共查询到20条相似文献,搜索用时 21 毫秒
1.
María C. Bernini Felipe Gándara Marta Iglesias Dr. Natalia Snejko Dr. Enrique Gutiérrez‐Puebla Prof. Elena V. Brusau Dr. Griselda E. Narda Dr. M. Ángeles Monge Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(19):4896-4905
The novel Yb succinate metal–organic framework exhibits a reversible single‐crystal to single‐crystal polymorphic transformation (see figure) when it is heated above 130 °C, returning to its initial form when back at room temperature. This transformation produces a change in the coordination sphere of the Yb atoms, which influences the catalytic activity of the material.
2.
Flexible and Hierarchical Metal–Organic Framework Composites for High‐Performance Catalysis 下载免费PDF全文
Dr. Ning Huang Hannah Drake Jialuo Li Dr. Jiandong Pang Dr. Ying Wang Shuai Yuan Qi Wang Peiyu Cai Dr. Junsheng Qin Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2018,57(29):8916-8920
The development of porous composite materials is of great significance for their potentially improved performance over those of individual components and extensive applications in separation, energy storage, and heterogeneous catalysis. Now mesoporous metal–organic frameworks (MOFs) with macroporous melamine foam (MF) have been integrated using a one‐pot process, generating a series of MOF/MF composite materials with preserved crystallinity, hierarchical porosity, and increased stability over that of melamine foam. The MOF nanocrystals were threaded by the melamine foam networks, resembling a ball‐and‐stick model overall. The resulting MOF/MF composite materials were employed as an effective heterogeneous catalyst for the epoxidation of cholesteryl esters. Combining the advantages of interpenetrative mesoporous and macroporous structures, the MOF/melamine foam composite has higher dispersibility and more accessibility of catalytic sites, exhibiting excellent catalytic performance. 相似文献
3.
David Farrusseng Dr. Sonia Aguado Dr. Catherine Pinel Dr. 《Angewandte Chemie (International ed. in English)》2009,48(41):7502-7513
The role of metal–organic frameworks (MOFs) in the field of catalysis is discussed, and special focus is placed on their assets and limits in light of current challenges in catalysis and green chemistry. Their structural and dynamic features are presented in terms of catalytic functions along with how MOFs can be designed to bridge the gap between zeolites and enzymes. The contributions of MOFs to the field of catalysis are comprehensively reviewed and a list of catalytic candidates is given. The subject is presented from a multidisciplinary point of view covering solid‐state chemistry, materials science, and catalysis. 相似文献
4.
Fabian Carson Dr. Santosh Agrawal Dr. Mikaela Gustafsson Agnieszka Bartoszewicz Francisca Moraga Prof. Xiaodong Zou Assoc. Prof. Belén Martín‐Matute 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(48):15337-15344
A ruthenium trichloride complex has been loaded into an aluminium metal–organic framework (MOF), MOF‐253, by post‐synthetic modification to give MOF‐253‐Ru. MOF‐253 contains open bipyridine sites that are available to bind with the ruthenium complex. MOF‐253‐Ru was characterised by elemental analysis, N2 sorption and X‐ray powder diffraction. This is the first time that a Ru complex has been coordinated to a MOF through post‐synthetic modification and used as a heterogeneous catalyst. MOF‐253‐Ru catalysed the oxidation of primary and secondary alcohols, including allylic alcohols, with PhI(OAc)2 as the oxidant under very mild reaction conditions (ambient temperature to 40 °C). High conversions (up to >99 %) were achieved in short reaction times (1–3 h) by using low catalyst loadings (0.5 mol % Ru). In addition, high selectivities (>90 %) for aldehydes were obtained at room temperature. MOF‐253‐Ru can be recycled up to six times with only a moderate decrease in substrate conversion. 相似文献
5.
