Vacuum ultra-violet spectra of transient molecules and radicals. Part 1.—CS and S 2

New absorption spectra of the transient species CS and S2 have been observed in the vacuum ultra-violet region. For S2, two overlapping systems designated (Eâ†�X) and (Fâ†�X) are reported for which the upper states exhibit (Ωc,ω) coupling. From a consideration of the new states, together with the data on the C state, a value for the ionization potential for S2 is derived as 9.40 ± 0.05 eV. The new bands reported for CS are discussed in terms of the established spectrum of CO, and the new states tentatively assigned.