A COMPARISON OF THE DETERMINATION OF STABILITY CONSTANTS OF COMPLEXES OF Cd(Ⅱ)WITH AMINO ACIDS AND SIMPLE PEPTIDES USING MICRO—pH—METRIC TITRATIONS AND CYCLIC VOLTAMMETRY

This paper reports the determination of stability constants for complexes of Cd(Ⅱ)with Gly,Ala,Val,Asp,Gly—Asp,Asp Gly,Gly—Gly and Gly—Gly—Gly using both micro—pH—metric titra-tions and the application of convolution—deconvolution cyclic voltammetry at 25℃ and I=0.10 mol·dm~(-3)(KNO_3).Stability constants were calculated from pH—metric data using the SUPERQUAD com-puter program and cyclic voltammograms were collected,stored and manipulated using the EG and GCONDECON 300 software.A considerably larger ligand:metal ratio(e,g.50:1)was possible usingvoltammetry.Evaluation of results from the two techniques suggests that stability constants for thespecies[CdL_2]and[CdL_3]are reliable when calculated fromvoltammetry while those for[CdL]are morereliable when determined by pH-metric titration.     

SYNTHESIS AND ELECTRONIC SPECTRA OF RUTNENIUM(Ⅱ)-1,1''''-BIISOQUINOLINE COMPLEXES

l,l'-biisoquinoline can coordinate with ruthenfum(Ⅱ) to form a new series of mononuclear complexes and the electronic absorption of these complexes were measured and reasonably assigned.     

SYNTHESIS AND MAGNETIC PROPERTY OF CARBOXYL BRIDGING DICOPPER(Ⅱ) COMPLEXES

Two new dicopper(Ⅱ) complexes with two carboxyl bridgings in one molecule[Cu(dm-phen)(HCOO)]_2(NO_3)_2 3H_2O(1). [Cu(ds-phen)(CH_3COO)]_2 (NO_3)_2 3H_2O(2). one dicopper(Ⅱ) complex with one carboxyl bridging and one hydroxo bridging in one molecule [Cu_2(OH)(C_2H_5COO)(ds-phen)_2]. (NO_3)_2 H_2O(3) and one cononuclear Cu(Ⅱ) complex [Cu(de-phen)(CF_3COO)](NO_3).H_2O(4)(dm-phen= 2,9-dimethyl-1,10-phenanthrolin)were prepared and characterized. The effective magnetic moment, u elf, was measured and their magnetic properties were discussed. The coordination modes of carboxyl moieties in all the title complexes were proposed.     

SYNTHESIS AND MAGNETISM OF BINUCLEAR COPPER(Ⅱ) COMPLEXES CONTAINING SALUCYLAMIDATOCUPRATE(Ⅱ)

New binuclear copper(Ⅱ) complexes, [Cu(samen)Cu(NO_2-phen)]·H_2O and [Cu(sampn)-Cu(NO_2-phen)]·2H_2O have been synthesized, where samen~(4-), sampn~(4-) and NO_2-phen denote N, N′-ethylenedisalicylamidate anion, N, N′-1, 2-propanedisalicylamidate anion and 5-nitro-1, 10-phenanthroline respectively. 3ased on IR, elemental analyses and electronic spectra, the complexes are proposed to have a phenoxy-bridged structure and to consist of the Cu(Ⅱ)ion in distorted planar environment. The complexes have been characterized with varlable-temperature magnetic susceptibility (4—300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral J=-63.0 cm~(-1) (samen) and J=-46.5cm~(-1) (sampn). This indicates the existence of antiferromagnetic spin exchange interaction among the metal ions.     

EFFECTS OF CONFORMATION OF POLYMER LIGANDS IN COPPER(Ⅱ) COMPLEXES ON CATALYLIC ACTIVITIES AND MECHANISM OF OXIDATIVE COUPLING OF β-NAPHTHOL

Copper(Ⅱ) complexes of sericin, chitosan, 6-and 2-aminodeoxystarch were used as catalysts in oxidative coupling of β-naphthol, the effects of conformation of the polymer ligands in these complexes on activities of the catalysts and mechanisms of the reaction were studied. It was found that if the catalysts react with the substrate by mechanism similar to the enzymic catalysis they must be composed of polymer ligands with highly coiled, especially with densely helicoidal, conformations. While catalysts composed of loosely coiled or helicoidal hgands react with the substrate through molecular collision and have relatively lower activities only. Under nitrogen, catalysts from sericin and chitosam reacting with β-naphthol give optically active β-binaphthol, rotating polarized light to right, but the stereoselectivities are rather low.     

