Molecular beam studies of the photodissociation of benzene at 193 and 248 nm

The photodissociation processes of benzene following excitation at 193 and 248 nm have been studied by molecular beam photofragmentation translational spectroscopy. When benzene was excited to the 1 B1u state by absorption at 193 nm, dissociation occurred through three primary channels, C6H5+H (80%), C6H4+ H2 (16%), and C5H3+CH3 (4%), following internal conversion to the vibrationally excited ground state. When benzene was excited to the 1 B2u state at 248 nm, two primary dissociation channels, C6H4+H2 (96%), and C5H3+CH3 (4%), were observed. Photodissociation to produce two C3H3 was induced by two photon absorption of benzene at both 193 and 248 nm. Numerous secondary photodissociation processes of the primary photoproducts were also observed at both 193 and 248 nm.