Crystal structure and density functional theory studies of toxic quinone metabolites of polychlorinated biphenyls

► Structure predictions of PCB quinones are of interest for toxicological studies. ► The inter-ring C1-C1′ bond is weakened by ortho chlorine substituents. ► Ortho chlorines increased the dihedral angle of PCB quinones. ► UB3LYP/6-311G∗∗ calculations yielded the best approximation. ► The structure of PCB quinones can be predicted using computational approaches.