A triple-monomer methodology to construct controllable supramolecular hyperbranched alternating polymers

A novel "D₃-AC-E₃" triple-monomer methodology was proposed to construct supramolecular hyperbranched alternating polymers. Two rigid homotritopic monomers tris(per-methylated pillar[5]arene) (D₃) and tris(benzo-21-crown-7) (E₃), and a heteroditopic monomer bearing a dialkylammonium salt and a neutral guest moiety, were prepared. The supramolecular hyperbranched alternating polymer was formed by selective binding interaction between the pillar[5]arene moiety with the neutral guest moiety and between the benzo-21-crown-7 group and the dialkylammonium salt group. The triple-monomer system was found to effectively avoid the formation of cyclic oligomers/gels/precipitates usually formed in the traditional "A₂ + B₃" double-monomer system. This study will be helpful in designing supramolecular hyperbranched polymers with controllable structure and function.