1220106-47-7Relevant academic research and scientific papers
Control of Reversible Activation Dynamics of [Ru{η6:κ1-C6H5(C6H4)NH2}(XY)]n+ and the Effect of Chelating-Ligand Variation
Martínez-Pe?a, Francisco,Pizarro, Ana M.
, p. 16231 - 16241 (2017)
The potential use of organoruthenium complexes as anticancer drugs is well known. Herein, a family of activatable tethered ruthenium(II) arene complexes of general formula [Ru{η6:κ1-C6H5(C6H4)NH2}(XY)]n+ (closed tether ring) bearing different chelating XY ligands (XY=aliphatic diamine, phenylenediamine, oxalato, bis(phosphino)ethane) is reported. The activation of these complexes (closed- to open-tether conversion) occurs in methanol and DMSO at different rates and to different reaction extents at equilibrium. Most importantly, RuII-complex activation (cleavage of the Ru?Ntether bond) occurs in aqueous solution at high proton concentration (upon Ntether protonation). The activation dynamics can be modulated by rational variation of the XY chelating ligand. The electron-donating capability and steric hindrance of XY have a direct impact on the reactivity of the Ru?N bond, and XY=N,N′-dimethyl-, N,N′-diethyl-, and N,N,N′,N′-tetramethylethylenediamine afford complexes that are more prone to activation. Such activation in acidic media is fully reversible, and proton concentration also governs the deactivation rate, that is, tether-ring closure slows down with decreasing pH. Interaction of a closed-tether complex and its open-tether counterpart with 5′-guanosine monophosphate revealed selectivity of the active (open) complex towards interaction with nucleobases. This work presents ruthenium tether complexes as exceptional pH-dependent switches with potential applications in cancer research.
Controlling the reactivity of ruthenium(II) arene complexes by tether ring-opening
Pizarro, Ana M.,Melchart, Michael,Habtemariam, Abraha,Salassa, Luca,Fabbiani, Francesca P.A.,Parsons, Simon,Sadler, Peter J.
, p. 3310 - 3319 (2010/05/15)
The closed- and open-tethered RuII Carene complexes [Ru II(η6:η1-C6H 5(C6H4)NH2)(en)]Cl2 (2) and [RuII(η6C6H5(C 6H4)NH2)Cl(en)]Cl (3), where en is ethylenedlamine, have been synthesized and their X-ray structures determined. Interconversion between 2 and 3, that Is, tethered-arene ring-closure and ring-opening, in different solvents has been investigated. Complex 2 opens in dimethylsulfoxide (DMSO) by solvent-induced dissociation of the NH2 group of the pendant arm. In methanol, however, equilibrium between 2 and 3 Is reached after 12 h when both species coexist In solution In a ratio of 2:1 (open/closed). In water (pH 7), complete ring closure of 3 to 2 at 298 K occurs in less than 2 h. The tether ring of complex 2 opens at basic pH and closes at neutral pH. Complex 2 opens over time (18 h) in concentrated HCl. The opening-closing process Is fully reversible in the pH range 2-12. Density Functional Theory calculations have been used to obtain insights into the electronic structure of complexes 2 and 3, their UV-vis properties, and their stability compared to their aqua derivatives. Control of tether-ring-opening can contribute toward a strategy for activation and for achieving cytotoxic selectivity of ruthenium arene anticancer drugs.
