The Uncommon Channel-Based Ln-MOFs for Highly Selective Fe3+ Detection and Superior Rhodamine B Adsorption

Two new isostructural 3D lanthanide-organic frameworks [H2N(Me)(2)] [Ln(3)(OH)(bpt)(3)(H2O)(3)] (DMF)(2)center dot(H2O)(4) (1-Ln; Ln = Sm and Eu) with a 1D channel (25 angstrom) have been successfully assembled from the rare trinuclear [Ln(3)(OH)(COO)(9)] clusters and biphenyl-3,4',5-tricarboxylic acid (H(3)bpt) and exhibit high stability towards water in the pH range 3-10. MOF 1-Eu is a promising luminescent probe for sensing Fe3+ in aqueous solution and is also selective towards rhodamine B (RhB) with a superior adsorption capacity of 735 mg g(-1), which is the highest among the reported Ln-MOFs for RhB removal so far. Periodic DFT calculations further confirmed the selective adsorption of rhodamine B over other dyes.