Continuous Variation of Lattice Dimensions and Pore Sizes in Metal-Organic Frameworks

The continuous variation of the lattice metric in metal-organic frameworks (MOFs) allows precise control over their chemical and physical properties. This has been realized herein by a series of mixed-linker and Zr₆-cluster-based MOFs, namely, continuously variable MOFs (CVMOFs). Similar to the substitutional solid solutions, organic linkers with different lengths and various ratios were homogeneously incorporated into a framework rather than being allowed to form separate phases or domains, which was manifested by single-crystal X-ray diffraction, powder X-ray diffraction, fluorescence quenching experiments, and molecular simulations. The unit cell dimension, surface area, and pore size of CVMOFs were precisely controlled by adopting different linker sets and linker ratios. We demonstrate that CVMOFs allow the continuous and fine tailoring of cell-edge lengths from 17.83 to 32.63 Å, Brunauer-Emmett-Teller (BET) surface areas from 585 to 3791 m²g^-1, and pore sizes up to 15.9 Å. Furthermore, this synthetic strategy can be applied to other MOF systems with various metal nodes thus allowing for a variety of CVMOFs with unprecedented tunability.