Incorporation of Clathrochelate-Based Metalloligands in Metal-Organic Frameworks by Solvent-Assisted Ligand Exchange

Iron(II) cage complexes with terminal 4-pyridyl groups can be incorporated in metal-organic frameworks (MOFs) via solvent-assisted ligand exchange (SALE). Paddle -wheeled MOFs with N,N'-di-4-pyridylnaphthalenete-tracarboxydiimide pillars were used as starting materials. Pillar exchange was nearly quantitative, despite the fact that the cage complexes are long (similar to 15 angstrom) and sterically demanding. The reactions provide products of high crystallinity, and the structures of daughter MOFs were determined by single crystal X-ray diffraction. The crystallographic analyses showed that some of the SALE experiments led to topological changes of the MOF structures.