Organometallic complexes containing phosphorus(V) bonded to a transition metal: derivatives of dicarbonyl(η-cyclopentadienyl)ferrate(1–)

Abstract

The complexes [Fe(η-C₅H₅)(CO)₂(PR₂E)][E = S, R = Me (I); E = S, R = OEt (II); E = Se, R = Ph(III)] have been synthesized by the reaction of Na[Fe(η-C₅H₅)(CO)₂] with PBrMe₂S, PCl(OEt)₂S, or PPh₂ClSe. The method seems to be valid for the preparation of a variety of the title complexes and suitable for a wider series of carbonylmetallate anions. On the basis of i.r. and ¹H n.m.r. data, the complexes are believed to contain an Fe–P rather than Fe–E bond. On treating tertiary phosphines, L (PPh₃ or PMe₂Ph), with the complexes (I)–(III), no evidence has been obtained for formation of phosphido-complexes and only substitution products of carbon monoxide have been obtained; using MeI or [OMe₃][BF₄] as reagents, the cations [Fe(η-C₅H₅)(CO)₂{PR₂(EMe)}]⁺ are obtained by S- or Se-methylation; Etl and [OEt₃][BF₄] react only with complex (I). The structure of the cationic complexes has been established by i.r. and ¹H n.m.r. Spectroscopy.