One-pot synthesis, characterization, optical studies and biological activities of a novel ultrasonically synthesized Schiff base ligand and its Ni(II) complex

Abstract

A novel tetradentate Schiff base ligand, 3-((2-(-(1-(2-hydroxyphenyl)ethylidene)amino)ethyl)imino)-2-pentone and its Ni(II) complex have been synthesized by green chemical, ultrasonication method. The ligand and metal complex were characterized analytically and spectroscopically by elemental analysis, HRMS, IR, 1H NMR, 13C NMR, UV–vis absorption spectroscopy, molar conductance, and magnetic susceptibility measurements. Powder XRD analysis was done to show the crystalline nature of the samples. The surface morphology and size of both ligand and complex were monitored by SEM and TEM microscopic techniques. Based on the various physicochemical measurements and spectral analysis, Ni(II) complex is assigned to an octahedral geometry. The optical bandgap energy, fluorescence spectrum lifetime analyses and chromaticity studies were accomplished to encounter the possibilities of optical applications. The fluorescence nature of both ligand and complex was found to be in the visible range. Optical bandgap energy values fall in the range of semiconductor materials. The chromaticity studies give the CIE 1931 coordinates and colour correlation temperature values of the samples. The ligand and the Ni(II) complex were screened for biological activities such as antimicrobial, antioxidant, and larvicidal activities. The results implied that the Ni(II) complex shows better antimicrobial, antioxidant and larvicidal activities than the free ligand.