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)][Cu2.5(bpp)3(Hbpp)]H0.5[BW12O40]·1.5H2O (1) and [Cu(en)2(H2O)]{[Cu(bpp)]3[AlW12O40]}·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 [Cu2.5(bpp)3(Hbpp)]3.5+ oligomers, leading to the formation of 1D helical chains which further attach to the macrocycles [Cu2(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.