Redox-induced solid-solid state transformation of tetrathiafulvalene (TTF) microcrystals into mixed-valence and π-dimers in the presence of nitrate anions

Tetrathiafulvalene (TTF), when dissolved in an organic solvent, can be electrochemically oxidized to the cation radical TTF+aEuro cent and the dication TTF2+. In aqueous Co(NO3)(2) electrolyte media, TTF chemically modified electrodes undergo a very different TTF to TTF(+aEuro cent)pathway to give two solid-solid state conversion reactions. Initially, the mixed-valent (TTF)(2)NO3, containing (TTF-TTF+aEuro cent) as a dimeric cation, is formed, which in turn can be oxidized to (TTF)(2)(NO3)(2), containing the (TTF+aEuro cent)(2) dimeric cation. These processes occur by nucleation-growth mechanisms on glassy carbon, platinum, gold and indium-tin oxide electrode substrates containing adhered TTF solid. The products have been characterized by spectroscopic and voltammetric methods and (TTF)(2)(NO3)(2) also has been synthesized by reaction of TTF+aEuro cent, prepared by bulk electrolysis in acetonitrile with (Bu4N)NO3, using the appropriate stoichiometric molar ratios.