Predicting the heat of formation of chlorinated phenols and associated chlorine isotopologues

Using quantum chemical techniques, the standard gas-phase enthalpies of formation of chlorinated phenols were calculated by two high level composite methods. The standard Gibbs free energies of formation of the chlorinated phenols were also estimated. The results are compared to experimental and other theoretical studies and generally good agreement between experiments and model prediction is found. We subsequently assess the influence of the position of chlorine in the aromatic ring and isotope fractionation caused by ³⁷Cl on the heat of formation of a series of polychlorinated phenols.