多元多金属含氧簇合物

多金属含氧簇合物是一大类具有独特结构和特殊性能的化合物，对于基础理论研究和实际应用均有重要意义，其中多元多金属含氧簇合物的重要性日益渐增，本文拟对多元多金属含氧簇合物的结构，性能和制备作扼要的评述。     

多酸构筑的单分子磁体

设计合成具有单分子磁体行为的分子磁性材料近年来受到广泛关注. 合成单分子磁体的一个常用策略是利用有机多齿含氧或含氮配体将各种自旋载体组装成簇,使之具有高基态自旋值(S)和负的单轴磁各向异性值(D),进而满足形成单分子磁体所需的磁能垒. 令人感兴趣的是近年来多酸发展成为一类构筑新型单分子磁体的无机建筑基元. 多酸是一类独特的具有富氧表面、可控的尺寸、形状和电荷的无机纳米级金属氧簇,同时,一系列缺位多酸衍生物能够结合各种过渡金属或稀土离子形成多核金属簇合物. 近五年来,多酸已作为一类无机多齿含氧配体成功构筑系列具有单分子磁体行为的新型过渡金属簇合物、稀土簇合物和3d-4f杂金属簇合物. 特别是一些缺位多酸配体能够为稀土离子提供完美的配体场,进而构筑新一代的单离子磁体. 此外,高自旋、磁各向异性单元(如单分子磁体)还可被均匀分散在具有孔道特征的多酸三级结构中,形成具有单分子磁体行为的多酸基复合材料. 最近,以多酸为模板构筑具有单分子磁体行为的多核簇合物也取得了新进展. 本综述旨在对近五年来利用多酸构筑的单分子磁体化合物进行评论,重点阐述利用多酸设计合成单分子磁体的策略、多酸在单分子磁体化合物结构中的作用和优势,以及多酸构筑单分子磁体这一研究课题的发展前景.     

铑钴四核簇合物的合成表征及其对苯乙烯的氢甲酰化反应性能的研究

研究表明，含有铑原子的异多核过渡金属羰基簇合物在一些催化反应中具有好的催化活性；有机膦是比羰基配位能力更强的一类配体，与簇合物中的金属配位后可使簇合物更趋稳定．过渡金属羰基簇合物骨架在催化反应过程中是否能够保持完整性一直是簇合物催化研究领域中的问题之一．为此，我们合成了标题簇合物2(n=1)和3(n=2)，     

若干簇合物的键价和催化反应机理

在“过渡金属簇合物的键价”一文中,我们提出计算簇合物中金属原子间键价的方法。它有助于了解簇合物的几何构型和化学性质,也可进一步了解簇合物的催化性能和催化机     

配合物[Cr3（μ3-O）（Tc）6（H2O）3]·（NO3）·4H2O的水热合成及晶体结构

0 引言 通过有限个过渡金属离子如Fe,Ni,Cr,Mn与O、OH、-O或-O2CR等桥联原子或基团键合形成的具有不同尺寸的环形轮状金属离子簇合物或分子簇合物是近年来的研究热点之一。它们不仅具有独特的结构,而且在催化、非线性光学、分子自组装等方面具有潜在的应用价值。特别是具有三角型结构的过渡金属-氧轮簇化合物由于可以作为单分子磁体的磁性交换和电子耦合的研究体系,     

(μ3-S)Fe2CoCu(PPh3)2(CO)8催化苯乙烯环丙烷化反应研究

以异核金属原子簇合物为催化剂的配位催化反应, 已在均相催化反应中得到应用. 簇合物中不同金属间的协同作用使其在催化领域展现出广阔的应用前景[1]. 然而,催化反应中簇合物是否以完整的骨架起催化作用,一直是人们关注的焦点. 在金属原子簇作催化剂前体的均相催化反应中,迄今只在少数的例子中有确凿的证据表明原子簇整体分子起催化作用[2]. 一般认为,在配位饱和的金属簇合物的催化反应中,簇合物稳定性越好,催化活性越差;而活性好的催化剂前体,簇合物骨架常解体.     

