Transition-metal ion modified monolacunary tungstates: Synthesis, structural characterization and property

Two organic–inorganic hybrids (H2bpp)4[PW11CuO39][PW12O40] (1) (bpp = 1,3-di(4-pyridyl)propane), H5(bpe)3[SiW11CoO39]·2H2O (2) (bpe = 1,2-di(4-pryridyl)ethylene) have been hydrothermally synthesized and characterized by IR, UV, powder and single crystal X-ray diffraction. The analysis results reveal that both of two compounds contain one-dimensional polyanionic chains of monosubstituted Keggin clusters through M–O–M (M = Cu/W/Co) linkages. In the crystal framework of 1 there are two types of nanosized polyanionic clusters of classic saturated Keggin-type [PW12O40]3− and Cu-doped [PW11CuO39]5− anions. The protonated discrete organic substrates either flexible bpp in 1 or rigid bpe in 2 are attached to the surrounding of polyanions via non-covalent interactions. The photoluminescence emissions of 1 and 2 in CH3OH solution at room temperature have been investigated. The photocatalytic activity of two complexes for methylene blue (MB) degradation under UV irradiation is explored.