X-RAY STRUCTURAL-ANALYSIS OF A NOVEL ORGANIC METAL (BEDT-TTF)4[HG2CL6].PHCL

X-ray structural analysis has revealed that reaction of (BEDT-TTF)[HgCl3]- with PhCl leads to the formation of a cation-radical salt (BEDT-TTF)4[Hg2Cl6]. PhCl, which exhibits a laminar crystal structure. The cationic layer is characterized by a grid or lattice network of contracted S...S intermolecular distances (3.396(4)-3.647(5) angstrom), which unite the BEDT-TTF cations in ribbons or bands, parallel to the [014BAR] direction, and which also bind the ribbons together in a direction close to the [010) axis. The presence of this type of lattice network explains the metallic nature of the conductivity of this salt (BEDT-TTF)4[Hg2Cl6].PhCl in the temperature range 300.0-1.5 K, and is the basis of assigning this salt to a new class of organic, two-dimensional conductors. The [Hg2Cl6]2- anions and PhCl solvent molecules are united via secondary Hg ... Cl 3.176(5) angstrom and Cl ... Cl 3.480(6) angstrom interaction forces to form centrosymmetric tetramers [Hg2Cl6PhCl]24-, stretched out along the [014] axis direction.