Antioxidant properties can be tuned in the presence of an external electric field: accurate computation of O–H BDE with range-separated density functionals

Abstract

In this article, we have studied the effect of the external electric field on the antioxidant properties of gallic and caffeic acids. The variation of the O–H bond dissociation enthalpy (BDE), adiabatic ionization energy, proton dissociation enthalpy, proton affinity and electron transfer enthalpy, in the presence of an external electric field is studied. It is found that the antioxidant properties can be tuned by the application of an external electric field. In addition, the O–H bond strength, qualitatively measured from the O–H bond length, is found to depend on the external electric field. Furthermore, the performance of seven range-separated density functionals in the presence of the external electric field is reported for the first time. On comparing with the composite model CBS-QB3, it is found that the LC-BLYP functional reproduces the O–H BDE with high accuracy.