THE INFRARED-SPECTRUM OF SULFUR-HEXAFLUORIDE SOLVATED IN LARGE MOLECULAR-HYDROGEN CLUSTERS

The infrared spectrum of SF6 and (SF6)2 in molecular hydrogen clusters containing approximately 1000 molecules has been measured. Absorptions are observed at 942.0 cm-1 for the monomer and at 928.5 and 949.6 cm-1 for the dimer, indicating that both species are solvated. The location of the impurities and the spectral shifts are analyzed in terms of the instantaneous dipole-induced dipole mechanism previously developed by Eichenauer and Le Roy. The relatively small discrepancy between the calculated and the observed shifts is explained in terms of an increased local density of hydrogen around the SF6 which is a result of the decrease in the zero-point energy caused by the deeper local potential.