Equilibrium acidities and homolytic bond dissociation energies of the acidicC-H bonds in N-substituted trimethylammonium and pyridinium cations

The effects of the alpha-Me3N+ andalpha-PyN+ groups on equilibrium acidities were determined, specifically their effects on carbon-acid substrates such as acetone, diethyl malonate, fluorene, 2-(phenyl-sulfonyl)fluorene, toluene, p-(phenylsulfonyl)toluene and others. Thetrimethylammonium and pyridinium groups had acidifying effects on the adjacent C-H bonds associated with coulombic stabilization of the negative charge by positive charges on the nitrogen atom. Pyridinium groups had opposite effects on adjacent radicals because they caused destabilization.