193 NM EXCIMER-LASER PHOTOCHEMISTRY OF BENZENE IN ARGON MATRICES

Reactions of C6H6 and C6D6 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 C6H6+ or to the sigma complex C6H6Cl+. Parallel experiments with C6D6 were conducted in support of these observations.