Synthesis and crystal structure of an organic semiconductor (ET)4[Hg2I6]

A new cation-radical salt (ET)₄[Hg₂I₆] (1), where ET is bis(ethylenedithio)tetrathiafulvalene, has been synthesized in the system ET-HgI₃^–-PhCl. An X-ray study of 1 (a=41.02(5),b=23.01(1),c=8.233(2) Å,V=7772(3) ų, space groupPc2₁b,Z=4,d_calc=2.308 g cm^–3) has established its composition, chemical formula, and the main structural features. The ET cation-radicals are packed in the conducting layer, the type of packing is ; the [Hg₂I₆]^2– anion has a dimeric structure. The temperature dependence of the conductivity of the (ET)₄[Hg₂I₆] crystals (₃₀₀=6 Ohm^–1 cm^–1) has a semiconducting character.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1240–1244, July, 1994.We thank M. G. Kaplunov for his participation in the discussion of the obtained results.This work was financially supported by the Scientific Council on the Problems of High-Temperature Superconductivity (Grant No. 90346 Metallorg) and the Russian Foundation for Basic Research (Project No. 93-02-2384).