Darkhalil Ikhlas D, Paquet Charles, Waqas Mohammad, Gounev Todor K, Durig James R
Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
Department of Chemistry, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 5;136 Pt A:42-50. doi: 10.1016/j.saa.2014.01.039. Epub 2014 Jan 24.
Variable temperature (-60 to -100 °C) studies of ethyldichlorophosphine, CH3CH2PCl2, of the infrared spectra (4000-400 cm(-1)) dissolved in liquid xenon have been carried out. From these data, the two conformers have been identified and the enthalpy difference has been determined between the more stable trans conformer and the less stable gauche form to be 88±9 cm(-1) (1.04±0.11 kJ/mol). The percentage of abundance of the gauche conformer is estimated to be 57% at ambient temperature. The conformational stabilities have been predicted from ab initio calculations by utilizing many different basis sets up to aug-cc-pVTZ for both MP2(full) and density functional theory calculations by the B3LYP method. Vibrational assignments have been provided for both conformers which have been predicted by MP2(full)/6-31G(d) ab initio calculations to predict harmonic force fields, wavenumbers of the fundamentals, infrared intensities, Raman activities and depolarization ratios for both conformers. Estimated r0 structural parameters have been obtained from adjusted MP2(full)/6-311+G(d,p) calculations. The results are discussed and compared to the corresponding properties of some related molecules.
已对溶解于液态氙中的乙基二氯膦（CH₃CH₂PCl₂）进行了变温（-60至-100°C）红外光谱（4000 - 400 cm⁻¹）研究。根据这些数据，已识别出两种构象异构体，并确定了较稳定的反式构象异构体与较不稳定的 gauche 构象之间的焓差为88±9 cm⁻¹（1.04±0.11 kJ/mol）。估计在环境温度下，gauche 构象异构体的丰度百分比为57%。已通过从头算计算预测了构象稳定性，在MP2（全）和密度泛函理论计算（采用B3LYP方法）中，使用了多达aug-cc-pVTZ的许多不同基组。已为两种构象异构体提供了振动归属，这两种构象异构体已通过MP2（全）/6 - 31G(d)从头算计算进行预测，以预测两种构象异构体的谐振力场、基频波数、红外强度、拉曼活性和去极化率。已从经调整的MP2（全）/6 - 311 + G(d,p)计算中获得估计r0结构参数。对结果进行了讨论，并与一些相关分子的相应性质进行了比较。
