A tetrathiafulvalene-based conjugated donor-acceptor-donor system

Unique donor-acceptor-donor systems possessing tetrathiafulvalene (TTF) and benzoquinone moieties have been prepared. The soluble, fully defined title systems show a charge-transfer absorption in solution and in the solid state. According to UV-transmission spectroscopy, the charge-transfer absorption in solution is an intramolecular process. In order to increase the acceptor ability of the quinone subunit, 1a has been protonated to a dication. Cyclic voltammetry shows the existence of two discrete oxidation states. It is thus possible to form charged species by either proton or electron transfer.