Spectroscopic, thermal, and anticancer investigations of new cobalt(II) and nickel(II) triazine complexes

ABSTRACT. The condensation of thiosemicarbazide with oxazolidinone produced 5-benzylidene-3-(4-chloro-phenyl)-6-oxo-5,6-dihydro-1H-[1,2,4]triazine-2-carbothioic acid amide (HL1). Co(II) and Ni(II) ions were reacted with the HL1 ligand. Elemental analysis and molar conductivity, along with mass, 1H-NMR, IR, UV-Vis, and X-ray powder diffraction spectral examinations, were used to reveal the chemical structure of the synthesized complexes. The stoichiometry of the complexes was determined to be 1:2 (metallic: moiety) using analytical, spectroscopic, and thermal data. The thermal properties of the complexes were explored using thermogravimetric (TG-DTG/DTA) methods, as well as the decomposition stages. Several kinetic thermodynamic parameters such as free activation energy (ΔG*), activation enthalpy (ΔH*), activation entropy (ΔS*), pre-exponential factor (A), and the activation energy (E*) were estimated. Inhibitory effects towards colon carcinoma cells (HCT cell line), hepatocellular carcinoma (Hep G2 cell line), and breast carcinoma (MCF-7 cell line) were verified using various concentrations of the samples. A colorimetric method was used to determine the cell viability percent in comparison to doxorubicin drug as a control.   KEY WORDS: 1,2,4-Triazines, Thiosemicarbazide, Thermogravimetric analysis, Non-electrolytes, Anticancer Bull. Chem. Soc. Ethiop. 2023, 37(5), 1151-1162.                                                       DOI: https://dx.doi.org/10.4314/bcse.v37i5.8