Synthesis of Bis (Benzoyl Acetone Ethylene Diimine) Schiff Base Complex of Nickel (II) Supported on Magnetite Silica Nanoparticles (Fe3O4@SiO2/Schiff-Base of Ni(II)) and Using It as an Efficient Catalyst for Green Synthesis of 1-Amidoalkyl-2-Naphthols

Abstract

In this research, magnetite nanoparticles as the core are fabricated by co-precipitation method from Fe(II) and Fe(III) chloride salts and then the surfaces of the nanoparticles are modiied to improve their performance. These modiications include the coating of silica and then the second layer by 3-amino propyl triethoxy silane (APTES) which causes the functionalization of magnetite nanoparticles with –NH2 groups. In the next step, an aliphatic tetra-dentate N2O2 Schif base was synthesized separately by condensation reaction between benzoyl acetone and ethylenediamine. This free Schif base has two C = O groups. By the condensation reaction between one C = O group of free Schif base and –NH2 group of functionalized magnetite silica, a tetra-dentate N3O Schiff base is immobilized on the magnetite silica surface. This tetra-dentate Schiff base supported on magnetite silica is a very good structure for the formation of stable metal complexes. The immobilized Schif base was converted to the Ni(II) Schif base complex by the reaction with Ni(II) acetate tetra-hydrate. This Ni(II) Schif base complex is immobilized on magnetite silica and shown as Fe3O4@SiO/Schif base of Ni(II). This core-shell nanostructure is fully characterized by techniques such as FT-IR, VSM, XRD, FE-SEM, EDX, TGA-DTA, AAS, BET, and BJH. In the last step, this nanocatalyst is used as an eicient catalyst for the solvent-free synthesis of amido alkyl naphthols by the condensation reaction between an aldehyde, 2-naphthol, and an amide. The reaction was monitored by TLC. At the end of the reaction, the nanocatalyst was removed easily from the reaction mixture by an external magnet. The products of 1-amidoalkyl-2-naphthols were identiied by FT-IR and 12HNMR techniques. Finally, the percentage yield of the reaction is calculated by measuring the mass of 1-amidoalkyl-naphthol synthesized in the presence of the catalyst.