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1.
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   

2.
A dinuclear copper(Ⅱ) complex[Cu2(TATP)2(L-Leu)2(CIO4)2]2·2H2Owas synthesized and characterized, where, TATP=1,4,8,9-tetraazatriphenylene, and L-Leu=L-leucinate. The complex was crystallized in the triclinic space group P1, with two independent molecules in a unit cell. Two Cu(Ⅱ) ions in each complex [Cu2(TATP)2(L-Leu)2(CIO4)2] molecule were found to be in different coordination geometries, i.e., Cu2 or Cu4 of a distorted square-pyramidal geometry coordinated with two nitrogens of TATP, the amino nitrogen and one carboxylate oxygen of L-Leu and one oxygen of perchlorate, and Cul or Cu3 with an octahedral geometry coordinated with the above stated similar coordinated atoms, and another carboxylate oxygen of L-Leu coordinating to Cu2 or Cu4. The complex can interact with CT-DNA by an intercalative mode and cleave pBR322 DNA in the presence of ascorbate.  相似文献   

3.
1 INTRODUCTION The syntheses and structures of carboxyl complex- es have captured the interest of chemists for years due to their potential applications in many fields, such as materials, medicine, molecular electro-che- mistry and biochemistry[1~3]. So far, to the best of our knowledge, cadmium complexes with aromatic carboxylic acid as ligands have been intensively studied[4~7], but those with heterocyclic carboxylic acid as ligands are much less. α-Furoic acid is widely used in orga…  相似文献   

4.
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   

5.
1 INTRODUCTION The polymeric metal complexes with extended structures are of great interest because of their useful chemical or physical properties[1]. Due to the noticeable fact that the aromatic polycarboxylate can provide versatile coordination mode and the non-coplanar structure of the carboxylate groups and the benzene rings, a lot of efforts in this field have been particularly directed to the preparation of aromatic polycarboxylate (such as phthalate, tere- phthalate and isophthal…  相似文献   

6.
蔡晓庆  胡茂林  陈帆 《结构化学》2007,26(1):103-107
1 INTRODUCTION The construction of coordination polymers based on metal centers and multifunctional bri- dging ligands is of great interest currently owing to their novel topologies and potential applica- tions in magnetism, catalysis, molecular recogni- tion, ion exchange, small molecular inclusion, nonlinear optical behavior, electrical conductivity, molecular sensing, and, in general, the rational design of new materials[1~4]. As is well known, ligands containing carboxylate groups are…  相似文献   

7.
1 INTRODUCTION In the design of crystal molecule, inorganic crystal engineering is one of the focused fields that are ever developing[1]. The introduction of different metal ions and bridging ligands often gives rise to novel physical and chemical properties[2~4]. Conse- quently, the supramolecular compounds constructed from weak interactions, such as hydrogen bond, π-π stacking, C–H???O interaction, ion-π interaction and hy- drophobing interaction, have become the new focus of cryst…  相似文献   

8.
A series of Ln(tmtaa)(Htmtaa)·CH_2Cl_2(Ln=Sm,Tb,Er and Yb)complexes were prepared and characterized byinfrared spectra,mass spectra and molecular electronic spectroscopy as well as DSC measurement.A sandwichstructure containing all the eight nitrogen atoms of tmtaa and Htmtaa was proposed for these complexes.X-rayphotoelectron spectra(XPS)of these complexes revealed that four nitrogen atoms of both tmtaa and Htmtaa werechemically equivalent to each other,respectively.The acidic hydrogen of Htmtaa did not bind specifically to any ni-trogen atom of Htmtaa,but was shared by all the four nitrogen atoms.The magnetic properties of these complexeswere found to be in good agreement with their theoretical values.  相似文献   

9.
毕文华  孙道峰  曹荣  李星  时茜 《中国化学》2004,22(3):271-274
Introduction Recently, many novel polymers with a variety of metal ions have been prepared and structurally characterized owing to the versatility of carboxylate ligands.1-5 Much attention has been devoted to this field partly because polymers of carboxylate ligands are good candidates for the investigation of exchange-coupling interactions between adjacent metal ions. A successful strategy to synthesize these complexes is the reaction of metal salts with properly selected multi-dentate carbox…  相似文献   

