Solvent-included ternary charge-transfer salt (BEDTTTF)2GaCl4(C6H5Cl)0.5, (BEDT-TTF = Bis(ethyelenedithio)- tetrathiafulvalene)

Abstract

The synthesis, crystal structure, and conductivity of a solvent-included ternary charge-transfer salt (BEDT-TTF)2GaCl4(C6H5Cl)0.5 (1) is described and interpreted. Electrochemical oxidation of neutral bis(ethyelenedithio)-tetrathiafulvalene (BEDT-TTF) in the presence of (Me4N)Ga(C2O4)Cl2 in a mixture of C6H5Cl and C2H5OH yields crystals of 1. Compound 1 crystallized as a monoclinic C 2/c space group with cell parameters: a = 47.0615(4) Å, b = 6.7895(1) Å, c = 31.6297(4) Å, β = 132.064(1)°, V = 7503.0(2) Å3, Z = 8 at 293 K and a = 46.4767(5) Å, b = 6.7398(1) Å, c = 31.0778(4) Å, β = 131.630(1)°, V = 7267.4(2) Å3, Z = 8 at 120 K. The formal charge of the donor molecule was assigned as +0.5 from bond lengths in the TTF core. The donor molecules stack with C-···S contacts along the c direction and side-to-side S...S contacts along the b direction to form a two-dimensional donor layer on the bc plane. In the anion sheet, C6H5Cl chain is sandwiched by two GaCl4- chains with Cl...Cl contacts. Compound 1 shows semiconductive behavior with Ea = 124 meV between room-temperature and 150 K and σ300K = 1 S·cm-1. © 2013 by the authors; licensee MDPI, Basel, Switzerland.