2-PHOTON PHOTOCHEMISTRY OF CS2 - FORMATION OF S2(V-LESS-THAN-OR-EQUAL-TO-2) AND CS(V-LESS-THAN-OR-EQUAL-TO-10) AT 308NM

Room-temperature CS2 is photolyzed at 308 nm in a low-pressure flow cell. Laser-excited fluorescence is used to observe both CS(upsilon-less-than-or-equal-to 10) and S2(upsilon-less-than-or-equal-to 2) products 10-mu-s after the excimer laser pulse. Both products display a quadratic dependence on the excimer laser intensity. These results are consistent with a two-photon excitation of CS2 to a high-lying electronic state (near 154 nm) which predissociates to S and CS, followed by reaction of the S atom with undissociated CS2.