Synthesis and electrochemistry of soluble double-bridged tetrathiafulvalene (TTF)-p-benzoquinone dyads

The synthesis of novel soluble unsymmetrically substituted TTF derivatives as precursors for the preparation of novel TTF-based donor-bridge-acceptor dyads is reported. Substitution on the acceptor p-benzoquinone moiety has a strong influence on the reduction potentials in compounds 18 which, however, do not show the presence of a charge transfer band in the electronic spectra. The cyclic voltammetry measurements reveal two oxidation waves for the TTF moiety and a third oxidation wave assigned to the hydroquinone moiety in 16 and 17. Compounds 18 show, in addition to the TTF oxidation waves, the presence of the reduction wave corresponding to the quinone moiety. The spectroelectrochemical study indicates the step formation of cation-radical and dication of the TTF fragment. (C) 1998 Elsevier Science Ltd. All rights reserved.