Cofacially constrained organic semiconductors.

The synthesis, spectroscopy, and electrochem. is presented of bis[oligo(thiophene)] monomers where the sterics of covalently attached subunits enforced oblique spatial orientations. The synthetic scheme applied to a variety of chromophores; std. bromination and cross-coupling chem. afforded bis(terthienyl)benzene systems in high yield. Model systems were prepd. consisting of mono(terthiophene)s to probe the effects that van der Waals contacts impose during electropolymn. and methyl-blocked analogs to examine the electrochem. properties of derivs. that do not undergo polymn. The extent of delocalization between chromophores as deduced from electrochem. studies is discussed and viable electrochromic polymers are demonstrated. [on SciFinder(R)]