Synthesis, Molecular Structure, and EPR Analysis of the Three-Coordinate Ni(I) Complex [Ni(PPh3)3][BF4]

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• 作者：V. V. Saraev ; P. B. Kraikivskii ; I. Svoboda ; A. S. Kuzakov ; R. F. Jordan
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：December 4, 2008
• 年：2008
• 卷：112
• 期：48
• 页码：12449-12455
• 全文大小：218K
• 年卷期：v.112,no.48(December 4, 2008)
• ISSN：1520-5215

文摘

The compound [Ni(PPh₃)₃][BF₄]·BF₃·OEt₂ was isolated in crystalline form from the olefin oligomerization catalyst system Ni(PPh₃)₄/BF₃·OEt₂ and structurally characterized by X-ray diffraction. The influence of vibronic coupling on the EPR parameters of three-coordinate metal complexes with a 3d⁹ electronic configuration was investigated within the framework of ligand field theory. Analytical expressions for g-tensor components and isotropic hyperfine coupling constants with ligand nuclei were obtained using first-order perturbation theory. It has been shown that the account of the vibronic interaction in the excited state predicts the existence of three-axial anisotropy of the g-tensor even at the level of first-order perturbation theory; two axes of the g-tensor located in a plane of three-coordinate structure can rotate about the main z axis when a compound is distorted by motion of ligands. It has been shown that in three points of the potential energy surface minimum, for which linear and quadric constants of the vibronic interactions have an identical signs, the HFS isotropic constant from one ligand is larger than HFS constants from the other two; for different vibronic constant signs the ratio between HFS constants varies on opposite. This theoretical researches are in the quality consent with experimental data for a three-coordinate Ni(I) and Cu(II) flat complexes.