Self-Assembly of a Giant Molybdenum Titanium-oxo Cluster [Mo42Ti12(O2)24] for Bifunctional Oxidation Catalysis

Abstract

The exploration of high-nuclearity molecular molybdenum titanium-oxo clusters (MoTOCs) and their reactivity is a great challenge for polyoxometalate chemistry and materials science. Herein, we report a giant MoTOC [K8(H2O)8][Ti12(O2)6(OH)12Mo42O124(O2)18(H2O)17] (1) by self-assembly of degraded lacunary isopolymolybdate fragments and peroxide–stabilized titanium ions in aqueous solution. Compound 1 features 54 metal centers and a rare pure inorganic triangular prism structure with a size of 1.8 × 1.8 × 1.5 nm3, which is the first and largest water-soluble MoTOC found to date. More importantly, it contains multiple peroxo groups on the surface, which makes it possess superior benzyl alcohol/benzaldehyde (photo)catalytic oxidation performance. This work opens an unusual avenue for the synthesis of giant MoTOCs.