Synthesis, electrical properties and crystal structure of a new et-based charge-transfer salt containing binuclear polychloride complex anion

A new charge-transfer salt containing hexachlorodicuprate (II) binuclear polychloride complex counter anions, ET2Cu2Cl6 (ET = BEDT-TTF = bis (ethylenedithio)-tetrathiafulvalene), was prepared. The room-temperature d.c. conductivity and relative resistance temperature dependence of the salt from room temperature down to 77 K along the longest crystal growth direction are reported. The crystal structure is determined by the X-ray diffraction method at room temperature. It belongs to the triclinicpl space group with crystallographic parameters of a = 11.379(4), b= 16.353(4), c = 9.054(4) A, α = 90.33(3), β= 100.69(3), γ= 100.06(2) °, V= 1628(1) A3, Z = 2, dc = 2.261 g cm−3, λ (Mo Kα) = 0.710 69 A, μ = 28.45 cm−1, F000 = 1104.00 and final R = 0.043, Rw = 0.057 for 2331 observed reflections. The structure consists of isolated ET stacks and the binuclear polychloride complex dianion (Cu2Cl6)2− sheets. In the donor stack, significantly short S···S contacts are observed.