Wu Fang, Chen Xiangjun, Shan Xu, Tian Shan Xi, Li Zhongjun, Xu Kezun
Hefei National Laboratory for Physical Sciences at Microscale, Department of Modern Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
J Phys Chem A. 2008 May 8;112(18):4360-6. doi: 10.1021/jp710757y.
The valence-shell electron momentum distributions for 1-butene are measured by electron momentum spectroscopy (EMS) employing non-coplanar symmetric geometry. The experimental electron momentum distributions are compared with the density functional theory (DFT) calculations using different-sized basis sets. Although the two conformers of 1-butene in the gas phase, namely the skew and syn, have very close ionization potentials, the electron momentum distributions, especially in the low momentum region, can show prominent differences for some of the valence orbitals. By comparing the experimental electron momentum profiles with the theoretical ones, the skew conformer is found to be more stable than the syn and their relative abundances at room temperature are estimated to be (69 +/- 6)% and (31 +/- 6)%, respectively. It demonstrates that EMS has the latent potential to study the relative stability of conformers.
采用非共面对称几何结构的电子动量谱（EMS）测量了1-丁烯的价壳层电子动量分布。将实验得到的电子动量分布与使用不同大小基组的密度泛函理论（DFT）计算结果进行了比较。尽管气相中1-丁烯的两种构象异构体，即扭曲式和顺式，具有非常接近的电离势，但电子动量分布，特别是在低动量区域，对于一些价轨道可能会显示出显著差异。通过将实验电子动量分布与理论分布进行比较，发现扭曲式构象异构体比顺式更稳定，并且估计它们在室温下的相对丰度分别为(69±6)%和(31±6)%。这表明EMS在研究构象异构体的相对稳定性方面具有潜在能力。
