Time-resolved resonance fluorescence detection of Br(P-2(3/2)) atom disappearance or appearance following 266-nm laser flash photolysis of CF2Br2/CH3SCH3/H-2/N-2 and Cl2CO/CH3SCH3/HBr/H-2/N-2 mixtures has been employed to study the kinetics of the reactions Br(P-2(3/2)) + CH3SCH3 <----> HBr + CH3SCH2 (1,-1) as a function of temperature over the range 386-604 K. Arrhenius expressions in units of cm(3) molecule(-1) s(-1) which describe the results are k(1) = (9.0 +/- 2.9) X 10(-11) {exp[(-2386 +/- 151)/T]} and k(-1) = (8.6 +/- 2.5) X 10(-13) {exp[(836 +/- 140)/T]}; errors are 2 sigma and represent precision only. To our knowledge, these are the first kinetic data reported for each of the two reactions studied. Second and third law analyses of the equilibrium data for reactions 1 and -1 have been employed to obtain the following enthalpies of reaction in units of kcal mol(-1) : Delta H-298 = 6.11 +/- 1.37 and Delta H-0 = 5.37 +/- 1.38. Combining the above enthalpies of reaction with the well-known heats of formation of Br, HBr, and CH3SCH3 gives the following heats of formation of the CH3SCH2 radical in units of kcal mol(-1) : Delta H-f,H-298 = 32.7 +/- 1.4 and Delta H-f,H-0,o = 35.3 +/- 1.4; errors are 2 sigma and represent estimates of absolute accuracy. The C-H bond dissociation energy in CH3SCH3 obtained from our data, 93.7 +/- 1.4 kcal mol(-1) at 298 K and 92.0 +/- 1.4 kcal mol(-1) at 0 K, agrees well with a recent molecular beam photofragmentation study but is 3 kcal mol(-1) lower than the value obtained from an iodination kinetics study.