CROSS-SECTIONS AND ENERGY DISPOSAL FOR CN(X) PRODUCED IN THE H + HCN REACTION AT 53 AND 58 KCAL MOL-1 COLLISION ENERGIES

Energy disposal in the CN(X) product of the H + HCN reaction has been studied by the method of time-resolved laser-induced fluorescence. Translationally hot H atoms were formed by photodissociation of H2S and HBr at 193 nm, leading to center-of-mass collision energies of 53 and 58 kcal mol-1. The rotational distributions for CN(X,v=0,1) can be well described by single Boltzmann temperatures of 1400 and 1600 K, respectively, and correspond to 12% of the H atom energy above an apparent threshold of about 30 kcal mol-1. Between 3% and 5% of the energy above this threshold is found in the CN(X) vibration. Cross sections for the production of CN(X) at the two H atom energies have been measured as 0.007 +/- 0.002 and 0.009 +/- 0.002 angstrom2, respectively.