Two-Photon Dissociation Study of CS2 Using Ion Imaging

The 1D2 and 3P2,1,0 electronic states of the S-atom photofragments following the two-photon dissociation of cold CS2 at 69399, 64893, 64496, 64320 cm-1, respectively, are probed using ion imaging. From the S-atom photofragment translational energy distribution we conclude that CS is produced in both the X1Σ+ and a3Π electronic states with a branching ratio CS(a3Π) + S(3P2)/CS(X1Σ+) + S(3P2) = 0.22 ± 0.05 (at 64893 cm-1), and 50% of the available energy is taken up by the CS internal degrees of freedom. By analyzing the photofragment angular distributions, we conclude that the excited electronic states involved in the photodissociation process are the Rydberg states with predissociation lifetimes estimated at ∼1 ps.