Vibrational relaxation of DF (v=1 and 3) in H2, D2, N2, and HF at 200 K

Abstract : The laser-induced fluorescence technique was used to measure the rate coefficients for the deactivation of DF(v = 1) and DF (v = 3) in H2, D2, N2, and HF at 200 + or - 5 K. The rate coefficients for deactivation by H2, N2, and HF were found to scale with v as v to the 1.9 + or - 0.1 power, essentially the same as the scaling at 295 K. The relaxation rates for DF(v = 1) were compared with data obtained at higher temperatures. At 200 K, the exchange probability of HF(1) + H2(O) was the same as that of DF(1) + D2(O) (within 10%) when the endothermicities were considered. (Author)