Photoabsorption and photoionization of chlorine dioxide
Photoabsorption and photoionization of chlorine dioxide
复制标题
二氧化氯的光吸收和光电离
DOI：
10.1021/j100106a007
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
H. Baumgaertel
中科院分区：
文献类型：
--
作者：
R. Flesch;E. Ruehl;K. Hottmann;H. Baumgaertel
二氧化氯在近紫外光下的光过程对高纬度地区，特别是南极洲的平流层光过程已变得非常重要。二氧化氯因其在近紫外光中的特定吸收截面而在其他吸收剂中被鉴定。二氧化氯的光化学对极地臭氧消耗的可能贡献最近已经被讨论。本文报道了二氧化氯(OCIO)的高分辨率光电子能谱和绝对(真空-紫外)吸收截面(6-25 eV)和离子碎裂。光电子能谱根据各种单重态和三重态阳离子的交换分裂效应以及与化学相关分子的比较来解释。真空-紫外吸收光谱显示不同的里德堡级数收敛到阳离子状态。这些Rydberg级数和它们的振动级数是由项值自变量、偶极子选择规则以及与光电子谱的比较来指定的。用光电离质谱计测量了OCIO的电离阈值和碎裂阈值。主要碎片是13.4 eV以上的ClO[sup+]。得到了生成热和键离解能等热力学数据。对于电子激发的中性分子，没有发现OClO[sup+]异构化的证据。参考文献54，更多？图6，表7。
Photoprocesses of chlorine dioxide in the near-UV have become highly important for stratospheric photoprocesses at high latitudes, especially in Antarctica. Chlorine dioxide has been identified among other absorbers because of its specific absorption cross section in the near-UV. Possible contributions of chlorine dioxide photochemistry to polar ozone depletion have been discussed recently. The high-resolution He I photoelectron spectrum and the absolute (vacuum-UV) absorption cross section (6-25 eV) as well as the ionic fragmentation of chlorine dioxide (OCIO) are reported. The photoelectron spectrum is interpreted in terms of exchange splitting effects of the various singlet and triplet cation states as well as by comparison to chemically related molecules. The vacuum-UV absorption spectrum shows different Rydberg series converging to the cation states. These Rydberg series and their vibrational progressions are assigned by term value arguments, dipole selection rules, and comparison with the photoelectron spectrum. Photoionization mass spectrometry is used for measurements of the ionization and fragmentation threshold of OCIO. The major fragment is ClO[sup +] which occurs above 13.4 eV. Thermomechanical data such as heats of formation and bond dissociation energies are derived. No evidence for isomerization of OClO[sup +] is found, as observed for the electronically excited neutral molecule. 54 refs.,more » 6 figs., 7 tabs.« less