Direct and Post‐Synthesis Incorporation of Chiral Metallosalen Catalysts into Metal–Organic Frameworks for Asymmetric Organic Transformations 下载免费PDF全文
Weiqin Xi Prof. Dr. Yan Liu Qingchun Xia Zijian Li Prof. Dr. Yong Cui 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(36):12581-12585
Two chiral porous metal–organic frameworks (MOFs) were constructed from [VO(salen)]‐derived dicarboxylate and dipyridine bridging ligands. After oxidation of VIV to VV, they were found to be highly effective, recyclable, and reusable heterogeneous catalysts for the asymmetric cyanosilylation of aldehydes with up to 95 % ee. Solvent‐assisted linker exchange (SALE) treatment of the pillared‐layer MOF with [Cr(salen)Cl]‐ or [Al(salen)Cl]‐derived dipyridine ligands led to the formation of mixed‐linker metallosalen‐based frameworks and incorporation of [Cr(salen)] enabled its use as a heterogeneous catalyst in the asymmetric epoxide ring‐opening reaction. 相似文献
6.
Highly Efficient Cooperative Catalysis by CoIII(Porphyrin) Pairs in Interpenetrating Metal–Organic Frameworks 下载免费PDF全文
Zekai Lin Dr. Zhi‐Ming Zhang Dr. Yu‐Sheng Chen Prof. Wenbin Lin 《Angewandte Chemie (International ed. in English)》2016,55(44):13739-13743
A series of porous twofold interpenetrated In‐CoIII(porphyrin) metal–organic frameworks (MOFs) were constructed by in situ metalation of porphyrin bridging ligands and used as efficient cooperative catalysts for the hydration of terminal alkynes. The twofold interpenetrating structure brings adjacent CoIII(porphyrins) in the two networks parallel to each other with a distance of about 8.8 Å, an ideal distance for the simultaneous activation of both substrates in alkyne hydration reactions. As a result, the In‐CoIII(porphyrin) MOFs exhibit much higher (up to 38 times) catalytic activity than either homogeneous catalysts or MOF controls with isolated CoIII(porphyrin) centers, thus highlighting the potential application of MOFs in cooperative catalysis. 相似文献
7.
Jurjen Spekreijse Prof. Lars Öhrström Prof. Johan P. M. Sanders Prof. Johannes H. Bitter Dr. Elinor L. Scott 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15437-15443
A simple, one‐step mechanochemical procedure for immobilisation of homogeneous metathesis catalysts in metal–organic frameworks was developed. Grinding MIL‐101‐NH2(Al) with a Hoveyda–Grubbs second‐generation catalyst resulted in a heterogeneous catalyst that is active for metathesis and one of the most stable immobilised metathesis catalysts. During the mechanochemical immobilisation the MIL‐101‐NH2(Al) structure was partially converted to MIL‐53‐NH2(Al). The Hoveyda–Grubbs catalyst entrapped in MIL‐101‐NH2(Al) is responsible for the observed catalytic activity. The developed synthetic procedure was also successful for the immobilisation of a Zhan catalyst. 相似文献
8.
9.
Silica‐Protection‐Assisted Encapsulation of Cu2O Nanocubes into a Metal–Organic Framework (ZIF‐8) To Provide a Composite Catalyst 下载免费PDF全文
Bo Li Dr. Jian‐Gong Ma Prof. Dr. Peng Cheng 《Angewandte Chemie (International ed. in English)》2018,57(23):6834-6837
The integration of metal/metal oxide nanoparticles (NPs) into metal–organic frameworks (MOFs) to form composite materials has attracted great interest due to the broad range of applications. However, to date, it has not been possible to encapsulate metastable NPs with high catalytic activity into MOFs, due to their instability during the preparation process. For the first time, we have successfully developed a template protection–sacrifice (TPS) method to encapsulate metastable NPs such as Cu2O into MOFs. SiO2 was used as both a protective shell for Cu2O nanocubes and a sacrificial template for forming a yolk–shell structure. The obtained Cu2O@ZIF‐8 composite exhibits excellent cycle stability in the catalytic hydrogenation of 4‐nitrophenol with high activity. This is the first report of a Cu2O@MOF‐type composite material. The TPS method provides an efficient strategy for encapsulating unstable active metal/metal oxide NPs into MOFs or maybe other porous materials. 相似文献
10.
