A novel Schiff base Mn(III) complex was successfully synthesized and covalently immobilized on silicacoated magnetic cobalt nanoparticles as a support. The prepared heterogeneous catalyst showed a high catalytic activity in the oxidation of alcohols with high yield and in a milder conditions. The synthesized hybrid nanomaterials were fully characterized by FT-IR spectra, XRD and EDAX analysis. Morphology of the nanomaterials was determined by SEM and TEM. Also, the metallic magnetic cobalt and silica in the core–shell structure were determined by XPS analyses. The synthesized catalyst shows a high catalytic activity in the oxidation of alcohols and sulfides to the corresponding aldehydes and sulfoxides. Also the magnetic properties of the magnetic support and hybrid nanomaterials were measured by AGFM analysis.