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1 INTRODUCTION More than 200 known metalloenzymes of a wide variety of types have been shown to contain zinc centers at their active sites (such as hydrolases, ligases and anhydrases)[1~3]. The active zinc centers in biological systems are usually surro…  相似文献   

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Synthesis and Structure of [Cu(OH)2(H2O)2(4—C5H4N—COOH)2]   总被引:1,自引:0,他引:1  
钟兆思  孙道峰 《结构化学》2001,20(6):478-480
1 INTRODUCTION Supramolecular chemistry and crystal engineering of coordination compounds have attracted considerable interests nowadays owing to the fascinating structural diversity and potential applications as functional materials[1,2]. Generally, architectures of supramolecules are formed through hydrogen bonds, ?- ?stacking interaction or other weak interactions between the molecules. Recently, many supramolecular compounds containing silver(I) and copper(II) species have been re-…  相似文献   

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1 INTRODUCTION Cadmium (Ⅱ) complexes have been exten- sively studied from both chemical and structural views, mainly due to the capability of cadmium (Ⅱ) (shared by most d10 metal ions) to adopt different modes of coordination determined by the consideration of size, as well as electrostatic and covalent bonding forces[1]. And the field of coordination polymers has witnessed tremendous growth over the last decade[2]. Many coordination polymeric networks have been shown to posses intere…  相似文献   

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1INTRODUCTIONThecurrentinterestinoxalatesreflectstheirstructuralrichnessandwideuseinanalyticalche-mistryandindustry[1].BecausemolybdenumintheVandVIoxidationstatesformsaconsiderablenumberofoxocomplexes,andtheequilibriainsolutionbetweenpolyoxomolybdenumspec…  相似文献   

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1 INTRODUCTION The design and synthesis of polynuclear com- plexes have attracted chemists?attention in the contemporary chemistry, since their clusters maybe lead to novel materials with magnetic, optical, electronic and catalytic properties of the constituent metals[1~3]. It is also prevalently interesting to synthesize high-nuclearity metal complexes for their nanoscopic dimensions[3, 4]. Spectroscopic properties of the lanthanides are widely used in the study of biological systems. …  相似文献   

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1 INTRODUCTION During the search of molecule-based materials with interesting properties such as catalysis, cla- thration etc., much attention has been focused on the synthesis of one-, two- and three-dimensional extended solids involving cadmium[1], as its d10 configuration permits a wide variety of geometries and coordination numbers. Rigid bridged ligands such as carboxylate groups are frequently used to construct these materials. Therefore, the coordi- nation chemistry of Cd(Ⅱ) ca…  相似文献   

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邵允  李春霞  陈亚光  刘群 《结构化学》2006,25(3):353-357
1 INTRODUCTION The investigation of coordination polymers has rapidly been expanded in last decade owing to their potential applications such as catalysis, molecular absorption, non-linear and magnetic materials. Among the varieties of such coordination polymers, the po- lymers of cadmium with dicarboxylates having fas- cinating structural topologies and good photolumi- nescence constitute a new family. Many reports are concerned about cadmium dicarboxylate polymers with 1D helix structu…  相似文献   

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IntroductionRecentlywehaveinvestigatedthestructuralchemistryofanumberofdi ortri organotinheteroaromaticcarboxyl ates.1 5Thesestudieshaveshownthatthestructureoforgan otinheteroaromaticcarboxylatesisdependentonboththena tureofthealkylorarylsubstituentboundtothetinatomandthetypeofcarboxylateligand .Inparticular,majorstructuralvariationsareobservedwhencarboxylateligandcontainsanadditionaldonoratom ,suchasapyridineNatom ,availableforcoordinationtotheSnatom .1 3,5 8Wehavenowturnedtothemonoorganotin…  相似文献   

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Synthesis and Structural Characterization of [Mn(sapn)(H2O)2]Br   总被引:1,自引:0,他引:1  
1 INTRODUCTION Many of the recent advances in the coordination chemistry of manganese have been driven by the involvement of the manganese in several biological redox-active systems[1,2], of which the most important is the oxygen-evolving complex (EOC) of photosystem II (PS II) in green plants [3]. Since the preparations and structural characterizations of the complexes containing N,O-donor ligands have been studied extensively as simple active-site models for the photosystem II[4,5]…  相似文献   

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1 INTRODUCTION The Schiff base ligands have been used to provide a stereochemically rigid ligand framework in homogenous precatalysts of some metals, such as salen Cr catalysts in asymmetric ring-opening re- action of epoxide[1] and salen Al in ring-opening polymerization of lactide and related cyclic esters[2]. Recently, it was reported that the bidentate Schiff base complexes of early and late transition metals can be served as promising alternatives to metal- locene catalysts for th…  相似文献   

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张玉华  袁建超 《结构化学》2001,20(5):363-368
1 INTRODUCTIONTransition metal clusters have been attracting intensive attention largely because they are suggested as active catalysts in a variety of homogeneous catalyzed reactions. However, no unequivocal proof exists that metal clusters themselves serve as the true catalysts among the catalytic process. In many cases it is known that fragments of the original clusters are the actual catalytic species. The unambiguous proof would be the use of a rigid chiral cluster to catalyze an asy…  相似文献   

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(NH3CH2CH2NH2)3[Mo(Ⅴ)O2(O2C6H4)2] (1), (NH3CH2CH2NH2)2.5[Mo(Ⅴ)o.sW(Ⅵ)o.502(O2C6H4)2] (2) and(NH3CH2CH2NH2)2[VC(Ⅵ)O2(O2C6H4)2] (3) were synthesized, structurally characterized by X-ray diffraction analysis, and studied on their interactions with ATP, their DNA cleavage activities and antitumor properties. The redox state of molybdenum was not changed on going from crystal to aqueous solutions in complexes 1 and 2, while tungsten underwent reduction from W(VI) to W(V) in complexes 2 and 3. ATP promoted the oxidation of both molybdenum and tungsten from M(Ⅴ) to M(Ⅵ) and the hydrolysis of catecholate ligands in solution consisting of ATP and the complexes. Complex 1 possesses fairly good activity to DNA cleavage and against tumor S180 in mice, and is more effective than the control drug cyclophosphamide under the identical conditions. However, complexes 2 and 3 exhibited marginal effectiveness. The effectiveness of anti-tumor of the complexes was related positively to their DNA cleavage activities and their hydrolysis of catecholate ligands.  相似文献   

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