SYNTHESES OF POLYMER-BOUND RHODIUM COMPLEXES AND THEIR APPLICATION AS CATALYSTS FOR THE HYDROFORMYLATION OF DIISOBUTYLENE (Ⅰ)

Copolymer of styrene-divinylbenzene in bead form (with DVB 8%, average pore radius 3.0×10~2, specific surface area 25m~2/g, particle size 0.2—0.4mm) was made by the suspension polymerization. After chloromethylation, the beads were then reacted with lithium diphenyl phosphine and various amines separately. Two types of polymeric ligands, i.e. polyvinylbenzyl diphenyl phosphine and eight kinds of polyvinylbenzyl amines were thus obtained. In order to prepare the polymer-bound rhodium complexes, the ligands were then reacted with [Rh(CO)_2CI]_2. The initial composition and structure of the polymeric complexes were verified by IR spectra. The complexes synthesized above were used to catalyze the hydroformylation of diisobutylene under conditions of 110℃, 100(120) kg/cm~2 and H_2/CO=1:1. The effects of the donor atoms (N, P) on the activity of the two types of catalysts and the N-substituted groups on the activity 'of polymeric amine-rhodium complexes were examined.     

SYNTHESIS AND CHARACTERIZATION OF THE SOLID COMPLEXES OF Mn(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Ag(Ⅰ), Cd(Ⅱ) NITRATES WITH DISUBSTITUTED BENZO CROWN ETHERS

Nine new solid complexes of Mn(Ⅱ),Co(Ⅱ),Cu(Ⅱ),Zn(Ⅱ.),Ag(Ⅰ) nitrates with 4',5'-dibromobenzo-15—crown—5(L_A),Ag(Ⅰ),Cd(Ⅱ)nitrates with tetrabromodibenzo—18—crown—6(L_B)and Cu(Ⅱ), Ag(Ⅰ) nitrates with 4'—bromo—5'—nitrobenzo—15—crown-5(L_c),having the compositions of M(NO_2)_2·L·nH_2O(M=Mn,Co, Zn,L=L_A,n=2;M=Cu,L=L_A,n=1.5; M=Cd, L=L_B,n=0; M=Cu,L=Lc,n=2) and AgNO_·L·nCH_3CN(L=LA,n=0; L=L_B,n=1; L=Lc,n=1/2) have been synthesized in nonaqueous solvent. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X—ray powder diffraction analysis, molar conductance and measuremends of solubility in some general solvents.     

THE INFLUENCE OF SUBSTITUENT ELECTRONIC EFFECT ON ETHYLENE OLIGOMERIZATION ACTIVITIES OF BIS(IMINO) PYRIDYL Fe(Ⅱ) CATALYSTS:A COMBINED MOLECULAR MECHANICS AND CHARGE EQUILIBRATION METHOD

Bis(imino)pyridyl Fe(Ⅱ) complexes are important catalysts in ethylene oligomerization for preparingα-olefins. The metal net charge-activity relationship of bis(imino)pyridyl Fe(Ⅱ) complexes was investigated by molecular mechanics (MM) and net charge equilibration(QEq) method with modified Dreiding force field.It was found that metal net charge was in reverse ratio to ethylene oligomerization activity.Electron-donor substituents with less steric hindrance to the central metal were favorable to Fe complex ...     

Theoretical Studies on the Excited-state Properties of Ru(Ⅱ) Polypyridyl Complexes

Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru(Ⅱ) polypyridyl complexes.     

