Syntheses, structures, and properties of 3D lanthanide coordination polymers based on pyridine-2,3,5,6-tetracarboxylate

Three new 3D lanthanide(III) coordination polymers with the formulas {K[Ln(pdtc)(H2O)]center dot H2O}(n)(Ln = Nd(1), Dy(2), Er(3); K4pdtc = potassium pyridine-2,3,5,6-tetracarboxylate) have been synthesized via hydrothermal methods and structurally characterized by X-ray single crystal diffraction analysis, elemental analysis and thermal gravimetric analysis. In complexes 1-3, the pdtc(4-) ligands adopt new coordination modes and the three complexes have similar 3D network structures which consist of dinuclear building units and novel K-O chains inserted into the structure. Furthermore, complex 2 shows corresponding characteristic luminescence and complex 3 exhibits weak antiferromagnetic properties.