Structural and Conformational Studies of <i>N</i>,<i>N</i>-Dichloroethanamine and <i>N</i>,<i>N</i>-Dichloro-2-propanamine by Gas Electron Diffraction Combined with ab Initio Calculations
作者:Toru Egawa、Masataka Ohtsubo、Hideki Nakagawa、Nobuhiko Kuze、Hideo Fujiwara、Shigehiro Konaka
DOI:10.1021/jp993053f
日期:2000.2.1
The molecular structure and conformation of N,N-dichloroethanamine (EtNCl2, NDCEA) and N,N-dichloro-2-propanamine (i-PrNCl2, NDCPA) were studied by gas electron diffraction. The optimized structures and the force constants obtained by MP2/6-31G** ab initio calculations were used in the analyses. The force constants were scaled to reproduce the vibrational wavenumbers of the gas-phase infrared spectra
通过气体电子衍射研究了 N,N-二氯乙胺 (EtNCl2, NDCEA) 和 N,N-二氯-2-丙胺 (i-PrNCl2, NDCPA) 的分子结构和构象。通过 MP2/6-31G** 从头计算获得的优化结构和力常数用于分析。力常数被缩放以再现本研究中测量的气相红外光谱的振动波数。在室温下,NDCEA 存在于 C1 和 Cs 形式的构象平衡中,C1 构象异构体的丰度为 79 ± 9%。NDCPA 的 C1 丰度为 88 ± 12%。NDCEA 的 C1 构象异构体的结构参数(rg 和∠α)如下:r(N−C) = 1.479(6) A;r(C−C) = 1.542(7) A;〈r(N−Cl)〉 = 1.759(2) A; = 1.107(8) A; ∠N−C−C = 108.2(8)°;<∠C-N-Cl> = 108.2(3)°; ∠Cl−N−Cl = 106.9(2)°;φ C-C-N-Clg