摘要:
Reactions between RuX(PPh3)2(eta-C5H5) (X = Cl, I) and C2(CO2Me)2 in MeOH in the presence of NH4PF6 have given three types of complex, which have been fully characterised by X-ray studies. These are the eta-4-diene complexes RuX{eta-4-CH(CO2Me) = C(CO2Me)C(CO2Me) = CH(CO2Me)}-(eta-C5H5) (1, X = Cl; 2, X = I) and the eta-5-cyclohexadienyl derivatives Ru(eta-5-C5H5){eta-5-C6H(CO2Me)6} (4) and Ru(eta-5-C5H5){eta-5-C6[C(CO2Me) = CH(CP2Me)](CO2Me)6} (5). The three complexes are formed by di-, tri- and tetra-merisation of the alkyne at the mononuclear ruthenium centre; the last reaction is unprecedented. Possible mechanisms are discussed.