Novel dinuclear (mu-Hydrido)(mu-alkylideneamido)ruthenium complexes, [(eta(5)-C(5)Me(5))Ru](2)(mu-L)(mu-H)(mu-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 [(eta(5)-C(5)Me(5))Ru(mu-H)(2)](2) reacts with acetonitrile or propionitrile in the presence of an arene such as toluene or naphthalene to generate the (mu-hydrido)(mu-alkylideneamido)-ruthenium complex (Cp'Ru)(2)(mu-L)(mu-H)(mu-N=CHR) (L=(arene); Cp'=eta(5)-C(5)Me(5)). The reaction of the (mu-alkylideneamido)ruthenium complex with ethylene gives the bis(ethylene)ruthenium complex [Cp'Ru(eta(2)-CH2=CH2)](2)-(mu-H)mu-N=CHCH3), which undergoes dehydrogenative coupling of the ethylene ligand to yield the mu-eta(2):eta(2)-s-cis-butadiene complex (Cp'Ru)(2)(mu-eta(2):eta(2)-CH2=CHCH=CH2)-(mu-H)(mu-N=CHCH3).