FRENCH-UKRAINIAN JOURNAL OF CHEMISTRY, cilt.12, sa.1, ss.92-110, 2024 (ESCI)
An ONO tridentate Schiff base derived from 3,5-dichlorosalicylaldehyde
and 2-amino-4-methylphenol (H2L)
and its complexes with VO(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and
Hg(II) were synthesized and characterized. The structures of the complexes were confirmed by
means of elemental analysis, molar conductivity, magnetic moment, UV-visible, fluorescence,
FT-IR and NMR spectroscopy. The M:L ratio is 1:2 in Fe(III) and Co(II)
complexes whereas 1:1 in the other complexes. It was observed that the Pd(II)
complex is 1:1 ionic while the others are non-ionic according to molar
conductivity measurements. H2L showed weak fluorescence at different
wavelengths in neutral, acidic and basic areas and in the form of some metal
complexes. The VO(II) and Cu(II) complexes increased the fluorescence effect
compared to the ligand, while the Fe(III) complex completely quenched it. Antibacterial
and antifungal activity of the compounds was evaluated against six bacteria and
three fungi. In general, all the
compounds showed moderate antimicrobial activity. It was observed that some of
the complexes exhibited higher activity towards S. epidermidis and S. aureus
compared to the ligand. Antioxidant activity of the compounds was investigated in
terms of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging and Cupric
Reducing Antioxidant Capacity (CUPRAC) methods. It was found that Zn(II) and
Pd(II) complexes showed higher antioxidant activity than the ligand and the
other complexes.