Rate constants and Arrhenius parameters for the reactions of primary, secondary, and tertiary alkyl radicals with tri-n-butyltin hydride

Article abstract of DOI:10.1021/ja00416a008

Rate constants for the title reactions have been measured over a range of temperatures by using laser flash photolytic techniques. At 300 K the rate constants are 10.₈, 2.0₁, 2.3₄, 1.3₅, 2.4₇, and 1.8₄ × 10⁶ M^-1 s^-1 for methyl, ethyl, n-butyl, isopropyl, cyclohexyl, and tert-butyl, respectively. The Arrhenius preexponential factors range from 10^9.39 M^-1 s^-1 for methyl to 10^8.43 M^-1 s^-1 for tert-butyl and activation energies from 3.97 kcal/mol for cyclohexyl to 2.95 kcal/mol for tert-butyl. The rate constant (k₁₀) for the 1,5-cyclization of 5-hexenyl radical to cyclopentylmethyl radical can be represented by log k₁₀/s_-1 = (10.37 ± 0.32) - (6.85 ± 0.42)/θ, where θ = 2.3RT kcal/mol.