Syntheses, crystal structures and properties of a series of isostructural lanthanide organic frameworks

Abstract

Nine lanthanide–organic frameworks [Ln(L)_1.5(H₂O)₃] (1-Ce, 2-Dy, 3-Eu, 4-Gd, 5-Ho, 6-Nd, 7-Pr, 8-Sm, and 9-Tb; H₂L = 4,4′-(1,2-dihydroxyethane-1,2-diyl)dibenzoic acid) have been synthesized under solvothermal conditions. Single-crystal X-ray diffraction analyses show that compounds 1–9 are isomorphic, in which each Ln atom is linked by L ligands to form a 3D framework with an unprecedented 4,4,6-connected topology. All these compounds have excellent solvent stability and can remain stable in boiling water for up to a week. Moreover, these compounds exhibit metal-dependent luminescence and magnetic properties. 3-Eu and 9-Tb exhibit relatively good fluorescence properties, 4-Gd shows ferromagnetic coupling, and the other compounds present antiferromagnetic coupling.