Spectroscopic and cytotoxic characteristics of (p-cymene)Ru(II) complexes with bidentate coumarins and density functional theory comparison with selected Pd(II) complexes

• Published in: Inorganica Chimica Acta 2017-02, Vol.456, p.105-112
• Main Authors: Skoczynska, Anna, Lux, Karin, Mayer, Peter, Lorenz, Ingo-Peter, Krajewska, Urszula, Rozalski, Marek, Dołęga, Anna, Budzisz, Elzbieta
• Format: Article
• Language: English
• Subjects: Arene-ruthenium(II) complexes; Coordination compounds; Coumarin; Cytotoxicity; Density functional theory; DFT calculations; Fourier transforms; Ligands; Lipophilicity; Mathematical analysis; NMR; Nuclear magnetic resonance; Platinum; Ruthenium; Ruthenium compounds; Spectrum analysis; Structural analysis; X-ray structure; X-rays
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2016.10.036

Two arene ruthenium(II) complexes were synthesized and fully characterized. DFT calculations were performed and compared with palladium(II) complexes with the same ligands. [Display omitted] •Two (p-cymene)-Ru(II) complexes 3a, 3b with bidentate coumarins were synthesized and characterized by FTIR, NMR, MS, elemental analysis, MTT assay, DFT calculations.•The X-ray structure was obtained for complex 3a.•In most cases the Ru(II) complexes exhibit better cytotoxic activity than ligands.•The DFT calculations for complexes 3a and 3b were compared with those for complexes Pd(II)_2a and Pd(II)_2b and that indicates that Pd(II) complexes are more lipophilic, which is usually associated with the enhanced cytotoxicity of metal complexes. This paper presents the synthesis of two new (p-cymene)-ruthenium(II) complexes 3a,b with the bidentate coumarin ligands 2a,b. Both complexes were characterized by FTIR spectroscopy, 1H NMR, 13C NMR, MS, elemental analysis and DFT calculations. The X-ray structure of complex 3a was also solved. The cytotoxic properties of both complexes were examined on human leukemia NALM-6 and HL-60 cells and melanoma WM-115 cells. The complexes possess higher cytotoxic activity than the ligands, but distinctive result is for complex 3b, which exhibited higher cytotoxic effect on WM-115 cells (IC50=60.2±7.8μM) in comparison to carboplatin (IC50=422.2±50.2μM). The results of DFT calculations performed at the BP86-D3/QZ4P level for Ru(II) complexes and Pd(II) complexes with the same ligands indicate that Pd(II) complexes are more lipophilic. Moreover the RP-TLC-Based Lipophilicity assessment was also performed.