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金属氧簇合物在催化、医药和材料等方面的应用越来越成为无机化学研究的热点[1~4]. 在众多的金属氧簇合物中, 只有几种双帽及四帽Keggin结构被合成出来[5 ~12], 而含有四帽假Keggin结构的钼钒氧簇合物尚未见报道. 相似文献
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新型化合物[Ni(en)2V6O14]n的水热合成与晶体结构 总被引:1,自引:0,他引:1
金属 -氧簇合物在催化吸附、医药临床、能量存储和材料科学等方面的应用越来越受到关注 [1~ 3 ] .钒 -氧簇合物的结构新颖 ,在材料领域中具有广泛的应用前景 .采用水热合成技术 ,以简单的无机、有机起始原料在相对低温下制备金属 -氧簇合物晶体是近年来刚刚兴起的研究工作 [4 ] ,并且已经合成出一维链状化合物 Cu(prn) 2 V2 O6[5]、层状结构 Ni(C10 H8N2 ) 2 V3 O8.5[6]及三维网状结构 (H2 en Me)[Ni(en) 2 V12 O2 8][7] .我们采用水热技术合成了由 { V V 2 O7} n 单元层与桥配体 [Ni(en) 2 ]2 +构建的三维无机 -有机化合物 [Ni(en… 相似文献
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多钒氧簇由于具有组成、结构和尺寸易于调控、氧化还原性以及低腐蚀性等优点,在光电、磁性、催化以及医药等领域具有广阔的应用前景,已成为多酸化学领域的研究热点之一。本文结合近年来国内外及本课题组关于多钒氧簇化学的研究,综述了多钒氧簇的合成、结构及性能研究进展,并对未来发展趋势进行了展望。 相似文献
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多钒氧簇由于具有组成、结构和尺寸易于调控、氧化还原性以及低腐蚀性等优点,在光电、磁性、催化以及医药等领域具有广阔的应用前景,已成为多酸化学领域的研究热点之一。本文结合近年来国内外及本课题组关于多钒氧簇化学的研究,综述了多钒氧簇的合成、结构及性能研究进展,并对未来发展趋势进行了展望。 相似文献
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无机-有机杂化钒氧酸盐由于其结构的多样性以及在催化、医药、光、电、磁等材料领域中的应用前景而受到人们的广泛关注。近年来这一研究领域的重大进步是将有机氮配体或者过渡金属配合物直接连接到矾氧骨架上以获得各种新奇结构。合成出许多属于L/V/O、MXLY/V/O、L/P/V/O和MXLY 相似文献
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金属 -氧簇合物在催化、医药和材料等方面的应用越来越成为无机化学研究的热点 [1~ 4 ] .在众多的金属 -氧簇合物中 ,只有几种双帽及四帽 Keggin结构被合成出来 [5~ 12 ] ,而含有四帽假 Keggin结构的钼 -钒 -氧簇合物尚未见报道 .我们用水热合成方法合成了第一个具有四帽假 Keggin结构“簇阴离子对”{Mo10 V6 O4 0 ( PO4 ) }2 的多金属氧簇 [Co( 2 ,2 - bipy) 3]4 [Mo10 V6 O4 0 ( PO4 ) ]2 · 4H2 O.该化合物是由四帽假Keggin结构“簇阴离子对”{Mo10 V6 O4 0 ( PO4 ) }2 和 4个配位阳离子 [Co( 2 ,2 - bipy) 3]2 +通过阴阳离… 相似文献
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Polyoxometalates represent a diverse range of molecular clusters with an almost unmatched range of physical properties and the ability to form structures that can bridge several length scales. The new building block principles that have been discovered are beginning to allow the design of complex clusters with desired properties and structures and several structural types and novel physical properties are examined. In this critical review the synthetic and design approaches to the many polyoxometalate cluster types are presented encompassing all the sub-types of polyoxometalates including, isopolyoxometalates, heteropolyoxometalates, and reduced molybdenum blue systems. As well as the fundamental structure and bonding aspects, the final section is devoted to discussing these clusters in the context of contemporary and emerging interdisciplinary interests from areas as diverse as anti-viral agents, biological ion transport models, and materials science. 相似文献
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Polyoxometalates represent a diverse range of molecular clusters with an almost unmatched range of physical properties and the ability to form structures that can bridge several length scales. The new building block principles that have been discovered are beginning to allow the design of complex clusters with desired properties and structures; several structural types and novel physical properties are examined herein. The overall message that is presented throughout is the possibility that polyoxometalate clusters could be excellent candidates to be exploited in the development of functional nanosystems or nanodevices. The concepts that underpin the development of nanoscale devices are discussed briefly, as are the considerable challenges that must be overcome to realise polyoxometalate-based functional nanosystems. 相似文献
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Redox and acid-base properties of dispersed oxide nanostructures change markedly as their local structure and electronic properties vary with domain size. These changes give rise to catalytic behavior, site structures, and reaction chemistries often unavailable on bulk crystalline oxides. Turnover rates for redox and acid catalysis vary as oxide domains evolve from isolated monomers to two-dimensional oligomers, and ultimately into clusters with bulk-like properties. These reactivity changes reflect the ability of oxide domains to accept or redistribute electron density in kinetically-relevant reduction steps, in the formation of temporary acid sites via reductive processes, and in the stabilization of cationic transition states. Reduction steps are favored by low-lying empty orbitals prevalent in larger clusters, which also favor electron delocalization, stable anions, and strong Br?nsted acidity. Isomerization of xylenes and alkanes, elimination reactions of alkanols, and oxidation of alkanes to alkenes on V, Mo, Nb, and W oxide domains are used here to demonstrate the remarkable catalytic diversity made available by changes in domain size. The reactive and disordered nature of small catalytic domains introduces significant challenges in their synthesis and their structural and mechanistic characterization, which require in situ probes and detailed kinetic analysis. The local structure and electronic properties of these materials must be probed during catalysis and their catalytic function be related to specific kinetically-relevant steps. Structural uniformity can be imposed on oxide clusters by the use of polyoxometalate clusters with thermodynamically stable and well-defined size and connectivity. These clusters provide the compositional diversity and the structural fidelity required to develop composition-function relations from synergistic use of experiments and theory. In these clusters, the valence and electronegativity of the central atom affects the acid strength of the polyoxometalate clusters and the rate constants for acid catalyzed elementary steps via the specific stabilization of cationic transition states in isomerization and elimination reactions. 相似文献
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Elizabeth Hampson Jamie M. Cameron Sharad Amin Joungman Kyo Julie A. Watts Hiroki Oshio Graham N. Newton 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18449-18453
Access to asymmetrically functionalized polyoxometalates is a grand challenge as it could lead to new molecular nanomaterials with multiple or modular functionality. Now, a simple one‐pot synthetic approach to the isolation of an asymmetrically functionalized organic–inorganic hybrid Wells–Dawson polyoxometalate in good yield is presented. The cluster bears two organophosphonate moieties with contrasting physical properties: a chelating metal‐binding group, and a long aliphatic chain that facilitates solvent‐dependent self‐assembly into soft nanostructures. The orthogonal properties of the modular system are effectively demonstrated by controlled assembly of POM‐based redox‐active nanoparticles. This simple, high‐yielding synthetic method is a promising new approach to the preparation of multi‐functional hybrid metal oxide clusters, supermolecular systems, and soft‐nanomaterials. 相似文献
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Designed Assembly of Heterometallic Cluster Organic Frameworks Based on Anderson‐Type Polyoxometalate Clusters 下载免费PDF全文
Dr. Xin‐Xiong Li Yang‐Xin Wang Prof. Dr. Rui‐Hu Wang Cai‐Yan Cui Dr. Chong‐Bin Tian Prof. Dr. Guo‐Yu Yang 《Angewandte Chemie (International ed. in English)》2016,55(22):6462-6466
A new approach to prepare heterometallic cluster organic frameworks has been developed. The method was employed to link Anderson‐type polyoxometalate (POM) clusters and transition‐metal clusters by using a designed rigid tris(alkoxo) ligand containing a pyridyl group to form a three‐fold interpenetrated anionic diamondoid structure and a 2D anionic layer, respectively. This technique facilitates the integration of the unique inherent properties of Anderson‐type POM clusters and cuprous iodide clusters into one cluster organic framework. 相似文献
