Synthesis and characterization of two new extended structures based on Anderson-type polyoxoanions

Two new chain-like polymers, (C6H5NO2)2Na2[(C6H5NO2)2NaCrMo6H6O24] 1 and (C6H5NO2)2[(H2O)6DyCrMo6H6O24]$4H2O 2, have been synthesized and characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction. Compound 1 is built up of [CrMo6H6O24]3K cluster as the structural motif covalently linked by sodium-pyridine-3-carboxylic acid fragments to yield unprecedented one-dimensional chains, which are further in close contact forming a three-dimensional supramolecular framework via extensive hydrogenbonding interactions among polyoxoanions, coordinated pyridine-3-carboxylic acid ligands and dissociated pyridine-3-carboxylic acid molecules. Compound 2 exhibits one-dimensional chain structure constructed from [CrMo6H6O24]3K building blocks and dysprosium cations, and adjacent chains are further pillared by free pyridine-4-carboxylic acid molecules to form an unusual two-dimensional supramolecular layer via hydrogen-bonding interactions. q 2005 Elsevier B.V. All rights reserved.