Theoretical investigations on mechanisms and kinetics of the CH3CFClO2· with ClO· reaction in the atmosphere.

ABSTRACT: The singlet and triplet potential energy surfaces of the ClO• radical reaction with the CH3CFClO2• radical have been investigated at the CCSD(T)/cc-pVTZ level based on the optimized geometries at the B3LYP/6-311++G(d,p) level. On the singlet potential energy surfaces (PES), the possible reaction involves association-dissociation, direct H-abstraction and Nucleophilic Substitution 2 (SN2) mechanisms. On the triplet PES, SN2 displacement and direct H-abstraction reaction pathways have been investigated, which are less competitive compared with the reaction pathways on the singlet PES. The rate constants have been calculated at 10-10 to 1010 atm and 200-3,000 K by Rice-Ramsperger-Kassel-Marcus (RRKM) theory for the important product pathways. At 200-800 K, IM1 produced (CH3CFClOOOCl) by collisonal deactivation is dominant; at high temperatures, the production P1 (CH3CFO?+?ClOOCl) becomes dominate. The calculated rate constants for CH3CFClO2•?+?ClO• are good agreement with the available experimental value. The atmospheric lifetime of CH3CFClO2• in ClO• is around 3.27 h. TD-DFT computations imply that IM1 (CH3CFClOOOCl), IM2 (CH3CFClOOClO) and IM3 (CH3CFClOClO2) will photolyze under the sunlight.

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC7338532 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature