Metal complexes of a tetrathiafulvalene 4,5-dithiolate. Synthesis, characterisation and properties of dianionic and neutral mercury complexes

Dianionic mercury bis(tetrathiafulvalene dithiolate) complexes [NMe4]2[Hg(R2C6S8)2](R = Et or Bu) and the corresponding oxidised neutral complex [Hg(R2C6S8)2](R = Et) have been prepared. The crystal structure of [NMe4]2[Hg(R2C6S8)2](R = Et) has been determined and shows that the tetrathiafulvalene dithiolate units are tetrahedrally co-ordinated around the central Hg atom. Cyclic voltammetry and ESR studies indicated that there is very little interaction between the two ligands. A compressed pellet of the powdered neutral complex exhibited an electrical conductivity of 10–5 S cm–1 at room temperature.