Polymer complexes. LXXI. Spectroscopic studies, thermal properties, DNA binding and antimicrobial activity of polymer complexes

• Published in: Applied organometallic chemistry 2018-08, Vol.32 (8), p.n/a
• Main Authors: Diab, M.A., El‐Sonbati, A.Z., Morgan, Sh.M., El‐Mogazy, M.A.
• Format: Article
• Language: English
• Subjects: antimicrobial activity; Cadmium; Chemistry; Deoxyribonucleic acid; DNA; DNA binding study; Energy gap; Hydrazones; Infrared radiation; Magnetic permeability; Manganese; Molecular orbitals; Nickel; polymer complexes; Polymers; quantum chemical parameters; Salmonella; Thermal analysis; Thermodynamic properties; Trivalent chromium; X-ray diffraction
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.4378

Polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) were prepared by the reaction of 3‐allyl‐5‐[(4‐nitrophenylazo)]‐2‐thioxothiazolidine‐4‐one (HL) with metal ions. The structure of polymer complexes was characterized by elemental analysis, IR, UV–Vis spectra, X‐ray diffraction analysis, magnetic susceptibility, conductivity measurements and thermal analysis. Reaction of HL with Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) ions (acetate or chloride) give polymer complexes (1–5) with general stoichiometric [M(L)(O2CCH3)(H2O)2]n (where L = anionic of HL and M = Co(II) (1) or Ni(II) (2)), [Mn(HL)2(OCOCH3)2]n (3), [Cr(L)2(Cl)(H2O)]n (4) and [Cd(HL)(O2CCH3)2]n (5). The value of HOMO–LUMO energy gap (ΔE) for forms (A‐C) of monomer (HL) is 2.529, 2.296 and 2.235 eV, respectively. According to ΔE value, compound has minimum ΔE is the more stable, so keto hydrazone form (C) is more stable than the other forms (azo keto form (A), azo enol form (B)). The interaction between HL, polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) with Calf thymus DNA showed hypochromism effect. The HL and its polymer complexes were tested against some bacterial and fungal species. The results showed that the Cr(III) polymer complex (4) has more antibacterial activity than HL and polymer complexes (1–3 and 5) against Bacillus subtilis, Staphylococcus aureus and Salmonella typhimurium. Optimized structure for keto hydrazone form of HL and absorption spectrum of HL in the presence of increasing amount of calf thymus DNA (CT‐DNA). Arrow indicates the change in absorbance upon increasing the CT‐DNA concentration. Inset: plots of [DNA]/(εa – εf) versus DNA concentration for HL. It was found that the absorption bands of the HL and its polymer complexes decrease with increasing concentration of CT‐DNA. The value of intrinsic binding constant (Kb) of HL with CT‐DNA was determined and it was found that the complexation lead to increases of the Kb value than HL free.