A valence photoelectron imaging investigation of chiral asymmetry in the photoionization of fenchone and camphor
A valence photoelectron imaging investigation of chiral asymmetry in the photoionization of fenchone and camphor
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DOI：
10.1002/cphc.200700748
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发表时间：
2008-02-22
期刊：
影响因子：
2.9
通讯作者：
Nahon, Laurent
中科院分区：
文献类型：
--
作者：
Powis, Ivan;Harding, Chris J.;Nahon, Laurent
利用光电子成像技术和圆偏振同步辐射研究了几种小茴香酮对映体的价电离光电子圆二色性。使用电子散射计算的结果的理论建模表明，所观察到的手性不对称的光电子角分布强烈依赖于最终状态的散射，并在用于这些计算的分子势的质量。然而，也观察到非常明显的依赖于电离发生的轨道。与以前获得的樟脑的类似结果的比较揭示了显着差异的PECD，即使当电离轨道本身基本上不受影响的甲基基团的取代位点的变化。PECD测量很容易区分这些分子，尽管它们非常相似的光电子光谱，证明PECD是一种结构敏感的探针。
Photoelectron circular dichroism (PECD) is investigated in the valence ionization of selected fenchone enantiomers using a photoelectron imaging technique and circularly polarized synchrotron radiation. Theoretical modelling of the results using electron scattering calculations demonstrates that the observed chiral asymmetry in the photoelectron angular distributions depends strongly upon the final state scattering, and upon the quality of the molecular potential used for these calculations. However, very pronounced dependence on the orbital from which ionization occurs is also observed. Comparison with analogous results previously obtained for camphor reveals striking differences in the PECD, even when the ionizing orbitals are themselves left substantially unaffected by the changes in methyl groups' substitution site. PECD measurements readily differentiate these molecules despite their very similar photoelectron spectra, demonstrating PECD to be a structurally sensitive probe.