The cothermolysis of [Cp-R(OC)Mo(mu-eta (2:2)-P-2)(2)- FeCpR'] (1) and tBuC=P (2) as well as PhC=CPh (3) affords the heterobimetallic triple-decker like dinuclear clusters [(Cp'''Mo)(Cp*Fe)(P(3)CtBU)(P-2)] (4), Cp''' = C(5)H(2)tBu(3)-1,2,4, Cp*' = C5Me4Et, and [(Cp*Mo)(Cp*Fe) (P2C2Ph2)(P-2)] (5) with a bridging tri- and diphosphabutadiendiyl ligand. 4 and 5 have been characterized additionally by X-ray crystallography.