title: Optically active ortho-metalated half-sandwich ruthenium complexes: solid-state NMR as a convenient tool to analyze mixtures of diastereomers.
abstract: Bulk solid samples of various ratios of the cyclometalated arene ruthenium diastereomers (S)Ru- and (R)Ru-[(eta(6)-C6H6)Ru(C6H4-2-(R)-CH(Me)NMe2)PMe2Ph](+)PF6(-) (3a/3b), of which the configurational stability at the metal center has been established by classical solution techniques, have been analyzed by the 13C cross-polarization magic angle spinning (CP-MAS) and 31P MAS NMR. The spectra obtained allowed us to detect both isomers and to estimate their respective proportions by 31P spectra. This technique was applied to a bulk solid sample of the diastereomers (S)Ru- and (R)Ru-[(eta(6)-C6H6)Ru(C6H4-2-(R)-CH(Me)NMe2)NCMe](+)PF6(-) (1a/1b), which were shown to be configurationally labile by classical solution experiments. Detection of isomer 1a only in the resulting 13C CP-MAS NMR spectrum demonstrated that there has been epimerization of 1b to 1a during crystallization, thus confirming the configurational lability at the metal center.
authors.affiliation: Laboratoire de Synthèses Métallo-Induites, UMR CNRS 7513 Université Louis Pasteur, 4 rue Blaise Pascal, 67070 Strasbourg, France.
authors.forename: V
authors.initials: V
authors.lastname: Ritleng
authors.forename: P
authors.initials: P
authors.lastname: Bertani
authors.forename: M
authors.initials: M
authors.lastname: Pfeffer
authors.forename: C
authors.initials: C
authors.lastname: Sirlin
authors.forename: J
authors.initials: J
authors.lastname: Hirschinger