Abstract
The binding and activation of small molecules (O2, NOx, CO, CO2, and H2O) by Cu, Ni, and sometimes Co sites in enzymes are key to their biological function. Not only are these small molecule activation reactions biologically important, but they also are of great interest from a synthetic catalysis perspective because of their known or potential involvement in industrial processes, new sustainable technologies, and environmental remediation. This chapter surveys recent efforts using synthetic Cu, Ni, and Co complexes to gain insights into the structures and properties of reactive intermediates involved in these activation reactions, and how these intermediates react with substrates.