Global dynamical analysis of vibrational manifolds of HOCl and HOBr under anharmonicity and Fermi resonance:the dynamical potential approach

The vibrational dynamics of HOCl and HOBr between bending and OCl/OBr stretching coordinates with anharmonicity and Fermi coupling is studied with the classical dynamical potential approach. The quantal vibrational dynamics is mostly mapped out by the classical nonlinear variables such as fixed points, except for the state energies, which are quantized. This approach is global in the sense that the focus is on a set of levels instead of individual ones. The dynamics of HOBr is demonstrated to be less complicated. The localized modes along the OCl/OBr stretching coordinates are also shown to have O-Br bonds more prone to dissociation.     

氧与次溴酸反应理论研究

用密度函数理论(DFT)对氧原子与次溴酸HOBr在势能面上的反应进行了研究,用B3LYP方法计算了势能面上各驻点物种的参数、能量等.结果表明:O与HOBr在势能面上有两个通道,简单可概括为摘H和摘Br反应,两通道的产物相同,均为HO、BrO.计算出反应热为42.3kJ/mol,根据等链反应特点,得到HOBr的生成热为-41.4kJ/mol.     

Studies of Atmospherically Relevant Reactions Using Differentially Pumped Mass Spectrometer and Fourier Transform Infrared Spectroscopy

This article describes recent studies of atmospherically relevant reactions using spectroscopic techniques by our group at the Wadsworth Center. Heterogeneous reactions of SO₂ with either HOBr or HOCl on ice have been studied using a coated-wall flow reactor coupled with differentially pumped quadrupole mass spectrometer, and the reaction of NO₂+HI has been investigated using Fourier transform infrared spectroscopy (FTIR). Reaction probabilities or rate constants have been determined at relevant atmospheric temperatures. Specular reflection-absorption infrared spectroscopy and the temperature programmed desorption technique were employed to study the adsorption of oxalic acid on a Cu surface at 175 K. Reflection-absorption infrared spectroscopy showed that oxalic acid is molecularly adsorbed on the Cu surface. The results obtained from these studies provide a better understanding of atmospheric reactions at a molecular level and enable an assessment of the relative importance of the reactions in the atmosphere.     

Global dynamical analysis of vibrational manifolds of HOCl and HOBr under anharmonicity and Fermi resonance: the dynamical potential approach

The vibrational dynamics of HOCl and HOBr between bending and OCl/OBr stretching coordinates with anharmonicity and Fermi coupling is studied with the classical dynamical potential approach. The quantal vibrational dynamics is mostly mapped out by the classical nonlinear variables such as fixed points, except for the state energies, which are quantized. This approach is global in the sense that the focus is on a set of levels instead of individual ones. The dynamics of HOBr is demonstrated to be less complicated. The localized modes along the OCl/OBr stretching coordinates are also shown to have O--Br bonds more prone to dissociation.