Creation of (σ+π)-Mixed Delocalization

We design and synthesize compounds bearing a new electronic delocalization system named (σ+π)-mixed delocalization, where a σ-delocalization unit on the periphery of a benzene ring can conjugate with a π-unit of another benzene ring oriented perpendicularly to the former benzene ring. The (σ+π)-mixed delocalization is evidenced by the HOMO structures, the increase in HOMO energy levels and a larger single-molecule conductance, compared to those of reference compounds with no (σ+π)-mixed delocalization.