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1.
1INTRODUCTION Recently,cyano-bridged lanthanide-transition me-tal complexes have been extensively investigateddue to their potential applications as precursors in the preparation of rare earth orthoferrites,fluores-cent and magnetic materials[1].Various complexes of this system have been obtained in order to ex-plore the relations between structures and pro-perties by using different ligands,such as DMF,4,4?-bipy,and so on,to fill the coordination sites of lanthanide ions[2～9].But up to… 相似文献
2.
1 INTRODUCTION Organic-inorganic hybrid materials and polyoxo-metalates have received much attention because of their intriguing structural diversity and potential applications in molecular adsorption, ion exchange, heterogeneous catalysis and nanotech nology as well as in electrical, magnetic and photochemical areas[1, 2]. One of the important ad- vances in the design of new organic-inorganic hybrid materials is utilizing poly- oxometalates’ coordination ability to produce poly- oxoanio… 相似文献
3.
GUO Wen-Juna ZHANG Han-Huia b HUANG Chang-Canga SUN Rui-Qinga CHEN Yi-Pinga CAO Yan-Ninga a 《结构化学》2005,(7)
1 INTRODUCTION It is well-known that bismuth and lead display attractive properties as promoting elements in noble metal-based catalysts[1], and thermal decomposition of ammonium metal oxalates can yield crystalline porous materials with a high surface area. This feature makes them attractive as precursors for catalysts and other nanocrystalline oxides[2]. Because of their topology, the oxalates themselves also possess inte- resting properties such as the capability of ion-exchange. The … 相似文献
4.
1INTRODUCTION There is currently considerable interest in the ra-tional design and controlled synthesis of metal-organic frameworks(MOFs)with unique structural motif on account of their promising applications as catalysts,gas storage,selective separation,sensor,ion exchange and magnetic materials[1,2].Particu-larly,the supramolecular architectures with helical structures have received much more attention over the past decades owing to their specific functions in biology.It is well recogn… 相似文献
5.
1 INTRODUCTION Polyoxometalates are the unique metal-oxygen clusters composed of transition metals in groups V and VI (Mo, W, V, Nb, Ta) in a high oxidation state showing a large structural varieties as well as inte- resting physical and chemical properties in diverse fields including catalysis, analytical chemistry, nanotechnology, chemical sensing, biochemical and geochemical processes, medicine and materials science[1～5]. Recently, there has been increasing interest in the synthesis… 相似文献
6.
1 INTRODUCTION The rational design and synthesis of new metal- organic frameworks have generated considerable interest in supramolecular chemistry and materials science owing to their intriguing structural diver- sities and potential applications as functional mate- rials[1～6]. Carboxylate-containing ligands have attrac- ted considerable attention because of the various coordination modes of carboxylate group, the ability to form hydrogen bonds and the potential applica- tions as functio… 相似文献
7.
WANG Yong-Jinga b ZHANG Han-Huia b② HUANG Chang-Canga b YU Xiao-Honga SUN Qiao-Zhena SUN Rui-Qinga a 《结构化学》2004,(8)
1 INTRODUCTION As a rich remarkable class of inorganic cluster systems, polyoxometalates continue to be the focus of significant attention in the 21th century because of their various and alluring topologies as well as their unusual physicochemical prope… 相似文献
8.
WEN Yi-Hang ZHANG Jian QIN Ye-Yan LI Zhao-Ji KANG Yao CHEN Yu-Biao CHENG Jian-Kai YAO Yuan-Gen② 《结构化学》2004,(9)
1 INTRODUCTION The increasing interest in inorganic-organic hybrid framework assemblies has resulted in a great number of research efforts focused on the develop- ment of new functional materials possessing various potential applications on catalysis, electrical conduc- tivity and magnetism[1～4]. In recent years, the inter- action of H2pdc with several metal ions has been extensively studied[5, 6] due to its unique ability to form stable chelates in diverse coordination modes such as bid… 相似文献
9.
Synthesis and Structural Characterization of [(C_2H_5)_4N][V~((V))O_2(OC_6H_3(OCH_3)CHNNCSNH_2)]·H_2O 总被引：1，自引：1，他引：0
1 INTRODUCTIONAlthough vanadium plays an increasingly recognized role as a biometal[1~4], little is known about the structure and function of vanadium compounds in living organisms. A classical and nevertheless rapidly developing field of application for oxovanadates and related compounds is their use as catalysts in polymerization and oxidation reactions[5,6], and recent interest has focused on oxovanadates as model compounds for the interaction of oxovanadates with the active sites of en… 相似文献
10.
1 INTRODUCTION Orotic acid (H3dtpc), an important pyrimidine derivative as the effective precursor in the biosynthesis of pyrimidine base of nucleic acids in living organisms, plays a unique role in bioinorganic and pharmaceutical. Aside from the biological interest, orotic acid is also interesting in coordination chemistry. Its ketonic and enolic tautomers along with asymmetric geometry make it to be a very good versatile polydentate ligand[1~5]. The incorporation of metals into supram… 相似文献
11.
