Ligational, density functional theory, and biological studies on some new Schiff base 2‐(2‐hydroxyphenylimine)benzoic acid (L) metal complexes

Abstract

The metal ions Co(II), Ni(II), Zn(II), Zr(IV), and Hg(II) reacted with synthesized Schiff base (L) in mole ratios 1:2 (M:L) formed metal complexes. The structure of the prepared compounds was identified based on the data obtained from elemental analyses, magnetic measurement, melting point, conductivity, Fourier‐transform infrared, UV–Vis., nuclear magnetic resonance spectroscopy, X‐ray diffraction (XRD) spectra, and thermal analysis (TG/DTG [thermogravimetric/differential thermal analysis]). The results indicate that the L bound as bidentate through the oxygen atom of the hydroxyl group and nitrogen atom of the azomethine group with the metal ions and the complexes is electrolyte in nature. TG/DTG studies confirmed the chemical formula for complexes. The kinetic and thermodynamic parameters such as E*, ΔH*, ΔS*, and ΔG* were determined by using Coats–Redfern and Horowitz–Metzger methods at n = 1 and n ≠ 1. The XRD patterns exhibited a semicrystalline nature lying between the amorphous and crystalline nature for L, (D), and (E), but the complexes (A), (B), and (C) possessed a crystalline character. Density functional theory confirmed the structural geometry of the complexes. In vitro antimicrobial activities were performed for L and its metal complexes.

Synthesis, structural elucidation, molecular modeling and antimicrobial studies of 6‐(2‐hydroxyphenylimine)‐2‐thioxotetrahydropyrimidin‐4(1H)‐one (L) Schiff base metal complexes

“…The magnetic moments of the complexes have been calculated at room temperature and the results suggest that the complexes (1) and (2) had a paramagnetic character with an effective value of 4.7 and 3.12. [ 6,17 ]…”

“…[ 33 ] The Schiff base Ni (II) complex absorption spectrum shows band at 510 nm which may be assigned to A 2g (F) → T 2g , transitions, in favor of octahedral geometry. [ 5,6,37 ]…”

“…In fact, Schiff bases are capable of stabilising several different metals in different oxidation states, regulating the performance of metals in a wide range of useful catalytic transformations. Schiff bases have a group of donors of NO or N 2 O 2 [ 5,6 ] and, in some situations, oxygen atoms can be substituted by sulphur, nitrogen or selenium atoms. Although the Schiff bases are considered to be good chelating agents and have little interest in their use for analytical purposes due to two serious drawbacks, they are insoluble in aqueous solutions and easily decompose into acidic solutions, restricting their use to simple conditions.…”

Spectral, thermal, antimicrobial studies for silver(I) complexes of pyrazolone derivatives

“…Eventually, the bacterial strains showed a varied response to the three free ligands and their complex antimicrobial activity, but the results indicated that the high activity of ligand complexes was better than their free ligands. The two fungal strains are more resistant to synthesis ligands and their complexes than bacterial strains [42][43][44][45][46].…”

Ligational and biological studies of Fe(III), Co(II), Ni(II), Cu(II), and Zr(IV) complexes with carbamazepine as antiepileptic drug

“…In addition, the subsistence of metallic ions will influence the medication's bioavailability. [ 19–21 ] In present paper, we have synthesized series of Fe(III), Co(II), Ni(II), Cu(II), and Zr(IV) complexes with CBZ. Complexes were established by elemental analysis, diverse spectroscopic methods (FT‐IR, UV‐visible, 1 H NMR, and mass spectra), magnetic susceptibility, molar conductivity, and thermogravimetric analysis.…”