Luminescent Ruthenium(II) Polypyridyl Functionalized Gold Nanoparticles; Their DNA Binding Abilities and Application As Cellular Imaging Agents

The synthesis and photophysical and biological investigation of Ru(II)-polypyridyl stabilized watersoluble, luminescent gold nanoparticles (AuNPs) are described. These structures bind to DNA and undergo rapid cellular uptake, being localized within the cell cytoplasm and nucleus within 4 h

Rhodium(III) and ruthenium(II) complexes of redox-active, chelating N-heterocyclic carbene/thioether ligands

International audienceHalf-sandwich rhodium(III) and ruthenium(II) complexes bearing a new redox-active ferrocenyl NHC–thioether ligand have been prepared. The synthesis of ferrocenyl thioether-imidazolium salts 3a and 3b was carried out via intermediate 2 using an improved procedure. Rhodium(III) complex 4 and ruthenium(II) complex 5 were obtained in good yields and were fully characterised by NMR spectroscopy, X-ray diffraction analysis and electrochemistry. Complex 4 shows a complex ABCD system by 1H NMR, which denotes conformational rigidity due to the presence of several bulky groups. Electrochemical analysis by cyclic voltammetry reveals reversible redox behaviour about the iron centre in 4 and 5, and indicates electronic communication between iron and rhodium or ruthenium

Palladium(ii) complexes with planar chiral ferrocenyl phosphane-(benz) imidazol-2-ylidene ligands

We describe here the first examples of planar chiral ferrocenyl phosphane-benzimidazol-2-ylidene ligands and their coordination chemistry with palladium(ii). All ligand precursors, namely enantiopure ferrocenyl phosphane-(benz)imidazolium salts, and all enantiopure palladium complexes have been fully characterised by 1H, 31P and 13C NMR, mass spectrometry and X-ray diffraction methods for seven examples. The potential of these very bulky bidentate ligands in catalysis was evaluated and compared to their imidazol-2-ylidene analogues. The influence of sterics was shown to be non-negligible as the bulkiest ligand gave the lowest activities in the asymmetric Suzuki-Miyaura reaction. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2014

Catalytic enantioselective intermolecular cycloadditions of 2-diazo-3,6-diketoester-derived carbonyl ylides with alkene dipolarophiles

Catalyzed cascade reactions that generate molecular complexity rapidly and in an enantioselective manner are attractive methods for asymmetric synthesis. In the present article, chiral rhodium catalysts are shown to effect such a transformation by using a range of 2-diazo-3,6-diketoesters with bicyclo[2.2.1]alkenes and styrenes as reaction partners. The reactions are likely to proceed by formation of a catalyst-complexed carbonyl ylide from the diazo compound, followed by intermolecular cycloaddition with the alkene dipolarophile. It was possible to obtain high levels of asymmetric induction [up to 89% enantiomeric excess (ee) and 92% ee for the two chiral catalysts investigated]. Enantioselectivity is not highly sensitive to substituent variation at the ketone that forms the ylide; however, branching does improve ee. Observations of dipolarophile-dependent enantiofacial selectivity in the cycloadditions indicate that the dipolarophile can be intimately involved in the enantiodiscrimination process