“Chemistry at the Intersection of Self-Assembly and Energy Conversion”
Nature often uses two or more metal centers, optimally organized both spatially and electronically, to carry out selective transformations. Polynuclear designs have long been recognized to offer unique advantages over mononuclear variants for certain transformations: For mechanisms wherein multiple oxidative addition or reductive elimination steps must occur, polynuclear systems provide redox leveling, and provide additional coordination sites. Many small molecule activations may proceed via unfavorable pathways if a suitable catalyst isn’t present. Coordination-driven self-assembly offers a novel route to construct cofacial and related multi-centered catalysts. The key to this strategy is the selection of complementary building blocks spanning Lewis-acid acceptors and basic donors with controllable orientations. This approach has the potential to greatly ease the synthesis of new catalysts with multiple, proximal active sites since each component can be prepared independently and then unified via self-assembly reactions which typically furnish thermodynamic products in high yields. This talk will focus on the self-assembly of cofacial electrocatalysts for oxygen reduction reactions of relevance to fuel cells with an emphasis on improving the selectivity and kinetics of porphyrin-based designs. Examples of extending this design strategy to other catalytically relevant building blocks will also be presented.
~Coffee/tea will be served prior to lecture~