Computational study on the thermal decomposition and isomerization of the CH3OCF2O• radical

Abstract

The geometries of the reactant, products, and transition states involved in the decomposition pathways of the CH3OCF2O• radical formed during the photooxidation of CH3OCHF2 (HFE-152a) have been optimized and characterized at the DFT-B3LYP level of theory using the 6–311G(d,p) basis set. Single-point energy calculations have been made at the G2M (CC,MP2) level of theory. Out of the four prominent decomposition channels considered, the β-C–O bond scission is found to be the dominant path involving a barrier height of 9.78 kcal mol–1 (1 cal = 4.184 J). The thermal rate constant for the above decomposition pathway is evaluated using canonical transition state theory (CTST) and was found to be 5.27 × 104 s–1 at 298 K and 1 atm (1 atm = 101.325 kPa).