Dissociation dynamics of methanol clusters following multiphoton ionization
Dissociation dynamics of methanol clusters following multiphoton ionization
复制标题
多光子电离后甲醇簇的解离动力学
DOI：
10.1021/j100348a031
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
A. Castleman
中科院分区：
文献类型：
--
作者：
S. Morgan;A. Castleman
在多光子电离(MPI)之后，中性甲醇团簇发生了众所周知的离子-分子反应，导致质子化团簇的产生。团簇离子的蒸发解离速率的测量范围从二聚体到MPI之后的21聚体。在初始电离事件后，根据蒸发系综模型，速率随时间呈递减趋势。电离后长时间测得的速率随团簇尺寸的增大呈现一致的趋势。这些发现与蒸发单分子解离的统计考虑是一致的。碰撞诱导解离截面一般随着尺寸的增大而增大；H{sup+}(CH{sub3}OH){sub3}的局部极小值的发现与其结构的预测是一致的。最后，通过单分子蒸发和碰撞诱导解离过程的组合，发现从一个小到H{sup+}(CH{sub3}OH){sub7}的团簇中损失了多达5个甲醇单体。
Following multiphoton ionization (MPI), neutral methanol clusters are found to undergo a well-known ion-molecule reaction which leads to the production of protonated clusters. Evaporative dissociation rates of the cluster ions are measured for sizes ranging from the dimer to the 21-mer following MPI. There is a general trend of the rates decreasing with time after the initial ionization event in accordance with the evaporative ensemble model. Rates measured at long times after ionization display a consistent trend of increasing with cluster size. These findings are shown to be in accord with statistical considerations of evaporative unimolecular dissociation. Collision-induced-dissociation cross sections are found to generally increase with size; the finding of a local minimum in the value for H{sup +}(CH{sub 3}OH){sub 3} is in agreement with predictions of its structure. Finally, through a combination of unimolecular evaporative and collision-induced-dissociation processes, as many as five methanol monomers are found to be lost from a cluster as small as H{sup +} (CH{sub 3}OH){sub 7}.