Physical properties of radical cation salts of the dimethylethylenedithiotetrathiafulvalene

Abstract Electrical conductivity and ESR experiments on several new salts of the unsymmetrical molecule dimethylethylenedithiotetrathiafulvalene are described. According to the ESR results, the compounds can be classified in two groups labelled α and β. The α compounds present similar magnetic behavior with an increase of the spin susceptibility at low temperature. The properties of the β samples are reminiscent of those of the TMTTF salts exhibiting either a spin-Peierls or an antiferromagnetic ground state below 20 K.