Reactivity of the ansa-bridged metallocene dichlorides [X(η5-C5H4)2]MCl2 (X = SiMe2, CMe2; M = Mo, W) toward metallophosphide anions [PPh2M′(CO)x]- (M′ = Cr, Mo, W, x=5; M′ = Fe, x=4).: Formation of heterobimetallic complexes by nucleophilic substitution on a cyclopentadienyl ligand or on the metal M

Two kinds of ansa derivatives, [SiMe2(eta(5)-C5H4)(2)]MCl2 and [CMe2(eta(5)-C5H4)(2)]MCl2 (M = Mo, W), are reacted with metallophosphide anions [PPh2M'(CO)(x)](-) (M' = Cr, Mo, W, x = 5; M' = Fe, x = 4). The silicon-bridged derivatives give the bimetallic systems [SiMe2(eta(5)-C5H4)(eta(5)-C5H3PPh2M'(Co)(x)]M(H)(Cl), which result from a regioselective substitution at the 3-position on the cyclopentadienyl ligand. In contrast, with the CMe2-bridged compounds, the substitution reaction occurs at the metallic center, giving Ic-phosphido bimetallic complexes [CMe2(eta(5)-C5H4)(2)]M(Cl)(mu-PPh2)M'(CO)(x). The solid-state structure of the bimetallic complex [CMe2(eta(5)-C5H4)(2)]W(Cl)(mu-PPh2)Fe(CO)(4) (7d) is reported.