Motivated by the ability to drive sol-gel transitions upon guest introduction for systems with super-stoichiometric Pd 2+ , we sought to explore a complementary mechanism to expand the scope of selective and predictable material property changes in nested polyMOC systems: the possibility for both sol-to-gel and gel-to-sol transitions driven by binding of the same guest, as well as reversible phase transitions when selective guest binding is attenuated. Previous reports have demonstrated that guest binding can drive self-sorting within heteroleptic MOCs formed from mixtures of chemically distinct but isostructural ligands. Specifically, in the absence of guest, statistical mixtures of heteroleptic cages arise; however, when a guest is added, the equilibrium is shifted toward the cage structure that binds the guest most strongly, typically resulting in narcissistic self-sorting (i.e., homoleptic MOCs are preferentially formed). A schematic for such behavior is shown in Figure for a mixture of L1 and an isostructural endo-pyridyl variant, L2, that on its own will form cages with no binding affinity for DAQ (vide infra). We reasoned that the same mechanism could be leveraged to produce topological changes in polyMOC gels fabricated with mixtures of distinct polymer-bound and small-molecule ligands that, on their own, would form MOCs of the same architecture, but with varying abilities to bind a specific guest as illustrated in Figure . If such self-sorting were sufficiently selective, sol-gel transitions could be achieved through the preferential incorporation of polymer-bound ligands into MOC structures via a favorable guest binding event (Figure panel 1 to 2). Further, such sol-gel transitions could have the potential to be reversible upon addition of a guest that non-selectively binds cage structures from the ensemble (Figure panel 2 to 3). With further addition of the selectively binding guest, another sol-gel transition may be achieved (Figure panel 3 to 4); this cycle could potentially be repeatable if stronger binding or greater equivalents of each type of guest (selective versus non-selective binding) were added. Such functions would be very difficult to achieve in traditional supramolecular networks.