Transition metal complexes derived fromN′‐(4‐fluorobenzylidene)‐2‐(quinolin‐2‐yloxy) acetohydrazide: Synthesis, structural characterization, and biocidal evaluation

Abstract

complexes of a synthetic novel hydrazone containing a quinoline moiety were prepared. The composition and structure of the prepared compounds were elucidated by spectral and analytical techniques. The results reveal that all complexes were formed in 1:1 mole ratio except Mn 2+ and Cu 2+ complexes (3) and (7), which were formed in 1 M:2 L mole ratio. It was also found that the ligand binds the metal ions via NO donor sites as a monobasic bidentate chelator in all complexes through the enolic carbonyl oxygen and azomethine nitrogen atoms. The electronic absorption spectra and magnetic moment data demonstrated square pyramidal and octahedral geometries for the VO 2+ and Ni 2+ complexes, respectively, while the other complexes adopted tetrahedral geometry. The thermal decomposition of the complexes was discussed in relation to structure. The thermal analysis data demonstrated that all complexes were decomposed in one, two, three or four stages starting with the dehydration process, removal of coordination water molecules or elimination of anions and ended with the formation of the metal oxide. The bactericidal activities of the prepared compounds demonstrated that hydrazone (1) exerted a highly inhibitory effect against B. subtilis while VO 2+ , Co 2+ , and Cu 2+ complexes (2), (4), and (7) showed an inhibitory effect against E. coli more than the tetracycline. Additionally, the inhibitory effect of the prepared compound against A. niger showed that the Cu 2+ complex (6) is the most active while the Ni 2+ , Cu 2+ , and Zn 2+ complexes (5-8) exhibited an extremely inhibitory effect against C. albicans.

Synthesis, characterization, and density functional theory studies of hydrazone–oxime ligand derived from 2,4,6‐trichlorophenyl hydrazine and its metal complexes searching for new antimicrobial drugs

“…[ 18 ] Pilichos et al studied the coordination and metal ion‐mediated transformation of a polydentate ligand containing oxime, hydrazone, and picolinoyl functionalities [ 19 ] while Drover et al described the preparation and characterization of tetranuclear, binuclear, and chain complexes with a hydrazone–oxime and hydrazone series. [ 20 ] Because of the interesting bioactivities of compounds incorporating both oxime and hydrazone moieties and for continuing of our previous work to explore the biological activities of metal complexes, [ 21–26 ] this research was devoted to the synthesis of new hydrazone–oxime derived from 2,4,6‐trichlorophenyl hydrazine and its Cd 2+ , Zn 2+ , Cu 2+ , Ni 2+ , Co 2+ , Fe 3+ , Mn 2+ , and VO 2+ complexes. The investigation of prepared compounds structure was done via spectral, analytical, and theoretical techniques such as infrared (IR), nuclear magnetic resonance (NMR), mass, electron spin resonance (ESR), and electronic absorption spectrum (EAS) as well as elemental, thermal and density functional theory (DFT) studies in addition to the magnetic and molar conductance measurements for complexes.…”

Synthesis, structural characterization, DNA cleavage studies, antimicrobial activities, and time‐killing kinetics of tetranuclear Cu (II) with partial cubane Cu4O4 cores and mononuclear Co (II) and Ni (II) complexes of a new acylhydrazone ligand

“…The 1 H-NMR and 13 C-NMR spectra of the ligand dissolved in DMSO-d6 were recorded on Bruker Avance III 500 MHz spectrometers using tetramethylsilane (TMS) as the internal standard. The IR spectra of the ligand and its metal complexes in the form of KBr pellets were recorded on a PerkinElmer FT-IR spectrophotometer in the range of 4000-400 cm −1 .…”

“…The structural information about Ligand ehbbhH 2 was deduced from the 1 H NMR and 13 C NMR spectra and its relevant chemical shifts. Figure S2a,b shows the NMR spectra of the ligand and Table S1 shows the NMR results of the ligand data (see Supporting Information).…”

“…These compounds have anti-uropathogenic, antiarthritic, antiproliferative, antibacterial, antiviral, antifungal, anti-inflammatory, antioxidant, anticoagulant, antituberculosis, and antitumor properties. [4,5,8,[13][14][15] Although hydrazones act as inhibitors of COX-2, they also have a role in the treatment of Alzheimer's disease. [13] In the present study, due to the wide applications of acyl hydrazone ligands and metal complexes, a novel chelating N 0 -(3-ethoxy-2-hydroxybenzylidene) isobutyrohydrazide (ehbbhH2) and tetranuclear Cu (II) with Cu 4 O 4 nuclei, and mononuclear Co (II) and Ni (II) were synthesized and their structures were determined.…”

“…[4,5,8,[13][14][15] Although hydrazones act as inhibitors of COX-2, they also have a role in the treatment of Alzheimer's disease. [13] In the present study, due to the wide applications of acyl hydrazone ligands and metal complexes, a novel chelating N 0 -(3-ethoxy-2-hydroxybenzylidene) isobutyrohydrazide (ehbbhH2) and tetranuclear Cu (II) with Cu 4 O 4 nuclei, and mononuclear Co (II) and Ni (II) were synthesized and their structures were determined. The structural characterizations of the obtained compounds were carried out by elemental analysis, infrared, nuclear magnetic resonance (NMR), mass and UV-Vis spectroscopy techniques, and EPR spectroscopy, thermal analysis, and magnetic susceptibility measurements were carried out for the complexes.…”