Dr. Nayarassery N. Adarsh Dr. Marinela M. Dîrtu Dr. Anil D. Naik Dr. Alexandre F. Léonard Dr. Nicolo Campagnol Dr. Koen Robeyns Dr. Johan Snauwaert Prof. Dr. Jan Fransaer Prof. Dr. Bao Lian Su Prof. Dr. Yann Garcia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4300-4307
A conformationally flexible triazole‐carboxylic acid ligand derived from an L ‐amino acid, namely, 4 H‐1,2,4‐triazol‐4‐yl‐acetic acid (αHGlytrz), has been exploited to synthesize a structurally diverse and functionally intriguing metal–organic framework with CuSiF6. The crystal structure reveals a novel single‐walled metal–organic nanotube (SWMONT), namely, {[Cu3(μ3‐OH)(H2O)3(Glytrz)3] ? SiF6 ? 8 H2O ? X}∞ ( 1 ), (where X=disordered lattice water molecules) having a pore size as large as zeolites. Compound 1 was synthesized as crystals, as powder, or as layers by precipitation/electrodeposition. Mercury intrusion porosimetry demonstrates the ability of this material to store metallic mercury, after a pressure treatment, contrary to previous literature examples. 相似文献
11.
12.
Pd Nanocubes@ZIF‐8: Integration of Plasmon‐Driven Photothermal Conversion with a Metal–Organic Framework for Efficient and Selective Catalysis 下载免费PDF全文
Qihao Yang Prof. Dr. Qiang Xu Prof. Dr. Shu‐Hong Yu Prof. Dr. Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2016,55(11):3685-3689
Composite nanomaterials usually possess synergetic properties resulting from the respective components and can be used for a wide range of applications. In this work, a Pd nanocubes@ZIF‐8 composite material has been rationally fabricated by encapsulation of the Pd nanocubes in ZIF‐8, a common metal–organic framework (MOF). This composite was used for the efficient and selective catalytic hydrogenation of olefins at room temperature under 1 atm H2 and light irradiation, and benefits from plasmonic photothermal effects of the Pd nanocube cores while the ZIF‐8 shell plays multiple roles; it accelerates the reaction by H2 enrichment, acts as a “molecular sieve” for olefins with specific sizes, and stabilizes the Pd cores. Remarkably, the catalytic efficiency of a reaction under 60 mW cm?2 full‐spectrum or 100 mW cm?2 visible‐light irradiation at room temperature turned out to be comparable to that of a process driven by heating at 50 °C. Furthermore, the catalyst remained stable and could be easily recycled. To the best of our knowledge, this work represents the first combination of the photothermal effects of metal nanocrystals with the favorable properties of MOFs for efficient and selective catalysis. 相似文献
13.
A Polyoxometalate‐Encapsulating Cationic Metal–Organic Framework as a Heterogeneous Catalyst for Desulfurization 下载免费PDF全文
Dr. Xiu‐Li Hao Yuan‐Yuan Ma Prof. Hong‐Ying Zang Dr. Yong‐Hui Wang Prof. Yang‐Guang Li Prof. En‐Bo Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3778-3784
A new cationic triazole‐based metal–organic framework encapsulating Keggin‐type polyoxometalates, with the molecular formula [Co(BBPTZ)3][HPMo12O40]?24 H2O [compound 1 ; BBPTZ=4,4′‐bis(1,2,4‐triazol‐1‐ylmethyl)biphenyl] is hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. The structure of compound 1 contains a non‐interpenetrated 3D CdSO4 (cds)‐type framework with two types of channels that are interconnected with each other; straight channels that are occupied by the Keggin‐type POM anions, and wavelike channels that contain lattice water molecules. The catalytic activity of compound 1 in the oxidative desulfurization reaction indicates that it is not only an effective and size‐selective heterogeneous catalyst, but it also exhibits distinct structural stability in the catalytic reaction system. 相似文献
14.
