AbstractKnown to be a facile irontricarbonyl transfer reagent, (η2‐cis‐C8H14)2Fe(CO)31 transfers its Fe(CO)3unit to a variety of ligands at low temperature. Stirring a THF mixture of 1 and PhC=CPh under N2(g) at −60 °C for 1 h then at room temperature overnight provides mainly a flyover‐bridge product [‐CPh=CPhC(0)‐CPh=CPh‐]Fe2(CO)62 with the organic bridge on diiron core in a complicated μ‐(1,2,5‐η3:1,4,5‐η3) fashion. The keto fragment in 2 comes presumably from the decomposition of 1 that liberates CO. However, stirring a THF mixture of 1 and PhC=CPh under CO(g) at −60 °C for 3 h then at room temperature overnight results in [‐C(0)CPh=CPhC(0)‐]Fe(CO)43, a compound not isolated in the earlier thermal or photochemical reactions of PhC=CPh with ironcarbonyl. The X‐ray structure determinations for