Coordinatively unsaturated diruthenium complexes:: Synthesis and X-ray crystal structures of [Ru2(CO)3L(μ-η1:η2-CCPh)(μ-PtBu2)(μ-Ph2PCH2PPh2)]

[Ru-2(CO)(4)(mu-H)(mu-(PBu2)-Bu-t)(mu-dppm)] (1) reacts with several phosphines (L) in refluxing toluene under substitution of one carbonyl ligand and yields the compounds [Ru-2(Co)(3)L(mu-H)(mu-(PBu2)-Bu-t)(mu-dppm)] (L=(PBu3)-Bu-n, 2a; L = PCy2H, 2b; L = dppm-P, 2 c; dppm = Ph2PCH2PPh2). The re activity of 1 as well as the activated complexes 2a-c towards phenylethyne was studied. Thus 1, 2a and 2b, respectively, react with PhC=CH in refluxing toluene with elimination of dihydrogen to the acetylide-bridged complexes [Ru-2(CO)(4)(mu-eta(1) : eta(2)-C=CPh) (mu-(PBu2)-Bu-t)(mu-dppm)] (3) and [Ru-2(CO)(3)L(mu-eta(1) : eta(2)-C=CPh)(mu-(PBu2)-Bu-t)(mu-dppm)] (4a and 4b). The molecular structures of 3 and 4a and determined were by crystal structure analyses.