A structure-activity relationship for the rate coefficient of H-migration in substituted alkoxy radicals

A framework is formulated for the development of a predictive structure-activity relationship for the temperature-dependent rate coefficients of H-migration in substituted alkoxy radicals. It is based on a multi-conformer transition state theory model, using quantum chemical characterizations of alkoxy radicals and their transition states for isomerisation. Using this framework, a SAR is then developed for the prediction of rate coefficients at 1 atm and T = 250-350 K, relative to a set of three reference reactions. The SAR covers 1,4-through 1,8-H-migration, as well as oxo- and hydroxy substitution in various positions relative to the radical oxygen and the migrating H.