RATES OF PROCESSES INITIATED BY PULSED-LASER PRODUCTION OF F ATOMS INTHE PRESENCE OF HCL, CH4, AND CF3H

Time-resolved vibrational chemiluminescence from HF has been recorded following the production of F atoms by the pulsed laser photolysis (la mbda = 266 nm) of F2 in the presence of HCl, CH4, and CF3H. In the fir st two cases, experiments have been conducted by observing emission fr om HF(nu = 3) at four temperatures from 295 to 139 K. Rate constants h ave been determined over this range of temperature for the reactions o f F atoms with HCl and CH4 and of CH3 radicals with F2, and for the re laxation of HF(nu = 3) by HCl and CH4. The reaction of F atoms with CF 3H is slower than those with HCl and CH4 and measurements on the emiss ion from HF(nu = 2) have been used to infer rate constants for reactio n and relaxation only at 295 K. (C) 1994 John Wiley & Sons, Inc.