Synthesis, crystal structure and magnetic properties of bis(3,4;3′,4′-ethylenedithio)2,2′,5,5′-tetrathiafulvalene-bis(cyanoimidodithiocarbonate)aurate(III), (bedt-ttf)[Au(cdc)2]

The new compound, (bedt-ttf)[Au(cdc)2], where bedt-ttf stands for bis(3,4;3′,4′-ethylenedithio)2,2′,5,5′-tetrathiafulvalene(+) and cdc for cyanoimidodithiocarbonate(2−), was synthesised. Its structure is monoclinic, space group P21/n, with cell parameters a = 6.9031(8) Å, b = 21.3213(16) Å, c = 7.9833(9) Å, β = 91.643(6)°, V = 1174.5(2) Å3 and Z = 2 and consists of alternated stacking of donor and acceptor moieties along c. This compound is a semiconductor with a room temperature resistivity of 6.5 × 103 Ω cm and an energy gap 2Δ = 0.51 eV. The anisotropy and thermal dependence of the ESR signal, only due to the bedt-ttf cations, was studied in the range 4–300 K. The static and EPR spin susceptibilities indicate an almost temperature independent value of 2.5 × 10−4 emu/mol ascribed to a three-dimensional network of antiferromagnetic interactions.

The new compound, (bedt-ttf)[Au(cdc)2], where bedt-ttf stands for bis(3,4;3′,4′-ethylenedithio)2,2′,5,5′-tetrathiafulvalene and cdc for cyanodithiocarbimate, was synthesised. Its structure is monoclinic, space group P21/n and consists in alternated stacking of donor and acceptor moieties along c. This compound is a semiconductor with a room temperature resistivity of 6.5 × 103 Ω cm. The anisotropy and thermal dependence of the ESR signal, only due to the bedt-ttf cations, was studied in the range 4–300 K. The static and EPR spin susceptibilities indicate an almost temperature independent value of 2.5 × 10−4 emu/mol ascribed to a three-dimensional network of antiferromagnetic interactions.Figure optionsDownload as PowerPoint slide