10.
吴思忠  陆世维 《中国化学》2003,21(4):372-376
The catalytic performance of Ni(η^5-Ind)2 complex in the dimerization of propylene was studied in combimation with an organoaluminum co-catalyst,eventually in the presence of a phosphine ligand.The effects of the type of aluminum co-catalyst and its relative amount,the nature of phosphine ligand and P/Ni ratio as well as the reaction temperature were examined.The results indicated that the nickel precatalyst exhibited high productivity for the propylene dimerization together with organoaluminum.It was likely to strongly modify the reactivity in the catalytic sytem when using phosphine ligand as additives,especially at the reaction temperature below 0℃.The catalytic system based on Ni(η^5-Ind)2 complex displaed an extremely high productivity(TOF up to 16900h^-1)and a good regioselectivity to 2,3-dimethylbutenes (2,3-DMB) in dimers(66.4%)under proper reaction parameters.  相似文献   

11.
牛德仲  陈久桐 《结构化学》2001,20(6):473-477
1 INTRODUCTION The polynuclear lanthanide complexes are specially interested and widely applied in the researches on light, electricity and magnetism[1~4], and the studies of the synthesis of polynuclear lanthanide complexes and its applications tend to be growing rapidly nowadays. Herein a report on the synthesis process and crystal structure of the title complex is presented. The crystal structure showed it is a non-electrolyte complex with one- dimensional chain. OCCOOPrOOCPr…  相似文献   

12.
The title compounds, Cu(L1)(C4H8NHO) and Ni(L2)(C4H8NHO) (H2L1 = 5-bromosalicylaldehyde-p-nitrobenzoylhydrazone, H2L2 = 5-bromosalicylaldehyde-p-hydroxybenzoylhydrazone), have been obtained and characterized by single-crystal X-ray diffraction. Complex 1 belongs to the triclinic system, space group P1 with a = 8.6960(2), b = 9.957(2), c = 11.878(2)A, α = 73.36(3), β = 78.25(3), γ = 82.64(3)°, V = 962.1(3) A^3, Mr= 512.81, Z = 2, F(000) = 514, Dc = 1.770 g/cm^3,μ(MoKα) = 3.251, R = 0.0337 and wR = 0.0846. Complex 2 is of monoclinic, space group P21/c with a = 13.313(2), b = 8.2096(1), c = 21.890(3) A,β = 125.737(3)°, V = 1941.9(4) A^3, Mr= 478.97, Z = 4, F(000) = 968, Dc = 1.638 g/cm^3,μ(MoKα) = 3.085, R = 0.0356 and wR = 0.0817. The ligands form a satisfactory N2O2 square plane around the metal centers in two compounds. Different patterns of hydrogen bonds are observed owing to the presence of different substituents on aromatic ring of the acylhydrazone Schiff bases. In complex 1, square-planar copper(Ⅱ) complexes are linked by intermolecular hydrogen bonds leading to zigzag infinite chains. In complex 2, the metal complexes are linked via hydrogen bonds to form corrugated sheets in a staggered fashion; 3D channels along the b axis are constructed through other non-covalent interactions between the neighboring layers.  相似文献   

13.
邸友莹张剑  谭志诚 《中国化学》2007,25(10):1423-1429
A coordination compound of erbium perchlorate with L-α-glutamic acid, [Er2(Glu)2(H2O)6](ClO4)4·6H2O(s), was synthesized. By chemical analysis, elemental analysis, FTIR, TG/DTG, and comparison with relevant literatures, its chemical composition and structure were established. The mechanism of thermal decomposition of the complex was deduced on the basis of the TG/DTG analysis. Low-temperature heat capacities were measured by a precision automated adiabatic calorimeter from 78 to 318 K. An endothermic peak in the heat capacity curve was observed over the temperature region of 290-318 K, which was ascribed to a solid-to-solid phase transition. The temperature Ttrans, the enthalpy △transHm and the entropy △transSm of the phase transition for the compound were determined to be: (308.73±0.45) K, (10.49±0.05) kJ·mol^-1 and (33.9±0.2) J·K^-1·mol^-1. Polynomial equation of heat capacities as a function of the temperature in the region of 78-290 K was fitted by the least square method. Standard molar enthalpies of dissolution of the mixture [2ErCl3·6H2O(s)+2L-Glu(s)+6NaClO4·H2O(s)] and the mixture {[Er2(Glu)2(H2O)6](ClO4)4·6H2O(s)+6NaCl(s)} in 100 mL of 2 mol·dm^-3 HClO4 as calorimetric solvent, and {2HClO4(1)} in the solution A' at T=298.15 K were measured to be, △dHm,1=(31.552±0.026) kJ·mol^-1, △dHm,2 = (41.302±0.034) kJ·mol^-1, and △dHm,3 = ( 14.986 ± 0.064) kJ·mol^-1, respectively. In accordance with Hess law, the standard molar enthalpy of formation of the complex was determined as △fHm-=-(7551.0±2.4) kJ·mol^-1 by using an isoperibol solution-reaction calorimeter and designing a thermochemical cycle.  相似文献   

