Theoretical study of gas phase reactions of important SOA intermediates: (cis- and trans-) BEPOX and β-IEPOX with OH radical

摘要

Mechanisms for hydroxide radicals reacting with 2,3-epoxy-1,4-butanediol (BEPOX) and 2-methyl-2,3-epoxy-1,4-butanediol (β-IEPOX) in the gas phase are investigated using quantum chemistry computations. Geometries of all the structures are optimized at the X3LYP/6-31+g(d,p) level. The ground-state energy for each structure is then refined at the CCSD(T)/6-31+g(d,p) level. All possible reaction paths for BEPOX and β-IEPOX are analyzed. The results show that during BEPOX and β-IEPOX gas phase reactions, hydrogen abstractions on C_(chain)-H are the most energetically favorable reaction paths (S3, S7) while the addition reactions (S6, S9) are not likely to occur. The present theoretical study is consistent with previous experimental results.