Synthesis, characterization, biological, X-ray diffraction analysis and computational chemistry studies of new 2-acetylpyridine derivative hydrazone and its Zn(II) complex

Abstract

A new aroyl hydrazone ligand ((E)-2-phenyl-N’-(1-(pyridine-2-yl)ethylidene)acetohydrazide) HL and its metal complex [ZnL2] (1) have been synthesized and characterized by using elemental analysis, IR and UV–vis spectroscopy methods. All data indicate that the ligand is coordinated through enolate oxygen, pyridine nitrogen and the imine nitrogen in enolic form towards the metal ions. The single crystal X-ray diffraction analysis and Density Functional Theory (DFT) calculations were carried out for HL and 1 structures. HL and 1 crystallize in the monoclinic and the orthorhombic with P 21/n and P b c n space group with a = 5.2051(4) Å, b = 10.0477(9) Å, c = 25.204(2) Å, with a = 14.1300(18) Å, b = 9.3287(13) Å, c = 21.491(3) Å, respectively. The geometries, molecular orbital energies, and stability of the molecular structures were investigated in different solvent environments by using DFT/B3LYP/6-311G (d, p) method. Theoretical UV–vis spectra of the molecular structures were obtained and the percentage contributions of atomic orbitals of functional groups of the molecular structures to the molecular orbital energy levels were calculated in water media. The global reactivity parameters of the molecular structures were calculated and the interactions between the molecules with DNA bases such as adenine, cytosine, guanine, and thymine were investigated by using the ECT (Electrophilicity-Based Charge Transfer) method and ΔN (charge transfer) parameters. All the compounds were screened for antibacterial activity against Gram-positive, Gram-negative and yeast by using minimal inhibitory concentration method (MIC). [ZnL2] (1) has been found to have more effect than HL in all microorganisms. Moreover, antioxidant activity was determined with the ABTS method. The DNA binding interactions was also determined experimentally by spectrophotometric and electrochemical methods. © 2020 Elsevier B.V.