Series of Water-Stable Lanthanide Metal-Organic Frameworks Based on Carboxylic Acid Imidazolium Chloride: Tunable Luminescent Emission and Sensing.

A series of isomorphic lanthanide metal-organic frameworks (Ln-MOFs), {[Ln(L)(HO)]·5HO} (, where Ln = Eu, Tb, Gd, and EuTb), have been synthesized by a rigid 1,3-bis(3,5-dicarboxyphenyl)imidazolium chloride (HLCl) ligand and Ln ions via a solvothermal method. Single-crystal X-ray diffraction indicated that exhibited similar three-dimensional porous frameworks with one-dimensional channels decorated by the uncoordinated carboxylate oxygen atoms. The luminescent sensing studies indicated that is an outstanding reusable luminescent probe suitable for the simultaneous detection of CrO, CrO, and MnO ions in an aqueous solution. Remarkably, the different proportions of Eu and Tb can be combined into the same Ln-MOF to yield a new series of differently doped MOFs. At the same excitation wavelength, they generated dual-emission peaks of Eu and Tb to show a gradual change in luminous color between yellow-green, yellow, orange, orange-red, and red. On the basis of the excellent optical properties of complexes, they can be employed as promising luminescent probe and multicolor tunable photoluminescence materials.