Tue February 05, 2013 By:

Answer the following question:

Expert Reply
Wed February 06, 2013
Bonding in ?-complexes is strongest when both the filled ?-bonding orbital of the ?-bonded ligand donates TO the metal and the empty ?* orbital on the ligand can accept electron density FROM the metal. A metal with a partially-filled set of d orbitals is able to participate in this synergistic mode of bonding; main group atoms virtually never have filled p? orbitals available for donating electron density to ?-complexed ligand, hence this kind of complex occurs only with transition metals.
Ask the Expert