A NEW MOLECULAR-METAL - (EDT-TTF)2[PD(DMIT)2]2

Combining the acceptor [Pd(dmit)2]2 (bis-(1,3-dithio-2-thione-4,5-dithiolato)-palladium) with the donor EDT-TTF (2-(1,3-dithiol-2-ylidene)-5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin) leads to two conductive phases, (EDT-TTF)2 [Pd(dmit)2]3 (120 S/cm at 300 K), the crystal structure of which contains [Pd(dmit)2]3 trimers [d(Pd-Pd) = 3.29 angstrom], and (EDT-TTF)2 [Pd(dmit)2]2 (55 S/cm at 300 K), the crystal structure of which is built of stacks of [Pd(dmit)2]2 dimers [d(Pd-Pd) = 3.02 angstrom]. Temperature-dependent conductivity measurements indicate that the later phase is a molecular metal down to low temperatures, i.e. 4 K at least. The kappa-type crystal structure of EDT-TTF is also described.