Two novel hybrid compounds based on [MW 12O 40] 5− (M = B, Al) heteropolyanions and copper coordination polymer with bpp ligands

Abstract

Under hydrothermal condition, two novel organic–inorganic hybrid compounds, [Cu(bpp)][Cu 2.5(bpp) 3(Hbpp)]H 0.5[BW 12O 40]·1.5H 2O ( 1) and [Cu(en) 2(H 2O)]{[Cu(bpp)] 3[AlW 12O 40]}·H 2O ( 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 [BW 12O 40] 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[AlW 12O 40] 2} unit is obtained by the interaction between two Keggin-type [AlW 12O 40] 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.