NEW PROCEDURE FOR THE SYNTHESIS OF (FULVALENE)DITUNGSTEN CARBONYL HALIDES AND CYCLOPENTADIENYLTUNGSTEN CARBONYL HALIDE-COMPLEXES WITH P-DONOR NUCLEOPHILES

The reactions of (eta(5):eta(5)-C10H8)W-2(CO)(6)I-2 and (eta(5)-C5H5)W (CO)(3)I With P-donor nucleophiles (L = P(OMe)(3), PPhMe2, P(n-Bu)(3), PPh2Me, P(p-tol)(3), P(m-tol)(3), and PCy3) in the presence of 2 and 1 equiv, respectively, of Me3NO yield (eta(5):eta(5)-C10H8)W-2(CO)(4)L 2I2 and (eta(5)-C5H5)W(CO)(2)-LI, respectively, as a mixture of cis/tr ans isomers. The relative proportion of these isomers is dependent of the stereoelectronic properties of the phosphine ligands. The X-ray st ructure of (eta(5):eta(5)-(C10H8)W-2(CO)(6)I-2 has been determined.