NEW HETERODIMETALLIC CYCLOPENTADIENYL CARBONYL-COMPLEXES - CRYSTAL-STRUCTURE OF (C(5)ME(4)ET)W(MU-CO)(3)RU(C(5)ME(5))

A series of heterodimetallic complexes of general formula (C(5)R(5))M( mu-CO)(3)RuC(5)Me(5) (M = Cr, Mo, W; R = Me, Et) has been prepared in good yields by the reaction of [C(5)R(5)M(CO)(3)](-) with [C(5)Me(5)Ru (CH3CN)(3)](+). (C(5)Me(4)Et)W(mu-CO)(3)Ru(C(5)Me(5)) was characterize d by a crystal structure determination. The W-Ru bond length of 2.41 A ngstrom is consistent with the formulation of a metal-metal triple bon d, while the unsymmetrical bonding mode of the three bridging carbonyl groups reflects the inherent non-equivalence of the two different C(5 )R(5)M-units. Using [CpRu(CH3CN)(3)](+) or [CpRu(CO)(2)(CH3CN)](+) as the cationic precursor leads to the formation of dimetallic species (C (5)R(5))M(CO)(5)RuC5H5 with both bridging and terminal carbonyl groups .