Assembly of a new Keggin polyoxometalate-templated complex using flexible bis(benzimidazole) ligand

A new inorganic-organic hybrid compound [Cu-2(L)(4)(H2O)(2)](SiW12O40)center dot 8H(2)O (1) [L = 1,1'-(1,4-butanediyl)bis-1H-benzimidazole] has been hydrothermally synthesized and characterized by IR, elemental analyses, XRD and TG analysis. Compound 1 exhibits a two-dimensional (2D) layer network constructed from metal-organic cations [Cu-2(L)(4)(H2O)(2)](n)(4n+). There exist pi-pi stacking interactions among the benzimidazole rings of the adjacent 2D layers leading to a double-sheet structure. The Keggin-type [SiW12O40](4-) anions acting as inorganic templates are sandwiched by the double-sheet structure. There exist hydrogen bonding interactions between [SiW12O40](4-) anions and double-sheet layers, which extend the 2D network to a 3D supramolecular framework. The electrochemical behavior and electrocatalysis of compound 1 have been studied. (C) 2010 Elsevier B.V. All rights reserved.