Photodissociation dynamics of 1,1-difluoroethylene at 157 nm excitation

Abstract

Photodissociation of 1,1-difluoroethylene (F2CCH2) at 157 nm has been investigated using photofragment translational spectroscopy. Five dissociation channels have been experimentally observed; molecular HF elimination, H atom elimination, molecular hydrogen (H2) elimination, F atom elimination, and double bond breaking. Molecular HF elimination and H atom elimination channels are found to be the two major dissociation pathways in photodissociation of F2CCH2 at 157 nm excitation. Molecular hydrogen (H2) elimination and double bond cleavage are also significant, while F atom elimination is a minor process. Product translational energy distributions for all dissociation channels have also been measured. All translational energy releases are peaked at energies away from zero, indicating that the dissociation of F2CCH2 at 157 nm excitation most likely occurs with exit barriers on the ground electronic potential surface through internal conversion from the initially excited electronic state. Branching ratios and averaged energy partitions for different channels have also been estimated.