Recoil energy distributions for dissociation of the van der Waals molecule p-difluorobenzene-Ar with 450-3000 cm-1 excess energy -: art. no. 104305
Recoil energy distributions for dissociation of the van der Waals molecule p-difluorobenzene-Ar with 450-3000 cm-1 excess energy -: art. no. 104305
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DOI：
10.1063/1.1858434
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发表时间：
2005-03-08
影响因子：
4.4
通讯作者：
Lawrance, WD
中科院分区：
文献类型：
--
作者：
Bellm, SM;Lawrance, WD
速度图成像已被用于测量对二氟苯- ar范德华配合物在（5(1)）过棒、（3(1)）过棒、（5(2)）过棒、（3(1)）过棒、（5(3)）过棒、（3(2)）过棒解离过程中释放的平动能的分布。这些状态跨越818-3317 cm（-1）的振动能量，对应于离解以上451-2950 cm（-1）的能量范围。平动能量释放（反冲能量）分布非常相似，在非常低的能量（10-20 cm(-1)）处达到峰值，在300 cm（-1）附近以指数方式衰减至接近零。释放的平均平动能很小，与初始振动能无关，所探测的振动能级范围在58-72 cm（-1）之间。研究的七个水平的平均值为63厘米（-1）。低比例的迁移转化为翻译在质量上符合尤因的动量差距模型[G。E. Ewing，法拉第讨论。73,325(1982)]。在分布中没有发现高能尾的证据，尽管实验可能不够灵敏，无法在高平动能量下检测到低比例的转移。释放的平均平动能比从三重态和正离子状态解离的类似系统所见的要低。
Velocity map imaging has been used to measure the distributions of translational energy released in the dissociation of p-difluorobenzene-Ar van der Waals complexes from the (5(1)) over bar, (3(1)) over bar, (5(2)) over bar, (3(1)5(1)) over bar, (5(3)) over bar, (3(2)) over bar states. These states span 818-3317 cm(-1) of vibrational energy and correspond to a range of energies above dissociation of 451-2950 cm(-1). The translational energy release (recoil energy) distributions are remarkably similar, peaking at very low energy (10-20 cm(-1)) and decaying in an exponential fashion to approach zero near 300 cm(-1). The average translational energy released is small, shows no dependence on the initial vibrational energy, and spans the range 58-72 cm(-1) for the vibrational levels probed. The average value for the seven levels studied is 63 cm(-1). The low fraction of transfer to translation is qualitatively in accord with Ewing's momentum gap model [G. E. Ewing, Faraday Discuss. 73, 325 (1982)]. No evidence is found in the distributions for a high energy tail, although it is likely that the experiment is not sufficiently sensitive to detect a low fraction of transfer at high translational energies. The average translational energy released is lower than has been seen in comparable systems dissociating from triplet and cation states.