Synthesis, structure and properties of lanthanoid(III) complexes based on N-heterocyclic dicarboxylic acid ligand

We study the non-covalent interactions within complexes and characterize the structure and properties of N-heterocyclic dicarboxylic acid rare earth complexes. The chelating ligand 2,2′-bipyridine-6,6′-dicarboxylic acid (H2bpdc) was reacted with neodymium nitrate hexahydrate and dysprosium nitrate pentahydrate in a solvothermal reaction to produce {[Nd(bpdc)(HCOO)(H2O)2]·H2O}n (A) and [Dy2(bpdc)3(H2O)2(DMF)]·3H2O (B), respectively. Single crystal X-ray diffraction characterization reveals that A is a metal organic framework, with the rare earth center adopting a nine-coordinated tricapped trigonal prism. In contrast, B forms an eight-coordinate triangular dodecahedron. Fluorescence analyses indicate that both A and B have excellent luminescence properties. The thermal stabilities of both complexes were examined using thermogravimetric analysis (TG and DTG), and A has better thermal stability than B.