Preparation of a series of heterobimetallic complexes containing bridging ethylidyne ligands by the reaction of diruthenium Bis(μ-ethylidyne) complex with 3d metal carbonyls: Alkylidyne−alkylidyne coupling reaction at the Ru2Fe site

• A heterometallic skeleton was formed by reacting diruthenium complex with metal carbonyl . • A μ 3 -alkyne complex was obtained via the alkylidyne−alkylidyne coupling. • π-Aromatic [Ru 2 C 2 ] core readily uptakes an electron-deficient organometallic species. • A μ-vinylidene−μ 3 -ethylidyne complex was obtained via the C−H abstraction by [Mn(CO) 5 ]. Diruthenium bis(μ-ethylidyne) complex [(Cp*Ru) 2 (μ-CMe) 2 ] ( 1 ) reacts smoothly with metal carbonyls of group 6–9 3d metals to afford heterobimetallic tri- and tetranuclear complexes. While bis(ethylidyne) complexes [(Cp*Ru) 2 (μ-CMe)(μ 3 -CMe)(μ-CO) 2 {Cr(CO) 3 }] ( 2 ) and [(Cp*Ru) 2 (μ 3 -CMe) 2 (μ-CO){Fe(CO) 3 }] ( 4 ) were obtained by the reaction of 1 with [Cr(CO) 6 ] and [Fe(CO) 5 ], respectively, the reaction with [Mn 2 (CO) 10 ] yielded μ-vinylidene−μ 3 -ethylidyne complex [(Cp*Ru) 2 (μ-C=CH 2 )(μ 3 -CMe)(μ-CO) 2 {Mn(CO) 3 }] ( 3 ) accompanied by the abstraction of a methyl proton by [Mn(CO) 5 ] • . By the reaction with an excess amount of [Co 2 (CO) 8 ], tetranuclear bis(μ 3 -ethylidyne) complex [(Cp*Ru) 2 (μ 3 -CMe) 2 (μ-CO){Co(CO) 2 } 2 ] ( 6 ) was exclusively obtained. These reactions implied that the delocalized π-electrons in the [Ru 2 C 2 ] core of 1 were used to construct the heterometallic skeleton with unsaturated organometallic species. Although complexes 2 and 3 underwent fragmentation upon gentle heating, 4 reacted with CO at 60 °C to yield μ 3 -η 2 (||)-butyne complex [(Cp*Ru) 2 (μ 3 -η 2 (||)-MeCCMe)(μ 3 -CO)(μ-CO){Fe(CO) 3 }] ( 5 ) via the alkylidyne−alkylidyne coupling. The density functional theory (DFT) calculations suggested that the C−C bond formation occurs via the intermediate containing μ- and μ 3 -ethylidyne ligands followed by the migration of the m -ethylidyne ligand across the Ru 2 Fe plane.