Synthesis and crystal structure of new organic conductor (EOET)(4)[Hg3Br8](EOET=4,5-ethylenedioxy-4 ',5 '-ethylenedithiotetrathiafulvalene)

A new organic conductor of the composition (EOET)(4)[Hg3Br8], where EOET is the asymmetric 4,5-ethylenedioxy-4',5'-ethylenedithiotetrathiafulvalene do nor, was synthesized [sigma(300) = 1-5 (Omega cm)(-1)]. The composition and structure of the crystals were determined by X-ray diffraction analysis. T he crystallographic parameters for (EOET)(4)[Hg3Br8] are a = 76.28 (2), b = 8.492 (5), c = 21.332 (5) Angstrom, beta = 90.05 (2)degrees, V = 13817 (3) Angstrom(3), space group P2(1)/c, Z = 4, rho(calcd) = 2.55 g/cm(3), R = 0. 098. The crystal structure is layered; the layers of the organic donors EOE T0.5+ alternate with the layers of the Hg3Br82- anions. The [Hg3Br8](2-) an ion, in which all Hg-Br bonds are covalent, is observed for the first time. In the crystal structure, two different packing modes coexist for the dono r layers.