Theoretical investigation on the reaction mechanism of CF3OCHF2 + O(1D)

The reaction mechanism of the multi-channel reaction of CF3OCHF2 + O(1D) has been investigated theoretically. Three possible initial association ways are found, i.e. O(1D) insertion into the C–H bond to form energy-rich intermediates a(a1 –a4 ) CF3OCF2OH, O(1D) insertion into the C–O bond to form energy-rich intermediate b CF3OOCHF2, O(1D) addition to the F atom to generate intermediates c CHF2OCF3O and c1 CF3OCFHOF. The geometries are optimized at the B3LYP/6-311G(d, p) level, and the energy profiles are further refined by MC-QCISD level of theory. The mechanism can generally be described as association, isomerization, and dissociation. There are five energetically accessible reaction pathways. Eight products are located on potential energy surfaces (PESs). It is predicted that the main products are P2 (F2CO + CF3OH), P3 (2F2CO + HF), and P4 (CF3OCFO + HF), while P1 (CF2O(O)CF3 + H) and P5 (CF3O + CF2HO) are minor products. Furthermore, to further reveal the thermodynamic properties, the enthalpies of formation of CF3OCHF2 are evaluated via isodesmic reactions at the MC-QCISD//B3LYP/6-311G(d, p) level and the reaction enthalpies of the major reaction channels are calculated at the same level.