ELECTRONIC QUENCHING OF CH(A(2)DELTA) AND NH(A(3)II) BETWEEN 300 AND 950 K

The electronic quenching of CH(A(2) Delta,upsilon = 0) by N-2, O-2, CO 2, N2O, and NH3 and NH(A(3) Pi,upsilon = 0) by NH3 was investigated to extend the previously studied low temperature range towards existing high temperature data. A pulsed CO, laser method of rapid heating was combined with the pulsed photolytical generation of the excited specie s for the study of fluorescence decays in the temperature range 300 to 950 K. Together with previous literature values from Crosley's group, rate data for some systems are now available for temperatures from 24 0 to 1800 K. The quenching of CH(A) by N-2, CO2 and N2O shows a pronou nced temperature dependence indicating a barrier on the reaction coord inate. Neither the united atom model nor the Parmenter-Seaver correlat ion nor the collision complex model reflect the temperature dependenci es observed for the quenching of CH(A) by most collision partners.