Pd(II) Schiff base complex anchored on MCM-41, a reusable catalyst for the Heck reaction

Abstract

A Palladium (II) Schiff base complex was implanted on the surface of MCM-41 to fabricate a simple and reusable catalyst using post-grafting methodology. The surface of MCM-41 initially modified with 3-chloropropyltriethoxysilane (CPTES), followed by the Schiff base ligand (PAL) and on reacting with PdCl2 results in the formation of MCM@CP@PAL@Pd complex. Characterization of the designed heterogeneous catalyst by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Microwave Plasma Atomic Emission Spectroscopy (MP-AES) and Brunauer–Emmett–Teller (BET) techniques indicated successful grafting of Palladium (II) complex inside the hexagonal channels of MCM-41.The MCM@CP@PAL@Pd catalyst was used for a good range of Heck reactions using different aryl halides with styrene or alkyl acrylate esters. The catalyst has low metal content, provides magnificent yield (95%) in a short time period (20 min), displayed excellent structural and chemical stability and can be reused seven times without remarkable change in its catalytic efficiency.