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1.
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
2.
Introduction The chemistry of the sandwich-type heteropoly-oxometalates encapsulating clusters of early transition metals is current of considerable interest with respect to the application of complexes in material science, medi-cine, catalysis and fundamental perspectives.1-4 The great advantage of these complexes is the possibility of varying either the type of the metallic cluster or the het-eroatom. The proximity of the transition metals pos-sessing unpaired electrons facilitates their cou… 相似文献
3.
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
4.
Synthesis and Crystal Structure of 18-Tungstotetranickel(II) diphosphate Na_(10){(PW_9O_(34))_2Ni_4(H_2O)_2}·26H_2O 总被引：1，自引：1，他引：0
CUI Chuan-Peng DAI Jing-Cao DU Wen-Xin WU Li-Ming FU Zhi-Yong HU Sheng-Min WU Xin-Tao② 《结构化学》2001,(4)
1 INTRODUCTIONThe inorganic chemistry concentrating on polyoxometallates, is in a position to connect elementary building blocks and their derivatives in different ways, enabling people to synthesize a large variety of remarkable substances, especially those in the "nanoworld". Of particular importance is the anionic-type which has {MOx}-type building-block units, where M stands for the d block elements in high oxidation states.[1] In 1973 Weakley, Evans and Showell isolated[2] K10P2W1… 相似文献
5.
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
6.
1 INTRODUCTION In the last few years, much attention has been paid to the molecular structure and biological activity of coordinated complexes in inorganic chemistry field. Ni(Ⅱ) is one of the commonest transition metals with two coordination numbers (4 and 6)[1～3]. Ge- nerally speaking, Ni(Ⅱ) coordination mode depends on the structure of ligand, solvent and reaction con- ditions, among which ligand plays a decisive role and determines not only the molecular structure of the complex bu… 相似文献
7.
《高等学校化学研究》2005,(1)
IntroductionCation- π interactions have come to be appreci-ated as an important noncovalent binding force inmany areas of modern chemistry,such as materialdesign,molecular biology,host- guest and supra-molecular chemistry[1_ 3 ] .These interactions havebeen investigated in the gas phase[4] ,in aqueousmedia by using synthetic receptors[5,6] ,in a numberof protein systems[1,5,7] and in many metal complex-es provided by crystallographic studies[8_ 16] .Cations thatshow cation-π interactions,inc… 相似文献
8.
1 INTRODUCTION The design and synthesis of organic-inorganic hy-brid compounds are of great interest owing to theirextensive theoretical and practical applications in ca-talysis, medicine, analytical chemistry, nanotechno-logy, electrochromism, magnetism and photochemis-try[1～5]. In heteropolyoxometalate chemistry, a newadvance is the decoration of polyoxoanions with va-rious organic and transition metal complex moieties.In contrast to a large number of known organic andtransition-metal-s… 相似文献
9.
1 INTRODUCTION Recently, the chemistry of lead is of interest in relation to its toxicity and effects on intelligence in human populations[1~3]. The design of drugs to coun- teract the effects of lead poisoning requires estab- lishing the preferred ligands of Pb(II) and their ste- reochemistry. Consequently, synthesis of chelated- form antidotes for lead(II) ion toxicosis has attracted more and more attention, and numerous reports con- cerning experimental coordination chemistry of lead(… 相似文献
10.
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
11.
1 INTRODUCTION Nickel is vital for organism as a trace element and it often acts as component or secondary factor of enzyme. In the latest two decades, biological inor- ganic chemistry of nickel has become one of the hottest fields and the coordination chemistry of nic- kel has made a great progress[1]. Complexes built upon organic aromatic carboxylic acid and metallic ion have attracted chemists’ interest for years due to their potential applications in material, medicine, molecular ele… 相似文献
12.
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
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1 INTRODUCTION The chemistry of polyoxometalates continues to attract interest as a result of their realized and potential applications in diverse fields, such as cata- lysis, analysis, biochemistry, medicine and material science[1～3]. In the past few … 相似文献
14.
1 INTRODUCTION Recently, the ternary or quaternary mixed anion complexes of cerium(III) containing 1,10-phenanthroline (phen) have attracted considerable attention due to their rich structural chemistry and appealing magnetic properties[1]. Panagiotopou… 相似文献
15.
The heat capacities of four RE isothiocyanate hydrates,Sm( NCS)3 6H2O,Gd( NCS)3 6H2O,Yb(NCS)3 6H2O and Y( NCS)3 6H2O,have been measured from 13 to 300 K with a fully-automated adiabatic calorimeter No obvious thermal anomaly was observed for the above-mentioned compounds in the experimental tem-peiatnre ranges.The polynomial equations for calculating the heat capacities of the four compounds in the range of 13-300K were obtained by the least-squares fitting based on the experimental Cp data.The Cp values below 13 K were estimated by using the Debye-Einstem heat capacity functions.The standard molar thermodynamic functions were calculated from 0 to 300 K.Gibbs energies of formation were also calculated. 相似文献
16.
1INTRODUCTION Investigation of the coordination chemistry of copper(II)continues to be stimulated by interest in developing modes for copper proteins and in under-standing the factors which give rise to the seemingly infinite variety of distortions from regular stereo-chemistry observed in Cu(II)complexes[1,2].For more than decades,due to the unique coordination polyhedra and their easy preparation,tripodal copper complexes have attracted much attention in addition to their special chemi… 相似文献
17.
Introduction The chemistry of organotin(IV) dithiocarbamate complexes was extensively studied due to their biological activities.1-5 To date, a large number of transition-metal complexes with dithiocarbamate have been synthesized and structurally characterized,6-9 including Ni(S2CNC4H8O)2, Cu(S2CNC4H8)2, Zn(S2CNC4H8O)2 and Fe(S2CNC4H8O)2(DMF). However, the chemistry of main-group metal complexes with dithiocarbamate has been scarcely studied, and few reports have appeared on the s… 相似文献
18.
WANG Ying ② YAN Lian-He 《结构化学》2006,(10)
1 INTRODUCTION The ability of dialkyldithiocarbamate anion, -S2- CNR2 (dtc) ligand, to bind metal has been known for many years[1, 2]. It forms a chelate with virtually all transition elements and is proven to be a versatile chelating agent for the separation and extract of metals in analytical chemistry and mineral floa- ting[3～5]. Water soluble dialkyldithiocarbamate com- plexes have been tested in various medical appli- cations[6]. Some of substituted dithiocarbamate salts also show … 相似文献
19.
The successful preparation of coordinationpolymers from modular precursors has provided afacile approach to develope solids and functionalmaterials[1— 4 ] . A popular strategy that could beemployed in the area is the adoption of bridgingligands such as cyanide,bi- pyridine,benzenetricarboxylate,etc.[3— 8] . In this context,multi- connecting carboxylates are at presentespecially interesting because they exhibit richcoordination chemistry by coordinating to metalions and have been proved to be… 相似文献
20.
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