A robust 3D In-MOF with an imidazole acid ligand as a fluorescent sensor for sensitive and selective detection of Fe3+ions

A stable 3D In(iii)-based metal-organic framework, [In(L)(mu(2)-OH)]center dot 0.5H(2)O (1) (where H2L = 5-(1H-imidazol-1-yl)isophthalic acid), was successfully synthesized and fully characterized. As established by single-crystal X-ray diffraction, the compound1has a 4,6-connected 3D architecture crystalized in the monoclinicC2/cspace group. On the basis of thermodiffractometry,1retains the crystallinity and the main framework below 450 degrees C. The structural integrity of1is sustainable in water, under harsh acidic and basic conditions (pH 2-13), and in common organic solvents, presenting excellent water stability and chemical stability. The photoluminescence properties of1are investigated as well. Remarkably, luminescence studies reveal that1can recognize Fe(3+)ions with high selectivity from mixed metal ions in aqueous solution through a luminescence quenching phenomenon. The results suggest that the MOF may serve as a potentially useful sensory material for the detection of metal cations, and this work also demonstrates that highly hydrolytically stable In(iii)-MOFs could be constructed and used for some meaningful applications in water.