Ordering Bent and Straight Dicarboxylate Linkers in an fcu Zirconium Metal-Organic Framework

The ordering of multiple organic linkers with different sizes and geometries on metal-organic frameworks (MOFs) offers structures with advanced complexity and functionality for enhanced properties. The selection of the components and the number of synthesis steps are commonly rationalized to match existing structural motifs in order to increase the probability of producing the designed new frameworks. Alternatively, combining multiple components, without a preconceived structural model, allows for the exploration of unprecedented structural characteristics. However, this approach requires a large number of experiments to identify both the composition and conditions for a successful synthesis. Here, we report a new Zr-MOF containing ordered straight and bent dicarboxylate linkers prepared by a one-pot synthesis. The discovery was made by high-throughput exploration of the chemical space composed of two linkers, the source of Zr, and the modulator. The linkers and the Zr₆ cluster are ordered on an fcu framework that is tetragonally distorted from its typical cubic symmetry. The arrangement of linkers with different sizes and geometries affords cages and windows with shapes that have not been reported previously, despite the plethora of known fcu-based MOFs. The new MOF exhibits chromatographic separation of the n-hexane/benzene/cyclohexane mixture and demonstrates reversible unbinding and rebinding of the bent linkers upon the addition and removal of protic solvents. The unusual structural properties of the new MOF arise from ordering linkers in a non-predetermined manner following high-throughput synthesis exploration.