Bond Dissociation Energies of O−H Bonds in Substituted Phenols from Equilibration Studies

摘要: Bond dissociation energies (BDE) of several phenolic compounds have been determined by studying the equilibration couples phenols and corresponding phenoxyl radicals means EPR spectroscopy. Measurements were carried out in highly concentrated solutions submitted to continuous photolysis presence di-tert-butyl peroxide. Since under this experimental condition decay was slower than hydrogen transfer reaction from phenoxyls, equilibrium concentrations two actually measured. Due fact that radical species are continuously generated solution, giving short-lived could also be investigated method. All examined characterized O−H bonds weaker parent compound, PhOH, their BDE values can calculated a good approximation an additive rule using fixed contributions for various substituents. Only case sterically c...