Synthesis, spectroscopic characterization, thermal behaviour, in vitro antimicrobial and anticancer activities of novel ruthenium tricarbonyl complexes containing monodentate V-shaped Schiff bases

The interaction of Ru-3(CO)(12) with a novel family of monodentate V-shaped Schiff base ligands (L1-4; L-1: (E)-1-(4-((4-bromobenzylidene)amino)phenyl)ethanone, L-2: (E)-1-(3-(4-(dimethylamino)benzylideneamino)phenyl)ethanone, L-3: (E)-1-(4-(4-(dimethylamino)benzylideneamino)phenyl)ethanone, L-4: (E)-1-(3-(3,4-dimethoxybenzylideneamino)phenyl)ethanone) in air under atmospheric pressure afforded the novel complexes [Ru(CO)(3)(L1-4)(2)]. The parent ligands and their complexes were characterized using elemental analyses and spectroscopic techniques. In addition, the structure of the representative ligand L-1 was determined using single-crystal X-ray analysis. The stereochemistry and theoretical optimization of the three-dimensional geometry of the ligands and their complexes were justified. In vitro antimicrobial screening against bacterial stains Escherichia coli and Staphylococcus aureus and fungus Candida albicans was conducted. Cytotoxicity of the compounds as anti-tumour agents was evaluated against liver carcinoma (HepG2), breast carcinoma (MCF7) and colon carcinoma (HCT-116) cell lines relative to cisplatin and doxorubicin. The complexes showed variable in vitro cytotoxic activities against the three studied cell lines, with IC50 values less than those of cis-platin, and thus appear to be building blocks for promising anti-tumour agents.