Electrochemistry and time dependent DFT study of a (vinylenedithio)-TTF derivative in different oxidation states

The electrochemical and spectroelectrochemical properties of a bis-pyrid-4-yl functionalised vinylenedithio-TTF derivative, 1, in solution are reported. The compound was immobilised on a Pt electrode and the resulting layers formed were investigated using electrochemical techniques. Two oxidation processes were observed for 1, typical of TTF derivatives. A solvent dependence study revealed that the stabilisation of the radical cation intermediate, 1+, towards further oxidation is achieved in solvents with a low Gutmann donor number such as dichloromethane. Analysis of 12+ in solution under aerobic and anaerobic conditions reveal that its stability is compromised in the presence of oxygen and therefore the stability of monolayers of 1 is greatly enhanced under anaerobic conditions. Time dependent DFT calculations of the compound in several oxidation states are discussed to obtain information on the location of the various redox processes.