REACTION DYNAMICS OF C(1D)+H2(V)-]CH(X2-PI)+H

The CH(X2PI,v,J,OMEGA,LAMBDA) product state distribution from the reaction C(1D) + H-2(v) --> CH+H was determined by laser-induced fluorescence (LIF) where the B2SIGMA-X2PI transitions were probed. Most of the available energy is released as translation. A nearly thermal rotational distribution is obtained for CH (v = 0,1). Only a small fraction, 4.1 X 10(-4), of the CH products is formed in the vibrationally excited state. A higher propensity for the production of CH in the symmetric PI(A') LAMBDA sublevels is evident. For studying the influence of vibrational excitation on the reaction dynamics, H-2 was excited to its first vibrational state via stimulated Raman pumping (SRP). H-2(v = 1) increases the reaction rate and enhances the population of higher rotational states, but diminishes the LAMBDA selectivity. The vibrational population ratio P(v = 0)/P(v = 1) of the CH product remains unaltered. Insertion of the C(1D) atom into the H-2 bond is the major reaction mechanism, but the probability for an abstractive process seems to increase when H-2(v = 1) is reacting with C(1D).