Designer Photocatalysts for Asymmetric Photochemistry

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

With the support of the Chemical Synthesis Program in the Division of Chemistry, Professor Tehshik Yoon of the University of Wisconsin–Madison is studying how to use light to improve the discovery and synthesis of structurally complex molecular frameworks, with implications for chemical biology, medicinal chemistry and materials chemistry. In photosynthesis, plants use the energy of light to produce sugars: this is a chemical process that ultimately is responsible for sustaining all life on earth. While chemists have also learned how to use light in chemical synthesis, they have developed no synthetic processes that can achieve the same level of structural complexity and atomic precision as natural photosynthesis. To approach this grand challenge, the Yoon laboratory is designing photocatalysts that can interact directly with small molecules and control how they react to form more complex products. Because this work has the potential to transform discovery in pharmaceutical and materials chemistry, the technical skill sets required to complete this research are in high demand. Thus, one broader impact of this research is the training of a diverse team of young chemists for careers at the cutting edge of the chemical industries. The Yoon group is also leveraging social media tools to present topics in contemporary chemistry to a global community of novice science students who might not otherwise have any exposure to these ideas. Under this award, Professor Tehshik Yoon and his team will design novel photocatalysts take advantage of recent discoveries in solar energy conversion. The team will modify the structures of the most robust and active molecular photocatalysts by introducing polar functional groups that can bind to simple organic substrates through hydrogen-bonding or Lewis acid-base interactions. This enforced proximity is expected to increase the efficiency by which the photocatalyst can influence a chemical reaction. It also provides an opportunity to tune the structure of the photocatalyst to modify the outcomes of the photochemical reaction. Yoon and his team will take an interdisciplinary approach to this research that combines chemical synthesis with computation and spectroscopy to elucidate the detailed mechanisms of photocatalytic reactions. Thus, the outcomes of this research will include both new methods for the synthesis of complex molecular compounds but also fundamental insights into the ways in which light energy can be used in chemical synthesis. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.