REACTIVITY OF THE ANSA-BRIDGED METALLOCENE DICHLORIDES [X(ETA(5)-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(e ta(5)-C5H4)(2)]MCl2 (M = Mo, W), are reacted with metallophosphide ani ons [PPh2M'(CO)(x)](-) (M' = Cr, Mo, W, x = 5; M' = Fe, x = 4). The si licon-bridged derivatives give the bimetallic systems e2(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 cont rast, with the CMe2-bridged compounds, the substitution reaction occur s at the metallic center, giving Ic-phosphido bimetallic complexes [CM e2(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.