Electronic Structures of CF3- for Studying Dissociative Electron Attachment to CF3 Radicals

Abstract

To elucidate the process of dissociative electron attachment (DA) to CF3 radicals, the potential energy surfaces of CF3, CF3- and the electronic state CF3-* temporally produced in DA are calculated at the MP2/6-311++G** level by Gaussian 98. The electron affinities (EA) of the CF3, vibrational frequencies of CF3 and CF3- are also calculated. Our results are in good agreement with the experimental values (cf. EA=1.72 eV, experimental value = 1.7±0.2 eV). It is elucidated that the electron capture by CF3 under the adiabatic approximation occurs by the incident of a low-kinetic energy (∼0.6 eV) electron. DA to CF3 is a slightly endothermic process with 0.2–0.4 eV. It is concluded that CF3 radicals produce F- ions via DA with low kinetic energies. This process is considered to be very important in the kinetics of low-energy electrons in fluorocarbon plasmas.