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)₄Hg₂Cl₆]· 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) Å), which unite the BEDT-TTF cations in ribbons or bands, parallel to the 014] 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)₄Hg₂Cl₆]·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) Å and Cl...Cl 3.480(6) Å interaction forces to form centrosymmetric tetramers Hg₂Cl₆PhCl]₂ ^4–, stretched out along the 014] axis direction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2062–2070, September, 1991.The authors wish to acknowledge R. N. Lyubovskaya for supplying the crystals and for helpful discussion of the results.