Theoretical study on HO2-initiated atmospheric oxidation of halogenated carbonyls

✍ Scribed by Bo Long; Zheng-Wen Long; Yi-Bo Wang; Wei-Jun Zhang; Chao-Yun Long; Shui-Jie Qin

• Book ID: 104577290
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 982 KB
• Volume: 112
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.23189

✦ Synopsis

Abstract

The initial reactions of HO~2~ with oxalyl dichloride, oxalyl dibromide, acetyl chloride, and acetyl bromide are studied for the first time using the density functional theory with CAM‐B3LYP and wB97XD, CBS‐QB3, and G3 theoretical methods and the transition state theory. The reactions occur via the similar mechanism that the prereactive complex is formed before the transition state and product. The calculated results demonstrate that the HO~2~ radical with ClC(O)C(O)Cl and BrC(O)C(O)Br reactions is feasible and could play a significant role in the atmosphere because the barriers are 0.13 kcal/mol, −0.05 kcal/mol with respect to the free reactants, respectively at the CBS‐QB3 level of theory. In addition, the rate constants of the HO~2~ + ClC(O)C(O)Cl and HO~2~ + BrC(O)C(O)Br reactions are computed to be 1.37 × 10^−15^ cm^3^ mol^−1^ s^−1^, 1.70 × 10^−15^ cm^3^ mol^−1^ s^−1^ at 298 K. However, the HO~2~ reactions with acetyl chloride and acetyl bromide are of no importance because of higher activated barrier and slower rate constant. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011