New building unit for rigid and coplanar oligo-aromatic molecular wires with insulating mantel

Molecular-scale electronic wires should consist of i) a highly-conjugated backbone for electron transport and ii) an insulating mantle to prevent unfavorable inter-chain hopping of the charges. We present a promising building block for this class of molecular wires; N-silylprotected 3′,4′,3″,4″-tetraaminoquaterthiophene. This molecule has a rigid and coplanar main chain surrounded by the electrically-inert alkyl groups of the substituents. MO calculations indicate that, in this system, the inter-unit steric repulsion prevents the conformational defects of the conjugated backbone.