乙胺价电子结构的电子动量谱学研究

Electron momentum spectroscopy study on valence electronic structures of ethylamine.

作者信息

Yan Mi, Shan Xu, Wu Fang, Xia Xuexin, Wang Kedong, Xu Kezun, Chen Xiangjun

机构信息

Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, China.

出版信息

J Phys Chem A. 2009 Jan 15;113(2):507-12. doi: 10.1021/jp808281w.

DOI:10.1021/jp808281w

PMID:19093860

Abstract

The valence-shell binding energy spectra and electron momentum profiles of gaseous ethylamine are measured by (e, 2e) electron momentum spectroscopy. When taking into account the Boltzmann-weighted abundance of 39% for trans and 61% for two equivalent gauche conformers coexisted in ethylamine, the thermally averaged electron momentum profiles for all valence orbitals calculated using B3LYP method with 6-311++G** and aug-cc-pVTZ basis sets reproduce the experimental ones well, which supports that the trans conformer is more stable. In addition, the controversial ordering of 2a'' and 7a' orbitals for the trans conformer is reassigned and an ionization band at about 13.7 eV, which was uncertain in previous literatures, is confirmed by comparing the experimental momentum profiles with the theoretical ones for the respective molecular orbitals. Furthermore, the ionization potentials and pole strengths for the inner valence orbitals are reported for the first time.

摘要

采用（e，2e）电子动量谱法测量了气态乙胺的价壳层结合能谱和电子动量分布。考虑到乙胺中反式构象异构体占39%、两个等效顺式构象异构体占61%的玻尔兹曼加权丰度，使用B3LYP方法和6-311++G**及aug-cc-pVTZ基组计算得到的所有价轨道的热平均电子动量分布与实验结果吻合良好，这支持了反式构象异构体更稳定的观点。此外，重新确定了反式构象异构体中2a''和7a'轨道存在争议的排序，并通过将实验动量分布与各个分子轨道的理论动量分布进行比较，证实了先前文献中不确定的约13.7 eV处的一个电离带。此外，首次报道了内价轨道的电离势和极强度。