High-resolution studies of perturbations in the 410 band of thioformaldehyde

The perturbations in the 41 level of the A1A2 excited state of thioformaldehyde (H2CS) are shown to be produced by interactions with the 2131, 4262, and 63 levels of the a3A2 state.Some of these perturbations have been studied with megahertz resolution using the techniques of intermodulated fluorescence and microwave-optical double resonance. A particularly clear example involving hyperfine levels is found in the interaction of the 170.17 (41) level of the A1A2 state with the 17 181,18 (4262) level of the a3A2 state.