The v-v energy transfer of highly vibrationally excited states (II) -: Vibrational quenching of CO(v) by H2O

The vibrational energy transfer from highly vibrationally excited CO to H2O molecules is studied by time-resolved Fourier transform infrared emission spectroscopy (TR FTIR). Following the 193 nm laser photolysis of CHBr3 and O-2 the secondary reactions generate CO(v). The infrared emission of CO(v-->v-1) is detected by TR FTIR. The excitation of H2O molecules is not observed. By the method of the spectral simulation and the differential technique, 8 rate constants for CO(v)/H2O system are obtained: (1.7+/-0.1), (3.4+/-0.2), (6.2+/-0.4), (8.0+/-1.0), (9.0+/-,2.0), (12+/- 3), (16+/-4) and (18+/-7) (10(-13)cm(3).molecule(-1).s(-1)). At least two reasons lead to the efficient energy transfer. One is the contributions of the rotational energy to the vibational energy defect and the other is the result of the complex collision. With the SSH and oh initio calculations, the quenching mechanism of CO(v) by H2O is suggested.