Tang Y, Lu C, Sun J, Shao Y, Gao Y, Fu Z. Computational investigations on the HO
2 + CHBr
2O
2 reaction: mechanisms, products, and atmospheric implications.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019;
26:2345-2352. [PMID:
30467745 DOI:
10.1007/s11356-018-3767-3]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/14/2018] [Indexed: 06/09/2023]
Abstract
Using quantum chemistry methods, mechanisms and products of the CHBr2O2 + HO2 reaction in the atmosphere were investigated theoretically. Computational result indicates that the dominant product is CHBr2OOH + O2 formed on the triplet potential energy surface (PES). While CBr2O + OH + HO2 produced on the singlet PES is subdominant to the overall reaction under the typical atmospheric condition below 300 K. Due to higher energy barriers surmounted, other products including CBr2O2 + H2O2, CBr2O + HO3H, CH2O + HO3Br, CHBrO + HO3 + Br, and CHBr2OH + O3 make minor contributions to the overall reaction. In the presence of OH radical, CHBr2OOH generates CHBr2O2 and CBr2O2 + H2O subsequently, which enters into new Br-cycle in the atmosphere. The substitution effect of alkyl group and halogens plays negligible roles to the dominant products in the RO2 + HO2 (X = H, CH3, CH2OH, CH2F, CH2Cl, CH2Br, CH2Cl, and CH2Br) reactions in the atmosphere.
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