Rovibrational Spectra of Water-Carbon Disulfide Complexes in the Bending Region of Water: Anomalous -to- Ratio.

Rovibrational spectra of DO-CS and HDO-CS van der Waals complexes have been measured in the bending region of DO/HDO by direct absorption in a slit supersonic jet expansion. The HO-CS dimer is reinvestigated in the bending region of HO with a higher rotational temperature compared with the previous study [Barclay, A. J. 2024, 26, 23053-23061], namely, ∼10 versus ∼2 K. Only the most stable isomer was observed, and precise molecular constants for these three complexes are determined. The HDO-CS complex in the supersonic jet was relaxed into an equilibrated population. But the line intensities for transitions originating from the = 1 levels in the ground state for both DO-CS and HO-CS are found to be significantly stronger than those predicted with normal nuclear spin statistical weights. This abnormality is likely due to the different yielding rates for the - and - spin species of DO-CS or HO-CS in the supersonic jet expansion.