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1.
1 INTRODUCTION There has been great and considerable interest in the study of copper nitrite complexes because they are relevant to the study of copper-containing enzymes involved in the denitrification process[1]; in particular, copper-nitrite complexes are potentially relevant to the nitrite reductases[2] (the enzyme from Achromobacter Cycloclastes) which convert NO2- to NO and/or N2O. Many attempts have been made to synthesize a variety of copper-nitrite complexes, in which the n…  相似文献   

2.
(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   

3.
冯云龙 《结构化学》2003,22(2):133-136
1 INTRODUCTION The interest in the complexes of transition metals with ligands ketoxime[1, 2] as potential models for metal binding sites in ferroverdin[3, 4] has prompted the investigation on the structures and the overall coordination geometry of the metal centers in these complexes. Oxime derivatives are interesting ligands since the ketoximes are found to chelate transition metals through the N (oxime) and O (ketone) atoms[5, 6]. However, monodentate coordination via only one O or …  相似文献   

4.
1 INTRODUCTION During the last decade the manganese che- mistry has aroused great interest due to its diverse redox functions of enzymes in photosystem Ⅱ and its specially structural, magnetic and spectroscopic properties[1, 2]. A lot of manganese complexes involving carboxylate ligands have been reported, and their properties been fully explored[3, 4]. The coordination environment of the manganese site in biosystem often consists of oxygen and nitrogen atoms from the carboxylate groups…  相似文献   

5.
Cis-dioxo-metal complex ( NH3CH2CH2NH2 ) 2.5 [ Mo0.5^(V)W0.5^(VI)O2 ( OC6H4O ) 2] 1 was obtained by the reaction of tetra-butyl ammonium hexamolybdotungstate with 1, 2-dihydroxybenzene in the mixed solvent of CH3OH, CH3CN and ethylenediamine,and characterized by X-ray diffraction, UV-vis and EPR analysis. Compared with its analogous complexes (NH3CH2CH2NH2)3[Mo^(V)O2(OC6H40)2] 2 and (NH3CH2CH2NH2)2[W^(VI)O2(OC6H4O)2] 3, the results show that tungsten(VI) is less active in redox than molybdenum (VI) and that the change of the valence induced by substitution of W(VI) for Mo(V) in EMO2(OC6H40)2]n- does not influence the coordination geometry of the complex anion in which the metal center exhibits distorted octahedral coordination with cis-dioxo catechol. The responses to EPR of complexes 1 and 2 are active but complex 3 is silent,and the UV-vis spectra exhibited by the three complexes are obvious different because of the different electronic configuration between the central Mo(V) and W(VI) ions in the complexes.It is noteworthy that complexes 1 and 2 have the similar EPR signal to flavoenzyme, suggesting that the three complexes have the same coordination geometry feature with the co-factor of flavoenzyme.  相似文献   

6.
1 INTRODUCTION Recently much more attention has been paid to palladium bidentate chelate. Such as palladium diphosphino complexes can be used to catalyze crossing-coupling[1] and monocoupling[2]; palladium diamine complexes can be used to catalyze norbornene polymerization[3] and it can also bind to biologically important molecules[4]. Owing to the above reasons, palladium(Ⅱ) complexes with these ligainds are well researched. However, the neutral analogs with derivatives of dithiole are…  相似文献   

7.
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   

8.
1 INTRODUCTION As one kind of compound with extensive phy- siological and pharmacology activities[1], 2-amino- pyridine is easy to form complexes, and some of which may catalyse hydrolysis of ester[2]. Acetyl- acetone is an useful intermediate in the synthesis of sulfanilamide, additive and catalyst[3]. Complexes containing acetylacetone take on excellent lumines- cent properties[4]. To be an active center of some sig- nificant enzymes[5, 6], zinc takes the form of its su- pramolecular co…  相似文献   

9.
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   

10.
1 INTRODUCTION Polythiotungstate complexes can be prepared from the protonation of one sulfur atom of [WS4]2- and subsequent intramolecular redox reactions[1,2]. For example, [(S)2W(m-S)2W(m-S)2W(S)2]2 was formed by the acidification of a diluted aqueous solution of (NH4)2[WS4] with dilute H2SO4[3]. When a diluted aqueous solution containing [WS4]2 was acidified with 0.1mol/L HCl, [(S)2W(m-S)2(O)- W(H2O)(m-S)2W(S)2]2 was formed[4]. [(S)2W- (m-S)2(S)W(m-S)2W(S)2]2 was form…  相似文献   

11.
1 INTRODUCTION Recently, the researches on inorganic-organic hy-brid compounds represent an advanced field in mate-rial science[1]. At the molecular level, the combina-tion of two extremely different components providesan avenue to design new hybrid materials as well asthe ability to modulate properties of one or more ofthe components[2~6]. Some attractive properties, suchas efficient luminescence[2~4], ideal thermal and me-chanical stability, interesting magnetic[5], non-linearoptical[…  相似文献   

