Absorption Spectra and Electrical Resistivities of Some Anomalously Composed Thiazine—Quinone Complexes

Abstract

Dibenzo[c,d]phenothiazine has been found to form a 2:1 complex with 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone and a 3:2 complex with the dibromo analog. The complexes exhibit resistivities of about 17 and 240 Ω·cm at 20°C, respectively. Since the infrared spectra indicate the presence of the semiquinone ion instead of the quinone molecule, the ground state of the complexes is characterized as essentially dative. The appearance of an electronic absorption band in the infrared region is noted in the anomalously composed complexes but not in the 1:1 complexes and is attributed to the interaction between the cationic radical and the neutral donor molecule.