14.
IntroductionThe coordination chemistry of zinc(Ⅱ)has beensubjected to extensive study in the past decades owingto its importance in life science[1].It has been foundthat zinc(Ⅱ)ions are crucially involved in the activesites of over300metalloenzymes and their role is notonly confined to catalysis and gene expression.Further-more,the presence of zinc(Ⅱ)helps to stabilize thetertiary and quaternary structures of proteins and nucle-ic acids[2—4].Like cadmium(Ⅱ),zinc(Ⅱ)is clearly amongthose m…  相似文献   

15.
1 INTRODUCTION The development of supramolecular and coordina- tion polymer complexes has recently attracted consi- derable attention due to the fundamental interest in self-assembly processes of transition-metal comple- xes, supramolecular chemistry and crystal enginee- ring[1~12]. The rational design of molecular architec- tures is essential for the creation of functional ma- terials with selective clathration[13, 14], molecular re- cognition[15, 16], catalysis[17, 18] and storage materi…  相似文献   

16.
The title complex [CoL(H20)3]2·H2O (C26H46N4O21S4CO2), where L = taurine-5- methyl-2-hydroxyisophthalaldehydes, has been synthesized and characterized by IR and X-ray diffraction analysis. The crystal of the complex belongs to the triclinic system, space group P1, with a = 11.197(4), b = 13.309(5), c = 14.486(5) ]A, a = 78.827(13),β = 70.547(11), γ = 81.058(13)°, Mr = 996.77, S = 1.08, V= 1987.2(13) A3, Z = 2, Dc = 1.666 g/cm3, F(000) = 1032,μ = 1.131 mm^-1, R = 0.0633 and wR = 0.1293. According to the structural analysis, the Co( Ⅱ ) ion adopts a slightly distorted six-coordinated octahedral geometry. One N atom of the Schiff base of each molecule was hydrogenated to form hydrogen bond with O atom. Two coterminous molecules packed in one crystal water molecule are linked by intermolecular hydrogen bonds, thus generating an infinite chain constructed by hydrogen bonds.  相似文献   

17.
HONG Jun 《结构化学》2008,27(5):539-542
The title complex, [Co(suc)(L)], 1 (L = 2-phenyl-lH-1,3,7,8-tetraazacyclopenta- [1]phenanthrene and H2suc = succinic acid) has been hydrothermally obtained and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group Pcca with a = 13.936(3), b = 9.918(2), c = 28.670(6)A, V = 3962.4(14)A^3, Z = 8, CoC23H16N4O4, Mr = 471.33, Dc = 1.580 g/cm^3, F(000) = 1928,μ(MoKa) = 0.907 mm^-1, R = 0.0543 and wR = 0.1336. Compound 1 exhibits one-dimensional chain structures which are further stacked by π-π interactions to give a supramolecular layer. Finally, the N-H...O hydrogen bonds between the nitrogen atom of L and carboxylate oxygen atom stabilize the structure of 1.  相似文献   

18.
The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3)A, V= 7446(2)A^3, Z= 8, Dc = 1.242 g/cm^3, μ=1.365 mm^-1, F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.  相似文献   

19.
Poly(vinyl chloride) supported tetraethylenepentamine (PVC-TEPA) has been found to be an efficient catalyst for the Knoevenagel condensation. A wide range of aromatic aldehydes easily undergo condensations with ethyl cyanoacetate and malononitrile in the commercial 95% ethanol in refluxing using PVC-TEPA as catalyst to afford the desired products of good purity in moderate to excellent yields. A recycling study confirmed that the catalyst could be reused, the yield of the desired condensation product were not reduced. The merits of this protocol are environmentally benign, simple operation, convenient work-up and good yields. Furthermore, the catalyst can easily be recovered and reused at five times with comparable yields.  相似文献   

20.
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   

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