BEDT-TTF salts of the unsymmetrical [M(tfadt)2]− dithiolene complexes (M = Ni, Au; tfadt = S2C2(CN)(CF3))

Two closely related 1:1 salts are obtained upon electrocrystallization of BEDT-TTF (BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene) in the presence of the isosteric [M(tfadt)2]− dithiolene complexes (tfadt: 1-trifluoromethyl-2-cyano-1,2-dithiolato), which essentially differ by their spin state, S = 0 in [Au(tfadt)2]−, S = 1/2 in [Ni(tfadt)2]−. In both [BEDT-TTF][M(tfadt)2] salts, the BEDT-TTF radical cations form chains with a strong lateral overlap and strong antiferromagnetic interactions while the paramagnetic anions in the nickel-containing salt [BEDT-TTF][Ni(tfadt)2] are essentially non-interacting. The structural differences between the nickel and gold complexes are analyzed and discussed.

In both 1:1 BEDT-TTF salts of the isosteric [M(tfadt)2]− dithiolene complexes [M = Au (S = 0), M = Ni (S = 1/2)], the BEDT-TTF radical cations form chains with lateral overlap and strong antiferromagnetic interactions. The differences between the salts with the paramagnetic nickel and diamagnetic gold complexes are analyzed and discussed.Figure optionsDownload as PowerPoint slide