Theoretical Investigations on Mechanisms and Pathways of C(2)H(5)O(2) with BrO Reaction in the Atmosphere

In this work, feasible mechanisms and pathways of the C(2)H(5)O(2) + BrO reaction in the atmosphere were investigated using quantum chemistry methods, i.e., QCISD(T)/6-311++G(2df,2p)//B3LYP/6-311++G(2df,2p) levels of theory. Our result indicates that the title reaction occurs on both the singlet and triplet potential energy surfaces (PESs). Kinetically, singlet C(2)H(5)O(3)Br and C(2)H(5)O(2)BrO were dominant products under the atmospheric conditions below 300 K. CH(3)CHO(2) + HOBr, CH(3)CHO + HOBrO, and CH(3)CHO + HBrO(2) are feasible to a certain extent thermodynamically. Because of high energy barriers, all products formed on the triplet PES are negligible. Moreover, time-dependent density functional theory (TDDFT) calculation implies that C(2)H(5)O(3)Br and C(2)H(5)O(2)BrO will photolyze under the sunlight.