Synthesis, physicochemical properties, and antitumor cytotoxic activity of the Mg(II) coordination complex containing 1,10-phenanthroline and sulfate ligands

The complex mer-triaqua-(1,10-phenanthroline)-(sulfate-O)-magnesium(II) was synthesized by the solvent slow evaporation method from the crystallization of an equimolar saturated solution of 1,10-phenanthroline and magnesium sulfate heptahydrate in a mixed solution of deionized water and DMF. The structural, vibrational, and thermal properties were studied by X-ray powder diffraction (XRPD), Fourier Transform Infrared Spec-troscopy (FT-IR), and thermoanalytical analyses. Calculations based on density functional theory (DFT) were also applied to the system for an accurate analysis of vibrational modes and to obtain theoretical data on the nature of bonds, chemical reactivity descriptors, electrostatic potential map, and electronic properties. XRPD results showed that the coordination compound in the study has monoclinic symmetry (space group P21/c) and contains four molecules per unit cell (Z = 4). The thermal measurements revealed that the material presents a thermo-dynamically irreversible process around 303 K, arising from the evaporation of three coordination water mol-ecules. In addition, all IR absorption bands were assigned, with contributions from the DFT calculations. Finally, cell viability assays were conducted, confirming the antitumor activity of the complex in MCF-7 (breast) and SiHa (cervical) cancer cells, exhibiting a considerable selective cytotoxic effect.