Hydrothermal synthesis and characterization of ternary lanthanide-2,2′-bipyridine-3,3′-dicarboxylate coordination polymers

Two lanthanide coordination polymers, [{Ln2(bpdc)3(phen)2(H2O)2} · (H2O)6]n (Ln = Dy (1); Ho (2)) were obtained from 2,2′-bipyridine-3,3′-dicarboxylic acid (H2bpdc), 1,10-phenanthroline (phen) and corresponding lanthanide oxides by hydrothermal synthesis. Polymers 1–2 are found to be isostructural. Single-crystal X-ray diffraction shows that 1–2 are all one-dimensional zigzag chain structures and extend to two-dimensional networks through π–π interactions and hydrogen bonds. Thermogravimetric analysis of 1–2 displays a considerable thermal stability. The variable-temperature magnetic susceptibility of both compounds was measured. Photoluminescence measurement indicates that 1 is a strong yellow emitter.