COORDINATION CHEMISTRY OF PERHALOGENATED CYCLOPENTADIENES AND ALKYNES.20. SYNTHESIS OF BIMETALLIC AND TRIMETALLIC CYMANTRENE DERIVATIVES WITH SILVER OR GOLD CONTAINING RING SUBSTITUENTS - FIRST OBSERVATION OFOXIDATIVE ADDITION OF A HALOGEN-CYCLOPENTADIENYL BOND TO A NI-0 FRAGMENT

Treatment of the perhalogenated cymantrenes [C5X4Br]Mn(CO)(3) (X = Cl, Br) with butyl lithium and Au(PPh3)Cl yields, depending on the reacti on conditions, the bi- or trimetallic sigma, pi-bridged cyclepentadien yl complexes [C5X5-n(AuPPh)(3n)]Mn(CO)(3) with n = 1 or 2. Similarly, the bimetallic complexes [C5Cl4(AgPPh3)]Mn(CO)(3) and [C5Cl4((AuCNBu)- Bu-t)]Mn(CO)(3) can be obtained. Addition of Ni[PBu3](2)(C2H4) to [C5C l4(AuPBu3)]Mn(CO)(3) generated in situ results in oxidative addition o f one ring CCl bond to Ni-0 to give [(CCl3)-Cl-5(AuPBu3)[Ni(PBu3)(2)Cl ]]Mn(CO)(3), the first complex with three different metals attached to one cyclopentadienyl ring. When the lithium cymantrenyl thiolates [C5 Cl3X(SLi)]Mn(CO)(3) (X = Cl, Li or SLi) are treated with Au(PPh3)Cl, t he gold thiolates [C5Cl3Y(SAuPPh3)]Mn(CO)(3) with Y = Cl, AuPPh3 or SA uPPh3 are formed. (C) 1997 Elsevier Science Ltd.