Abstract
In the present work, a series of aryl-cycloplatinated(II) complexes with general formula [Pt(C ^ N)(Ar)(κ 1 -dppm)], 1, [C ^ N = 7,8-benzoquinolinyl (bzq) or 2-phenylpyridinyl (ppy); Ar = C 6 F 5 or p-MeC 6 H 4 , dppm = 1,1-bis(diphenylphosphanyl)methane] was employed in the reaction with AuCl(SMe 2 ) in order to generate heterobimetallic Pt II -Au I complexes, [Pt(C ^ N)(Ar)(µ-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 κ 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(µ-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-MeC 6 H 4 )(µ-dppm)Au(Cl)], 2b, effectively causes cell death in MCF-7 cancer cell line by inducing apoptosis. Fluorescence microscopy experiments for 2a were performed.
Original language | English |
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Pages (from-to) | 1360-1373 |
Number of pages | 14 |
Journal | European Journal of Inorganic Chemistry |
Volume | 2019 |
Issue number | 10 |
DOIs | |
Publication status | Published - 14 Mar 2019 |
Externally published | Yes |
Funding
This work was supported by the Institute for Advanced Studies in Basic Sciences (IASBS) Research Council (G2018IASBS32629) and the Spanish MINECO (Project CTQ2016-78463-P). N. G. is grateful for a UR grant. M. F. is grateful to the Medicinal Chemistry, school of pharmacy, Ahvaz Jundishapur University of Medical Sciences (GP96075) and the Iran National Science Foundation (Grant no 96007334).
Funders | Funder number |
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Ministerio de Economía y Competitividad | CTQ2016-78463-P |
Iran National Science Foundation | 96007334 |
Ahvaz Jundishapur University of Medical Sciences | GP96075 |
Norges forskningsråd | G2018IASBS32629 |
Institute for Advanced Studies in Basic Sciences |
Keywords
- Cytotoxicity
- Gold
- Heterobimetallic complexes
- P ligands
- Photophysics
- Platinum