Metal complexes of hydrazone–oxime derivative as promising in vitro antimicrobial agents against some fungal and bacterial strains

Abstract

In this study, Cu2+, Co2+, Ni2+, Mn2+, Zn2+, Fe3+, VO2+, and UO22+ complexes derived from a NNO tridentate chelating hydrazone–oxime, namely, N′‐((2E,3Z)‐3‐(hydroxyimino)butan‐2‐ylidene)benzohydrazide (H2L,1) were prepared. The elemental, thermo‐gravimetric, spectral, molar conductivity, and magnetic measurements were applied to elucidate the compositions and structures of these new compounds. In addition to the density functional theory (DFT), studies were employed to acquire optimal structures and quantum chemical parameters. The analyses indicate that the chelator reacted as a neutral or mononegative tridentate ligand bonded to the metal ions via the enolic/ketonic carbonylic oxygen, protonated/deprotonated oximatic nitrogen, and azomethine nitrogen atoms adopting square planar or distorted octahedral geometry. The structural characterization of hydrazone–oxime and its complexes was supported by DFT calculations according to the DFT‐B3LYP procedure and 6‐311+G(d,p) basis set. The theoretical data revealed that the reactivity of the complexes is greater than the free hydrazone–oxime (H2L,1), and there is a good agreement between the practical and theoretical data. The thermogravimetric investigation shows that the complexes break down in two to four decomposing steps in temperature range extended from 50 to 1000°C. In vitro antimicrobial activity data demonstrated an increase in activity of the hydrazone–oxime (H2L,1), upon chelation, and some metal complexes show enhanced antibacterial and antifungal agents.

Monometallic complexes of novel dihydrazone‐oxime ligand: Synthesis, structure, spectral, DFT, and in vitro bioactivity investigation against fungal, bacterial, and tumor cells

“…The Cu 2+ , Ni 2+ , Mn 2+ , Co 2+ , and Zn 2+ complexes (2)(3)(4)(5)(6)(7)(8)(9) were produced by mixing a filtrated ethanolic solution ( [24][25][26] CH 3 ), 2.09 (s, 3H, [27][28][29] CH 3 ).…”

“…[78,80,81] The μ eff values for Cu 2+ complexes (2-5) are in range extended from 1.66 to 1.80 BM, which is compatible with spin-only value for Cu 2+ complexes. [78] In the EAS of Ni 2+ complex, there are three peaks at 1017, 711, and 499 nm, which is ascribed to the electronic 3…”

“…and 3 A 2g (F) ! 3 T 1g (P)(ν 3 ) transitions correspondingly indicating that this Ni 2+ complex has a tetrahedral structure (Figure 2).…”

“…Schiff base ligands, particularly those with the hydrazide-hydrazone and oximatic moieties [(C=O) NHN=CH] and [(C=O)NHN=CC=NOH], have been discovered to be good pharmacophores for the design and development of a variety of bioactive compounds. [1][2][3][4][5] The compounds that incorporate hydrazide-hydrazone and/or oximatic moiety as well as their metal complexes are broadly employed in various applications such as anti-HIV, antihyperglycemic, [6,7] antifungal, [2][3][4] anticancer, [8] anti-tuberculosis, [9] anti-infective, [10] antitrypanosome, [11] insecticidal, [12] antibacterial, [2][3][4][5] antiradical, [13] anticholinesterase, [14] antitumor, [5,15,16] antioxidant, [17][18][19] antidepressant and nootropic, [20] antiinflammatory, [21,22] gastroprotective, [23] antimalarial, [24] antiviral activities, [22,25,26] and DNA cleavage. [27] Furthermore, these compounds also have the potential to be an excellent candidate for oral medicines, such as their use to treat genetic illnesses like thalassemia.…”

“…[37] Many scientists have recently investigated the preparation and characterization of metallic complexes with hydrazone or hydrazone-oxime chelators, as well as their biological activities. [2,3,38,39] The current study devoted to the preparation of Cu 2+ , Ni 2+ , Mn 2+ , Co 2+ , and Zn 2+ complexes of dihydrazone-oxime incorporating isatinic moiety, namely, 3-((3-(hydroxyimino)butan-2-ylidene)hydrazono) indolin-2-one (HL,1). The molecular structure of these designated compounds was investigated by NMR, electronic absorption, infrared, and mass spectra as well as elemental, thermal, and theoretical tools.…”