Electronic quenching of

The electronic quenching of CH(A2Δ,ν = 0) by N2, O2, CO2, N2O, and NH3 and NH(A3Π,ν = 0) by NH3 was investigated to extend the previously studied low temperature range towards existing high temperature data. A pulsed CO2 laser method of rapid heating was combined with the pulsed photolytical generation of the excited species for the study of fluorescence decays in the temperature range 300 to 950 K. Together with previous literature values from Crosleyʹs group, rate data for some systems are now available for temperatures from 240 to 1800 K. The quenching of CH(A) by N2, CO2 and N2O shows a pronounced temperature dependence indicating a barrier on the reaction coordinate. Neither the united atom model nor the Parmenter-Seaver correlation nor the collision complex model reflect the temperature dependencies observed for the quenching of CH(A) by most collision partners.