Reactions of rhodium (II) acetate with non-lacunary Keggin and Dawson polyoxoanions and related catalytic studies

Reactions of non-lacunary Keggin ([PW12O40]3−) and Dawson ([α-P2W18O62]6−) polyoxometalates with rhodium (II) acetate have been studied. In the first case reaction yields the layered coordination polymer Li3[(Rh2(CH3COO)4)2(PW12O40)]·12.5 H2O (1), where polyoxoanions are coordinated via oxygen atoms to the {Rh2}4+ core. In the case of [α-P2W18O62]6− dirhodium clusters do not coordinate the polyoxoanion directly; however, they form K7[P2W18O62][Rh2(CH3COO)4X]·nH2O, where X = Cl, n = 11.37 (2); Br, n = 11.1 (3), which contain polymeric chain polyanions catena-[Rh2(CH3COO)4X]nn− (X = Cl, Br). Coordination polymer 1 is active in total oxidation of hydrogen and olefin at relatively low temperatures.

Rhodium (II) acetate reacts with non-lacunary polyoxometalates to form coordination polymers. The structure strongly depends on if halogenide anions are present in solution: {Rh2(OAc)4} units either coordinate POM directly or form infinite polymeric chains {Rh2(OAc)4Cl}nn−. Catalytic activity was tested.Figure optionsDownload as PowerPoint slideHighlights
► Reactivity of Rh2(OAc)4 with non-lacunary POMs reported.
► POM/Rh2(OAc)4-based coordination polymers obtained.
► Catalyze total oxidation of olefins and H2.