CARBENE FORMATION FROM CPM(SNPH3)(CO)2 (M = FE, RU) - CRYSTAL-STRUCTURES OF CPFEI(CO)(=C(OET)PH), CPRUI(CO)(=C(OET)PH) AND CPRUI(CO)(=C(NHME)PH)

Addition of LiPh followed by [Et3O][BF4] to CpM(SnPh3)(CO)2 (M = Fe, Ru) gives the carbene complexes CpM(SnPh3)(CO){C(OEt)Ph}. These undergo aminolysis on treatment with EtNH2 or MeNH2 to form the amino carbenes CpFe(SnPh3)(CO){C(NHEt)Ph} and CpRu(SnPh3)(CO){C(NHMe)Ph}, respectively. All four compounds react with iodine, the SnPh3 group being replaced by I to give the new carbenes CpMI(CO){C(X)Ph} (M = Fe, Ru; X = OEt; M = Fe, X = NHEt; M = Ru, X = NHMe). The IR and NMR spectra show that the amino carbenes exist as single isomers while the ethoxy carbenes form fluxional isomeric mixtures. The compounds CpFeI(CO){C(OEt)Ph}, CpRuI(CO){C(OEt)Ph} and CpRuI(CO){C(NHMe)Ph} have been studied by X-ray diffraction. In each case the geometry about the metal is essentially conventional, with the carbene groups eclipsed by the MCO groups. © 1990.