Magnetic Mesoporous Silica Nanocomposite Functionalized with Palladium Schiff Base Complex: Synthesis, Characterization, Catalytic Efficacy in the Suzuki-Miyaura Reaction and alpha-Amylase Immobilization

摘要

Magnetic mesoporous silica nanocomposite, Fe3O4-MCM-41, was functionalized with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS) and then condensed with 5,5 '-methylene bis(salicylaldehyde), followed by N(4)-phenylthiosemicarbazide to produce a ONS Schiff base grafted nanocomposite. Finally, by adding palladium(II) acetate, the palladium Schiff base complex was immobilized on magnetic nanocomposite. The characterization of new nanocomposites was carried out by means of several techniques such as FT-IR, XRD, FE-SEM, HRTEM, EDS, BET, VSM, XPS, DRS and TGA. The new nanocatalyst, Fe3O4@MCM-41-SB-Pd, was used in synthesis of symmetrical and unsymmetrical biaryl compounds via the Suzuki-Miyaura cross-coupling of phenylboronic acid with aryl halides. This catalyst was easily recovered by applying an external magnetic field and reused for several times without significant loss of its catalytic activity. Also the ability of synthesized mesoporous nanocomposites for enzyme immobilization was investigated and results showed that they efficiently immobilized alpha-amylase enzyme.