO3 the 1H NMR data were identical to those of the diacids (=protonated linkers) dissolved in pure DMSO. This allowed for simple structure elucidation through data comparison. CsF/DCl dissolves not only PIZOFs but also the hydrolytically very stable UiO‐66. 相似文献
17.
Dr. Paul Smart Dr. Charles A. Mason Jason R. Loader Dr. Anthony J. H. M. Meijer Prof. Alastair J. Florence Dr. Kenneth Shankland Dr. Ashleigh J. Fletcher Dr. Stephen P. Thompson Dr. Michela Brunelli Dr. Adrian H. Hill Prof. Lee Brammer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(11):3552-3557
18.
Dr. Sang Soo Han Dr. Dong Hyun Jung Dr. Seung‐Hoon Choi Prof. Jiyoung Heo 《Chemphyschem》2013,14(12):2698-2703
We have used grand canonical Monte Carlo simulations with a first‐principles‐based force field to show that metal–organic frameworks (MOFs) with Li functional groups (i.e. C? Li bonds) allow for exceptional H2 uptake at ambient temperature. For example, at 298 K and 100 bar, IRMOF‐1‐4Li shows a total H2 uptake of 5.54 wt % and MOF‐200‐27Li exhibits a total H2 uptake of 10.30 wt %, which are much higher than the corresponding values with pristine MOFs. Li‐functionalized MOF‐200 (MOF‐200‐27Li) shows 11.84 wt % H2 binding at 243 K and 100 bar. These hydrogen‐storage capacities exceed the 2015 DOE target of 5.5 wt % H2. Moreover, the incorporation of Li functional groups into MOFs provides more benefits, such as higher delivery amount, for H2 uptake than previously reported Li‐doped MOFs. 相似文献
19.
Symmetry‐Guided Synthesis of Highly Porous Metal–Organic Frameworks with Fluorite Topology
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Muwei Zhang Ying‐Pin Chen Mathieu Bosch Thomas Gentle III Kecheng Wang Dawei Feng Dr. Zhiyong U. Wang Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2014,53(3):815-818
Two stable, non‐interpenetrated MOFs, PCN‐521 and PCN‐523, were synthesized by a symmetry‐guided strategy. Augmentation of the 4‐connected nodes in the fluorite structure with a rigid tetrahedral ligand and substitution of the 8‐connected nodes by the Zr/Hf clusters yielded MOFs with large octahedral interstitial cavities. They are the first examples of Zr/Hf MOFs with tetrahedral linkers. PCN‐521 has the largest BET surface area (3411 m2 g‐1), pore size (20.5×20.5×37.4 Å) and void volume (78.5%) of MOFs formed from tetrahedral ligands. This work not only demonstrates a successful implementation of rational design of MOFs with desired topology, but also provides a systematic way of constructing non‐interpenetrated MOFs with high porosity. 相似文献
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Synthesis,Water Adsorption,and Proton Conductivity of Solid‐Solution‐Type Metal–Organic Frameworks Al(OH)(bdc‐OH)x(bdc‐NH2)1−x
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Mixed‐ligand metal–organic frameworks Al(bdc‐OH)x(bdc‐NH2)1?x (H2bdc‐NH2=aminoterepthalic acid, H2bdc‐OH=hydroxyterephthalic acid) were synthesized and their water adsorption behavior and proton conductivity were investigated. All obtained compounds were isostructural to MIL‐53 (MIL=Materials of Institut Lavoisier) according to XRD measurements under ambient humidity conditions, and were also found to be single phase across the whole mixing ratio from the XRD measurements under humidified conditions. This result clearly shows that all compounds are a solid‐solution‐type mixture of ligands. MIL‐53‐NH2 adsorbs one water molecule per formula with humidification whereas MIL‐53‐OH adsorbs five water molecules. The mixing ratio of the ligands in Al(OH)(bdc‐OH)x(bdc‐NH2)1?x affected the gate‐opening pressure for water adsorption and total water uptake. Proton conductivity of these compounds largely depends on the adsorbed amount of water, which indicates that the proton conductivity of these compounds depends strongly on the hydrogen‐bond network of the conducting media. 相似文献