Some ruthenium complexes derived from 1,4-diethynylbenzene: molecular structure of Ru{η3-C[C(CN)2]C(C6H4CCH-4)C(CN)2}(PPh3)Cp

Reactions of Ru(CCC6H4CCR-4)(PPh3)2Cp [R=SiMe3 (1), H (3)] are described. With Co2(CO)8 reactions occur at the CC triple bond furthest from the ruthenium centre; in contrast, tetracyanoethene gave Ru{η3-C[C(CN)2]C(C6H4CCR-4)C(CN)2}(PPh3)Cp (R=SiMe3, H), the molecular structure of the latter being determined. Protonation or methylation of 3 occurs at Cβ to give the expected vinylidene complexes. With 3, metallation (LiBu), Sonogashira and oxidative coupling reactions were demonstrated. Coupling with appropriate metal substrates gave a variety of complexes containing RuCCC6H4CCM (M=W, Rh, Ir, Pt, Au, Hg) moieties.