通过D̃(A)电子态研究HO和DO的光解离动力学。

Photodissociation dynamics of HO and DO via the D[combining tilde](A) electronic state.

作者信息

Chang Yao, Zhou Jiami, Luo Zijie, Chen Zhichao, He Zhigang, Yu Shengrui, Che Li, Wu Guorong, Wang Xingan, Yuan Kaijun, Yang Xueming

机构信息

Department of Chemical Physics, School of Chemistry and Materials Science, University of Science and Technology of China, Jinzhai Road 96, Hefei, Anhui 230026, P. R. China.

出版信息

Phys Chem Chem Phys. 2020 Feb 28;22(8):4379-4386. doi: 10.1039/c9cp05321b. Epub 2020 Jan 6.

DOI:10.1039/c9cp05321b

PMID:31904071

Abstract

Photodissociation dynamics of HO and DO via the D[combining tilde] state by one-photon excitation have been investigated using the H/D atom Rydberg tagging time-of-flight technique. The TOF spectra of the H/D-atom product in both parallel and perpendicular polarizations have been measured. Product translational energy distributions and angular distributions have been derived from TOF spectra. By simulating these distributions, quantum state distributions of the OH/OD product as well as the state-resolved angular anisotropy parameters were determined. The most important pathway of HO/DO dissociation via the D[combining tilde] state leads to highly rotationally excited OH/OD(X, v = 0) products, while vibrationally excited OH/OD products with v≥ 1 comprise only one third of the total OH/OD(X) population. The branching ratios of OH(A)/OH(X) and OD(A)/OD(X) have also been determined, 1.0/3.0 for HO at 122.12 nm and 1.0/2.2 for DO at 121.95 nm, which are reasonably consistent with the values predicted by the previous theory.

摘要

利用氢/氘原子里德堡标记飞行时间技术，研究了通过单光子激发经由D[波浪线组合]态的HO和DO的光解离动力学。测量了平行和垂直偏振下氢/氘原子产物的飞行时间光谱。从飞行时间光谱中导出了产物平动能分布和角分布。通过模拟这些分布，确定了OH/OD产物的量子态分布以及态分辨角各向异性参数。经由D[波浪线组合]态的HO/DO解离的最重要途径导致产生高度转动激发的OH/OD(X, v = 0)产物，而v≥1的振动激发的OH/OD产物仅占总OH/OD(X)总数的三分之一。还确定了OH(A)/OH(X)和OD(A)/OD(X)的分支比，在122.12 nm处HO为1.0/3.0，在121.95 nm处DO为1.0/2.2，这与先前理论预测的值合理一致。