Anchoring of Copper Complex in MCM-41 Matrix:  A Highly Efficient Catalyst for Epoxidation of Olefins by tert-BuOOH

• Published in: Langmuir 2007-02, Vol.23 (5), p.2492-2496
• Main Authors: Jana, Sreyashi, Dutta, Buddhadeb, Bera, Rajesh, Koner, Subratanath
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Porous materials; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la062409t

A complex moiety containing copper (II) has been anchored covalently into the organic-modified Si−MCM-41 to prepare a new catalyst. The amine group containing organic moiety 3-aminopropyl-triethoxysilane has been first anchored on the surface of Si−MCM-41 via silicon alkoxide route. The amine group upon condensation with salicyldehyde affords a bidentate ligand in the mesoporous matrix for anchoring copper(II) ions. The prepared catalyst has been characterized by UV−vis, electron paramagnetic resonance (EPR), and infrared (IR) spectroscopic analysis, small-angle X-ray diffraction, and N2 sorption study. A remarkable difference in the pore structure has been observed after the immobilization of copper(II) complex in Si−MCM-41. The catalyst showed excellent catalytic efficiency in epoxidation reactions with various olefinic compounds including styrene and allyl alcohol, using tert-BuOOH as oxidant. Notably, styrene shows unprecedented high conversion (97%) as well as epoxide selectivity (89%) with tert-BuOOH over the Cu−MCM-41 catalyst.