Temperature dependence of the probability of vibrational energy exchange between the stretching modes in H2O/D2O + Ar collisions

✍ Scribed by J. Ree; H.K. Shin

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 802 KB
• Volume: 193
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85658-w

✦ Synopsis

The vibrational energy exchange between the stretching modes of Hz0 in the H20+Ar collision has been studied in a semiclassical method in the temperature range of 200-3000 K. The energy exchange probability increases slowly, but nearly linearly, with temperature over the entire range, reflecting a near-resonant case. The intermolecular removal of the energy mismatch (AE= + cm-' ) by translation is found to be nearly as efftcient as the intermolecular transfer to the rotational motion. The energy exchange probability for D,O+Ar is less efficient by a factor of about two over the temperature range in both the intramolecular VR and intermolecular VT processes. The lower efficiency found in the VR step is due to a slower rotational motion of D20, while that in the VT process is due to a larger energy mismatch for the DzO + Ar collision ( AE= + 122 cm-' ) . The effect of molecular attraction is found to be important in the energy exchange process especially near room temperature, and the use of empirically determined attractive energies for the H20-Ar complex is found to be valuable at such temperatures.