A new Nickel Complex of Lysine on Mesoporous KIT-6 as a Recoverable and Selective Catalyst in the Synthesis of Tetrazoles

In this work, the surface of mesoporous KIT-6 was functionalized by lysine for easy metal complexation. Then, nickel ions became complex with immobilized lysine on the surface of KIT-6 (Ni-lysine@KIT-6). In continuation, Ni-lysine@KIT-6 was characterized by atomic absorption spectroscopy (AAS), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and wavelength dispersive X-ray spectroscopy (WDX) techniques. SEM images indicated that Ni-lysine@KIT-6 was formed in spherical structures with uniform size. EDS and WDX analysis shows that Ni-lysine@KIT-6 was formed from O, Si, N, C, and Ni elements. BET method shows that Ni-lysine@KIT-6 was synthesized with good surface area. Therefore, Ni-lysine@KIT-6 was used as an efficient, reusable, and homoselective catalyst in synthesizing tetrazoles. Finally, the recoverable and heterogeneous nature of Ni-lysine@KIT-6 was investigated, and this catalyst was recycled and reused several times.