Conformational stability of CH3CH2P(Z)F2(Z=O,S) from temperature dependent FT-IR spectra of rare gas solutions and ro structural parameters
作者:J.R. Durig、J.B. Robb、J. Xiao、T.K. Gounev
DOI:10.1016/s0022-2860(99)00194-5
日期:2000.1
Abstract Variable temperature (from −55 to −150°C) studies of the infrared spectra (3500–400 cm−1) of ethylphosphonic difluoride, CH3CH2P(O)F2 and ethylphosphonothioic difluoride, CH3CH2P(S)F2 dissolved in liquid xenon or krypton have been recorded. From these data, the enthalpy differences have been determined to be 76±9 cm−1(0.91±0.11 kJ/mol), for CH3CH2P(O)F2 with the trans conformer the more stable
摘要 乙基膦酰二氟化物 CH3CH2P(O)F2 和乙基硫代膦酰二氟化物 CH3CH2P(S)F2 溶解在液态氙或氪中的红外光谱 (3500–400 cm-1) 的变温(从 -55 到 -150°C)研究已被记录。根据这些数据,已确定焓差为 76±9 cm-1(0.91±0.11 kJ/mol),对于 CH3CH2P(O)F2,反式构象异构体更稳定,而 53±7 cm-1(0.63 ±0.08 kJ/mol) 对于 CH3CH2P(S)F2,但使用 gauche 构象异构体更稳定。两种分子都给出了完整的振动分配,这与从 ab initio MP2/6-31G(d) 计算中获得的预测频率一致。优化的几何形状、构象稳定性、谐波力场、红外强度、拉曼活动、和去极化率已从 RHF/6-31G(d) 和/或 MP2/6-31G(d) ab initio 计算中获得。在适当的时候将这些量与相应的实验量以