SYNTHESIS AND CHARACTERIZATION OF CO2-BRIDGED RUTHENIUM-ZIRCONIUM ANDRHENIUM-ZIRCONIUM COMPLEXES

The synthesis and characterization of the CO2-bridged complexes CpRu( CO)(2)(CO2)Zr-(X)Cp(2) (2a, 3a, 5a; X = Cl, Me, SnPh(3)), CpRe(CO)(NO )(CO2)Zr(X)Cp(2) (2b, 3b, 5b; X = CI, Me, SnPh(3)), and CpRu(CO)(2)(C O2)SnPh(3) (4) are described. Compounds 2a,b have been structurally ch aracterized. The geometry about the zirconium atom in 2a,b is edge-cap ped tetrahedral, All compounds have been characterized by solid-state IR data; comparisons of these data with those from other symmetrical m u(2)-eta(3)-CO2 compounds show that, although v(asym) for the CO2 liga nd varies slightly with the metallocarboxylate fragment, it is highly dependent upon the coordination geometry of the metal center which bin ds the two carboxyl oxygens.