Nonadiabatic Decomposition of N2O in the Deactivation of O(1<i>D</i>) by N2

Abstract

An extension of a flash-photolysis method described previously was used to measure the following absolute rate constants (all in liter per mole·sec): O(1D)+O3→2O2k2=2.0±1.0×1011,O(1D)+N2→O(3P)+N2k4a=1.3±0.6×1010,O(1D)+Xe→O(3P)+Xek4b=3.5±1.7×1010,O(1D)+Ar→O(3P)+Ark4c∼5×107. The efficiency with which the O(1D)→O(3P) transition is induced by collisions depends specifically on the added gas. The results for deactivation by nitrogen are discussed in terms of the formation of an N2O* intermediate in a high level of vibrational excitation. Dissociation to N2+O(3P) at this energy level (85.2 kcal) is compared with thermal decomposition of N2O where predissociation to a state which correlates with O(3P) occurs at a lower energy level (〈ε〉=61.8 kcal).