Vibrational relaxation studies of systems with strong intermolecular interactions at low temperatures in the gas phase and in cryogenic solutions

Infrared fluorescence and double infrared resonance have been used to measure the V-T relaxation of CD₃F and CD₄ in mixtures with He, Ne, Ar, Kr, Xe and HCl in the gas phase and in the liquid Ar, Kr, Xe. It is shown that the temperature dependence of V-T probabilities in the interval 350–150°K can be attributed to an increasing influence of long range forces. In the mixture CD₃F + HCl, where H-bonded complexes CD₃F…HCl have been formed, the vibrational relaxation rate considerably increases with decreasing temperature. It is found that the probabilities of V-T energy transfer in cryogenic solutions are lower than those measured in the gas phae.