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2 Polish Journal of Chemistry

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Influence of Vibration Changes on Jahn-Teller Distortion in [Fe(H2O)6]2+ and [Fe(NO)(H2O)5]2+

Sun H. T., Li Y. M., Wang Z. Z., Su C. F., Zhou Z. Y., Tang K.

Polish Journal of Chemistry

2009

Vol. 83, nr 2

303-313

Density functional theory (DFT) calculation and vibrational modes have been reported for the ferrous hexaaquo ions and ferrous cinqueaquo nitrosyl ions, using B3LYP gradient-corrected density functionals at standard 6-31+G(d) basis. The effect of hydrogen bonding in solvents has been influenced by polarizable continuum models (PCM). The optimized structures predict an abnormal FeO6 octahedron for Fe(H2O)6]2+ reflect ing a Jahn-Teller distortion with the H2O molecules lying in the FeO4 plane in vacuo. In [Fe(NO)(H2O)5]2+, the Jahn-Teller distortion is more evident and the H2O molecules are pushed from the FeO4 plane. Then compared with the PCM methods, the Jahn-Teller distortion has been found to strengthen in the polarizable continuum model. Moreover, with the investigation of the vibrational mode and occupied orbital, we have found that the Jahn-Teller distortion has stronger influence on nitrosyl group than on H2O molecules.

Synthesis, characterization and magnetism of tetracarboxylato-bridges dinuclear nickel(II) complexes

Yan C.W., Li Y.T., Sun H.T., Liao D.Z.

Polish Journal of Chemistry

1998

Vol. 72, nr 9

2045-2051

Five new tetracarboxylato-bridges dinuclear nickel(II) complexes of the formula [Ni2(PMTA)L4], where L denotes 4,7-diphenyl-1,10-phenanthroline (Ph2-phen); 2,9-dimethyl-1,10-phenanthroline (Me2-phen); diaminoethane (en); 1,3-diaminopropane (pn) and 1,2-diaminopropane (ap); and PMTA represents the tetraanion of pyromellitic acid, have been synthesized and characterized by elemental analyses, molar conductivity and room temperature magnetic moment measurements, and by spectroscopy. It is proposed that these complexes have PMTA-bridged structures and consist of two nickel(II) ions in a distorted octahedral environment. The complexes [Ni2(PMTA)(Ph2-phen)4] (1) and [Ni2(PMTA)(Me2-phen)4] (2) were further characterized by variable temperature magnetic susceptibility measurements (4-300 K) and the observed data were treated in terms of two theoretical models, givinh the exchange integrals J=-2.85 cm(-1) for (1) and -1.96 cm(-1) for (2). The result indicates that there is very weakly antiferromagnetic spin-exchange intraction between two the Ni(II) ions within each molecule.