核磁共振谱鉴定有机金属配合物结构的新进展

含有M—C键的金属有机配合物,除金属簇固定到载体上产生的部分顺磁阴离子物种外,其余大多数具有抗磁性,这就为NMR谱研究金属有机配合物和簇提供了可能性.含7-,8-配合物的金属有机配合物和部分簇合物又多属立体非刚性,呈现出流变性,在溶液中其分子可发生位点交换、构象翻转等呈现出复杂的动力学行为.NMR谱跟踪金属有机配合物的反应机理、催化性能及动力学行为将日益发挥着巨大作用.     

三维骨加{[Cu（1,2—pn）2]4[V18O42（H2O）]}n·8nH2O化合物的水热合成和晶体结构

物材多孔材料广泛应用于吸附、形状和尺寸选择性的多相催化和离子交换．利用有机胺分子的模板和结构导向作用已设计合成了许多沸石分子筛、中孔MCM－41和非致密过渡金属磷酸盐等多孔性氧化料[’－“．过渡金属氧簇结构中普遍存在金属－金属键,业已证明金属氧簇合物具有催化活     

具有四帽假Keggin结构"簇阴离子对"的多金属氧簇[Co(2,2-bipy)3]4[MoⅤ5MoⅥ5VⅣ6O40(PO4)]2·4H2O的水热合成与晶体结构

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.     

环形镧系分子簇合物的组装与单分子磁体性质

由于稀土离子具有很强的磁各向异性,近年来基于单核或多核稀土化合物的单分子磁体研究得到了人们广泛的关注.环形簇合物是一类特殊的簇合物,也称分子轮或金属冠醚.设计合成环形稀土簇合物不仅可以获得新的稀土单分子磁体,而且环形簇合物中稀土离子磁偶极的涡旋分布还可以产生环形磁矩,因而在量子计算、信息存储、自旋分子器件等方面具有潜在的应用.鉴于环形稀土簇合物特别是含奇数核的环形簇合物的合成依然充满挑战,本综述将着重阐述已报道的环形稀土簇合物的组装规律、结构特点及磁性研究.     

Surfactant‐Encapsulated Polyoxometalates as Immobilized Supramolecular Catalysts for Highly Efficient and Selective Oxidation Reactions

A type of interesting immobilized supramolecular catalysts based on surfactant‐encapsulated polyoxometalates has been developed for oxidation reactions. Through a sol‐gel process with tetraethyl orthosilicate, hydroxyl‐terminated surfactant‐encapsulated polyoxometalate complexes have been covalently and uniformly bound to a silica matrix with unchanged complex structure. The formed hybrid catalysts possess a defined hydrophobic nano‐environment surrounding the inorganic clusters, which is conducive to compatibility between the polyoxometalate catalytic centres and organic substrates. The supramolecular synergy between substrate adsorption, reaction, and product desorption during the oxidation process has been found to have an obvious influence on the reaction kinetics, with the activity of the catalyst being greatly improved. The supramolecular catalysts performed effectively in the selective oxidation of several different kinds of organic compounds, such as alkenes, alcohols, and sulfides, and the main products were the corresponding epoxides, ketones, sulfoxides, and sulfones. More significantly, the catalyst could be easily recovered by simple filtration, and the catalytic activity was well retained for at least five cycles. Finally, the present strategy has proved to be a general route for the fabrication of supramolecular hybrid catalysts containing common polyoxometalates suitable for various purposes.     

