Phototriggered Formation of a Supramolecular Polymer Network Based on Orthogonal H-Bonding and Host-Guest Recognition

S upramolecular polymer networks(SPNs) have gained increasing research attention due to their reversible and tunable nature in the preparation of adaptive materials. The use of hierarchical self-assembly techniques is an emerging strategy for the fabrication of smart supramolecular polymer networks, but corresponding study is still rare. Herein, we have reported a novel supramolecular polymer network through complementary host-guest interactions and phototriggered quadruple H-bonding cross-linking. Specifically, we design and synthesize an H1G1-type monomer consisting of a benzo-21-crown-7(B21C7) host(H1), a dialkylammonium salt guest(G1) and a photolabile o -nitrobenzyl ether protected ureidopyrimidinone(Upy) moiety. B21C7 and ammonium moieties can first form a linear supramolecular polymer through complementary host-guest interactions. Under photoirradiation, the Upy groups on the SP side chains were released, and the obtained linear supramolecular polymer could be further transformed into SPN through a quadruple H-bonding cross-linking. Meanwhile, the in situ transformation in the solid state is also accompanied by pronounced enhancement in mechanical properties, which provides foundation for further application of materials in different scenarios.