Two novel hybrid compounds based on [MW12O40]5- (M = B, Al) heteropolyanions and copper coordination polymer with bpp ligands

Under hydrothermal condition, two novel organic-inorganic hybrid compounds, [Cu(bpp)][Cu-2.5(bpp)(3)-( Hbpp)]H-0.5[BW12O40]center dot 1.5H(2)O (1) and [Cu(en)(2)(H2O)]{[Cu(bpp)](3)[AlW12O40]}center dot H2O (2) (bpp = 1,3-bis(4-pyridyl) propane; en = ethylenediamine), have been synthesized based on B/Al atom-centered Keggin-type polyoxometalates combined with Cu ions and bpp ligands. The two compounds are characterized through single-crystal X-ray diffraction analysis, elemental analyse, IR, UV and TG. For compound 1, as the nodes, the [BW12O40](5) polyanions link to the [Cu-2.5(bpp)(3)(Hbpp)](3.5+) oligomers, leading to the formation of 1D helical chains which further attach to the macrocycles [Cu-2(bpp)(2)](2+) via the Cu-O weak interaction to construct the 2D "wave-like" layers. For compound 2, the {[Cu(bpp)](4)[AlW12O40](2)} unit is obtained by the interaction between two Keggin-type [AlW12O40](5) polyanions and one tetranuclear macrocycle composed by four [Cu(bpp)](+) complex cations. Furthermore, the units are sandwiched by two 1D "wave-like" polymeric chains resulting in a new 1D structure. In addition, the electrochemical properties and electrocatalytic activities of these two compounds have been studied in this paper. (C) 2010 Elsevier B.V. All rights reserved.