Direct covalent attachment of Mn(III) salophen complex to the hydroxyapatite-encapsulated gamma-Fe2O3 nanocrystallites: an efficient magnetic and reusable catalyst for oxidation of alcohols

摘要

In the present work, the highly efficient oxidation of alcohols catalyzed by manganese(III) salophen acetate, [Mn(salophen)OAc], supported on hydroxyapatite coated magnetite nanoparticles, HAp-Fe2O3, is reported. First, the HAp-Fe2O3 nanoparticles were modified with 5-chloromethyl-2-hydroxybenzaldehyde and then using 1,2-diamino benzene, 2-hydroxybenzaldehyde and Mn(CH3COO)(2)center dot 4H(2)O, [Mn(salophen)OAc] was synthesized and attached to the support via covalent linkages. The prepared catalyst was characterized by FT-IR spectroscopy, X-ray diffraction, diffuse reflectance UV-Vis spectrophotometry and scanning electron microscopy. This new heterogeneous catalyst was used for efficient oxidation of alcohols with NaIO4 at room temperature. This new heterogeneous catalyst is of high reusability in the oxidation reactions, in which the catalyst was reused several times without significant loss of its catalytic activity.