Heterobimetallic Pt-II-Au-I Complexes Comprising Unsymmetrical 1,1-Bis(diphenylphosphanyl)methane Bridges: Synthesis, Photophysical, and Cytotoxic Studies.
by Shahsavari, H. R.; Gimenez, N.; Lalinde, E.; Moreno, M. T.; Fereidoonnezhad, M.; Aghakhanpour, R. B.; Khatami, M.; Kalantari, F.; Jamshidi, Z.; Mohammadpour, M.
In the present work, a series of aryl-cycloplatinated(II) complexes with general formula [Pt((CN)-N-<^>)(Ar)(kappa(1)-dppm)], 1, [(CN)-N-<^> = 7,8-benzoquinolinyl (bzq) or 2-phenylpyridinyl (ppy); Ar = C6F5 or p-MeC6H4, dppm = 1,1-bis(diphenylphosphanyl)methane] was employed in the reaction with AuCl(SMe2) in order to generate heterobimetallic Pt-II-Au-I complexes, [Pt((CN)-N-<^>)(Ar)(mu-dppm)Au(Cl)], 2, featuring a dppm bridge between the metal centers. The expectation was to induce metallophilic character into the excited state and to reduce non-radiative deactivation pathways of the dangling auxiliary kappa(1)-dppm ligand through molecular motions, to improve the photophysical properties. After characterization of the new complexes by means of NMR spectroscopy and X-ray crystallography technique, the photophysical properties of all the complexes were investigated by UV/Vis and photoluminescence spectroscopy. Both of the monometallic complexes and heterobimetallic products have shown to be luminescent in different states and temperature conditions. However, by addition of Au-I, the impact on the photophysics of the heterobimetallic products in relation to the precursors with dangling dppm is minimal, a finding which can be attributed to the absence of a Pt-II-Au-I bond in these compounds. Indeed, the character of the excited states of the monomer Pt-II complexes and their corresponding bimetallic Pt-II-Au-I ones are similar, as confirmed by density functional theory (DFT) and time resolved DFT (TD-DFT) calculations. The cytotoxic activities of the compounds along with that of [ClAu(mu-dppm)AuCl] were evaluated against human breast cancer (MCF-7), human lung cancer (A549), human ovarian cancer (SKOV3) and non-tumorigenic epithelial breast (MCF-10A) cell lines. The highest activity was found for the heterometallic Pt-Au species, suggesting a cooperative effect of both metallic fragments. The most cytotoxic compound, i.e. [Pt(bzq)(p-MeC6H4)(mu-dppm)Au(Cl)], 2b, effectively causes cell death in MCF-7 cancer cell line by inducing apoptosis. Fluorescence microscopy experiments for 2a were performed.
- Journal
- European Journal of Inorganic Chemistry
- Volume
- 2019
- Issue
- 10
- Year
- 2019
- Start Page
- 1360-1373
- URL
- https://dx.doi.org/10.1002/ejic.201801297
- ISBN/ISSN
- 1434-1948; 1099-0682
- DOI
- 10.1002/ejic.201801297