Time-resolved Fourier transform infrared study of the photodissociation of 1,1-difluoroethene at 193 nm

Abstract

We have measured vibrational and rotational population distributions for the excited HF product of the 193 nm photolysis of CH2CF2. Approximately 15% of the available energy is released as vibrational energy of HF, and the estimated nascent HF rotational energy corresponds to about 10% of the total available energy. The relative vibrational populations can be fit to a linear surprisal. We have compared the vibrational distribution to that observed from this reaction with different amounts of available energy, and to the HF vibrational distributions produced in the dissociation of other fluoroethenes. While results differ among the various experiments considered, overall more than the amount of vibrational energy expected statistically is deposited in HF. The rotational population distributions we observe fit both a Boltzmann distribution and an information theoretic model corresponding to a nearly statistical energy distribution.