Synthesis and properties of new TTP donors composed of TTF and TSF moieties

Several derivatives of bis-fused donors composed of TTF and TSF (1, 2), and the vinyl analogues (3,4), have been synthesized. Cylic voltamograms of 1-4 consist of four pairs of one-electron redox waves. The first redox potential of la is comparable to that of the corresponding sulfur analogues BDT-TTP, indicating the positive charge formed by the first oxidation mainly distributes over the TTF moiety. In contrast, the second redox potential is higher than that of BDT-TTP due to occurrence of the second oxidation on the TSF moiety. The donors la, 3a and 4a form highly conducting TCNQ complexes and I3− salts (σrt = 3 - 36 S cm-1 on a compressed pellet) with very low activation energies of 0.0094 - 0.040 eV.