Infrared Study of Anthraquinone-Anion-Radical and its180 Labelled Isomer

Abstract Infrared spectra of anthraquinone and anthraquinone-180-anion-radicals have been investigated. Anion-radicals have been obtained by electrochemical reduction of anthraquinone and anthraquinone-180 in dimethylsulf-oxide-d6. Band assignment has been performed using the group vibrational concept and isotopic shift data. The assignment of IR active C[dbnd]O stretching band and the other bands in 1150–1800 cm−1 region of anthraquinone anion-radical (anthrasemiquinone) have been discussed and compared with those of some other 180 labelled anion-radicals. A decrease of 182 cm−1 has been found forafter transformation of the neutral quinone into anion-radical.