Metal-Organic Frameworks with Boronic Acid Suspended and Their Implication for cis-Diol Moieties Binding

Introduction of accessible boronic acid functionality into metal-organic frameworks (MOFs) might to endow them with desired properties for potential applications in recognition and isolation of cis-diol containing biomolecules (CDBs). However, no investigation is found to address this topic until now. Herein, Cr-based MOFs of MIL-100 (MIL stands for Materials from Institut Lavoisier) integrated with different pendent boronic acid group (MIL-100-B) are reported. This new functional material is successfully prepared using a simple metal-ligand-fragment coassembly (MLFC) strategy with isostructure to the parent MIL-100 as verified by X-ray diffraction characterization. The integration and content tunability of the boronic acid group in the framework are confirmed by X-ray photoelectron spectroscopy and B-11 NMR. Transmission electron microscopy reveals that MIL-100-B can evolve into well-defined morphology and nanoscale size at optimized boronic acid incorporating level. The obtained MOFs exhibit comparable surface areas and pore volumes with parent MIL-100 and present exceptional chemical stability in a wide pH range. The inherent boronic acid components in MIL-100-B can effectively serve as the recognition units for the cis-diol moieties and consequently enhance the capture capabilities for CDBs. The exceptional chemical stability, high porosity, and good reusability as well as the intrinsic cis-diol moieties recognition function prefigure great potential of the current MIL-100-B in CDBs purification, sensing, and separation applications.