The Enthalpy of Formation of Substituted Phenols and Dihydroxybenzenes for a Group Contribution Method with “Chemical Accuracy”

Abstract

In this paper we validate Group Contribution (GC) parameters for substituted phenols and dihydroxybenzenes including catechol, resorcinol and hydroquinone with respect to a recently developed Group Contribution method for estimating the heat of formation of organic compounds with chemical accuracy (1 kcal/mol). For the compounds studied, we found differences greater than this threshold between experimental data from different publications. Using quantum mechanical methods in conjunction with common knowledge from physical organic chemistry, we were able to validate the GC model values and thereby extend the applicability range of the previously developed model. It could be concluded that most GC-predicted values can be considered trustworthy, assuming the B3LYP correction for steric interaction between ortho t-butyl and hydroxyl groups is included. As with earlier studies, we found that G4 quantum-calculated values can serve as a reliable source of gas-phase heats of formation of organic compounds.