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Polyoxometalate Clusters Integrated into Peptide Chains and as Inorganic Amino Acids: Solution‐ and Solid‐Phase Approaches 下载免费PDF全文
Carine Yvon Dr. Andrew J. Surman Dr. Marie Hutin Jennifer Alex Dr. Brian O. Smith Dr. De‐Liang Long Prof. Leroy Cronin 《Angewandte Chemie (International ed. in English)》2014,53(13):3336-3341
General synthetic methods for the grafting of peptide chains onto polyoxometalate clusters by the use of general activated precursors have been developed. Using a solution‐phase approach, pre‐synthesized peptides can be grafted to a metal oxide cluster to produce hybrids of unprecedented scale (up to 30 residues). An adapted solid‐phase method allows the incorporation of these clusters, which may be regarded as novel hybrid unnatural amino acids, during the peptide synthesis itself. These methods may open the way for the automated synthesis of peptides and perhaps even proteins that contain “inorganic” amino acids. 相似文献
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Tucher J Wu Y Nye LC Ivanovic-Burmazovic I Khusniyarov MM Streb C 《Dalton transactions (Cambridge, England : 2003)》2012,41(33):9938-9943
The photochemical properties of homo- and heterometallic molybdate-based Lindqvist polyoxometalate clusters are investigated in a comparative study and it is shown that vanadium substitution can be used as a facile synthetic tool to optimize the visible light absorption and photocatalytic activity of the cluster. The mono-vanadium substituted unit, [VMo(5)O(19)](3-) shows light absorption up to 480 nm whereas the light absorption of the molybdate analogue [Mo(6)O(19)](2-) is mainly in the UV region below 400 nm. The electronic absorption properties of both clusters are further investigated using TD-DFT calculations which show that vanadium incorporation leads to the formation of low-energy O → V LMCT transitions. In comparative photochemical dye decomposition test reactions under UV and Vis irradiation, a higher reactivity is observed for [VMo(5)O(19)](3-) together with turnover numbers of more than 1600. In addition it is shown that under anaerobic conditions, the photoreaction proceeds faster than in the presence of oxygen, suggesting that oxygen acts as a quencher in one of the photoredox steps. 相似文献
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Sub-nanometre sized metal clusters, with dimensions between metal atoms and nanoparticles, have attracted more and more attention due to their unique electronic structures and the subsequent unusual physical and chemical properties. However, the tiny size of the metal clusters brings the difficulty of their synthesis compared to the easier preparation of large nanoparticles. Up to now various synthetic techniques and routes have been successfully applied to the preparation of sub-nanometre clusters. Among the metals, gold clusters, especially the alkanethiolate monolayer protected clusters (MPCs), have been extensively investigated during the past decades. In recent years, silver and copper nanoclusters have also attracted enormous interest mainly due to their excellent photoluminescent properties. Meanwhile, more structural characteristics, particular optical, catalytic, electronic and magnetic properties and the related technical applications of the metal nanoclusters have been discovered in recent years. In this critical review, recent advances in sub-nanometre sized metal clusters (Au, Ag, Cu, etc.) including the synthetic techniques, structural characterizations, novel physical, chemical and optical properties and their potential applications are discussed in detail. We finally give a brief outlook on the future development of metal nanoclusters from the viewpoint of controlled synthesis and their potential applications. 相似文献