Novel Gold(III), Palladium(II) and Copper(II) Schiff Base Complexes Derived from 1-Hydroxy-2-acetonaphthone and Phenylethyl Amine: Synthesis, Characterization and Biological Studies

Abstract

In this work, a novel Schiff base from 1-hydroxy-2-acetonaphthone and phenyl ethylamine and its metal complexes were synthesized and characterized using UV-visible, FT-IR, 1H and 13C NMR, SC-XRD, LCMS, TGA-DSC and powder X-ray diffraction. The IR data indicated that the ligand was coordinated via bidentate bonding through the oxygen atom of naphthone and nitrogen atom of azomethine unit. The TGA-DSC analysis of Au(III), Pd(II), and Cu(II) revealed the presence of coordinated water molecules. According to powder X-ray diffraction data, the Schiff base ligand exhibits a tetragonal crystal structure, Au(III) complex has a cubic crystal structure, while Pd(II) and Cu(II) complexes have monoclinic crystal structures. The synthesized metal complexes were examined for their in vitro antibacterial bioactivity against the Gram-negative bacteria E. coli, P. aeruginosa and Gram-positive S. aureus, B. subtilis as well as their in vitro antifungal activity against the two fungus C. albicans and A. niger. According to the biological findings, the synthesized metal complexes exhibited better antimicrobial activities compared to the Schiff base ligand. Similar, outcomes were followed in the antioxidant activity analysis, where the synthesized Schiff base metal complexes had DPPH radical scavenging activity.