Computational Studies on Metathetical and Redox Processes of HOCl in the Gas Phase. 1. Reactions with H, O, HO, and HO2

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2009-07, Vol.113 (30), p.8811-8817
• Main Authors: Xu, Z. F, Lin, M. C
• Format: Article
• Language: English
• Subjects: A: Molecular Structure, Quantum Chemistry, General Theory
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp905136h

The potential energy surfaces of four reactions including (a) HOCl + H, (b) HOCl + O, (c) HOCl + HO, (d) HOCl + HO2, have been studied by the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVDZ, CCSD(T)/aug-cc-pVTZ//CCSD/cc-pVDZ, and CCSD(T)/6-311+G(3df,2p)//BH&HLYP/6-311+G(3df,2p) levels of theory. For both HOCl + H and HOCl + O, the direct Cl-abstraction channels take place via the lowest energy barriers; for both HOCl + HO and HOCl + HO2, the lowest energy barrier channels are the indirect H-abstraction reactions by HO x (x = 1, 2) via long-lived reaction intermediates. The rate constants for the low barrier channels have been calculated in the temperature range 200−3000 K by statistical theory. The predicted rate constants for HOCl + H and HOCl + HO are in good agreement with experimental results whereas that for HOCl + O was found to be in disagreement with the majority of available experimental data, suggesting a need for further improvement in theory and/or experiment.