193 nm excimer laser photochemistry of benzene in argon matrices

Abstract

Reactions of C 6H 6 and C 6D 6 after 193 nm excimer laser irradiation have been studied by the trapping of products into an argon matrix at 14 K. IR spectroscopy was used to identify the product species; most were known species arising from either isomerization or fragmentation. The ratio of isomerization product to fragmentation product was seen to vary as a function of sample concentration. Addition of Cl 2 as an electron trap to aid in cation formation led to a number of chlorinated benzene species as well as biphenyl. A set of bands was also observed that could be photobleached by a mercury arc lamp; these bands may be due either to C 6H 6 + or to the σ complex C 6H 6Cl +. Parallel experiments with C 6D 6 were conducted in support of these observations.