Abstract
Ring substituted (R=tBu, SiMe3) metallocene dichlorides undergo a nucleophilic substitution on one of the two rings upon the action of LiPPh2M'(CO)x salts with the formation of chloro-hydrido complexes [C5H3(R)PPh2M'(CO)x](C5H4R)M(H)Cl. Their UV irradiation leads to the chloro-bridged M(μ-Cl)M' separable diastereoisomers. Use of the ansa-metal-locene dichlorides [Me2X(C5H4)2MCl2] (X=Si or C) allowed the access to the new bridging system [M(μ-PPh2, μ-Cl)M′] (M=Mo, W ; M'=W).