《Angewandte Chemie (International ed. in English)》2017,56(20):5512-5516
Hollow metal–organic frameworks (MOFs) are promising materials with sophisticated structures, such as multiple shells, that cannot only enhance the properties of MOFs but also endow them with new functions. Herein, we show a rational strategy to fabricate multi‐shelled hollow chromium (III) terephthalate MOFs (MIL‐101) with single‐crystalline shells through step‐by‐step crystal growth and subsequent etching processes. This strategy relies on the creation of inhomogeneous MOF crystals in which the outer layer is chemically more robust than the inner layer and can be selectively etched by acetic acid. The regulation of MOF nucleation and crystallization allows the tailoring of the cavity size and shell thickness of each layer. The resultant multi‐shelled hollow MIL‐101 crystals show significantly enhanced catalytic activity during styrene oxidation. The insight gained from this systematic study will aid in the rational design and synthesis of other multi‐shelled hollow structures and the further expansion of their applications. 相似文献
15.
16.
Xiaoying Xu Stephan M. Rummelt Flavien L. Morel Dr. Marco Ranocchiari Prof. Dr. Jeroen A. van Bokhoven 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15467-15472
Steric hindrance by a metal–organic framework (MOF) is shown to influence the outcome of a catalytic reaction by controlling the orientation of its intermediates. This is demonstrated using an organocatalyst, phosphine MOF LSK‐3, which is evaluated with the aid of molecular modeling and NMR spectroscopy techniques. This report is the first application of phosphine MOFs in organocatalysis and explores the potential of a framework steric hindrance to impose selectivity on a catalytic reaction. These findings expand the opportunities for control and design of the active site in the pocket of heterogeneous catalysts. 相似文献
17.
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
18.
19.
A Stable Microporous Mixed‐Metal Metal–Organic Framework with Highly Active Cu2+ Sites for Efficient Cross‐Dehydrogenative Coupling Reactions 下载免费PDF全文
Xiu‐Li Yang Chao Zou Dr. Yabing He Min Zhao Prof. Dr. Banglin Chen Prof. Dr. Shengchang Xiang Prof. Dr. Michael O'Keeffe Prof. Dr. Chuan‐De Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1447-1452
Two metalloporphyrin octacarboxylates were used to link copper(II) nodes for the formation of two novel porous mixed‐metal metal–organic frameworks (M′MOFs) containing nanopore cages (2.1 nm in diameter) or nanotubular channels (1.5 nm in diameter). The highly active Cu2+ sites on the nanotubular surfaces of the stable porous M′MOF ZJU‐22 , stabilized by three‐connected nets, lead to the superior catalytic activity for the cross‐dehydrogenative coupling (CDC) reaction. 相似文献
20.
A Metal–Organic Framework with Cooperative Phosphines That Permit Post‐Synthetic Installation of Open Metal Sites 下载免费PDF全文
Samuel G. Dunning Gianne Nandra Adam D. Conn Wenrui Chai R. Eric Sikma Ji Sun Lee Pranaw Kunal Joseph E. Reynolds III Jong‐San Chang Alexander Steiner Graeme Henkelman Simon M. Humphrey 《Angewandte Chemie (International ed. in English)》2018,57(30):9295-9299
PCM‐101 is a phosphine coordination material comprised of tris(p‐carboxylato)triphenylphosphine and secondary pillaring groups coordinated to [M3(OH)]5+ nodes (M=Co, Ni). PCM‐101 has a unique topology in which R3P: sites are arranged directly trans to one another, with a P???P separation distance dictated by the pillars. Post‐synthetic coordination of soft metals to the P: sites proceeds at room temperature to provide X‐ray quality crystals that permit full structural resolution. Addition of AuCl groups forces a large distortion of the parent framework. In contrast, CuBr undergoes insertion directly between the trans‐P sites to form dimers that mimic solution‐phase complexes, but that are geometrically strained due to steric pressure exerted by the MOF scaffold. The metalated materials are active in heterogeneous hydroaddition catalysis under mild conditions, yielding different major products compared to their molecular counterparts. 相似文献