Reactivity of biologically important reduced pyridines. VIII. A semiempirical (AM1) study of the oxidation of 3-substituted-1-methyl-1,4-dihydropyridines

Significant linear correlations were observed between AM1-derived adiabatic, but not vertical, ionization potentials and the log of ferricyanide-mediated oxidation of 3-substituted-1-methyl-1,4-dihydropyridines. This result is consistent with a rate-determining electron loss in the reaction sequence and suggests molecular relaxation subsequent to the initial electron transfer. In addition, useful relationships were generated between oxidation rate and absolute electronegativity, a parameter derived from hard-soft acid-base theory.