氯代甲苯双电荷离子的单分子解离反应研究

研究了在70 eV电子轰击电离条件下，氯代甲苯及氯化苄产生的双电荷离子[C_7H_7Cl]~(2＋)、[C_7H_6Cl]~(2＋·)和[C_7H_5Cl]~(2＋)为母体的两种类型单分子解离反应．主要讨论了亚稳双电荷离子的异构化反应、失H解高的“偶电子规则”以及单分子电荷分离过渡态的结构．

A Study on the Unimolecular Decomposition of the Doubly Charged Ions Produced from 4 Chloro-toluene Isomers

The unimolecular charge separations and neutral loss decompositions of the doubly charged ions [C_7H_7Cl]~(2+), [C_7H_6Cl]~(2+·) and [C_7H_5Cl]~(2+) produced in the ion source by 70 eV electron impact from 3 chloro-toluenes and benzyl chloride isomers were studied using MIKES. The isomerizations for these ions are prior to the decompositions, which make the MIKES for 4 isomers almost identical. The ejections of H depend on whether the parent ion is an odd-electron or an even-electron ion. The even-electron doubly charged ions can only decompose to even-electron fregments by loss of even-number of H atoms, and we called the phenomena as even-electron rule. The structures of the transition states for charge separations are usually different from the structures of neutral molecules. Several structures were discussed based on the values of the kinetic energy releases (T) during the charge separation processes.