Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, The Netherlands.
J Chem Phys. 2023 Apr 28;158(16). doi: 10.1063/5.0146754.
We study the vacuum ultraviolet (VUV) photodissociation dynamics of carbonyl sulfide (OCS) by using the time sliced velocity map ion imaging technique. Experimental images of the dissociative O (3PJ=0,1,2) products were acquired at five VUV photolysis wavelengths from 133.26 to 139.96 nm that correspond to the F Rydberg state of OCS. High vibrational states of the carbon monosulfide (CS) co-products are partially resolved in the images. The product total kinetic energy releases, angular distributions, and the product state branching ratios were derived from the experimental images. Notably, it is found that the anisotropic parameters change systematically with the photolysis wavelength. The anisotropic parameters and the product state branching ratios are significantly sensitive to the J quantum number of the O (3PJ) products. The phenomenon indicates that multiple nonadiabatic pathways are strongly involved in the photodissociation processes.
我们使用时间切片速度映射离子成像技术研究了羰基硫（OCS）的真空紫外（VUV）光解动力学。在对应于 OCS 的 F 里德堡态的 133.26 至 139.96nm 的五个 VUV 光解波长下，获得了离散的 O（3PJ=0,1,2）产物的实验图像。在图像中部分分辨出了碳一硫化物（CS）的高振动态产物。从实验图像中推导出了产物总动能释放、角分布和产物态分支比。值得注意的是，发现各向异性参数随光解波长系统地变化。各向异性参数和产物态分支比对 O（3PJ）产物的 J 量子数具有显著的敏感性。这一现象表明，在光解过程中涉及到多个非绝热途径。
