Theoretical studies on atmospheric reactions of CH2FO2 with HO2 and HO2⋅H2O complex

The formations of CHFO, 1O2, O3 and 3O2 in CH2FO2 + HO2 and CH2FO2 + HO2⋅H2O reaction are studied by employing the quantum chemical calculations with B3LYP and CCSD(T) theoretical methods, canonical variational transition (CVT) state theory with small curvature tunneling (SCT) correction. The calculated results show that the formations of CHFO and 3O2 are main products in the naked reaction of CH2FO2 + HO2. When water is added, the formations of CHFO and O3 are main products in CH2FO2 + HO2⋅H2O reaction. Moreover, the calculated rate constants for the title reaction without and with a water molecule show that, although the single water molecule plays a positive catalytic effect on enhancing the rate for CHFO and O3 formation, in humid conditions the effective rate of CH2FO2 + HO2 reaction will changes little with respect to dry conditions.