Spectroscopic, computational, and biological activity studies of bivalent metal complexes of (E)-N′-(4-(dimethylamino)benzylidene) isonicotinohydrazide

Abstract

(E)-N′-(4-(Dimethylamino)benzylidene) isonicotinohydrazide (HL) ligand with bidentate O, N-donor configuration and its coordination complexes with Zn(II), Cd(II), and Pt(II) metal centers were synthesized. All substances were characterized using elemental analysis, molar conductivity, thermal analysis, NMR (¹H and ¹³C), and FT-IR spectral data. The HL ligand was coordinated as a bidentate chelating ligand via the oxygen of the carbonyl group and the nitrogen of the azomethine group. The thermal properties of the compounds were assessed by simultaneous thermogravimetric-differential thermal analysis measurements, and the findings related to the hypothesized structures. The structures were theoretically examined using density functional theory computations with the B3LYP functional and with the 6-31+G(d,p) basis set for C, H, N, and O atoms, and the LANL2DZ effective core potential for the metal centers (Zn, Cd, and Pt) for the coordination compounds. Molecular electrostatic potential was computed to examine the reactive characteristics of the compounds. The compounds were evaluated in vitro for their antibacterial effects on Escherichia coli and Staphylococcus aureus. The Pt(II) complex displayed the highest antibacterial effect, whereas the Zn(II) complex exhibited moderate inhibitory activity, and the Cd(II) complexes were less active.