1INTRODUCTION Studies on the syntheses,structures,and proper-ties of lanthanide-transition metal complexes are currently of great interest not only due to their beha-viors as good models to investigate the nature of magnetic exchange interactions between3d and4f metal ions in magnetic materials but also to the fascinating coordination properties of Ln(III)[1～6].Although some infinite lanthanide(III)-transition metal compounds have been obtained by the con-ventional self-assembly reacti… 相似文献
12.
1 INTRODUCTION Manganese has been implicated as an essential part of the active center in various manganese enzymes. Various nuclearities have been observed from mononuclear atom in superoxide dismutase [1] to the tetranuclear atom of oxygen evolution in photosystem II[2]. The manganese active centers in biological systems are surrounded by O and N coordination sphere[3, 4]. Synthetic efforts have produced a great variety of Mn clusters with varying nuclearity and oxidation states. Si… 相似文献
13.
1 INTRODUCTION Crystal engineering and the design of solid-state architectures have recently become areas of increasing interest[1, 2]. Such crystal engineering may afford new materials with useful properties such as catalytic activity, micro-porosity, nonlinear optical activity, cooperative magnetic behavior and so on. Polynitrile-ligand is one of the ideal multi-functional ligands for crystal engineering and many complexes with polynitriles as ligands have been found to show the spe… 相似文献
14.
1 INTRODUCTION Chemistry of manganese cluster has become an attractive research field because of the involvement of manganese in several biological redox-active sys- tems[1,2], especially in the oxygen-evolving complex (OEC) of photosystem Ⅱ (PSⅡ) in green plants[3]. It was thought that the coordination environment of Mn in OEC contains O and N donors, and the bind- ing of aqua to the Mn site may be important to the oxidation of aqua for the evolution of dioxygen[4, 5]. In recent … 相似文献
15.
1 INTRODUCTION Since Bedard et al. reported microporous tin(IV) sulfides synthesized by hydrothermal method in the presence of organic amine in 1989[1, 2], a number of thiostannates have been synthesized using hydro- or solvothermal techniques with organic amines as tem- plates. The structures of the resulting tin(IV) sulfi- des are related to the types of organic amines. Two- dimensional polyanions of the types of [Sn3S7]2- and [Sn4S9]2-, which are denoted as SnS-1 and SnS-3, respe… 相似文献
16.
1 INTRODUCTION The investigation of Shiff base complexes con- taining sulfur and complexes of amino acid Schiff bases[1, 2] has recently aroused considerable interest due to their antiviral, anticancer and antibacterial activities. Taurine, known as 2-aminosulfonic acid, is indispensable to human beings and plays an im- portant role in physiological functions. In this con- tribution, we present the synthesis and crystal struc- ture of a new binuclear Zn(II) dimmer with a tri- dentate Sc… 相似文献
17.
People have long been interested in the coordination polymers of terbium! with carboxylic acids for those polymers often have peculiar structure and luminescent feature. They can be used as extraction and separation agents, bactericides, luminescent and functional materials. For example, they are used in the production of plastic membranes, lighting materials, developing materials and ornament materials[1～3]. In chemical literature, we can find many research reports about ternary complexes of… 相似文献
18.
Introduction Flavonoids exist widely in edible plants, and have pharmacological activity. They played a major role in the successful medical treatments at ancient times, and their uses have been persevered up to now.1-3 Flavonoid sulfates were found in a large number of plant species. They occupy an important position in the field of natu-ral products chemistry since they provide structures consisted of organic and inorganic components. The pharmacological assay revealed that flavonoid sulfat… 相似文献
19.
《结构化学》1992,(2)
<正> (NH4)11[Na(H2O)2P4W14O58)·12H2O, Mr = 4099. 39, triclinic, space group P1, a = 14. 376(2), b = 19.861(9), c=13. 010(3)(?) , α=104. 68(2), β=91. 37(1), γ= 104. 05(2)°, V = 3471. 1 (?)3, Z = 2, Dc=3. 922g/cm3, μ (MoKα) = 238. 274cm-1, F(000) = 3664, R = 0.0510, Rw = 0. 0665 for 9260 observed reflections with I> 3σ(I). The polyanion [Na(H2O)2P4W14O58]11- consists of two PW7O29 subunits anisostructurally, two linkage phosphorous atoms and one sodium ion with two water ligands as well. The geometries of tungsten atoms within these two subunits are almost the same as those in K12P4W14O58· 21H2O[2]. The four phosphorous atoms are in PO4 coordinations. The sodium ion locates nearly at the center of the polyanion, and is coordinated by two water molecules, five oxygen atoms of the anion and one phosphorous atom with Na-P = 3. 053(3) (?). Due to the presence of the sodium atom, the interactions between oxygen and tungsten atoms in the polyanion are somewhat weakened. 相似文献
20.
1 INTRODUCTION Polyoxometalates are metal-oxygen clusters with almost unrivaled versatility, which results from their enormous structural variety, range of sizes, tunable redox properties and fascinating catalytic activi- ties[1~7]. Therein, an important progress in transition metal oxide cluster chemistry has been the study of polyoxoanion-substituted and supported inorganic or organometallic complexes[8, 9]. However, modified polyoxoanions with divalent first-row transition me- tal as c… 相似文献