气相中二氯苯的双电荷离子[C6H4CI2]^2+和[C6H3CI]^2+的动能谱研究

本文利用质量分析离子动能(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[C6H4CI2]^2+和[C6H4CI]^2+双电荷离子的单分子电荷分离(CS)反应。根据测定和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[C6H4CI2]^2+的分解反应区分二氯苯的位置异构体。

A study of ion kinetic energy spectrometry of o-, m-and p-dichloro benzene doubly charged ions [C6H4CI2]^2+ and [C6H4CI]^2+ in gas phase

The unimol. charge-sepn. reactions of the doubly charged ions [C6H4Cl2]2+, [C6H3Cl]2+ produced in the ion source by electron impact from o-, m-, and p-dichlorobenzene were studied using mass analyzed 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 Coulomb energy, it can be used to calculate the approx. distances R between the 2 charges immediately before decomposition of the ions. From these data, some structural information about transition states could be provided. The electron-capture-induced decomposition (ECID) and collision-induced dissociation (CID) processes of these ions were also studied. The CID reactions of (C6H4Cl2)2+ could be used to distinguish the 3 dichlorobenzene isomers.