THE INFRARED SPECTRUM OF CARBON MONOXIDE IN CO–He MIXTURES AT HIGH PRESSURES

Abstract

The 1–0 and 2–0 infrared bands of carbon monoxide were measured in CO–He mixtures at pressures up to 3 000 atm at 295 °K. Extrapolation of the integrated intensities of the bands gave the absolute intensities, Γ01 = 2 686 ± 44 and Γ02 = 9.29 ± 0.27 cm2 per mole. A slight increase in the band intensities with pressure is due to apparent induced absorption. A moment analysis of the bands, as proposed by Gordon, shows the presence of a torque due to intermolecular forces which hinders the molecular rotation; the magnitude of the torque derived from the analysis varies linearly with the density of the perturbing gas.