Vibrational energy relaxation has been studied for CD₃F diluted in liquid and solid Xe, Kr, Ar near the melting points. On solidification of the Xe and Kr, a hopping increase of the relaxation time is revealed, whereas the liquid to solid-state transition in Ar solution is accompanied by a small decrease in time. The temperature dependence of the vibrational relaxation rate, obtained on the basis of low-density gas-phase, liquid, solid and low-temperature matrix measurements, is discussed in terms of simple binary and collective approaches.