Photocatalyzed Hdrogen/Deuterium Exchange in Molecules Confined within Functional Nanopores

Oregon State University, Corvallis OR

Investigators

Abstract

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Kyriakos C. Stylianou and his team at Oregon State University will investigate the fundamental mechanisms of metal-organic framework (MOF)-based photocatalysis. Photocatalysis offers significant advantages over conventional catalysis by using renewable sunlight as an energy source. However, challenges exist, including limited material diversity, catalyst stability, product separation difficulties, sustainable light utilization, and achieving high specificity in complex reactions. Therefore, the development of highly specific and robust heterogenous photocatalysts synthesized from abundant starting materials is of great interest. MOFs are candidates for photocatalysts as their internal porous structures and high surface areas can lead to enhanced catalytic efficiency and selectivity. Although MOFs have showcased their potential as photocatalysts, there is still a pressing need to develop a deeper understanding of their underlying mechanisms and the factors that dictate their efficiency and selectivity. Professor Stylianou’s team will investigate hydrogen-deuterium (H/D) isotope exchange using photoactive MOFs to aid in the identification of structure-activity relationships and to assess how MOF properties influence photocatalytic activity. In terms of broader impacts, this research will develop new catalysts which are appealing particularly to the pharmaceutical industry, where highly selective and sustainable catalysts can lead to breakthroughs in the development of medications. Additionally, Dr. Stylianou is actively engaged in outreach programs to educate and engage the public in science. He strives to spark interest in STEM among young students by exposing them to research and nurturing scientific qualities such as autonomy, skillset development, critical thinking, inclusivity, teamwork, and community involvement. These efforts include presentations and workshops at elementary and high schools focused on increasing awareness of materials’ impact and sponsoring his graduate students to participate in Oregon Museum of Science and Industry Science (OMSI) communication fellowships, where they communicate science to children and the general public. This work supported by the Chemical Catalysis program in the Division of Chemistry is expected to elucidate the fundamental structure-activity relationships that govern MOF photocatalysis and lead to the development of sustainable and highly selective photocatalysts for application in chemical feedstock and pharmaceutical industries. H/D exchange is sensitive to hydrogen atom transfer (HAT) and single electron transfer (SET) reactions. Monitoring the extent and kinetics of H/D exchange through in-situ nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) can provide insights into the occurrence and rates of HAT and SET reactions in MOFs, providing a vital mechanistic perspective. Dr. Stylianou hypothesizes that the extent and kinetics of MOF photocatalyzed H/D exchange delineate the influence of MOF chemical and optoelectronic properties, ultimately dictating their propensity to initiate HAT and/or SET processes. This investigation will establish photoactive MOFs as a unique platform for conducting H/D exchange reactions in a single step on both labile (i.e, formyl C—H) and stable (i.e., C(sp3)—H) bonds, and elucidate design principles for novel MOFs capable of facilitating stereospecific H/D exchange at chiral centers. 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.