C2H4 bridge-dissociation reactions

Similar C2H4 bridge-dissociation reactions occured when [Fe(CO)2(S4)] was treated with LiBEt(H or metallic sodium, or in reactions between [Fe(CO)5] or [Fe(CO)3(butadiene)] with S). These reactions yielded IFelTTCeUrhl2, [Fe(CO)(S2C6H4)2]2, or IFelCOE CeHrh]2 and probably involve the [Fe°(S4)] intermediate species (94). 

The reaction of Cp2Tav(H)3 with IrIX(CO)(dppe) (X = Br, I dppe= l,2-bis(diphenylphos-phino)ethane) was rapid and led to clean formation of /uc-Irm(H)3(CO)(dppe) and Cp2TamX or Cp2TamXL (in the presence of added L = CO, C2H4, PrC=CPr).4 6 The total results were consistent with the formation of hydrido- and halo-bridged intermediates in which transfer of all hydrido and halo ligands occurred before dissociation into the mononuclear products. 

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