| -Acyl PTOC carbamates, PTOC imidate esters, and N-(phenylthio)amides were used successfully for the first time as amidyl radical precursors in laser flash photolysis (LFP) studies. The kinetics of 6-exo cyclization of amidyl radical generated from these precursors demonstrated that the rate constants of the 6-exo cyclization of amidyl radical were in excellent agreement despite varying precursors. The calibrated reactions of 6-exo cyclization of amidyl radical were employed in indirect studies of bimolecular rate constants as demonstrated in the determination of the rate constants for tin hydride trapping reactions. The calibrated tin hydride trapping reaction was then used to calculate rate constants for 5-exo cyclization of the simple amidyl radicals. The observed rate constants for 1,5-translocation of N-acyl carbamoyloxyl radicals were greater than ;The kinetics of metal complexed dialkylaminyl radical were determined directly by LFP The radical was generated by photolysis of the corresponding PTOC carbamate in the presence of Lewis acids. In tetrahydrofuran, the systems studied displayed saturation kinetics from which rate constants and complexation equilibrium constants were obtained by non-linear regression from the observed rate constant and the Lewis acid concentration. The degree of kinetic activation by the Lewis acids was much less than that observed upon protonation of neutral aminyl radicals.;The kinetic studies of ring opening of the (N-butyl-2-pyrrolidinyl)methyl radical to the N-butyl-4-pentenaminyl radical as well as the reverse reaction were determined at 50;The unimolecular cyclizations of the... |
