摘要:

The character of the photo-induced metastable state is investigated via molecular-orbital calculation. The anisotropic g-factor and the hyperfine coupling constants are simulated based on the extended-Hückel calculation. The most plausible environment around the metastable PtIIIis found to be a spin-soliton like state, whose spin-orbital mainly comprises one platinum and one chlorine atoms. The vibration mode of the elemental unit of the complex is calculated for both high- and low-temperature structures employing a density-functional method.

ISSN:1058-725X    

DOI:10.1080/10587250008038257

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

New quasi-one-dimensional halogen-bridged platinum binuclear mixed-valence compounds, A4[Pt2(pop)4I]·nH2O (A=alkaline metal and NH4, and; n=0, 2 and 4) have been synthesized. The Li, Na and K compounds take structures -Pt2.5+-Pt2.5+-X-Pt2.5+-Pt2.5+-X- (a). On the other hand, the Cs and Rb compounds take structures …Pt2+-Pt2+…X-Pt3+-Pt3+-X… (b). Interestingly, the NH4compound takes a phase transition between (a) and (b) around 200K.

ISSN:1058-725X    

DOI:10.1080/10587250008038258

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The synthesis and characterization of hexametallic host molecules is described. The new molecules utilize 2,2′-bipyrimidine to bridge rhenium(I) tricarbonyls at three points along the short edge of the cavity, and triply functional pyridine-based ligands (2,4,6-tripyridyl-1,3,5-triazine or 1,3,5-tris(4-ethynylpyridyl)benzene) as a top and bottom. Modeling has been done to determine the volumes of the cavities and the sizes of the entry ports for the host molecules.

ISSN:1058-725X    

DOI:10.1080/10587250008038259

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A hyperbranched polymer constructed by platinum-acetylide units has been synthesized by self polycondensation of a dinuclear platinum complex having one terminal acetylene and two platinum-chloride groups as an AB2monomer in the presence of a copper catalyst in amine. The hyperbranched polymer is soluble in common organic solvents and characterized by means of spectral analyses and GPC.

ISSN:1058-725X    

DOI:10.1080/10587250008038260

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The synthesis, characterization and the magnetic properties of MIIX2, CoII5(OH)8X2·nH2O, and MII2(OH)3X·nH2O, where M = Cu, Ni or Co and X = N(CN)2or C(CN)3, are reported. Long range ferromagnetic magnetic ordering is observed for MII(N(CN)2)2, M = Ni and Co and for NiII2(OH)3X·nH2O, while CoII5(OH)8X2·nH2O exhibits ferrimagnetism. Short range ferromagnetic interaction is observed for CoII(C(CN)3)2and antiferromagnetic for NiII(C(CN)3)2. The copper compounds behave as paramagnets with small antiferromagnetic exchange interaction. The magnetic hardness spans the range of coercive fields from 400 to 12000 Oe at 2 K.

ISSN:1058-725X    

DOI:10.1080/10587250008038261

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

1-D system:Copper(II) complex with pentadentate strand-type ligand involving two imidazole groups exhibits a self-complementary double-faced H-bonding recognition and enantioselective self-assembly behavior. The mono-deprotonated complex includes one imidazole and one imidazolate moiety, and due to the spiral arrangement of the acyclic ligand, inducesC(clockwise) andA(anticlockwise) enantiomers. The complex functions as chiral building component and aggregates into …CCCC… and …AAAA… homochiral 1D zigzag-chains, owing to hydrogen-bonding between the imidazole and imidazolate groups of adjacent homochiral units.

ISSN:1058-725X    

DOI:10.1080/10587250008038262

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Heat capacity is very sensitive to the change in the long- and short-range order effects, which crucially depend on lattice dimensionality and spin-spin interaction. Dimensional crossover is often encountered in actual molecule-based or metal-assembled magnets and thus phase transitions due to the spin ordering may occur at low temperatures even for low-dimensional magnets. The important factor governing the short-range order effect due to magnetic fluctuation is the number of the nearest neighbor magnetic ions as well as the lattice dimensionality.

ISSN:1058-725X    

DOI:10.1080/10587250008038263

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Rhodium(II) benzoate bridged by pyrazine derivatives occlude a large amount of N2gas, reversibly. The maximum amounts of the occluded N2were 1.8, 1.7, 0.5, 0.1, 1.3, and 1.3 mol per one mole of rhodium(II) salt with 2-methylpyrazine, 2,3-dimethylpyrazine, quinoxaline, 1,5-naphthyrizine, and triethylenediamine, respectively, indicating the presence of a large number of micropores in these rhodium(II) carboxylates. The porous structure which is formed by the self-assembly of linear rhodium(II) benzoate-pyrazine derivatives was deduced by analogy to the structure of rhodium(II) benzoate-pyradine reported previously.

ISSN:1058-725X    

DOI:10.1080/10587250008038264

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The bis-μ-dicarboxylate ruthenium (II,III) complexes, Ru (II,III)2L2Br (L=trans-O2C-CH═CH-CO2(1),trans-trans-O2C-CH═CH-CH═CH-CO2(2), and p-O2C-C6H4-CO2(3)), were prepared and their gas-occlusion properties were measured. The effective magnetic moments at room temperature are in the range 3.76 and 4.02 BM per dinuclear, consistent with the values of Ru(II)-Ru(III) compounds. All these complexes are capable of occluding a large amount of gas. The maximum amounts of occluded nitrogen for1-3are 0.6, 0.9, and 1.4 moles per one mole of ruthenium atoms, respectively. These amounts are almost the same as those of the correspondent chloride complexes. This suggests that bromide complexes1-3would form a highly similar capillary structure to that of ruthenium (II,III) dicarboxylate bridged by chloride atoms.

ISSN:1058-725X    

DOI:10.1080/10587250008038265

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

New coordination polymers of copper(II) and copper(I), [Cu(tfa)2(pyz)2]n(Htfa = trifluoroacetic acid, pyz = pyrazine) (1), [Cu2(tfa)2(CH3O)2-(pyz)2]n(2), and [Cu2(tfa)2(pyz)3]n(3), have been synthesized and characterized structurally. The crystal structure of2consists of methoxo-bridged dinuclear copper(II) units which are connected by pyrazine molecules to form a two-dimensional network. The crystal structure of3shows a two-dimensional net-like structure, where each copper(I) atom has a distorted tetrahedral arrangement. The magnetic property of2is antiferromagnetic.

ISSN:1058-725X    

DOI:10.1080/10587250008038266

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor