Organic Metal with a High Oxidation State (+5/3), (TTM-TTP)(I3)5/3.

The crystal structure of the title compound, where TTM–TTP is 2,5-bis [4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalene, has been determined by X-ray analysis. The donors form a uniform stack, which is responsible for metallic conduction down to TMI = 20 K. The anions are composed of discrete I3− and an infinite chain of I3−. Each donor has anomalously large positive charge of +5/3.