A binuclear copper(II) complex based on hydrazone ligand: Characterization, molecular docking, and theoretical and antimicrobial investigation

Abstract

A new binuclear copper(II) complex [Cu 2 L 2 (μ-SO 4 )(dmf)] with the 2-acetylpyridinebenzoylhydrazone (HL) ligand was synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), ultravioletvisible (UV-Vis), single-crystal X-ray diffraction, density functional theory (DFT), and molecular docking studies. The crystal structure revealed each copper(II) atom coordinated to the NNO chelating system of the anionic hydrazone ligand and a sulfate bridged. The copper ions are connected by a sulfate bridge, which keeps a distance of 3.292(3) Å between the two copper(II) centers. Additionally, only one of the copper(II) atoms is coordinated to the oxygen atom of the N,N-dimethylformamide (dmf) solvent molecule, resulting in two different geometry to each metal center. CuÁÁÁO interactions are observed for the secondary coordination sphere of Cu1 and Cu2 atoms with distances of 2.545(2) and 2.821(3) Å, respectively. Theoretical studies with DFT were performed to optimize the geometry of the complex and investigate its spectroscopic properties supporting the experimental results. Two different approaches were used in computational calculations, the plane wave using Perdew-Burke-Ernzerhof (PBE) functional and the localized basis set using the following functionals: B3LYP, B3PW91, CAM-B3LYP, LC-wPBE, M06-2X, ωB97-XD, PBE1PBE, and HSEH1PBE. The in vitro antibacterial potential of the new complex was evaluated against pathogenic bacteria and fungi and compared with the free ligand. The molecular docking was used to predict the inhibitory activity of the ligand and complex against one Gram-positive bacteria (Enterococcus faecalis), one Gram-negative bacteria (Enterobacter aerogenes), and one fungi (Candida albicans) species.

Effects of changing ions on the crystal design, non-covalent interactions, antimicrobial activity, and molecular docking of Cu(II) complexes with a pyridoxal-hydrazone ligand

“…The hypsochromic displacement of the π→π* band corresponding to the π→π* transition of the azomethine can be observed, which decreases to 326 nm in MeOH and 331 nm in DMF; this is indicative of the coordination of the group to the Cu(II) atom. The ligand–metal charge transition (LMCT) can be attributed in the range of 406–411 nm in MeOH and 413–415 nm in DMF as an indication of the coordination of the hydrazone to the Cu(II) atom ( Santiago et al, 2022 ). In addition, to observe d-d transitions of the metal center, the electronic spectra of the complexes were determined at a higher concentration (2 mM) in methanol ( Supplementary Figure S15 and Supplementary Table S3 ).…”

“…Due to our structural and biological interests in the study of new metal complexes based on hydrazone ( Santiago et al, 2020 ; Santiago et al, 2022 ), we here study the reactions and resulting crystal structures between pyridoxal-benzoylhydrazone ligand and different Cu(II) salts. The compounds were analyzed by single-crystal X-ray diffraction, mass spectrometry, FT-IR, UV-Vis, and molecular docking.…”

The Local Vibrational Mode Theory and Its Place in the Vibrational Spectroscopy Arena

“…LMA has begun to be used by other research groups for a number of different topics. For example, the Gatto group 197 has utilized LMA to decompose normal modes into local modes (via CNM procedure) of heterogeneous atoms in a binuclear copper(II) complex with a hydrazone ligand. They were able to determine the information that is hidden in the vibrational normal modes and compare the local vibrational frequencies from different DFT functionals with their experimental spectra results.…”

Metal recognition behaviour study of coumarin containing benzimidazole moiety

“…All calculations were carried out by using the density functional theory (DFT) approximation and utilizing the Gaussian 09 (G 09) computational codes to implement Becke's three-parameter hybrid exchange and the Lee-Yang-Parr non-local correlation functionals (B3LYP) (Santiago et al, 2022). The standard 6-311G (d,p) basis set was used for all the computations involving the lighter elements (C, H, N and O) and the LanL2DZ effective core potential for the Cu atom (Kruse et al, 2012;Adamo et al, 2013).…”