Preparation, Characterization and Catalysis of Intrazeolite Molybdenum, Cobalt and Cobalt–Molybdenum Sulfide Clusters: A Molecular Approach to Hydrodesulfurization Catalysts

Better understandings of the nature of Co–Mo sulfide catalysts are of great importance to a rational design of highly active hydrodesulfurization catalysts on a molecular level. Synthesis of uniform binary sulfide clusters well-defined in structure and thermally stabilized on a support is desirable for such purposes. In the present study, successful preparations, using metal carbonyls as precursors, of Mo, Co and Co–Mo sulfide clusters encaged in zeolite are reported. The structure, location and catalytic properties of the clusters are described on the basis of XPS, XAFS, XRD, XRF, IR, HREM and adsorptions of benzene and NO. Implications for the generation of catalytic synergy between Co and Mo sulfides are presented in brief. It is suggested that the host–guest interactions between zeolite framework oxygens and precursor molecules and product clusters are crucial to the size and structure of the intrazeolite clusters.     

ZnCuCoAlNO3型四元水滑石及其多氧阴离子柱撑物的合成与催化氧化性能

Anionic clay, ZnCuCoAlNO₃ and its polyoxometalate intercalates were synthesized, and were characterized by XRD, IR, ³¹PMAS NMR, DTA and elemental analysis. The pillared products are found to be effective catalysts for oxidation of cyclohexene with molecular oxygen under mild reaction conditions     

无机-有机多金属砷钒氧簇合物的合成及研究进展

多金属砷钒氧簇合物由于具有结构多样性、优良的物理特性以及广泛的应用前景而引起人们的关注。该类簇合物的合成战略是将有机配体和过渡金属配合物连接到砷钒氧骨架上以获得各种新奇结构。按此策略人们合成出一系列新奇的无机有机砷钒氧簇合物。本文综述了多金属砷钒氧簇合物的合成方法、结构性质等方面的研究进展,并对其今后研究前景进行了展望。     

Towards Polyoxometalate‐Cluster‐Based Nano‐Electronics

We explore the concept that the incorporation of polyoxometalates (POMs) into complementary metal oxide semiconductor (CMOS) technologies could offer a fundamentally better way to design and engineer new types of data storage devices, due to the enhanced electronic complementarity with SiO₂, high redox potentials, and multiple redox states accessible to polyoxometalate clusters. To explore this we constructed a custom‐built simulation domain bridge. Connecting DFT, for the quantum mechanical modelling part, and mesoscopic device modelling, confirms the theoretical basis for the proposed advantages of POMs in non‐volatile molecular memories (NVMM) or flash‐RAM.     

ZnCuCoAlNO_3型四元水滑石及其多氧阴离子柱撑物的合成与催化氧化性能

ＺｎＣｕＣｏＡｌＮＯ３型四元水滑石及其多氧阴离子柱撑物的合成与催化氧化性能郭军＊黄兰芳＊＊矫庆泽张斌蒋大振（吉林大学化学系，长春１３００２３）闵恩泽（石油化工科学研究院，北京１０００８３）关键词：ＺｎＣｕＣｏＡｌＮＯ３四元水滑石杂多阴离子柱撑物合成催...     

Enantiopure 1,1'-binaphthyl-based polyoxometalate-containing molecular hybrids

The first chiral molecular hybrids based on covalently linked polyoxometalate clusters and enantiopure 1,1'-binaphthyl units have been prepared. Their structures have been confirmed by (1)H NMR, FTIR, and ESI-MS measurements. Such hybrids show moderate chiroptical behavior in solutions, and Cotton effects are observed up to 450 nm, indicating chiral extension from the binaphthyl core to the cluster-containing pi-conjugated arms.     

Towards polyoxometalate-integrated nanosystems

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.     

超临界CO2中醇类的分子氧氧化*

本文以催化剂体系为主线,介绍了超临界二氧化碳中以分子氧代替化学计量氧化剂的醇类清洁氧化技术的研究进展。分析了所研究的催化剂体系的催化性能,主要有钯、铂、钌、金等金属催化剂以及杂多酸催化剂体系;介绍了超临界二氧化碳体系中相行为的影响。指出超临界二氧化碳中醇类清洁氧化技术的研究才刚刚起步,其中高效催化剂体系的开发是超临界二氧化碳中醇类清洁氧化技术能否工业化的关键。