Ligand substitution in the cyclopentadienyltricarbonyltungsten radical

Article abstract of DOI:10.1021/om00139a031

The substitution reactions of the CpW(CO)₃ radical with phosphines and phosphites have been studied by using a competition experiment. Reaction of CpW(CO)₃H with Ph₃C in the presence of Ph₃CCl and the ligand gave CpW(CO)₃Cl (2) and CpW(CO)₂(PR₃)Cl (3) as the only metal-containing products. Plots of 3/2 vs. [PR₃] were found to be linear with zero intercepts. The reactivity order PBu₃ > P(OPh)₃ > PPh₃ was observed, and substitution was significantly inhibited by CO. Furthermore plots of 3/2 vs. 1/[Ph₃CCl] at constant ligand concentration were found to be linear under nitrogen, but [Ph₃CCl] independent under CO. These results were interpreted in terms of an associative substitution pathway.