THE VIBRATIONAL DEACTIVATION OF THE BENDING MODES OF CD4 AND CH4 MEASURED DOWN TO 90-K

Rate constants are reported for the vibrational deactivation of the bending modes of CD4 and CH4 in the temperature range 295 to 90 K for the former and 295 to 140 K for the latter. A large number of collision partners was investigated with twelve systems being studied for CD4 relaxation and six for CH4. These experiments used the laser induced fluorescence technique. CD4 was directly excited to the upsilon4 level using a TEA CO2 laser, while the upsilon4 level of CH4 was populated by collisional pumping from CD4. The rate constants obtained agree well with previous data for the systems where comparison with other studies is possible.