The methyl radical combination rate constant as determined by kinetic spectroscopy

The rate constant for the reaction has been determined by means of vacuum ultraviolet flash photolysis and time-resolved kinetic spectroscopic observations of the 1504-Å absorption band of CH₃. The measurements made using three different sources of methyl radicals (azomethane, dimethylmercury, and ketene-hydrogen) were in accord and yielded a value for the rate constant of k₁ = (9.53 ± 1.17) × 10^?11 cc molec^?1 sec^?1. A detailed error analysis is presented. The f-value for the 1504-Å band of CH₃ is determined to be (2.5 ± 0.7) × 10^?2.