Synthesis and catalytic properties of copper(II) Schiff-base complex immobilized silica materials

Cu(II) Schiff base complex immobilized silica was prepared via the one pot reaction of thiophene-2-carbaldehyde with silica functionalized 3-aminopropyltriethoxysilane (APTES) and copper acetate by refluxing in ethanol. The formation of this complex was confirmed by FT-IR, UV–DRS, XRD, SEM, EDX, ICP-AES and BET analytical methods. In addition, the catalytic activity of the as synthesized Cu(II) Schiff base complex immobilized silica was evaluated through the oxidative coupling of benzylamines to the corresponding imines. The catalyst was easily recovered and reused for five times without any significant loss of its catalytic activity.