Theoretical study on the radical anions and reductive dechlorination of selected polychlorinated dibenzo-p-dioxins

► Neutrals and anions of nine selected PCDD congeners were investigated at DFT level. ► The PCDDs dechlorination pathway can be predicted based on their anionic states. ► EAAda of the PCDDs are significantly correlated with the dechlorination kinetics. ► The dechlorination of PCDDs is kinetically dominated by electron transfer step. ► An exponential correlation was found between PCDD residues and reaction time.