Synthesis, structure and properties of novel TTF dimers bridged by two trisulfide chains

We synthesized novel TTF dimer molecules in which two TTF moieties are connected to each other by two trisulfide chains. Structure of tetrakis(methylthio) derivative 1 is cyclophane-like one and interplanar distance in the dimer is 3.86 å. 1 shows two pairs of reversible one-electron redox waves (+0.57 and +0.67 V vs. Ag/AgCl in PhCN) and one pair of reversible two-electron redox wave (+1.15 V). The ClO4− salt of 1 has 1:2 (Donor:Anion) composition and is an insulator. On the other hand the PF6− salt of bis(trimethylene) derivative 2 has one-dimensional columnar donor array with 1:1 composition and shows semiconducting behavior (σrt = 10−1 Scm−1).