p-Type Semiconducting Dendrimers Bearing Thiophenyl Peripheral Moieties: Effect of Alkyl Chains on Molecular Packing Geometry

First generation thiophene‐labeled conjugated dendrimers have been synthesized through the Heck coupling reaction between the 5‐vinyl‐[2,2′]bithio‐ phenyl derivative and 1,2,4,5‐tetrabromo‐benzene as a core. One dendrimer has hexyl groups at the periphery and the other does not have it. They display a considerably better solubility than the linear conjugated oligothiophene. We observe drastic spectral change in a film state of dendrimer due to crystallization and a high extent of intermolecular interaction. Effect of peripheral alkyl groups on the intermolecular interaction and lamella orderness was investigated using two dendrimers.