Acidities and hemolytic bond dissociation energies (BDEs) of benzyl-tyoe C-H bonds in sterically congested substrates

Bond dissociation energies and hydronium ion concentrations at equilibrium of benzylic carbon to hydrogen bonds in dimethyl sulfoxide are presented. Nineteen triphenylmethanes, three dihydroanthracenes and nine xanthenes were used in the experiment. The resonance effect due to the solvation of a substituent induced a conformational alteration to allow for conjugative overlap of the anion and the substituents. The effect of substituents far from the carbanion was found to be negligible.