Cage-like CuCs-Phenylsilsesquioxanes: Synthesis, Supramolecular Structures, and Catalytic Activity.

A small family of nonanuclear CuCs-based phenylsilsesquioxanes - were prepared by a convenient self-assembly approach and characterized by X-ray diffraction studies. The compounds and show some unprecedented structural features such as the presence of a [PhSiO] silsesquioxane ligand and a CuCs nuclearity in which the metal cations occupy unusual positions within the cluster. Copper ions are "wrapped" into a silsesquioxane matrix, while cesium ions are located in external positions. This resulted in cesium-involved aggregation of coordination polymer structures. Both compounds and realize specific metallocene (cesium-phenyl) linkage between neighboring cages. Compound is evaluated as a catalyst in the Baeyer-Villiger (B-V) oxidation of cyclohexanone and tandem cyclohexane oxidation/B-V oxidation of cyclohexanone with -chloroperoxybenzoic acid (mCPBA) as an oxidant, in an aqueous acetonitrile medium, and HNO as the promoter. A quantitative yield of ε-caprolactone was achieved under conventional heating at 50 °C for 4 h or MW irradiation for 30 min (for cyclohexanone as substrate); 17 and 19% yields of lactone upon MW irradiation at 80 °C for 30 min and heating at 50 °C for 4 h, respectively (for cyclohexane as a substrate), were achieved. Complex was evaluated as a catalyst for the oxidation of alkanes to alkyl hydroperoxides and alcohols to ketones with peroxides at 60 °C in acetonitrile. The maximum yield of cyclohexane oxidation products was 30%. Complex exhibits high activity in the oxidation of alcohols.