Synthesis, characterization and modeling structures of isatin-3-Girard T (IGT) and P (IGP) hydrazone complexes

New bis hydrazone: Synthesis, X-ray crystal structure, DFT computations, conformational study and in silico study of the inhibition activity of SARS-CoV-2

The aim of this work was to synthesize new bis hydrazone derived from benzil in good yield, namely: (1Z,2Z)-1,2-bis (3-Chlorophenyl Hydrazino) Benzil, encoded by 3-Cl BHB. The benzil (or 1,2-diphenyl ethanedione) reacts with 3-Cl phenyl hydrazine by reflux method using ethanol as solvent to obtain the target compound. The obtained product is depicted by UV-Vis, IR spectroscopy and XRD-crystals analysis. All various contacts intra and intermolecular found in 3-Cl BHB were determined by the X-ray diffraction technique performed on single crystals. On the other hand, the optimized geometric structure of 3-Cl BHB was computed by the DFT/B3LYP method with 6-31 G (d, p) level. So, the bond lengths and angles, frontier molecular orbitals (FMO), surface electrostatic potential of the molecule (MEP), global reactivity descriptors, Mulliken atomic charges, computed vibrational analysis and electronic absorption spectrum were determined to get a good understanding of the electronic properties and the active sites of 3-Cl BHB, then to compare them with experimental data. Additionally, a conformational study was carried out using the same method (DFT). The structure-activity relationships established through molecular docking studies showed that 3-Cl BHB structure strongly binds to the receptors Mpro (-8.90 Kcal/mol) and RdRp (-8.60 Kcal/mol) which confirm its inhibition activity against COVID-19.

Comparative studies, synthesis, spectroscopic and characterization of N-methylisatin-3-Girard's T and P hydrazone complexes

Different types of complexes derived from the reactions of N-methylisatin Girard's T hydrazone, N,N,N-trimethyl-2-[(2z)-2-(1-methyl-2-oxo-1,2-dihydro-3H-indole-3-ylidene) hydrazino]-2-oxo-ethan ammonium chloride (MIGT) and N-methylisatin Girard's P hydrazone, 1-{2-(2z)-2-[(1-methyl-2-oxo-1,2-dihydro-3H-indole-3-ylidene) hydrazino]-2-oxoethyl}pyridinium chloride (MIGP) with Fe(3+), Al(3+), Sb(3+) and Sn(2+) salts were synthesized. The isolated complexes were characterized by elemental analyses, molar conductivities, spectral (IR, UV-Vis., (1)H NMR, mass), magnetic moments and thermal measurements. The values of conductance suggest that the complexes are conducting in polar solvents (EtOH, H2O and DMF). The IR spectra suggest that the ligands coordinate in a bidentate and/or tridentate manner via the carbonyl groups of both N-methylisatin and Girard's T and/or P and the (CN) group. The solvents inside and outside the coordination sphere were determined by weight loss and TGA methods. The octahedral geometry of the complexes is confirmed using spectral, magnetic and DFT method from DMOL(3) calculations. The ligands and their metal complexes were tested against different strains of bacteria and fungi.

Comparative spectroscopic and DFT calculations of binary and ternary complexes derived from 4-allyl-1-(2-hydroxybenzoyl) thiosemicarbazide (L¹) and 2,2'-dipyridyl

Five metal complexes derived the reactions of 4-allyl-1-(2-hydroxybenzoyl) thiosemicarbazide (L(1)) with MX2 (M=Co(2+), Cu(2+) and Zn(2+) ions; X=Cl(-) in case of Co(2+) and Cu(2+) ions and Cl(-) and Ac(-) in case of Zn(2+) ion) in EtOH were synthesized and characterized. The results suggested that the binary and ternary complexes have the general formulae, [Cu(L(1)-2H)(EtOH)], [Co(L(1)-2H)(H₂O)₂]⋅H₂O and [Zn(L(1)-2H) (H₂O)1/2]⋅½EtOH, [Cu₂(dipy)(L(1)-2H)(OH)₂(H₂O)], [Co(dipy)(L(1)-2H)]⋅4H₂O and [Zn(dipy)(L(1)-2H)]. The binary and ternary complexes were characterized by elemental analyses, molar conductivities, spectral (IR, UV-vis; (1)H NMR, mass), thermal (TGA, DTG) and magnetic moments measurements. The mode of chelation is suggested using spectral data. The existence of OH group in the ternary complexes is confirmed from the results of IR, mass and (1)H NMR spectra. All the geometries of the ligands and the complexes are confirmed using DFT method from DMOL(3). The biological activity for the L(1) and two metal complexes were tested against DNA.