Absolute rate constants for the reactions between amino and alkyl radicals at 298 K

The absolute rate constants for the reactions of NH 2 radicals with ethyl, isopropyl, and t ‐butyl radicals have been measured at 298 K, using a flash photolysis–laser resonance absorption method. Radicals were generated by flashing ammonia in the presence of an olefin. A new measurement of the NH 2 extinction coefficient and oscillator strength at 597.73 nm was performed. The decay curves were simulated by adjusting the rate constants of both the reaction of NH 2 with the alkyl radical and the mutual interactions of alkyl radicals. The results are k (NH 2 + alkyl) = 2.5 (±0.5), 2.0 (±0.4), and 2.5 (±0.5) × 10 10 M −1 ·s −1 for ethyl, isopropyl, and t ‐butyl radicals, respectively. The best simulations were obtained when taking k (alkyl + alkyl) = 1.2, 0.6, and 0.65 × 10 10 M −1 ·s −1 for ethyl, isopropyl, and t ‐butyl radicals, respectively, in good agreement with literature values.