Untersuchungen zur P–P‐Bindungsknüpfung in der Koordinationssphäre von Übergangsmetallen

Investigations of P–P Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of CpW(CO)₃]^– with PCl₃ leads to the transition metal substituted dichlorphosphines {CpW(CO)₃}PCl₂] ( 1 ) and {Cp(CO)₃W}PCl₂{WCl(CO)₂Cp}] ( 2 ). The X‐ray structure of 2 reveals the Lewis acid/base character of this compound. Reactions of 1 and Cr(CO)₅Cp*PCl₂], respectively, with metalates of the type M(CO)₃Cp′]^– (M′ = Mo, W; Cp′ = η⁵‐C₅H₄tBu) afford the cyclo‐P₃ complexes (η³‐P₃)MCp′(CO)₃] ( 3 ) (M = W) and ( 4 ) (M = Mo) and the compounds (μ,η²‐P₂{Cr(CO)₅}₂){Mo(CO)₂Cp}₂] ( 5 ) and {μ₃‐PW(CO)₃Cp′}{W(CO)₂Cp′}₂] ( 6 ), respectively. Complex 6 possesses a planar homoleptic W₃P moiety revealing delocalised multiple bonds within the W₂P‐subunit. Reducing (CO)₅WPCl₃] with magnesium leads to the formation of the phosphinidene complex {(CO)₅W}₂PCl], whereas the reduction of CpW(CO)₃PCl₂] ( 1 ) with magnesium yields the cyclo‐P₃ complex 3 together with P₄ phosphorus.