Lanthanide-Based Metal-Organic Frameworks Containing "V-Shaped" Tetracarboxylate Ligands: Synthesis, Crystal Structures, "Naked-Eye" Luminescent Detection, and Catalytic Properties.

Three lanthanide-based metal-organic frameworks, [Tb(HMDIA)(HO)]·HO (), [Ho(HMDIA)(HO)]·(HO) (), and [Nd(HMDIA)(HO)]·(HO) () from the same V-shaped ligand 5,5'-methylenediisophthalic acid (HMDIA), were prepared by mixing Ln and HMDIA under solvothermal conditions. The crystal structures of the three complexes were determined by single-crystal X-ray diffraction. The different coordination modes of the organic ligands resulted in different framework structures among the three complexes. The luminescent properties of in the ultraviolet-visible region were also studied. Interestingly, the bright-green emitter showed high selectivity and sensitivity to allow the naked-eye visualization of Fe ions and picric acid (PA) explosive, and both sensing mechanisms were revealed. Finally, and were shown to work as heterogeneous catalysts for the cyanosilylation reaction of aromatic aldehydes, and the catalysts could be recycled at least three times without any decrease in activity.