Norman Greenwood

Norman Greenwood coauthored research on the reactions of boron-hydride clusters with cobalt, rhodium, and iridium complexes. A reported borallyl iridium product illustrates how a cluster can become a multidentate ligand.

The chemistry extends the usual picture of a ligand as a single atom donating one electron pair. Several atoms of a cluster fragment can participate in bonding, so cluster identity and coordination mode must both be specified.^[ref]