Donor/acceptor-substituted radiaannulene segments of 6,6,12-graphyne

Abstract

A selection of five donor/acceptor-functionalized radiaannulenes was efficiently synthesized via a series of palladium-catalyzed couplings. These donor/acceptor segments of the elusive 6,6,12-graphyne allotrope are strong chromophores and undergo reductions into dianions corrrelating with Hammett substituent constants. Crystal data reveal planar structures of the cyclic cores, but twisting of the aryl substituents with torsional angles independent on the donor/acceptor character.