Rate constant for the reaction of bromine atoms with ethane: Kinetic and thermochemical implications

Relative-rate kinetic experiments were carried-out at T = 310 ± 3 K to determine rate constant ratios for the reactions of Br atoms with C2H6(1), CH2ClBr(2) and neo-C5H12(3). Br atoms were produced by stationary photolysis of Br2 and the consumption of the reactants was determined by gas-chromatography. k 2/k 1 = 1.174 ± 0.053 and k 3/k 1 = 0.458 ± 0.027 were determined (with 1σ precision given). The rate constant ratios were resolved to absolute k 1 values, and k 1(310 K) = (2.27 ± 0.30) × 105 cm3 mol−1 s−1 was recommended. The recommended k 1 was applied in a third law analysis providing Δf H o 298(C2H5) = (122.0 ± 1.9) kJ mol−1.