One- and two-photon-resonant multiphoton ionization spectra of CS2 from 45 500 to 48 100 cm−1

One- and two-photon-resonant multiphoton ionization spectra of the low energy region of the intense 1 B2 state of room temperature CS2 are reported. A comparison of these with one another, as well as with absorption spectra, yields a frequency of 46 247 cm−1 for the electronic origin of the transition. Most of the intense features in this region can be assigned as transitions to excited state bending levels. The frequency of this mode in the excited state is found to be 429 cm−1, in excellent agreement with results from the higher energy region of the spectrum. Two-photon excitation is used to observe, for the first time, the excited state antisymmetric stretch mode. Its frequency is 1567 cm−1, close to the corresponding ground state value.