Pentamethylcyclopentadienylruthenium complexes: IV. Pentamethylcyclopentadienyl(halo)ruthenium(III, II/II, or II), and pentamethylcyclopentadienyl(alkoxo)ruthenium(II) complexes

Treatment of [Cp *RuCl 2] 2 ( 1a) (Cp * = η 5-C 5Me 5) with NaBr KI leads to the complexes [Cp *RuBr 2] 2 ( 1b) and [Cp *RuI 2] 2 1c). Reduction of these Ru III halides with cobaltocene gives pentane-soluble, paramagnetic, molecular mixed valence Ru III/II complexes [Cp *Ru(μ-X) 3RuCp *] ( 3a, 3b, 3c) and on further reduction Cp *Ru II halides [Cp *RuX] n ( 4a, 4b, 4c, X = Cl, Br, I). Treatment of 1a with alcohol in the presence of K 2CO 3 gives the Ru II alkoxo complexes [CpRuOR] 2 ( 16a–16d; R = CH 3, C 2H 5, C 3H 7, C 4H 9). 16a gives a 4a upon treatment with Me 3SiCl. The spectroscopic charactristics, physical properties and cleavage and complexation reactions of the halo and alkoxo complexes are described.