Successive photosubstitution of hexchlorobenzene with cyanide ion

A study was conducted on a novel nucleophilic polysubstitution reaction of hexachlorobenzene (HCB) with cyanide ion in acetonitrile/water. The findings indicate that an electron acceptor is not required for successive photocyanations of HCB with high quantum yield. Sensitization and quenching results suggest a triplet reactive excited state. However, variation of [HCB] at constant [CN-] indicates that the reaction becomes less efficient with increasing [HCB].