Infrared absorption spectroscopy of rare-gas – CO2 clusters produced in supersonic expansions

Abstract

Infrared absorption spectra are reported for rare-gas–carbon dioxide van der Waals complexes in the region of the ν₃ fundamental vibrational transition of CO₂ using a pulsed molecular beam and a diode laser. The observed linewidths of 90 MHz (f.w.h.m.) allowed the determination of rotational constants for the ground and first excited vibrational states along with the frequencies of the band origins and centrifugal distortion constants which were constrained to be equal in both vibrational states. Effective structures of the complexes have been determined.