Leung Helen O, Marshall Mark D, Stuart Devon J
Department of Chemistry, Amherst College, P.O. Box 5000, Amherst, Massachusetts 01002-5000, United States.
J Phys Chem A. 2020 Mar 5;124(9):1798-1810. doi: 10.1021/acs.jpca.0c00327. Epub 2020 Feb 21.
In common with the homologous 3,3-difluoro- and 3,3,3-trifluoro-species, 3-fluoro-1,2-epoxypropane is a small chiral molecule with a simple rotational spectrum, making it potentially useful for chiral analysis via conversion of enantiomers into spectroscopically distinct diastereomers through formation of noncovalently bound complexes. The rotational spectrum of 3-fluoro-1,2-epoxypropane (FO) and of its heterodimer with the argon atom are obtained, along with several isotopologues of each, using Fourier transform microwave spectroscopy from 5.6 to 18.1 GHz, and their structures determined. Surprisingly, the structure of 3-fluoro-1,2-epoxypropane-argon does not show a strong similarity to those previously determined for 3,3-difluoro-1,2-epoxypropane-argon and 3,3,3-trifluoro-1,2-epoxypropane-argon but instead is more analogous to that of propylene oxide-argon. Equilibrium structural parameters and mapped electrostatic potential surfaces obtained via quantum chemistry calculations are used in rationalizing this result.
与同源的3,3 - 二氟和3,3,3 - 三氟物种一样，3 - 氟 - 1,2 - 环氧丙烷是一种具有简单旋转光谱的小型手性分子，这使得它有可能通过将对映体转化为通过形成非共价结合复合物而具有光谱差异的非对映体来用于手性分析。利用5.6至18.1 GHz的傅里叶变换微波光谱法获得了3 - 氟 - 1,2 - 环氧丙烷（FO）及其与氩原子的异二聚体的旋转光谱，以及它们各自的几种同位素异构体，并确定了它们的结构。令人惊讶的是，3 - 氟 - 1,2 - 环氧丙烷 - 氩的结构与先前确定的3,3 - 二氟 - 1,2 - 环氧丙烷 - 氩和3,3,3 - 三氟 - 1,2 - 环氧丙烷 - 氩的结构没有很强的相似性，而是更类似于环氧丙烷 - 氩的结构。通过量子化学计算获得的平衡结构参数和映射的静电势表面被用于合理解释这一结果。
