Modeling kinetic shifts in threshold collision-induced dissociation. Case study: Dichlorobenzene cation dissociation
Modeling kinetic shifts in threshold collision-induced dissociation. Case study: Dichlorobenzene cation dissociation
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模拟阈值碰撞引起的解离的动力学变化。
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
P. Armentrout
中科院分区：
文献类型：
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作者：
F. Muntean;Lars V. Heumann;P. Armentrout
阈值碰撞诱导解离（CID）的邻位和帕拉异构体的二氯苯阳离子解离的研究进行。从头计算系统上进行调查的势能面相对于Cl原子损失的细节，并提供CID截面建模所需的分子参数。动力学位移对CID阈值测定的影响进行了研究，使用一个模型，结合统计单分子衰变理论。使用单分子解离速率常数作为早期的光电子-光离子-符合（PEPICO）实验提供的能量的函数的模型进行测试。CID模型中涉及的不同可能的参数集，它们对解离速率的影响，以及它们对最终CID阈值确定的影响进行了讨论。观察到一个紧密的过渡态比一个相空间限制松散的过渡态能更好地再现实验解离速率，这一结果与实验结果一致。
A threshold collision-induced dissociation (CID) study is performed on dichlorobenzene cation dissociation of both the ortho and para isomers. Ab initio calculations are performed on the system to investigate the details of the potential energy surface with respect to Cl atom loss and to provide the molecular parameters necessary for CID cross section modeling. The effects of kinetic shifts on the CID threshold determinations are investigated using a model that incorporates statistical unimolecular decay theory. The model is tested using unimolecular dissociation rate constants as a function of energy provided by earlier photoelectron–photoion-coincidence (PEPICO) experiments. The different possible sets of parameters involved in the CID model, their effect on the dissociation rates, and their effect on the final CID threshold determination are discussed. A tight transition state is observed to reproduce the experimental dissociation rates better than a phase-space limit loose transition state, a result a...