Syntheses,Crystal Structures and DNA-binding Properties of Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) Complexes Containing Imidazolium Derivatives

Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) complexes(1~4) based on 2-(2-pyridyl)benzimidazole(pbm) and 4,4'-oxybisbenzoic acid(H2odc) were synthesized. The formulas of these complexes are [Cd(pbm)(odc)2](1), [Co(pbm)(odc)2](2), [Cu(pbm)(odc)2](3) and [Zn(pbm)(odc)2](4) confirmed by single-crystal X-ray diffraction analysis, which shows that complexes 1, 2 and 4 belong to monoclinic system with space group P21/n, while complex 3 belongs to monoclinic system with space group P21/c. The binding properties of complexes 1~4 with CT-DNA are evaluated by ultraviolet spectrum, fluorescence spectra and viscosity measurements. The results indicate that complexes 1~4 have strong interaction with CT-DNA binding. These complexes exhibit an electrostatic or groove mode in respect of binding with DNA, which can effectively destroy DNA. And this binding mode may be applied to the interaction between the complexes and cancer cell DNA. Therefore, we hope to provide a theoretical and scientific basis for the research of anti-cancer drugs.     

间硝基苯乙酮双缩硫代对称二氨基脲Cu(Ⅰ)、Zn(Ⅱ)、Fe(Ⅱ)Sn(Ⅱ)、Pb(Ⅱ)配合物的直接电化学合成

Cu(Ⅰ), Zn(Ⅱ), Fe(Ⅱ), Sn(Ⅱ), Pb(Ⅱ) complexes of 1,5-bis(3-nitroacetophenone) thiocarbohydrazone were synthesized by the electrochemical oxidation of anodic metal in non-aqueous solvents. The complexes were characterized by elemental analysis, IR UV, magnet     

ESR study on some copper(Ⅱ)complexes of bis(4''''-benzo-15-crown-5)

ESR measurements have been carried out for some copper(Ⅱ) complexes of bis(4'-ben-zo-15-crown-5) at 77 K.The results of ESR spectrometric titration indicated that the binuclear com-plexes were prepared in the present system.The binuclear complexes revealed characteristic ESRg-anisotropies (gZ相似文献   

CATALYTIC COPOLYMERIZATION OF STYRENE AND ETHYLENE BY NEUTRAL NICKEL(Ⅱ) COMPLEXES IN EMULSION

Emulsion copolymerization of styrene and ethylene catalyzed by a series of neutral nickel(Ⅱ) complexes was carried out in an aqueous system to give high-molecular-weight copolymers.The copolymers and emulsions were characterized by an array of techniques including NMR,GPC,TEM,WAXD and DSC.The results indicate that the copolymers obtained are mostly block copolymers of polyethylene with random insertion of styrene units,and their M_W is in the range of 10~5-10~6.By enhancing the electron withdrawing of th...     

THE CRYSTAL STRUCTURE OF BIS(N-METHYLIMIDAZOL)- PALLADIUM OXALATE MONOHYDRATE

<正> INTRODUCTION. In recent years, Zhang Liangfu et al. were successful in using complexes composed of chelate ligand of diphosphine, dinitrogen and transition metal elements of lower valence multi-electrons to activate C-H bond. Recently, we synthesized complexes of bis(N-methylimidazol) ligand with palladium(Ⅱ) or platinum(Ⅱ) oxalate. These compounds activate also     

APPLICATIONS OF DSCPCF MODEL IN RARE EARTH COMPLEXES(Ⅴ)——ANALYSIS OF SPECTRA OF THE NEODYMIUM AND ERBIUM TETR A (2-THENOYLTRIFLUOROACETONE) MONO PIPERIDINE COMPLEXES

The complexes, Nd(TTA)_4·HP and Er(TTA)_4·HP, have been prepared, and their UV-VIS-NIR absorption spectra measured. The matrix element expressions with J=1/2—15/2 of f~3 and f~(11) configurations in D_4 symmetry field were derived with the Double Sphere Coordination Point Charge Field Model. And the influence of change in symmetry of the complex unit REO_8 on splitting of their levels was discussed. Based on theoretical calculations, the absorption peaks in the spectra were assigned.     

ESR SPECTRA STUDY OF COPPER(Ⅱ) COORDINATION COMPLEXES OF PYRIDI

The ESR spectra of powdered samples of Cu(Ⅱ) complexes with pyridine and its sixhomologues and pyrrol, aniline, as well as their solutions are measured at 77K in this paper.The electronic levels of these complexes are calculated from the ESR spectral parameters.It is found that the non-pyridine ligands of complexes which can be substituted by pyridinemolecules of solvent in solution of pyridine/chloroform form Py_4Cu~(2 ). A molecular configura-tion is proposed. for Py_4Cu~(2 ) in solution. It is shown that the treatment with D_(2h) symmetryinstead of D_(4h) symmetry leads to a more satisfactory explanation of the ESR spectra.     

