New Procedure for the Synthesis of (Fulvalene)ditungsten Carbonyl Halides and Cyclopentadienyltungsten Carbonyl Halide Complexes with P-Donor Nucleophiles

The reactions of (η5:η5-C10H8)W2(CO)6I2 and (η5-C5H5)W(CO)3I 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 (η5:η5-C10H8)W2(CO)4L2I2 and (η5-C5H5)W(CO)2LI, respectively, as a mixture of cis/trans isomers. The relative proportion of these isomers is dependent of the stereoelectronic properties of the phosphine ligands. The X-ray structure of (η5:η5-(C10H8)W2(CO)6I2 has been determined.