The Cation-radical Salts Derived from Benzo- and Dibenzo-phenothiazines

Abstract The chloride, iodide, and perchlorate of benzo- and dibenzo-phenothiazine cation-radicals have been prepared by the reaction of an equimolar mixture of the thiazine and its S-oxide with an appropriate acid. The vibrational spectra of the products have been found to be in close agreement with those of the bromides made by the familiar oxidation of thiazines with bromine. The results of electronic spectral and ESR measurements have furnished further support for our conclusion that the thiazine cation-radical salts can be prepared by the above-mentioned reaction. The electronic spectra of the iodides of benzophenothiazines have been found to differ markedly from those of other salts and to bear a resemblance to those of the low-resistivity iodine complexes.