Volume 25 , Issue 2 , December 2023 , Pages 25-49
Hanar Q. Hassan 1 ; Karzan A. Abdalkarim 1 ; Dalia A. Abdul 1 ; Aso H. Hasan 2 ; Diary I. Tofiq 1 ; Rebaz F. Hamarawf 1 ; Shujahadeen B. Aziz 3 ; Kawan F. Kayani 1
1 Department of Chemistry, College of Science, University of Sulaimani, Qliasan street, 46001 Sulaymaniyah, Kurdistan Region, Iraq
2 Department of Chemistry, College of Science, University of Garmian, Bardesur Street 46021, Kalar, Kurdistan Region, Iraq
3 Research and Development Center, University of Sulaimani, Qliasan Street, 46001 Sulaymaniyah, Kurdistan Region, Iraq
The design of trivalent metal complexes involves choosing suitable ligands that can bind
to the metal and confer the desired properties. In this study, novel trivalent metal
complexes (TVMCs) of Ru, Fe, and Cr were synthesized from a newly developed
hydroxy-rich Schiff base ligand (LH2) derived from 4,4'-oxydianiline with 2, 4-
dihydroxybenzaldehyde, which is referred to as N, N`-bis [ 2,4-dihydroxyphenylmethylidene] 4,4'-oxydianiline (LH2). The ligand synthesis was performed using reflux
without a catalyst in ethanol. The products underwent thorough characterization
experimentally by various techniques such as: FT-IR, 1H-NMR, 13C-NMR, Powder
XRD, elemental analysis, UV-Visible, conductivity, magnetic susceptibility, and thermal
gravimetric analysis. The molar conductance measurements suggest that the complexes
are non-electrolytes and do not contain conductive species outside the coordination
sphere. Thus they can be formulated as [MLCl(H2O)].nH2O. Magnetic moment and
electronic spectral studies confirmed that all complexes exhibit octahedral geometry
around the metal ion. Furthermore, density functional theory (DFT) calculations were
performed theoretically to investigate the structures, frontier molecular orbitals (HOMO
and LUMO), molecular electrostatic potential (MEP), and electron localization function
(ELF) for all complexes, utilizing the Gaussian09 software and the B3LYP/6-311+G(d,
p) level. In vitro experiments were conducted to evaluate the antibacterial activity of the
compounds against both Gram-negative (Escherichia coli) and Gram-positive
(Staphylococcus aureus) bacterial species, using the agar diffusion method. The results
indicate that the Fe(III)-complex exhibits noteworthy inhibitory effects on both Grampositive and Gram-negative bacteria, with a maximum inhibition zone.