Three New Polyoxoniobates Functioning as Different Oxidation Catalysts

Three new multifunctional isopolyniobates based on {Nb 24 O 72 }, namely, [Cu(en) 2 ] 9.75 [Cu(en) 2 (H 2 O)] 4 [KNb 24 O 72 H 9.25 ] 2 ·36.5H 2 O ( 1 ), [Cu(en) 2 ][Cu(en) 2 (H 2 O)] 12 [Cu(en) 2 (H 2 O) 2 ] 3 [KNb 24 O 72 H 7 (H 2 O) 2 ] 2 ·99H 2 O ( 2 ), and [K(H 2 O) 4 ][Cu(en) 2 (H 2 O) 2 ] 5 [Cu(en) 2 (H 2 O)] 8.25 [Cu(en) 2 ] 2 [K 0.5 Nb 24 O 72 H 7.75 ] 2 ·115.31H 2 O ( 3 ) (en = ethylenediamine), were obtained and characterized by IR, powder X-ray diffraction, single-crystal diffraction analysis, etc. Single-crystal analyses of the three compounds shows that all their clusters exhibit the same bowl-shaped structure, while the different transition metal complexes (TMCs) make compounds 1 – 3 show three entirely different packing structures. The catalytic properties of the three compounds as catalysts for Rhodamine B (RhB) photocatalytic degradation, styrene oxidation, and oxygen evolution reaction (OER) have been assessed, and all the compounds have good catalytic effects on the three different catalytic processes.