Coordinating behavior of hydrazone ligand bearing chromone moiety towards Cu(II) ions: Synthesis, spectral, density functional theory (DFT) calculations, antitumor, and docking studies

A new hydrazone ligand (FCSH; HL) was successfully synthesized by the reaction of salicylaldehyde hydrazone with 3-formylchromone. Seven copper(II) hydrazone complexes have been synthesized by using several copper(II) salts (acetate, nitrate, sulfate, perchlorate, chloride, and bromide). Elemental analysis, electronic, infrared, mass, nuclear magnetic resonance, electron spin resonance spectra, thermal analysis, molar conductivity, and magnetic susceptibility measurements were used to characterize structures of the hydrazone ligand and its complexes. The ligand behaves as monobasic tridentate for all complexes except complex 2 (monobasic tetradentate) and complex 4 (neutral tridentate). All metal complexes exhibited octahedral geometries. With the aid of Coats-Redfern equations, the kinetic parameters (E-a, A, increment H, increment S, and increment G) of the thermal decomposition stages were calculated and discussed. At the B3LYP/6-311G(d,p) level engaged in the Gaussian 09 program, density functional theory (DFT) calculations were carried out to inspect the optimized structures of the chelating agent and its complexes. The hydrazone ligand and its copper(II) complexes showed antitumor activity towards HepG2 cell line. The docking study of the hydrazone ligand and its copper(II) complexes was investigated with the active site of the CDK2 kinase.