飞行时间质谱仪中Ni^+与酯分子束流的气相反应及机理

Gas Phase Reactions of Ni^+ With Molecular Flows of Esters and Their Mechanism in the Time-of-Flight Mass Spectrometer

在一个石英反应室内，让激光解离的Ｎｉ＋与连续喷入的酯类化合物分子束流反应， 生成的产物离子经飞行时间质谱仪检测，研究了Ｎｉ＋与乙酸乙酯、乙酸丙烯酯、乙酸乙烯酯、 乙酸丁酯的气相反应。根据如下机理满意地解释了发生的反应：（１）Ｎｉ＋与酯形成激发态络合 物；（２）β－Ｈ迁移至烃氧基的氧上形成Ｎｉ＋的双配体化合物离子；（３）失去一中性配体分子得 Ｎｉ＋的单配体化合物离子。由酯的 Ｈ离和Ｄ（Ｎｉ＋－Ａ）（Ａ为配体）可推测产物离子和它们的相 对强度。

In a small quartz cell, reactions of laser ablated Ni+ with molecular flows of CH3COOC2H5, CH3COOCH=CH2,CH3COOCH=CHCH3 and CH3COOBu-n have been studied in the gas phase and their products were detected by the time of flight-mass- spectrometer. All reactions can be explained reasonally by the following mechanism=(l)The formation of Ni+-ester activated complex; (2) A hydrogen shift onto alkoxy oxygen from β position of one of the alkyl groups to produce two fragments bound to Ni+;(3) The competitive dissociation to lead to product ions and neutral molecules. The product ions and their relative intensities were determined by the values of Hdiss and D(Ni+-A).