A new organic-inorganic hybrid compound based on lanthanide-organic chain and Keggin-type polyoxometalate

The reaction between a double-betaine-containing ligand and DyH[Pmo(11)VO(40)]center dot nH(2)O led to a new polyoxometalate-based lanthanide-organic hybrid compound with the molecular formula [Dy(HL)(L)(1.5) (H2O)(3)][PMo11VO40]center dot 8H(2)O (1) (L=1,4-bis(pyridinil-4-carboxylato)-1,4-dimethylbenzene). Compound 1 was characterized by elemental analyses, TG, IR, XPS and the single-crystal X-ray diffraction. Compound 1 possesses a cationic 1D polymeric chain [Dy(HL)(L)(1.5)(H2O)(3)](n)(4n+) with cyclic-, chain- and semi-cyclic-like fragments, corresponding to three different configurations of the double-betaine-containing ligand. These 1D chains are connected together by the H-bonds and pi-pi interactions to form a 3D supramolecular framework, encapsulating the vanadium-substituted Keggin-type polyoxoanions [PMo11VO40](4-) and the solvent molecules. This composite compound displays electrocatalytic activities towards the reduction of nitrite and the luminescent property. (C) 2011 Elsevier B.V. All rights reserved.