Constitutional Dynamic Networks in Fluorous Biphasic Systems: Switching between Equilibrium and Out-of-Equilibrium States under Selective Pressure of Reversible Liquid–Liquid Phase Separation

<jats:p>Dynamic covalent libraries (DCvLs) allow constitutional adaptation in response to environmental changes. Here, we investigate three DCvLs based on imine and Knoevenagel-exchange reactions in a fluorous biphasic system, where reversible liquid–liquid phase separation (LLPS) exerts a selective pressure, driving constitutional adaptation through transient out-of-equilibrium states toward phase-specific network reorganization. Upon LLPS, a homogeneous 2D square network system transitions into a biphasic 3D prismatic network, triggering the partitioning of constituents across the phase boundary, followed by dynamic covalent component exchange. This sequence leads to synergistic upregulation of phase-adapted constituents and reveals a compartmentalized selection mechanism. Full cycles of reversible adaptation (through heating – phase mixing, cooling – phase separation, and re-equilibration sequences) were achieved, highlighting both thermodynamic and kinetic contributions to network behavior. The present work illustrates how structural, spatial, and dynamic parameters intertwine in the evolution of constitutional networks under physical constraints, and offers new avenues for designing responsive systems at and out of equilibrium.</jats:p>