Conformations of Organophosphine Oxides

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• 作者：Nuwan De Silva ; Federico Zahariev ; Benjamin P. Hay ; Mark S. Gordon ; Theresa L. Windus
• 刊名：Journal of Physical Chemistry A
• 出版年：2015
• 出版时间：August 13, 2015
• 年：2015
• 卷：119
• 期：32
• 页码：8765-8773
• 全文大小：536K
• ISSN：1520-5215

文摘

The conformations of a series of organophosphine oxides, OP(CH₃)₂R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P鈥揅 bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 force field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes鈥攁n essential part of understanding the chemistry of these compounds. The predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH₂CH₃)₃, and triphenylphosphine oxide, OP(Ph)₃.