Four coordination networks based on the {ε-PMoV8MoVI4O40(OH)4Zn4} Keggin unit (εZn) have been synthesized under hydrothermal conditions. (TBA)3{PMoV8MoVI4O36(OH)4Zn4}[C6H4(COO)2]2 (ε(isop)22) is a 2D material with monomeric εZn units connected via 1,3 benzenedicarboxylate (isop) linkers and tetrabutylammonium (TBA) counter-cations lying between the planes. In (TPA)3{PMoV8MoVI4O37(OH)3Zn4}[C6H3(COO)3] (TPA[ε(trim)]∞∞), 1D inorganic chains formed by the connection of εZn POMs, via Zn–O bonds, are linked via 1,3,5 benzenetricarboxylate (trim) ligands into a 2D compound with tetrapropylammonium (TPA) cations as counter-cations. (TBA){PMoV8MoVI4O40Zn4}(C7H4N2)2(C7H5N2)2·12H2O (ε(bim)44) is a molecular material with monomeric εZn POMs bound to terminal benzimidazole (bim) ligands. Finally, (TBA)(C10H10N4)2(HPO3){PMoV8MoVI4O40Zn4}2(C10H9N4)3(C10H8N4) (ε22(pazo)44) is a 1D compound with dimeric (εZn)2 POMs connected by HPO32− ions and terminal para-azobipyridine (pazo) ligands. In this compound an unusual bond cleavage of the central NN bond of the pazo ligand is observed. We report also a green chemistry-type one-step synthesis method carried out in water at room temperature using ε22(pazo)44 and ε(isop)22 as reducing agent of graphite oxide (GO) to obtain graphene (G). The POM@G hybrids were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, powder X-ray diffraction, energy dispersive X-ray analysis, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and cyclic voltammetry.
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