Electrical properties and crystal structures of metallic TMVT salts

Abstract

The TMVT-based salts (TMVT)2X (X–=AsF6– and ClO4–) have been characterized by X-ray crystallography, electrical resistivity measurements, thermoelectric power measurements and EPR studies. Although an increase in resistivity was observed in both salts, the thermoelectric power indicated that these salts retain essentially metallic states. In contrast with this result, the tight-binding band calculation of these salts suggested that their Fermi surfaces are quasi-one-dimensional and inclined to be nested. The X-ray crystallographic analyses revealed that their structures are similar to that of (TMVT)2PF6, and consist of donor stacks with no dimerization, wherein there are several chalcogen‥chalcogen contacts shorter than the sum of the van der Waals radii within and between the stacks.