Synthesis and characterization of the novel extended TTF-type donors with thiophenic units

Two new TTF-based donors that are dithiolene ligand precursors, 3-{5-[(2-cyanoethyl)thio]-2-(5,6-dihydrothieno[2,3-d][1,3]dithiol-2-ylidene-1,3-dithiol-4-yl)thio}propanenitrile, dtdt (1) and 3-({5-[(2-cyanoethyl)thio]-2-thieno[2,3-d][1,3]dithiol-2-ylidene-1,3-dithiol-4-yl)thio}propanenitrile, α-tdt (2), were synthesized and characterized. The electrochemical properties of these compounds were studied by cyclic voltammetry (CV) in acetonitrile. Compound 1 shows two reversible oxidation process at ¹E_1/2 = 0.639 V and ²E_1/2 = 0.997 V versus Ag/AgCl. This same processes occurs at ¹E_1/2 = 0.612 V and ²E_1/2 = 0.906 V in the case of 2. The crystal structures confirm the ability of these molecules to establish interactions with their neighbours through the peripheral sulfur atoms.