Photofragment translational spectroscopy with state-selective "universal detection": The ultraviolet photodissociation of CS2

We have investigated the photodissociation of CS2 at 193 nm using the techn ique of photofragment translational spectroscopy. The utilization of vacuum ultraviolet synchrotron radiation for product photoionization has permitte d a determination of the vibrationally resolved translational energy distri bution for the CS+S(D-1) channel and the translational energy distribution for the CS+S(P-3) channel. A simulation of the coincident S(D-1) translatio nal energy distribution is consistent with a CS vibrational distribution of 0.02:0.17:0.19:0.46:0.15 in nu = 0:1:2:3:4 and an average rotational energ y of similar to 1-3 kcal/mol. We find that the S(P-3)/S(D-1) branching rati o is 3.0 +/- 0.2, in good agreement with previous reports. Both asymptotic channels exhibit similar velocity dependent anisotropy parameters that decr ease with decreasing translational energy release. The results extend earli er reports and provide further insight into the dissociation dynamics at 19 3 nm. (C) 2000 American Institute of Physics. [S0021-9606(00)00311-1].