Synthesis, crystal structure, electrochemical properties and DFT calculations of three new Zn(II), Ni(II) and Co(III) complexes based on 5-bromo-2-((allylimino)methyl)phenol Schiff-based ligand

Abstract

Abstract In this work, a new Schiff base ligand (HL: 5-bromo-2-((allylimino)methyl)phenol) was prepared from the reaction of 5-bromo salicylaldehyde and allylamine. Then, three new Schiff base complexes, ZnL2 (1), NiL2 (2) and CoL3 (3), were synthesized through the reaction of Zn(NO3)2·6H2O, Ni(OAC)2·4H2O, and CoCl2·6H2O with the new Schiff base ligand in methanol or chloroform. The ligand and its related complexes were characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, and 1H- NMR technique. The molecular structures of complexes (1–3) were determined by the single crystal X-ray diffraction technique. The crystallographic data revealed that complexes 1 and 2 are four-coordinated by two phenolate oxygen and two imine nitrogen atoms of two Schiff base ligands. On the other hand, the metal center is six-coordinated by three phenolate oxygen and three imine nitrogen atoms of three Schiff base ligands in 3. Eventually, DFT calculations and the study of electrochemical properties were performed on the new three complexes.