化学学报 ›› 2011, Vol. 69 ›› Issue (08): 919-924. 上一篇    下一篇

研究论文

碰撞能对O(1D)+HBr→OH+Br反应的极化分布的影响

金坤,许雪松*,尹淑慧,李磊   

  1. (大连海事大学物理系 大连 116026)
  • 投稿日期:2010-07-29 修回日期:2010-11-03 发布日期:2010-11-15
  • 通讯作者: 许雪松 E-mail:xuxuesong@dlmu.edu.cn
  • 基金资助:

    辽宁省教育厅高等学校科研计划项目;辽宁省博士科研启动基金项目;中央高校基本科研业务费专项基金

Effects of Collision Energy to Polarization Distribution of O(1D)+HBr→OH+Br Reaction

JIN Kun, XU Xue-Song, YIN Shu-Hui, LI Lei   

  1. (Department of Physics, Dalian Maritime University, Dalian 116026)
  • Received:2010-07-29 Revised:2010-11-03 Published:2010-11-15

运用准经典轨线法结合Peterson从头计算势能面, 在碰撞能分别为20.9, 41.80和66.88 kJ/mol时, 对放热反应O(1D)+HBr (v=0, j=0)→OH+Br (DH=-252.89 kJ/mol)进行了细致的立体动力学性质研究. 反映kj 两矢量相关的函数P(θr)的分布表明产物分子的转动角动量j 在垂直于反应物相对速度矢量k的方向上有强烈的取向分布, 且随碰撞能的变化比较明显|反映k, k j 三矢量相关的函数 的分布表明产物转动角动量j 不仅有沿着y轴的取向效应, 还有沿着y轴正向的弱定向效应, 且这种弱定向效应随碰撞能的增加有所减弱|描述产物转动角动量j 的空间分布函数 在(90°, 90°)和(90°, 270°)两处有两个明显的分布, 随着碰撞能的增加, 这两个集中分布越来越密集, 碰撞能对该分布有一定的影响. 产物分子的极化主要集中在垂直于散射面的平面内. 除此之外, 极化微分反应截面(PDDCSs)给出了反应产物的散射方向.

关键词: O(1D)+HBr, 准经典轨线方法, 矢量相关, 立体动力学

Theoretical studies of the stereodynamics for the exoergic reation O(1D)+HBr→OH+Br have been carried out using the quasi-classical trajectory method on the ab initio global potential energy surface at three collision energies (20.90, 41.80 and 66.88 kJ/mol). The distribution P(θr) of angle between k and j shows that the rotational angular momentum polarization of the product molecule is quite strong and sensitive to increasing collision energy. The function which reflecting the angle distribution of three vectors correlation k-k -j indicates that j is not only aligned, but also oriented preferentially along the positive direction of the y-axis. With the increasing collision energy the orientation becomes weaker and weaker. There are two obvious distributions at (90°, 90°) and (90°, 270°) for the product rotational angular momentum , and the two distributions become intensive with the increase of collision energy, so the collision energy plays an important role in the distribution for the title reaction. The two distributions indicate that the product molecule is preferentially polarized perpendicular to scattering plane. In addition, the polarization dependent generalized differential cross-sections show the scattering direction of the product.

Key words: O(1D)+HBr, quasi-classical trajectory method, vector correlations, stereodynamics

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