Comprehensive Analysis of Metal Complexes Derived from 2-Picolinic Acid: Structural, Chemical, and Functional Insights

Non-aqueous method was used for synthesis of metal (II) complexes of picolinic acid and characterization was done using different techniques including infrared (FT-IR), Ultraviolet-visible, ¹H-NMR and Electron Spin Resonance (ESR) spectroscopy. Other studies including conductance, magnetic susceptibility and thermal analysis were also carried out. The thermal analysis indicated that these complexes are thermally stable and start to decompose at temperatures above 260°C. The FT-IR spectroscopy also established the presence of important functional groups found in the metals and the respective ligands groups such as C=O, C=N, O- H, C= C and M-O. The thermogravimetric analysis showed that these complexes are not hydrated. Electronic spectra revealed additional information about the complexes’ geometry: cobalt and nickel complexes were octahedral, while the copper complex displayed distorted octahedral geometry. Additional investigations on these metal complexes were electrochemical studies. Lastly, the activity of the complexes against an array of microorganisms was evaluated. The nickel (II) complex exhibited the greatest inhibition against four chosen strains of bacteria tested, which were superior among other tested complexes.