Voltammetric, Spectroscopic, and Microscopic Investigation of the Oxidation of Solid and Solution Phases of Tetrathiafulvalene (TTF) to (TTF) 2 MO 4 (M=Mo, W)

Abstract The diffusion‐controlled solid−solid‐state transformation of TTF to (TTF) 2 MoO 4 and (TTF) 2 WO 4 is reported at TTF‐modified glassy carbon, indium tin oxide (ITO), Au, and Pt electrodes in contact with aqueous MoO 4 2− or WO 4 2− electrolytes. Electrocrystallization of (TTF) 2 MoO 4 and (TTF) 2 WO 4 onto the electrode surface also was achieved by oxidation of TTF to TTF + in the presence of Na 2 MoO 4 and Na 2 WO 4 in the mixed CH 3 CN/H 2 O (90 : 10 v/v) solvent containing 0.1 M Bu 4 NPF 6 as the supporting electrolyte. Mechanistic aspects of the solid−solid state interconversion reactions and electrocrystallization have been probed by using cyclic voltammetry, chronoamperometry, electrochemical quartz crystal microbalance (EQCM), and electrochemical surface plasmon resonance (ESPR), whereas the morphology of the electrocrystallized materials was established by using scanning electron microscopy (SEM). Vibrational (IR, Raman) and UV/Vis spectroscopic methods, as well as other techniques, were used to establish that the products of electrooxidation are (TTF) 2 MoO 4 and (TTF) 2 WO 4 .