Lanthanide metal-organic frameworks as multifunctional luminescent sensor for detecting cations, anions and organic solvent molecules in aqueous solution

A series of water-stable isostructural mono/bimetallic lanthanide metal-organic frameworks (Ln-MOFs) {[Eu5xTb5(1-x)(OH)(6)(TZI)(3)(DMA)(1.5)(H2O)(10.5)]center dot DMA center dot 0.5H(2)O}n (x = 1.0 (1), 0.5 (3), 0.4 (4), 0.3 (5), 0.2 (6), 0.1 (7), 0.05 (8), 0 (2), H(3)TZI = 5-(1H-tetrazol-5-yl)isophthalic acid) were synthesized. These Ln-MOFs exhibit 3D frameworks in which 1D chains based on pentanuclear [Ln(5)(mu(3)-OH)(6)(COO)(5)](4+) clusters are linked by TZI backbones. The luminescent investigations revealed that compounds 1 and 2 not only exhibit characteristic Eu3+ and Tb3+ emissions in the red and green regions, respectively, but also can sensitively and selectively detect Fe3+ cations, CO32-, PO43-, AsO43- anions and acetone molecules in aqueous solution. In addition, the luminescent colors of the bimetallic (Tb5(1-x):Eu-5x) compounds can easily be tuned by doping isostructural Ln- MOFs with Eu3+ and Tb3+ ions. This work presents some good candidate materials for the potential multifunctional sensors.