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The reaction of Tetrahiafulvalenyllithium with Eschenmoser's salts is reported for the first time. It allows the synthesis of the title compounds in one step.

The title compounds have been prepared in one or two steps, either formyltetrathiafulvalene or tetrathiafulvalenyllithium as starting materials.

The synthesis is described of a series of conjugated donor-π-acceptor molecules where 1,3-diselenoles are the electron donor moieties and dicyanomethylene or N-cyanoimine groups function as the acceptor moieties. Alkenes and aryl groups act as the conjugated spacers. The UV-VIS absorption spectra of these molecules in solution possess a low energy band resulting from intramolecular charge transfer; the wavelength of this band varies significantly with the structure of the spacer group. The solution redox properties, studied by cyclic voltammetry, reveal a reversible one-electron oxidation wave, attributed to the formation of the radical cation of the 1,3-diselenol-2-ylidene moiety, and an irreversible one-electron reduction to form the radical anion located on the dicyanomethylene or N-cyanoimine groups. The X-ray crystal structure of 9 9-(1,1-dicyanomethylene)-10-(4,5-dimethyl-1,3-diselenol-2-ylidene)-9,10-dihydroanthracene 14 is reported. The molecule is strained and adopts a “butterfly conformation” in the ground state due to unfavourable peri-interactions between the 1,3-diselenole selenium atoms and the peri hydrogens.

The synthesis of new π-electron donors of benzotetrathiafulvalene derivatives 4-11 with one or two hydroxyl functions and additional sulfur or selenium atoms is described. Their redox potentials were measured by cyclic voltammetry. Radical cation salts (RCS) and charge-transfer complexes (CTC) were prepared and their conductivities were measured. Some of the RCS are semiconductors.

A short synthesis of tetraformyltetraselenafulvalene (TFTSeF) is presented, and a few preliminary results emphasize its use as an efficient precursor of tetrasubstituted TSeFs such as a tetravinylic derivative, via a Wittig reaction, and tetrakis(hydroxymethyl)–TSeF by a simple NaBH4 reduction.