Novel Dinuclear (μ-Hydrido)(μ-alkylideneamido)ruthenium Complexes, [(η5-C5Me5)Ru]2(μ-L)(μ-H)(μ-NCHR) (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 5 -C 5 Me 5 )Ru(μ-H) 2 ] 2 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) 2 (μ-L)(μ-H)(μ-N CHR) (L = (arene); Cp‘ = η 5 -C 5 Me 5 ). The reaction of the (μ-alkylideneamido)ruthenium complex with ethylene gives the bis(ethylene)ruthenium complex [Cp‘Ru(η 2 -CH 2 CH 2 )] 2 (μ-H)(μ-N CHCH 3 ), which undergoes dehydrogenative coupling of the ethylene ligand to yield the μ-η 2:η 2 -s- cis -butadiene complex (Cp‘Ru) 2 (μ-η 2:η 2 -CH 2 CHCH CH 2 )(μ-H)(μ-N CHCH 3 ).