Synthesis and spectroscopic characterization of soluble mixed-ligand diruthenium complexes: potential application as anti-cancer agents.
Date
2018
Authors
Mashiloane, Karabo
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Abstract
Three mixed-ligand metal-metal bonded complexes containing one unsymmetrical anionic bridging ligand were successfully synthesized and characterized as to their electrochemical and spectroscopic properties. The investigated mono-substituted diruthenium complexes have the general formula, Ru2(OAc)3(L)Cl, where OAc = acetate anion and L = anilinopyridinate bridging ligand (ap, 2-Meap, 2-Fap). UV/Visible spectroscopy studies reveal that the investigated diruthenium complexes exist in the forms Ru2(OAc)3(L)Cl and [Ru2(OAc)3(L)]+ in solution. The two forms are observed as a split band in the 500 – 700 nm visible region. A collapse of one band is seen upon reaction of the complexes with excess halide (Cl-, Br-) indicating an equilibrium shift towards the neutral species in solution, whereas a reaction with AgBF4 precipitates the chloride as the AgCl salt, leaving only the cationic species in solution. Electrochemical characterization of the mixed-ligand diruthenium complexes conclusively reveals a stable Ru25+ oxidation state in all three complexes. Upon an applied potential in a non-coordinating solvent, each complex undergoes a reversible one-electron oxidation and reduction process accessing the Ru26+, and Ru24+ oxidation states respectively. The treatment of human breast adenocarcinoma MCF-7 cells with these water-soluble complexes results in a less than 50 % cell survival. This demonstrates significance of solubility in the development of metallodrugs for cancer treatment.
Description
A dissertation submitted to the Faculty of Science, in partial fulfilment of the requirements for the award of Master of Science degree, University of the Witwatersrand, Johannesburg, 2018
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Citation
Mashiloane, Karabo Concious (2018) Synthesis and spectroscopic characterization of soluble mixed-ligand diruthenium complexes: potential application as anti-cancer agents, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/24928