Structure of Flavones and Flavonols. Part II: Role of Position on the O-H Bond Dissociation Enthalpy

Abstract

The enthalpies of bond dissociations of the hydroxyl groups, the energy of the highest occupied molecular orbi-tals and the corresponding radicals spin densities of all possible ten isomeric mono-hydroxyl flavones are calcu-lated by means of 3-parameter Becke, Lee, Yang and Parr functional. The structural factors affecting these de-scriptors of radical-scavenging activity are outlined. The results obtained show that the hydroxyl groups in ring A and C are more involved in the process of a radical-capturing than recently believed.