Synthesis, structure and redox behaviour of tethered arene–ruthenium(II) complexes

Facile Arene Ligand Exchange in p-Cymene Ruthenium(II) Complexes of Tertiary P-Chiral Ferrocenyl Phosphines

“…22 Usually, arene displacements of this kind are achieved with labile η 6 -coordinated ligands, for example, electron-poor arenes such as alkyl benzoates. 40−42 The solid-state structure of 4a confirmed the η 6 -coordination of the terminal phenyl ring of the 2-biphenylyl substituent (Figure 2).…”

“…This reaction is particularly remarkable because the displacement of the p -cymene fragment as the first step of tethering is generally known to proceed rather sluggishly or is even reported to be impossible . Usually, arene displacements of this kind are achieved with labile η 6 -coordinated ligands, for example, electron-poor arenes such as alkyl benzoates. − The solid-state structure of 4a confirmed the η 6 -coordination of the terminal phenyl ring of the 2-biphenylyl substituent (Figure ).…”

p-Cymene ruthenium thioether complexes

“…Recent work on similar (g 6 -arene)dichloro complexes bearing arylalkyl substituted phosphines with flexible alkyl spacers has disclosed, that, upon thermal treatment, the coordinated arene is readily replaced by a dangling aryl substituent [3,[25][26][27]. This reaction provides an easy access to tethered complexes where the phosphine substituted arene serves as an eight electron donor chelate ligand.…”

“…Reduction, however, remained a completely irreversible process. The mono(thioether) complexes undergo oxidation at potentials near 0.85 V whereas the cationic bis(thioether) derivative 3 is much harder to oxidize and gives an E 1/2 of +1.44 V. The oxidation potentials of 2a-c and of the related SMe 2 derived complex 2d are by about 100 mV higher than those of similar phosphine derivatives [26,[37][38][39], and this signals that SR 2 ligands are inferior electron donors compared to phosphines. A similar anodic shift is seen for the reduction peak potential of 3 compared to 2a-c.…”

Intramolecular dehydrofluorinative coupling of η6-arene and fluoroarylphosphine ligands in ruthenium complexes

“…The method provides a convenient route to complexes of tridentate tethered h 5 ,kP-cyclopentadieneide-phosphine ligands, which can be difficult to access by other routes [5]. Although tethered h 6 ,kParene-phosphine ligands are more readily accessible by other methods [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], intramolecular coupling of ligands is still attractive for reasons of enhanced regio-and stereo-selectivity. A small number of intramolecular coupling reactions that afforded complexes of h 6 ,kP-arene-phosphine ligands have been reported [21][22][23].…”