Exploring “nested” non-covalent interactions in metal–organic cage-cross-linked polymers to facilitate new functions for supramolecular polymer networks

Supramolecular polymer networks contain non-covalent cross-links that enable access to broadly tunable mechanical properties and stimuli-responsive behaviors; the incorporation of multiple unique non-covalent cross-links within such materials further expands their mechanical responses and functionality. This talk will introduce the concept of leveraging “nested” supramolecular crosslinks, wherein two distinct types of non-covalent interactions exist in parallel within polymer networks, to control bulk material functions. To demonstrate this concept, we use polymer-linked Pd₂L₄ metal–organic cage gels (polyMOCs) that form hollow MOC junctions through metal–ligand coordination. These polyMOC junctions also host small-molecule guests, leading to a nested combination of host–guest binding and metal–ligand coordination where the (thermo)dynamics of the former affect the latter, ultimately translating to substantial guest-dependent changes in bulk material properties that could not be achieved in traditional supramolecular networks with multiple interactions in series.