Novel Dinuclear (μ-Hydrido)(μ-alkylideneamido)ruthenium Complexes, [(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ru]<sub>2</sub>(μ-L)(μ-H)(μ-NCHR) (R = Me, Et; L = MeCN, Arene), as Precursors of Active Species for Bimetallic Activation. Dehydrogenative Coupling of Ethylene in a Dinuclear Ruthenium Complex

The dinuclear ruthenium tetrahydride [(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Ru(μ-H)<sub>2</sub>]<sub>2</sub> reacts with acetonitrile or propionitrile in the presence of an arene such as toluene or naphthalene to generate the (μ-hydrido)(μ-alkylideneamido)ruthenium complex (Cp‘Ru)<sub>2</sub>(μ-L)(μ-H)(μ-NCHR) (L = (arene); Cp‘ = η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>). The reaction of the (μ-alkylideneamido)ruthenium complex with ethylene gives the bis(ethylene)ruthenium complex [Cp‘Ru(η<sup>2</sup>-CH<sub>2</sub>CH<sub>2</sub>)]<sub>2</sub>(μ-H)(μ-NCHCH<sub>3</sub>), which undergoes dehydrogenative coupling of the ethylene ligand to yield the μ-η<sup>2</sup>:η<sup>2</sup>-s-<i>cis</i>-butadiene complex (Cp‘Ru)<sub>2</sub>(μ-η<sup>2</sup>:η<sup>2</sup>-CH<sub>2</sub>CHCHCH<sub>2</sub>)(μ-H)(μ-NCHCH<sub>3</sub>).