Synthesis and characterization of some new metal complexes derived from heterocyclic hydrazones

Abstract

New hydrazone ligands (HL1 & H2L2) have been prepared by the condensation of salicylaldehyde hydrazone with 3-formylchromone and 5-acetyl-4-hydroxy-2H-1,3-thiazine-2,6(3H)-dione, respectively. The structure of the ligands was elucidated by different physicochemical and spectroscopic techniques. The reactions of the hydrazone ligands with various salts of some metal ions: Cu(II), Ni(II), Co(II) and Cd(II) were carried out. The newly prepared metal complexes were identified by elemental analyses, IR, electronic, mass, and ESR spectra as well as magnetic susceptibility measurements, molar conductivity and thermal gravimetric (TGA) analysis. The hydrazone ligand (HL1) behaves as monobasic or neutral tridentate and bis(bidentate) chelating agent via γ–pyrone oxygen, azomethine nitrogen and phenolic oxygen atom, while the hydrazone ligand (H2L2) behaves as bis(monobasic bidentate) and dibasic tetradentate chelating agent via azomethine nitrogen and phenolic oxygen atoms. The obtained complexes include neutral mononuclear and binuclear complexes. The data showed that the complexes have octahedral and tetrahedral geometry. Activation energy parameters (ΔG, ΔH, ΔS and Ea) of the metal complexes were calculated using Coats-Redfern method. The molecular structural parameter of the ligands and their metal complexes have been calculated on the basis of DFT level implemented in the gaussian 09 program at the B3LYP/6-311G (d,p) level. The ligands and their metal complexes were screened as an antitumor agent towards Hepatocellular carcinoma cell line (HepG-2). The molecular docking studies of the free ligands and their metal (II) complexes were reported and the results of this study have expanded the scope of developing these compounds as promising antitumor drugs.