Chain architecture dependent 3-dimensional supramolecular assembly of rod-coil molecules with a conjugated hexa-p-phenylene rod

摘要

We have prepared hexa-p-phenylene based rod-coil molecules with identical coil volume fractions, but different poly(propylene oxide) (PPO) coil architectures (linear versus dibranched), and investigated their self-assembling behavior in the solid state by small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) techniques. Rod-coil molecules with a linear PPO coil showed a honeycomb-like lamellar assembly of rod segments with hexagonally arrayed PPO coil perforations. In contrast, the rod-coil molecules with dibranched PPO coils self-organized into rod bundles with a body centered tetragonal symmetry surrounded by a PPO coil matrix. These results demonstrate that the steric hindrance at the rod/coil interface arising from coil architectural variation is a dominant parameter governing supramolecular rod assembly in the rod-coil system.