Rare Earth -MOFs: From Synthesis to Their Deployment for Amine-Sensing Application in Aqueous Media.

The pursuit of developing sensors, characterized by their fluorescence-intensity enhancement or "turn-on" behavior, for accurately detecting noxious small molecules, such as amines, at minimal levels remains a significant challenge. Metal-organic frameworks (MOFs) have emerged as promising candidates as sensors as a result of their diverse structural features and tunable properties. This study introduces the rational synthesis of a new highly coordinated (6,12)-connected rare earth (RE) -MOF-3, by combining the nonanuclear 12-connected hexagonal prismatic building units, [RE(μ-O)(μ-X)(OH)(HO)(OC-)], with the 6-connected rigid trigonal prismatic extended triptycene ligand. The resulting Y--MOF-3 material is distinguished by its high microporosity and Brunauer-Emmett-Teller surface area of approximately 1282 m/g, which offers notable hydrolytic stability. Remarkably, it demonstrates selective detection capabilities for primary aliphatic amines in aqueous media, as evidenced by fluorescence turn-on behavior and photoluminescence (PL) titration measurements. This work emphasizes the potential of MOFs as sensors in advancing their selectivity and sensitivity toward various analytes.