气相中二氯苯的双电荷离子[C_6H_4Cl_2]^(2+)和[C_6H_3Cl]^(2+)的动能谱研究

A Study of Ion Kinetic Energy Spectrometry of o-, m- and p-Dichloro Benzene Doubly Charged Ions [C_6H_4Cl_2]^(2+) and [C_6H_2Cl]^(2+) in Gas Phase

本文利用质量分析离子动能谱(MIKES)和碰撞诱导解离(CID)技术,研究了邻、间、对二氯苯分子在电子轰击质谱(EIMS)中产生的[C_6H_4Cl_2]^(2+)和[C_6H_3Cl]^(2+)双电荷离子的单分子电荷分离(CS)反应.根据测定的CS反应的动能释放值T和由此估算的反应过渡态的电荷间距的最小值R,推测过渡态的结构.有趣的是,可以利用双电荷离子[C_6H_4Cl_2]^(2+)的分解反应区分二氯苯的位置异构体.

The unimolecular Charge separation reactions of the doubly charged iona [C_6H_4Cl_2]^(2+), [C_6H_3Cl]^(2+) produced in the ion source by electron impact from o-, m-, and p-dichloro benzene have been studied using mass analysed ion kinetic energy spectrometry. The values of kinetic energy releases (T) can be calculated from the energy dispersion of product ions. As T essentially reflects the release of coulombic energy, which can be used to calculate the approximate distances R between the two charges immediately before decomposition of the ions. From these data, some structural information about transiton states could be provided. The ECID and OID processes of above doubly charged ions, have also been studied. We found that the OID reactions of (G_6H_4Cl_2)^(2+) could be used to distinguish three dichloro benzene isomers.