Mixed Ligand PolyMOFs via RAFT Polymerization
The synthesis of metal–organic frameworks with organic linkers connected through a flexible polymer backbone (polyMOFs) has relied on macromolecular ligands with limited control over molecular weight and dispersity. An approach utilizing a reversible deactivation radical polymerization (RDRP) would significantly expand the scope of this emerging class of materials. Herein, we report the synthesis of polyMOFs from macromolecular ligands prepared by reversible addition fragmentation chain transfer (RAFT) polymerization, in which the key MOF-forming benzenedicarboxylic acid (H2bdc) linkers are on pendant side chains. While the macromolecular ligands alone were found to produce amorphous materials upon exposure to metal ions, addition of 1–3 equivalents of free H2bdc yielded mixed-ligand polyMOFs with tunable properties based on the amount of H2bdc added, including stability under ambient conditions and BET surface areas up to 608 m2/g. The combination of RDRP and mixed ligand strategies opens new possibilities for tuning the properties of polyMOFs through tailoring macromolecular ligand architecture and free linker composition.