Temperature Dependence of O(1S) Deactivation by CO2, O2, N2, and Ar

The collisional deactivation of O(1S) by CO2, O2, N2, and Ar has been investigated as a function of temperature in the range from 200 to 450°K. O(1S) was produced in a pulsed mode by vacuum ultraviolet flash photolysis of CO2. The decay of O(1S) was observed by the 5577 Å emission as a function of time after the production pulse. Deactivation rate constants were derived from the dependence of the decay rate on the concentrations of added gases. Arrhenius plots yielded the following results: kCO2=3.3× 10−11 exp(−2630± 200/RT) cm3molecule−1· sec−1,kO2=4.9× 10−12 exp(−1700± 200/RT) cm3molecule−1· sec−1,kN2<5× 10−17cm3molecule−1· sec−1 (independentoftemperature),kAr<5× 10−17cm3molecule−1· sec−1 (independentoftemperature).In the case of N2 and Ar the collisional enhancement effect of the O(1S) emission was observed and was found to be independent of temperature.