Mendola Daniele, Saleh Nidal, Hellou Nora, Vanthuyne Nicolas, Roussel Christian, Toupet Loïc, Castiglione Franca, Melone Federica, Caronna Tullio, Fontana Francesca, Martí-Rujas Javier, Parisini Emilio, Malpezzi Luciana, Mele Andrea, Crassous Jeanne
Sciences Chimiques de Rennes, UMR 6226, and Institut de Physique de Rennes, UMR 6251, CNRS, Université de Rennes 1, Campus de Beaulieu , 35042 Rennes Cedex, France.
Dipartimento di Chimica Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano , Piazza L. da Vinci 32, 20133 Milano, Italy.
Inorg Chem. 2016 Mar 7;55(5):2009-17. doi: 10.1021/acs.inorgchem.5b02276. Epub 2015 Dec 8.
The synthesis and structural characterization of azahelicene platinum complexes obtained from cis-PtCl2(NCEt)(PPh3) and from ligands that differ in terms of both the position of the nitrogen atom and the number of fused rings are reported. These square-planar complexes of the general formula PtCl2(nHm)(PPh3) (n = 4, 5; m = 5, 6) display mainly a cis configuration. However, by X-ray crystallographic analysis, we show that for both PtCl2(4H6)(PPh3) and PtCl2(5H6)(PPh3) there is chirality control of the cis/trans stereochemistry. Indeed, starting from a racemic mixture of aza[6]helicene, platinum complexes with a cis configuration are invariably obtained, and the more thermodynamically stable trans isomers are formed when using enantiopure ligands. We further corroborated these results by NMR analysis in solution.
