Hydrothermal syntheses and characterization of three lanthanide coordination complexes constructed by 2,2＇：6＇,2＇＇-terpyridine and 2,2＇-biphenyldicarboxylic acid

Two 1D coordination polymers [Ln2（dpdc）3（tpy）2·H2O]n [Ln=Nd 1, Yb 2, H2dpdc=2,2＇-biphenyldicarboxylic acid and tpy= 2,2＇：6＇,2＇＇-terpyridine] and one dinuclear complex Er2（dpdc）2（Hdpdc）2（tpy）2 3 were obtained via hydrothermal reactions and determined by X-ray diffraction analysis. The crystal structure data of 1 and 2 revealed that two coordination polymers were isostructural and possessed a 1D chain framework consisting of eight-coordinated Ln（III） centers. In the asymmetric unit, the two Er（III） ions in 3 were both nine-coordinated and had similar coordination environments. The Er（III） ions were bridged by dpdc2-ligands into dinuclear structures. The complexes were also characterized by IR spectra and thermogravimetric analysis. The solid fluorescence of 1 and 3 was also investigated at room temperature.