Assembly of three 3-D MOFs from 2-phenyl-4,5-imidazole dicarboxylate and oxalate

Three lanthanide-organic polymers, {[Ln(mu(3)-HPhIDC)(mu(2)-C2O4)(0.5)(H2O)]center dot 2H(2)O}(n) (Ln = Nd (1), Sm (2), and Tb (3)), have been isolated from the reaction of 2-phenyl-1H-imidazole-4,5-dicarboxylic acid (H3PhIDC) with equal amount of Ln(III) salts under solvothermal condition with the rigid coligand oxalate. The three polymers, which are isomorphous and isostructural, have been structurally characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. Each exhibits a 3-D framework constructed from infinite 2-D layers joined by mu(2)-C2O4, which are composed of mu(3)-HPhIDC2- and trivalent lanthanide. Thermal properties have also been investigated.