Hydrothermal synthesis and crystal structures of two novel rare earth coordination polymers based on pyridine-2,6-dicarboxylic acid

Two novel rare earth coordination polymers, [La(pydc)2(H2O)][La(pydc)(H2O)2]·H2O (1) and [Sm(pydc)2(H2O)][Sm(pydc)(H2O)2]·H2O (2) (pydc ¼ pyridine-2,6-dicarboxylate) were hydrothermally synthesized and characterized by the elemental analyses, IR spectra and TG analyses. Single crystal X-ray diffractions show that 1 and 2 are isostructural compounds. In the compounds of 1 and 2, the 1D lanthanide helical chains are connected each other by lanthanide binuclear dimer as building blocks to form a novel 3D covalent framework. q 2004 Elsevier B.V. All rights reserved.