The bonding of other unsaturated hydrocarbons to transition metals

The bonding of other unsaturated hydrocarbons to transition metals 

The 18 available electrons in ferrocene (ten from the two C5H5 ligands and eight from the iron atom) may be placed into the nine M.Os. of lowest energy. 

As the 3-electron n--allyl- and the 4-electron ir-butaxliene-metal systems have no elements of rotational symmetry about the z-axis, a very large 

The bonding of all unsaturated hydrocarbon ligands to transition metals thus consists of two or more parts— 

The example of cyclo-octatetraene emphasizes that all the carbon-carbon double bonds in a di- or poly-olefin are not necessarily used in complex formation. Other examples are found elsewhere in this book— butadieneFe(CO)4 (p 172) and cycloheptatrieneFe(CO)3 (p 197). 

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