Application of Changes in Atomic Charges Resulting from Different Electrochemical Oxidation Mechanisms for the Estimation of the First Oxidation Potential of Flavonoids

In addition to our model based on the sum of the differences in the net atomic charges between a cation and a neutral flavonoid (Sigma(s(C)) Delta NAC(Cat-Neut)) over the carbon atoms in the flavonoid skeleton, here I present two complementary models for the estimation of the first electrochemical oxidation potential, E-p1. The models were also based on the sum of differences in the net atomic charges, but between other species of a flavonoid; between a radical and an anion of a flavonoid, Sigma(s(C)) Delta NAC(Rad-Anion), and between a radical and a neutral flavonoid, Sigma(s(C)) Delta NAC(Rad-Neut). These three variables are connected with different mechanisms (SET-PT, SPLET and HAT) of electron loss during the electrochemical oxidation of a flavonoid. It was shown that the best model for the given set of 29 flavonoids was obtained by using mean values of all of the three variables as a variable (R-2 = 0.974, S.E. = 0.042 and S.E.(cv) = 0.45) which could mean that all three mechanisms are equally possible.

Automated summary

The study introduces models based on differences in net atomic charges to explore the mechanisms of electron loss during the electrochemical oxidation of flavonoids. The best model for a given set of flavonoids combines all three variables, suggesting that multiple mechanisms are at play.