Immobilized Copper(II) Diisatin–Schiff Base Complex on AgCo <sub>3</sub> O <sub>4</sub> Nanoparticles as Efficient Catalysts for Styrene Oxidation
Mohamed Shaker S. Adam, M.M. Makhlouf, Hussah Alawisi, Amel Taha, Hazem S. Ahmed, Hanaa A. Hassanin
Abstract
Abstract To advance the industrialization of the chemical productions, i.e., the organo‐oxidizing reactions, a mono‐organometallic Cu(II) diisatin–Schiff base complex (Cu(HmeL) 2 Cl 2 ) is constructed from the complexing action of isatin–Schiff base ligand (HmeL) with half the amount of copper(II) chloride. The chemical structure of HmeL and Cu(HmeL) 2 Cl 2 was established with many spectroscopic methods. The heterogeneity of Cu(HmeL) 2 Cl 2 was accomplished within a processive coating of the AgCo 3 O 4 nanoparticles (as Cu(HmeL) 2 Cl 2 @AgCo 3 O 4 ). The internal structure, the elemental composition, and the surface morphology of nano‐Cu(HmeL) 2 Cl 2 @AgCo 3 O 4 composite were examined using different spectroscopic‐microscopic techniques. The micrographs showed a nanocluster‐shaped formation of Cu(HmeL) 2 Cl 2 @AgCo 3 O 4 nanocomposite. The catalytic productivity of Cu(HmeL) 2 Cl 2 (as a homogeneous catalyst) and Cu(HmeL) 2 Cl 2 @AgCo 3 O 4 nanocomposite (as a nanocatalyst) was studied for the optimization in the redox productivity of styrene, as a representative example of olefins, to the corresponded epoxide (2‐phenyloxirane) using an aqueous H 2 O 2 under the control of temperature, time, and solvent (in an aerobic environment). For the optimized environment, the monooxygenation achievement of the homogeneous catalyst (Cu(HmeL) 2 Cl 2 ) was adjusted with a lower temperature (80 °C after 5 h) with yielding 87% compared to the heterogenized phase (nano‐Cu(HmeL) 2 Cl 2 @AgCo 3 O 4 composite precatalyst (90 °C after 5 h), with 90%. The coated AgCo 3 O 4 nanoparticles improved the catalytic potential of Cu(HmeL) 2 Cl 2 complex in the yield of the selective product. The heterogeneity of Cu(HmeL) 2 Cl 2 complex modified its reusing ability with 7 successful trials over that of the homogenous phase of Cu(HmeL) 2 Cl 2 complex catalyst in the oxygenation system of styrene (three successful trials only).