Imaging rotational energy transfer: comparative stereodynamics in CO + N 2 and CO + CO inelastic scattering
Imaging rotational energy transfer: comparative stereodynamics in CO + N 2 and CO + CO inelastic scattering
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旋转能量转移成像：CO N 2 和 CO CO 非弹性散射的立体动力学比较
DOI：
10.1039/d3cp02229c
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发表时间：
2023
影响因子：
3.3
通讯作者：
Parker, David H.
中科院分区：
文献类型：
--
作者：
Sun, Zhong-Fa;Scheidsbach, Roy J.;van Hemert, Marc C.;van der Avoird, Ad;Suits, Arthur G.;Parker, David H.
已经使用交叉分子束方法在用于先前公开的报告中描述的13 CO + CO旋转非弹性散射的运动学等效条件下研究了基态转振态13 CO分子与N2分子碰撞中的状态-状态旋转能量转移（Sun等人，Science，2020，369，307-309）。采用（1 + 1′ + 1′′）VUV共振增强多光子电离方案，结合速度图离子成像，对13 CO分子碰撞激发产物进行了探测。我们提出了微分截面和散射角分辨旋转角动量排列力矩提取实验测量的13 CO + N2散射图像，并比较它们与理论预测从准经典轨迹（QCT）上新计算的13 CO-N2势能面（PES）。实验和理论之间的一致性很好，这证实了13 CO-N2势能面对于实验研究的1460 cm−1碰撞能量的准确性。比较了~（13）CO + N_2与~（13）CO + CO碰撞的实验结果。角分辨的产品旋转角动量对齐时刻的两个散射系统是非常相似的，这表明，碰撞诱导的对齐动态观察到的两个系统是由硬壳性质为主。然而，与13 CO + CO测量相比，13 CO + N2的DCS中的主要彩虹最大值在更多的后向散射角处一致地达到峰值，并且次要最大值变得不那么明显，这意味着13 CO-N2 PES的各向异性较小。此外，前向散射组件与高旋转激发看到13 CO + CO没有出现在实验中的13 CO-N2，并没有预测的QCT理论。碰撞动力学行为中的一些差异可以通过两个系统的PES属性之间的比较来预测。更具体的行为也预测从13 CO + N2轨迹的相对碰撞几何形状的依赖性的分析相比，13 CO + CO轨迹，这表明特殊的'do-si-do'途径调用13 CO + CO是不有效的13 CO + N2碰撞。
State-to-state rotational energy transfer in collisions of ground ro-vibrational state 13CO molecules with N2 molecules has been studied using the crossed molecular beam method under kinematically equivalent conditions used for 13CO + CO rotationally inelastic scattering described in a previously published report (Sun et al., Science, 2020, 369, 307–309). The collisionally excited 13CO molecule products are detected by the same (1 + 1′ + 1′′) VUV (Vacuum Ultra-Violet) resonance enhanced multiphoton ionization scheme coupled with velocity map ion imaging. We present differential cross sections and scattering angle resolved rotational angular momentum alignment moments extracted from experimentally measured 13CO + N2 scattering images and compare them with theoretical predictions from quasi-classical trajectories (QCT) on a newly calculated 13CO–N2 potential energy surface (PES). Good agreement between experiment and theory is found, which confirms the accuracy of the 13CO–N2 potential energy surface for the 1460 cm−1 collision energy studied by experiment. Experimental results for 13CO + N2 are compared with those for 13CO + CO collisions. The angle-resolved product rotational angular momentum alignment moments for the two scattering systems are very similar, which indicates that the collision induced alignment dynamics observed for both systems are dominated by a hard-shell nature. However, compared to the 13CO + CO measurements, the primary rainbow maximum in the DCSs for 13CO + N2 is peaked consistently at more backward scattering angles and the secondary maximum becomes much less obvious, implying that the 13CO–N2 PES is less anisotropic. In addition, a forward scattering component with high rotational excitation seen for 13CO + CO does not appear for 13CO–N2 in the experiment and is not predicted by QCT theory. Some of these differences in collision dynamics behaviour can be predicted by a comparison between the properties of the PESs for the two systems. More specific behaviour is also predicted from analysis of the dependence on the relative collision geometry of 13CO + N2 trajectories compared to 13CO + CO trajectories, which shows the special ‘do-si-do’ pathway invoked for 13CO + CO is not effective for 13CO + N2 collisions.