Transition
metals can assemble to form multinuclear complexes by
engaging in direct metal-to-metal interactions. Metal–metal
covalent bonds provide a large perturbation in electronic structure,
relative to mononuclear metal ions, and the unique properties of these
dinuclear fragments can be harnessed in a broad range of applicationsfor
example, as chromophores in photochemical processes, redox centers
in molecular electronics, or structural elements in metal–organic
materials. There is a growing body of evidence that metal–metal
bonds may also be formed under conditions relevant to catalysis and
play a key role in transformations that were previously assumed to
only involve mononuclear species. These findings have stimulated interest
in characterizing multinuclear reaction pathways and developing well-defined
multinuclear platforms as catalytic active sites. In this Perspective,
we present case studies in this emerging area of catalysis research,
emphasizing the impact of metal–metal bonding in either enhancing
or depressing the rate and/or selectivity of a catalytic organic transformation.