Crystal structure and physical properties of (TTM-TTP)AuI2

Abstract

Crystal structure analysis of new organic conductors (TTM-TTP)AuI₂ and (TTM-TTP)AuBr₂ , where TTM-TTP is 2,5-bis[4,5-bis(methylthio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalene, has been carried out. The donor to anion ratio is 1:1 and the donors form highly one-dimensional columns. These materials, however, show dimerization of the donor molecules along the stacking direction. Therefore the energy gap appears at the Fermi level, and these salts become band insulators. The observed temperature dependence of the conductivity is semiconducting, but the room-temperature conductivity is comparatively high, 10–40 S cm^–1 .