In situ alkaline media: Synthesis, spectroscopic, morphology and anticancer assignments of some transition metal ion complexes of 1-((2-aminophenylimino) methyl) naphthalen-2-ol Schiff base

Abstract

Four Schiff base complexes of Cu(II), Co(II), Ni(II) and Zn(II) metal ions were synthesized by reaction of 1-((2-aminophenylimino)methyl)naphthalen-2-ol (HL) with metal(II) chloride salts. The geometric structures of these complexes were elucidated based on different types of analyses like elemental analyses and spectroscopic instruments (FT-IR, UV–Vis., mass and 1H NMR). Microanalytical analysis was confirmed the 1:1 stoichiometry ratio (metal: HL). The molar conductance values (3.80–5.59 μS) referred that all HL complexes have an electrolytic behavior in comparable with free HL data (1.35 μS) except for non-electrolytic copper(II) complex (1.46 μS). The general formulas of the synthetic complexes were [M(L)(H2O)3]+.Cl−.3H2O (M = Co2+ & Ni2+), [Zn(L)(H2O)]+.Cl− and [Cu(L)(Cl)(H2O)2]. The assignments of FTIR spectra confirmed that the deprotonated HL Schiff base ligand acts as a tridentate NNO chelate through oxygen O of phenolic group and both nitrogen atoms of NH2 and CN azomethine groups. The electronic, magnetic and electron spin resonance analyses revealed that all complexes are six coordinated but zinc(II) complex is four coordinated geometry. The thermogravimetric analyses (TGA/DTG) and differentially thermal analyses (DTA) of the free HL chelate and its complexes have been performed under N2 atmosphere. The final thermal decomposition residue of metal-Schiff base complexes has been MO formula. The crystalline surface morphology of the solid products were investigated dependent on X-ray diffractometer and scanning electron microscopy. The efficiency of antimicrobial (bacteria & fungi) and anticancer of colon carcinoma HCT-116 cell lines were assessed against free HL Schiff base ligand and their four complexes.