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

The synthesis and characterization of the CO2-bridged complexes Cp*Ru(CO)(2)(CO2)Zr-(X)Cp(2) (2a, 3a, 5a; X = Cl, Me, SnPh(3)), Cp*Re(CO)(NO)(CO2)Zr(X)Cp(2) (2b, 3b, 5b; X = CI, Me, SnPh(3)), and Cp*Ru(CO)(2)(CO2)SnPh(3) (4) are described. Compounds 2a,b have been structurally characterized. The geometry about the zirconium atom in 2a,b is edge-capped tetrahedral, All compounds have been characterized by solid-state IR data; comparisons of these data with those from other symmetrical mu(2)-eta(3)-CO2 compounds show that, although v(asym) for the CO2 ligand varies slightly with the metallocarboxylate fragment, it is highly dependent upon the coordination geometry of the metal center which binds the two carboxyl oxygens.