THE EFFECT OF REAGENT TRANSLATIONAL EXCITATION ON THE DYNAMICS OF THEREACTION H-2-]HCL(V',J')+CL(CL)

We use fast time-resolved Fourier transform spectroscopy and low press ure infrared chemiluminescence techniques to determine the product ene rgy distribution in the title reaction. We create the,reagent hydrogen . atoms; with 2.3 eV of translational excitation by photofragmentation of H2S at 193 mm, and observe the time evolution of the infrared chem iluminescence from the product HCl(v',J') under single gas kinetic col lision conditions. The initial vibrational distribution, determined fr om the first observation after creation of the H atoms is P(v' = 1:2:3 :4:5:6:7:8) = 1.0:0.84:0.74:0.59:0.34:0.24:0.17:0.13. The initial HCl rotational distribution in each vibrational level is broad, showing no identifiable maximum. The fraction of the total available energy ente ring HCl vibration and rotation, respectively, are 0.19 and 0.10. The time evolution of the observed vibrational and rotational distribution s gives information about the changes in the reaction dynamics consequ ent on reduction of the reagent translational energy.