Cation-radical salts with organometallic gold anions. X-ray structure of [TTFPh]2[Au(C6F5)2]

The combination of tetrathiafulvalene (TTF) and 4,4′-diphenyltetrathiafulvalene with organoaurate(I) and organoaurate(III) salts, under a controlled current, affords crystalline solids containing organometallic anions: (TTFPh2)2[Au(C6F5)2], (TTFPh2)[Au(C6F3H2)2], (TTF)[Au(C6F5)Cl], (TTFPh2)2.5[Au(C6F5)2Cl2], (TTF)[Au(C6F3H2)2Cl2] and (TTFPh2)[Au(C6F5)2I2] which show moderate or low conductivities. (TTFPh2)2[Au(C6F5)2] has been studied by X-ray diffraction studies and shows stacks of TTFPh2 parallel to the x axis, with the planar [Au(C6F5)2]− anions arranged in the interstices with their CAuC axes approximately perpendicular to the stacks. Its conductivity has been studied at different temperatures showing a semiconductor behaviour with an Ea = 0.13 eV in the range of 300-200 K. Below 200 K the activation energy shows a gradual decrease until Ea = 0.012 at T = 77 K.