Spectra and structure of silicon containing compounds. XL. Infrared and Raman spectra, conformational stability, vibrational assignment and ab initio calculations of ethylmethylsilyl difluoride
作者:James R. Durig、Chunhua Pan、Gamil A. Guirgis
DOI:10.1016/s0022-2860(03)00341-7
日期:2003.8
constants, vibrational frequencies, infrared intensities, Raman activities and depolarization ratios, and energy differences have been obtained for the trans and gauche conformers from ab initio MP2/631G(d) calculations. Relatively complete vibrational assignments are proposed for both conformers based on the relative infrared and Raman spectral intensities, infrared band contours, depolarization ratios
摘要 记录了气态和固态的红外(3100-40 cm -1 )光谱和液态乙基甲基二氟化硅(CH 3 CH 2 SiF 2 CH 3 )的拉曼(3100-20 cm -1 )光谱。trans 和 gauche 构象异构体都已在流体相中被识别,但只有 trans 构象异构体保留在固体中。已经记录了溶解在液态氪中的乙基甲基二氟化硅的红外光谱的变温(-105 至 -150 °C)研究,并且已确定焓差为 20±4 cm -1 (0.24±0.05 kJ/mol) 与反式构象异构体更稳定。在环境温度下,估计存在 64±1% 的 gauche 构象异构体。几何参数、谐波力常数、振动频率、红外强度、拉曼活动和去极化率,已经从 ab initio MP2/631G(d) 计算中获得了反式和 gauche 构象异构体的能量差异。基于相对红外和拉曼光谱强度、红外波段轮廓、去极化率和法向坐标计算,对两种构象异构