Design of New Tetrazine-Triphenylamine Bichromophores - Fluorescent Switching by Chemical Oxidation

Original new fluorescent and electroactive compounds have been prepared, which feature two different fluorescent groups linked through an oxygen atom spacer. We describe here the synthesis, photophysical and electrochemical properties and their interplay, and our theoretical calculations. These molecules are composed of two fluorophores, an electron-rich triphenylamine unit and an electron-poor tetrazine unit. Although the bichromophores are not fluorescent in the neutral state due to a photoinduced electron transfer from the triphenylamine unit to the tetrazine unit, one can restore the fluorescence by oxydation of the triphenylamine moiety. Thus, a redox-fluorescent switch has been realized.