Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom.
J Chem Phys. 2010 Mar 14;132(10):104311. doi: 10.1063/1.3352549.
Spectra of triply charged carbon disulphide have been obtained by measuring, in coincidence, all three electrons ejected in its formation by photoionization. Measurements of the CS(2)(3+) ion in coincidence with the three electrons identify the energy range where stable trications are formed. A sharp peak in this energy range is identified as the (2)Pi ground state at 53.1+/-0.1 eV, which is the lowest electronic state according to ab initio molecular orbital calculations. Triple ionization by the double Auger effect is provisionally divided, on the basis of the pattern of energy sharing between the two Auger electrons into contributions from direct and cascade Auger processes. The spectra from the direct double Auger effect via S 2p, S 2s, and C 1s hole states contain several resolved features and show selectivity based on the initial charge localization and on the identity of the initial state. Triple ionization spectra from single Auger decay of S 2p-based core-valence states CS(2)(2+) show retention of the valence holes in this Auger process. Related ion-electron coincidence measurements give the triple ionization yields and the breakdown patterns in triple photoionization at selected photon energies from 90 eV to above the inner shell edges.
三重态二硫化碳的光谱是通过测量其光致电离形成时所有三个被逐出的电子而获得的。与三个电子同时测量 CS(2)(3+)离子，确定了稳定三价离子形成的能量范围。在这个能量范围内，一个尖锐的峰被确定为（2）Pi 基态，其能量为 53.1+/-0.1 eV，这是根据从头算分子轨道计算得出的最低电子态。根据两个俄歇电子之间的能量分配模式，双俄歇效应的三重电离被暂时分为直接和级联俄歇过程的贡献。通过 S 2p、S 2s 和 C 1s 空穴态的直接双俄歇效应产生的光谱包含几个可分辨的特征，并基于初始电荷定位和初始态的身份表现出选择性。来自 S 2p 基芯价态 CS(2)(2+)的单俄歇衰变的三重电离光谱显示，在这个俄歇过程中，价电子空穴得以保留。相关的离子-电子符合测量给出了在选定的光子能量范围内，从 90 eV 到内壳边缘以上，三重光致电离的三重电离产率和击穿模式。
