Anchoring of Copper(II) Schiff Base Complex into Aminopropyl-Functionalised MCM-41: A Novel, Efficient and Reusable Catalyst for Selective Oxidation of Alcohols
A copper(II) complex containing tetradentate N2O2 Schiff base ligand immobilized into aminopropyl-functionalised MCM-41 (mobile crystalline material number 41), was prepared and characterized by Fourier-transform infrared, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, N2 adsorption–desorption and inductively coupled plasma analysis techniques. The novel heterogeneous catalyst, MCM-41-pr-NH2-CuL, can be successfully applied for efficient and selective oxidation of different primary and secondary alcohols to the corresponding carbonyl compounds using hydrogen peroxide as an oxidant in acetonitrile at 60 °C. The effect of reaction parameters such as solvent, amount of catalyst, temperature and kind of oxidant on the oxidation of benzyl alcohol was also studied. The prepared catalyst could be recovered and reused four times without important loss of its catalytic performance. The heterogeneous MCM-41-pr-NH2-CuL catalyst was found to be catalytically more active in the oxidation of alcohols compared to the similar type of copper(II) Schiff base complex in homogeneous media under the same reaction conditions.
KeywordsTetradentate Schiff base Copper(II) complex MCM-41 Heterogeneous catalyst Alcohol oxidation Hydrogen peroxide
The support of this work by Vali-e-Asr University of Rafsanjan is acknowledged. The authors also thank Prof. Majid Moghadam from University of Isfahan, Dr. Atena Naeimi from Jiroft University and Dr. Masoud Karimi-Pour from Vali-e-Asr University of Rafsanjan for their valuable helps.