Syntheses and properties of ethanediylidene-2,2′-bis(5-dicyano-methylene-3-thiolene) and its dibromo derivatives as new extensively conjugated electron acceptors

Abstract The title compounds 3 were synthesized as the first vinylogous hetero-TCNQs. Their cyclic voltammetry demonstrated the coalescence of the first and second reduction potentials owing to the extensive conjugation. The unsymmetrical dibromo derivative 3c formed highly conductive charge-transfer complexes with tetrathiotetracene and 2,3-dimethyl-1,4,9,10-tetraselenoanthracene.