12.
曾正志 《中国化学》2002,20(5):474-478
Two new Complexes(Cp)2Ti(Cin)2and (CP2)Ti(Tzea)2(CP=Cyclopentadienyl η^5-C5H5)have been synthesized in THF by the reaction of HCin(Cincofen,2-phenylquinoline-4-carboxylic acid)or HTzea(5-phenyltetrazolyl-2-ethanoic acid)with(Cp)2TiCl2,and characterized by elemental analyses,IR,1H NMR and 13C NMR,UV spectra,molar conductivity,TGDTA.In the complexes the carboxyl groups are coordinated to Ti(IV)in a monodentate manner,The inhibitory actions of the complexes on mice ear tumefaction caused by croton oil and the rat foot granulation growth produced by cotton wool are higher than those of the corresponding ligands HCin,HTzea and [(Cp)2TiCl2],while their toxicities are lower than those of the free ligands.ηη  相似文献   

13.
高山  霍丽华  赵辉  赵经贵 《结构化学》2005,24(5):499-503
1 INTRODUCTION Supramolecular chemistry of manganese(II) car- boxylate coordination polymers has been inten- sively studied in recent years, within which ligand design is an important aspect in adjusting the coordi- nation framework and functionalities of the complexes formed[1~4]. Carboxyphenoxyacetic acids (CPOAH2), which have been known to show biological activities and are widely used in agriculture, are a family of multidentate flexible ligands with versatile binding abilities. …  相似文献   

14.
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   

15.
1 INTRODUCTION The complexes containing dithiolate ligands have played a well-established role in modern coordination chemistry[1]. There is continuous interest in complexes of chalcogenolate ligands with transition metals such as complexes of Pd[1], Mo[1], Au[2], Ir[3~6], Rh[4, 5], Co[7] and Re[1, 8] containing a chelating 1,2-dicarba-closo-dodecabarane-1,2-dich- alcogenolate ligand. Some of these complexes have become important in the study of new molecular materials[1, 9, 10]. Th…  相似文献   

16.
1INTRODUCTION Manganese complexes have drawn considerable interests in recent years because they can serve as models for active sites of manganese-containing me-talloenzymes,such as photosystem II(PSII),man-ganese superoxide dismutase(MnSOD),manganese ribonucleotide reductase(MnRR)et al[1].The binu-clear manganese enzymes,including catalase,MnRR and arginase,were indicated to have carboxylato-,oxo-,hydroxo-or aquo-bridged cores[2~4].Structures with Mn substituted into the iron ribon…  相似文献   

17.
1 INTRODUCTION Recently coinage metal complexes of poly- dentate phosphines are of great interest owing to the applications in diverse areas such as supramolecular design, photophysics and catalysis[1~4]. It is well- known that the binuclear coinage metal complexes of diphosphine [M2(diphosphine)2(MeCN)2]2+ (M = Cu, Ag, Au)[5~16] are excellent precursors for the design of polynuclear or polymeric materials with desired properties due to the easy substitution of weakly coordinated ac…  相似文献   

18.
1 INTRODUCTION In contrast to the old-line academic and practical studies of 1-phenyl-3-methyl-4-benzoyl-5-pyrazo- lone (PMBP) on the metal coordination chemistry[1], the complexes of β-ketoamines derivated from PMBP received little attention due to its complicated com- plexation. However, in recent years, there has a sudden growth of this area as a result of its timely interest in biological activities[2]. Recently, a series of β-ketoamines[3] containing PMBP have been prepared fro…  相似文献   

19.
1 INTRODUCTION Macrocyclic ligands and their metal complexes have received much attention due to their applications in ion transport, ion separation and as models in biomimic researches[1~7]. The synthetic methods of macrocyclic ligands and their metal complexes are mainly divided into three kinds[8]. The first one is synthesizing free ligand, then forming the metal complexes; the second is template synthesis; and the third is synthesizing the end-off or side-off precursor ligand, then c…  相似文献   

20.
冯云龙 《结构化学》2002,21(1):22-25
1 INTRODUCTION A number of isonitroso-b-diketones and isonitroso-b-ketoesters such as isonitrosoacetyl- acetone(Hiaa), isonitrosobenzoylacetone(Hiba) and isonitrosoethylacetoacetate (Hieaa) have been employed as reagents in spectrophotometric determination of iron, palladium and ruthenium[1]. Transition metal complexes of such ligands[2] are potential models for metal binding sites in ferroverdin[3]. They were found as dyes and light-absorbing agents for the acceleration of the sol…  相似文献   

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