ORGANOMETALLIC TRANSITION METAL DERIVATIVES CONTAINING FLUORINE .4. REACTIONS OF PERFLUOROALKYL DERIVATIVES OF CYCLOPENTADIENYLMENTAL CARBONYLS OF IRON AND MOLYBDENUM WITH TERTIARY PHOSPHINES

Ultraviolet irradiation of the perfluoroalkyliron derivatives RfFe(CO)2C5H5 [Rf=C2F5 and (CF3)2CF] with the saturated chelating ditertiary phosphine (C6H5)2PCH2CH2P(C6H5)2(Pf-Pf) results in stepwise substitution of the carbonyl groups giving first the monodentate monometallic derivatives RfFe(CO)(Pf-Pf)(C5H5) and then the carbonyl-free bidentate monometallic derivatives RfFe(Pf-Pf)(C5H5). By contrast, UV irradiation of the same perfluoroalkyliron derivatives with the unsaturated chelating ditertiary phosphine cis-(C6H5)2PCH=CHP(C6H5)2 (cPf=Pf) proceeds directly to the carbonyl-free bidentate monometallic derivatives RfFe(cPf=Pf)(C5H5) without formation of an isolable monodentate monometallic derivative. UV irradiation of the RfFe(CO)2C5H5 derivatives with triphenylphosphine gives the substitution products RfFe(CO)[P(C6H5)3](C5H5) (Rf=CF3, CF3CO, C2F5, and (CF3)2CF); IR and NMR spectral data on the compound of this type with the relatively bulky (CF3)2CF group suggest the presence of conformational isomers arising from hindered rotation about the iron-perfluoroalkyl bond. Similar UV irradiation of the molybdenum derivative CF3Mo(CO)3C5H5 with the appropriate tertiary phosphines gives the substitution products CF3Mo(CO)2[P(C6H5)3](C5H5) and CF3Mo(CO)(Pf-Pf)(C5H5). An improved preparation of the RfFe(CO)2C5H5 [Rf=C2F5F and (CF3)2CF] derivatives from the corresponding perfluoroalkyliron tetracarbonyl iodides RfFe(CO)4I and thallium(I) cyclopentadienide is described. © 1969.