Theoretical study of the substituent effects on O–H BDE of trans-resveratrol derivatives in water and benzene: NBO analysis of intramolecular hydrogen bonds

Abstract

The effect of solvents and intramolecular hydrogen bonds on the three O–H bond dissociation enthalpies (BDEs) of non-substituted and substituted trans-resveratrols has been studied in water and benzene using DFT/B3LYP method. The formation of strong intramolecular hydrogen bonds in several radicals results in low BDEs. The solvent alters the intramolecular hydrogen bonds stabilization energies. In electron-withdrawing groups where the substituent causes high polarity of the parents and especially radicals, the effect of the solvent is stronger. When the substitution has a poor effect on the resveratrol molecule, the solvent has weak influence on formed radical stability, too. Besides intramolecular hydrogen bonds, the position, as well as electron-donating or electron-withdrawing character of a substituent in both, polar or nonpolar solvents, is able to affect OH BDEs substantially.