Syntheses, structures and properties of two copper-2-picolinic-acid germanomolybdate hybrids with mixed organic components

Abstract

Two inorganic–organic hybrids based on saturated α-Keggin-type germanomolybdates with mixed organic components [H2DAP]2[Cu(PA)2][α-GeMo12O40]·8H2O (1) and [NH4]2[H8L] [Cu(PA)2][α-GeMo12O40]·8H2O (2) (DAP=1.2-diaminopropane, HPA=2-picolinic acid, H6L=1,3-bis[tris(hydroxymethyl)methylamino]propane) have been obtained via the conventional aqueous solution method and structurally characterized by elemental analysis, IR spectra, thermogravimetric (TG) analysis and single-crystal X-ray diffraction. 1 stands for an one-dimensional linear organic–inorganic hybrid germanomolybdate chain constructed from classical Keggin [α-GeMo12O40]4− units supported by [Cu(PA)2] linkers, whereas 2 represents the first hybrid germanomolybdate containing the H6L component and consists of a saturated α-Keggin polyanion [α-GeMo12O40]4−, a diprotonated [H8L]2+ cation, a copper coordination complex [Cu(PA)2], two ammonium cations [NH4]+ and eight lattice water molecules. Furthermore, the electrochemical and electrocatalytic properties of 1 and 2 have also been investigated in detail.