Pillar[5]arene–neutral guest recognition based supramolecular alternating copolymer containing [c2]daisy chain and bis-pillar[5]arene units

A novel supramolecular alternating copolymer with [c2]daisy-chain dimer and macrocycle host dimer as repeating units has been fabricated. A key factor for this new assembly strategy is based on a [c2]daisy-chain pseudorotaxane bearing additional unbound recognition sites at both ends, which was successfully achieved from a careful designed heterotritopic (AB₂-type) copillar[5]arene. By utilizing the intermolecular host–guest interactions between the double-threaded dimer and a pillar[5]arene dimer, a linear supramolecular polymer was prepared. These results provided not only a convenient approach for the construction of [c2]daisy chain based supramolecular polymers, but also a novel method for building supramolecular alternating copolymers.