CRYSTAL STRUCTURES OF COPPER (Ⅱ) AND COBALT (Ⅲ) COM- PLEXES OF o-HYDROXYBENZYLGLYCINATE (HBG)

<正> The structures of two complexes C(CuOC6H4CH2NHCH2COO)2 (H2 O)]·H2P(1) and [Co(NH3)6[Co(OC6H4CH2NHCH2COO)2]2[C1]·10H2O (2) were determined by X-ray analyses. Compound (1) crystallizes in the orthorhombic space group P212121 with a=11. 357(1),b= 24. 304(2),c=7.317(4) A,Z= 4;While compound (2) in the monoclinic space group A2/a(C2/c) with a=23. 486(9) ,b=26. 605(6) ,c= 10. 542(1) A,γ= 128. 42(4)°,Z= 4. In compound (1),two Cu(Ⅱ) ions are bonded together by the phenolic oxygen atoms of two tridentate chelating ligands and each of them is separately coordinated by the carboxyl oxygen,amino nitrogen of each chelate ligand and by the fifth oxygen atom as well (from aqua or the carbonyl group in adjacent molecule). Thus the coordination of each Cu(Ⅱ) is a square pyramid with distances of 1. 93- 1. 97A to the four corner atoms and 2. 30 and 2. 32 A to the apex atoms. The whole molecule has an approximately planar configuratioir with the two pyramid apexes pointing towards one side. Compound (2) consists of     

Synthesis and catalytic activity of novel heteronuclear Ln(Ⅲ)-Cu(Ⅱ) complexes with noncyclic polyether-amino acid Schiff base

A series of novel heteronuclear Ln(Ⅲ)-Cu(Ⅱ) complexes with noncyclic polyether-amino acid Schiff base were synthesized. The general formula is [LnCu_2(H_2TALY)(NO_3)_5](NO_3)_2' nH_2O(Ln=La, Nd, Sm, Gd, n= 4; Ln=Yb, Y, n=3), where H_2TALY = tetraglycol aldehyde bis-lysine Schiff base. It is the first time to report the synthetic method for this new Cu(Ⅱ) complexes and Ln(Ⅲ)-Cu(Ⅱ) heteronuclear complexes. The complexes were characterized by elemental analysis, IR spectra, TG-DTA, magnetic susceptibility, and especially by a 500 MHz NMR spectrometer for 2D-COSY NMR. Coordination mechanism and structures of complexes have been suggested as well. Of particular interest is the potential that the novel complexes obtained may be used as a catalyst, which prompted us to investigate them. It shows 100% conversion with the viscosity-average molecular weight 120 000 for the polymerization of methyl methacrylate (MMA) without addition of any cocatalyst. Furthermore, the complexes with such aliphatic Schiff bas     

Synthesis and Magnetic Properties of Copper (Ⅱ) Complexes with Pyridine N-Oxide-2-ylmethy-lidenedithiocarbazate as Ligands

A series of copper (Ⅱ) complexes with pyridine N- oxide- 2- ylmethylidened-ithiocarbazates as ligands were synthesized and characterized by IR spectra, electronic spectra and magnetic moments measurement at room temperature. Variable temperature magnetic susceptibilites (3-300K) of four complexs were measured and fitted with the Bleaney-Bowers dimer equation by considering the magnetic interaction between molecules. The fitting results show the existence of intramolecular ferromagnetic interactions and intermolecu-lar anti-ferromagnetic interactions in these copper( Ⅱ) complexes.     

SYNTHESIS AND PROPERTIES OF POLYMERIC BIS (ETHYLENEDITHIO)-TETRATHIAFULVALENES

A polymer containing bis(ethylenedithio)-tetrathiafulvalene moiety wassynthesized and its electrochemical properties were studied by cyclic voltammetry. Thecharge transfer complexes of the polymer with TCNQ and I_2 were obtained by chemicaloxidation in dichlorobenzene. All of them are semi-conductors. A film of the polymer wasobtained by casting. Its conductivity, after oxidation with iodine, is 2.24×10~(-6)S·cm~(-1)and its conducting state is stable in air.