Experimental and theoretical studies of new Co(III) complexes of hydrazide derivatives proposed as multi‐target inhibitors of SARS‐CoV‐2

Abstract

Cobalt(III) complexes with Schiff base ligands derived from hydrazone, (HL 1 = (E)-N 0 -(3,5-dichloro-2-hydroxybenzylidene)-4-hydroxybenzohydrazide, HL 2 = (E)-N 0 -(3,5-dichloro-2-hydroxybenzylidene)-4-hydroxybenzohydrazide (3,5-dibromo-2-hydroxybenzylidene), and HL 3 = (E)-4-hydroxy-N 0 -(2-hydroxy-3-ethoxybenzylidene)benzohydrazide), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, and cyclic voltammetry. X-ray diffraction was used to determine the single crystal structure of the complex (1). Co(III) was formed in a distorted, very regular octahedral coordination in this complex; three pyridine moieties complete this geometry. Schiff base complexes' redox behaviors are represented by irreversible (1), quasi-reversible (2), and quasi-reversible (3) voltammograms. A density functional theory (DFT)/B3LYP method was used to optimize cobalt complexes with a base set of 6-311G. Furthermore, fragments occupying the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were investigated at the same theoretical level. Quantum theory of atoms in molecules (QTAIM) computations were also done to study the coordination bonds and non-covalent interactions in the investigated structures. Hirshfeld surface analysis was used to investigate the nature and types of intermolecular exchanges in the crystal structure of the complex (1). The capacity of cobalt complexes to bind to the major protease SARS-CoV-2 and the molecular targets of human angiotensin-converting enzyme-2 (ACE-2) was investigated using molecular docking. The molecular simulation methods used to assess the probable binding states of cobalt complexes revealed that all three complexes were stabilized in the active envelope of the enzyme by making distinct interactions with critical amino acid residues. Interestingly, compound (2) performed better with both molecular targets and the total energy of the system than the other complexes. K E Y W O R D S4-hydroxybenzohhydrazide, Co(III) complex, electrochemical properties, theoretical study, X-ray crystallography

Synthesis, spectra, crystal structure, Hirshfeld surface analysis, DFT calculations and molecular docking evaluation on novel mononuclearZn(II), Mn(III) and Co(III) Schiff base complexes derived from 2- hydroxy-1-naphthaldehyde

“…According to the discussed results, it is concluded that computational chemistry correctly suggests the structure of all complexes. Also, the energy gap difference shows well the stability, hardness and reactivity of the complexes, the higher the energy gap difference, the higher the stability and chemical hardness and low reactivity of the complex [41,42].…”

“…Interesting results were collected by mapping frontier molecular orbitals (FMOs). The calculated LUMO values indicate the ability to accept electrons (nucleophilicity), while the obtained HOMO values determine the nature of the molecule to donate electrons (electrophilicity) [41,43]. If the calculated LUMO energy value is lower, it indicates a high ability to accept electrons [41,43].…”

“…The calculated LUMO values indicate the ability to accept electrons (nucleophilicity), while the obtained HOMO values determine the nature of the molecule to donate electrons (electrophilicity) [41,43]. If the calculated LUMO energy value is lower, it indicates a high ability to accept electrons [41,43]. By observing the results obtained in Table 5, it is concluded that complex (3)…”

New Cu(II), Mn(II) and Mn(III) Schiff base complexes cause noncovalent interactions: X-ray crystallography survey, Hirshfeld surface analysis and molecular simulation investigation against SARS-CoV-2

“…These proteins were downloaded from a protein database (6M03, 6Y2F. PDB http://www.rcsb.org./pdb ) for the binding process [ 22 , 23 ]. Water molecules, heteroatoms and structural ligands 6M03 and 6Y2F were removed using Discovery Studio software ( https://www.3ds.com/support ) [22] , [23] , [24] , [25] , [26] , [27] .…”

Phytic acid-modified graphene/cobalt oxide nanocomposites: synthesis, characterization, theoretical studies, antiproliferative properties, and catalytic activities

“…The results were analyzed using the Molegro Virtual Viewer software (MVD), Chimera 1.5.3, and Discovery Studio 3.0 from Accelrys and DS Visualizer. 68 The XRD pattern of graphene oxide is given in Fig. 2(a)-(i).…”