Bi- and triheteronuclear complexes of uranium and group VI transition metals

The new heterobimetallic compounds Cp₃U[OCM(CO)₂Cp′] containing uranium and group VI transition metals are synthesized from Cp₃UCl and Na[M(CO)₃Cp′] or from Cp₃UCH₃ and H[M(CO)₃Cp′] (M = Mo, W; Cp = C₅H₅; Cp′ = C₅H₅ or C₅Me₅). In a same manner, the trimetallic Cp₂U[OCMo(CO) ₂Cp]₂ is obtained starting from Cp₂U(NEt₂)₂ and H[Mo(CO)₃Cp]. All these complexes exhibit low CO stretching frequencies characteristic of isocarbonyl linkages between uranium and Mo or W atoms.