Novel Nanoparticle‐Sized Cu(II), Ru(III), and Th(IV) Chelates Derived From Quinaldine Azo Dye Ligand: DFT Studies, Molecular Docking, and Applications in Drug Development and Catalysis

ABSTRACT Three novel complexes of copper(II), ruthenium(III), and thorium(IV) ions with quinaldine azo dye ligand HL were synthesized in nanoscale. Applying mass spectroscopy, electronic, infrared, 1 H NMR, elemental, and thermal investigations, their structures were examined. By using azo nitrogen and hydroxyl oxygen atoms to coordinate as a monobasic bidentate, it was found that the ligand displayed bicapped square antiprism geometry with thorium(IV) metal ion, square pyramidal arrangement in copper(II) complex and octahedral configuration in ruthenium(III) complex. In order to confirm the complexes' geometrical arrangement, theoretical investigations were carried out using DFT/B3LYP/6–311 + G(d,p)/LANLDZ. The dipole moment, geometrical configuration, energetic parameters, and HOMO–LUMO gap of energy have been calculated. The compounds were formed in nanometric forms, as indicated by the mean particle sizes obtained by applying TEM. Based on TEM images for the complexes of copper(II), ruthenium(III), and thorium(IV), their average particle sizes were 11.04, 3.89, and 1.52 nm, respectively. PANC‐1 and A‐549 cells were used in the tests to evaluate the compounds' anticancer activity against the vinblastine reference. The findings confirm the great cytotoxicity effect of the free ligand and its complexes against the investigated cell lines using different doses of the examined compounds. Ru(III) and Cu(II) complexes exhibited cytotoxic effectiveness greater than that of vinblastine. The azo ligand, HL , exhibited the strongest antibacterial activity that is superior to that of the conventional medicines themselves and greater than that of its metal complexes. The most physiologically active compound's ideal conformation was found using molecular docking research, and the manner in which the Ru(III) complex and the enzyme of Panc‐1 link together was determined. It interacts in three different modes with the target receptor (PANC‐1): hydrophobic force, electrostatic force, and H‐bond. In addition to increasing the candidate activity, these interactions can be used to design and predict new, effective compounds. The capacity of the ligand and its complexes to act as heterogeneous catalysts for the oxidation of methyl violet 2B was examined. The ruthenium(III) and thorium(IV) complexes generated the greatest catalytic efficiencies.