New Schiff base ligand N-(2-hydroxy-1-naphthylidene)- 2-methyl aniline and its nano-sized copper(Ⅱ) complex: synthesis, characterization, crystal structure and application as an electrochemical sensor of 2- phenylphenol in the presence of 4-chlorophenol

摘要

A new bidentate Schiff base ligand [HL = N-(2-hydroxy-l-naphthylidene)-2-methyl aniline] and its mononuclear Cu(Ⅱ) complex with formula [CuL_2] were prepared and characterized by Fourier-transform infrared (FT-IR), Nuclear Magnetic Resonance [~1H and~(13)Cl{~1H} NMR], Ultraviolet-visible (UV-Vis) spectroscopic methods, and elemental analysis. The Schiff base ligand [HL] and Cu(Ⅱ) complex [CuL_2] crystal structures were determined using the single crystal X-ray diffraction method. The data of crystal structure indicated a bidentate method of coordination for the Schiff base by NO donor sets in a regular square-planar fashion. The nano-sized [CuL_2] was synthesized by the sonochemical method and was detected by X-ray powder diffraction (XRD), Field Emission Scanning Electron Microscopes (FE-SEM), and FT-IR spectroscopy. The average particle size in nano-sized [CuL_2] was approximately 55 nm. The nano-complex [CuL_2] was used in a modified screen-printed electrode (modified SPE) as an electrochemical sensor for the detection of 2-phenylphenol. The oxidation reaction of 2-phenylphenol at the modified electrode indicated a linear range of 0.01-600.0 μM and the recognition limit was 8.0 μM. The proposed electrode shows two well-separated oxidation signals for 2-phenylphenol and 4-chlorophenol, which makes it suitable for the simultaneous determination of these analytes. The fabricated sensor was successfully applied for the designation of 2-phenylphenol in lemon rind, orange rind, and water samples with satisfactory recovery.