Dissociation channels of c-C4F8 to C2F4 in reactive plasma

Abstract

Abstract Progress in computational methods and personal computing has made possible more accurate estimations for primary dissociation channels and energies. The main dissociation route is revealed to be via the 7E excited state with an energy of 12.23 eV, which is composed of transitions from the highest occupied molecular orbital with b1 symmetry to some degenerate unoccupied e molecular orbitals. The main contributing e orbitals consisted of antibonding combination of C2F4 π-bonding orbitals. This degenerate 7E state is lowered by non-adiabatic transitions through the conical interactions on the dissociating route to 2C2F4, so the energy is finally relaxed at the dissociative second lowest 1E excited state leading to 2C2F4 production. In the electron attachment process, the calculated results show that the F− ion is produced from the excited states of the D4h c-C4F8 − ion through conical interactions at the energies of 4.3 eV, 5.6 eV, and 5.0 eV, along the C–F dissociation route.