10.1021/ja954268f.s002 Osama M. Musa Osama M. Musa John H. Horner John H. Horner Haifa Shahin Haifa Shahin Martin Newcomb Martin Newcomb A Kinetic Scale for Dialkylaminyl Radical Reactions American Chemical Society 1996 order rate constants hydrogen atom donors unimolecular rate constants methyl Bu 3 SnH dialkylaminyl radicals Calibrated hydrogen atom donors tran tin hydride reactions Dialkylaminyl Radical Reactions PTOC alkyl radicals 1996-04-24 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/A_Kinetic_Scale_for_Dialkylaminyl_Radical_Reactions/3659382 A kinetic scale for dialkylaminyl radicals was established by measuring unimolecular rate constants for a series of dialkylaminyl radical clocks that spans eight orders of magnitude and using clock reactions to measure the second order rate constants for reactions of several hydrogen atom donors. <i>N</i>-Hydroxypyridine-2-thione derivatives of carbamic acids (so-called PTOC carbamates) were used as radical precursors in direct, laser-flash kinetic measurements and in indirect, radical chain kinetic studies. The calibrated radical clocks are <i>N</i>-methyl-6,6-diphenyl-5-hexenaminyl, <i>N</i>-methyl-<i>trans</i>-5-phenyl-4-pentenaminyl, <i>N</i>-methyl-5,5-diphenyl-4-pentenaminyl, <i>N</i>-methyl-<i>trans</i>-2-phenylcyclobutanaminyl, and <i>N</i>-methyl-<i>trans</i>-2-phenylcyclopropanaminyl. Calibrated hydrogen atom donors are Bu<sub>3</sub>SnH, <i>t</i>-BuSH, PhSH, and PhSeH. Whereas the tin hydride reactions with dialkylaminyl radicals are slower than reactions with alkyl radicals, the polarity-matched reactions of the electron-rich dialkylaminyl radicals with the electron-poor hydrogen donors <i>t</i>-BuSH, PhSH, and PhSeH have rate constants nearly equal to those for reactions of alkyl radicals with the same donor.