The measurement of rate constants for the vibrational deactivation of 12C 16O by H 2, D 2 and 4He in the gas phase down to 35 K

Abstract

Rate constants for the vibrational deactivation of 12C 16O by H 2, D 2 and 4He have been determined by laser-induced fluorescence in the gas phase at low temperatures. The rate constants for 12C 16O(ν=1)H 2 and 12C 16O(ν=1)D 2 have been measured down to 35 K and those for 12C 16O(ν=1) 4He have been measured to 40 K. This extension of our previous data has been made possible by the adoption of a frequency-doubled CO 2 laser. The rate constants for 12C 16O(ν=1)H 2 and 12C 16O(ν=1)D 2 show a minimum at 50 K, whereas that for 12C 16O(ν=1) 4He steadily decreases with lowering temperature throughout the range studied here.