Recent advances in cooperative activation of CO and NO by bimetallic coordination complexes or binuclear reaction pathways.

The gaseous small molecules, CO and NO, play important roles in climate change and ozone layer depletion, and they hold promise as underutilized reagents and chemical feedstocks. However, productive transformations of these heteroallenes are difficult to achieve because of their inertness. In nature, these gases are cycled through ecological systems by metalloenzymes featuring multimetallic active sites that employ cooperative mechanisms. Thus, cooperative bimetallic chemistry is an important strategy for synthetic systems, as well. In this Perspective, recent advances (since 2010) in cooperative activation of CO and NO are reviewed, including examples involving s-block, p-block, d-block, and f-block metals and different combinations thereof.