Framework-Imprint Synthesis of Linear Porous Organic Polymers

Linear porous organic polymers (L-POPs) are rare species within the broad family of POPs due to the complexity of molecular design for preserving intrinsic free volume. With the absence of rigid structural unit, relaxed polymer chains undergo aggregation and dense packing, severely limiting the specific surface area. As a result, the preparation of L-POPs remains a formidable challenge. Herein, we overcome the above limitation by introducing a framework-imprint synthesis (FIS) strategy that exploits a sacrificial crystalline metal-organic framework (MOF) as a pore template. Specifically, triazolate L-POPs with flexible monomers are constructed via azide-alkyne click reaction within the confined nanochannels of the MOF host. The as-synthesized L-POP nanoparticles retain the octahedral morphology upon removal of the MOF scaffold. This process yields abundant hierarchical porosity comprising both micropores and mesopores, driven by the spatially organizing of polymer chains, which are impossible through solvothermal polymerization.