Engineering Bimetallic Active Sites in Metal–Organic Frameworks: Challenges and Opportunities

Examples of two metal centers working synergistically to catalyze challenging chemical transformations can be found throughout biological and synthetic systems. In each case, specific metal identities, ligand environments, and metal–metal distances are required. The structural precision needed to engineer a productive, surface-supported bimetallic active site represents an opportunity for metal–organic frameworks. In this perspective, we summarize the different ways binuclear metal active sites have been synthesized in metal–organic frameworks and applied in catalysis. Selected examples from the literature will be highlighted to illustrate both the diversity of synthetic approaches as well as the diversity of bimetallic structures.