Vibrational relaxation of D<inf>2</inf>O (v<inf>2</inf>)

Abstract

The method of laser-excited vibrational fluorescence has been used to measure vibrational relaxation rates for the bending mode of D2O in collisions with D2O, D2, HD, H2, He, and Ar. The rate constants at 295 K are found to be (3.2±0.2)x10-11, (3.6±0.2)x10-13, (1.2±0.1)x10-12, (3.3±0.2)x10-12, (7.1±0.9)x10-14, and (3.0±1.2)x10-14 cm3 molecule-1 sec -1, respectively. Relaxation times have been measured for two D 2O-HDO-H2O mixtures and relaxation probabilities, P D2O-HDO and PD2O-H2O were estimated to be not very different from PD2O-D 2O. The temperature dependence of the relaxation was measured for pure D2O. The rates are (1.80±0.08)X 10-11 at 400, (2.1±0.1)x10-11 at 350 and (4.0±0.3)x 10 -11 cm3 molecule-1 sec-1 at 260 K. The corresponding probabilities are fit by P(T) = C exp(ε/kT) with ε = (778±34) K and C = 1.1x10-2. © 1980 American Institute of Physics.