Converting 3D rigid metal-organic frameworks (MOFs) to 2D flexible networks via ligand exchange for enhanced CO2/N2 and CH4/N2 separation.

We report a synthetic strategy for constructing a novel flexible MOF from a rigid parent structure by ligand exchange. This is the first reported study on introducing flexible heterogeneity into a rigid structure via substantial structural rearrangement. The daughter material exhibits enhanced gas separation selectivity compared with the parent.