CAREER: Palladium-Catalyzed C-H Activation/C-C Cross-Coupling of CH4 Hydrates and Plasma using Cyclodextrin Ligand in Multiphase Microsystems

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1453062 - HartmanScience and engineering innovations over the last decade have enabled domestic natural gas resources that could sustain the U.S.'s energy, materials, commodity, pharmaceutical, and fine chemicals processing infrastructure. Natural gas, water science, and their symbiosis are keys to sustainability, and novel, economical approaches to the use of natural gas in organic synthesis at moderate temperatures (200 degC) remains a challenge. The physics and the chemistry of water and methane (i.e., the largest component fraction of natural gas) have relevance in the atmospheric and planetary sciences. Massive quantities of natural gas are entrapped in crystalline water throughout the world, from the deep seabed to beneath the polar ice regions. Natural gas has merit for its use in organic synthesis but the challenges are in the controlled activation of carbon-hydrogen bonds of methane at moderate temperatures and their functionalization via carbon-carbon cross-coupling with aryl heteroatoms. This project involves the synergy of the five sciences: 1) CH4 hydrates/plasma, 2) cyclodextrin (CD) catalysis, 3) palladium-catalyzed C-H activation/C-C crosscoupling,4) microreaction engineering, and 5) multiphase microfluidics with online analytics. If successful, this research could reduce the cost of current synthetic methodologies of Pd-catalyzed methylations of aryl heteroatoms for fine chemicals and pharmaceuticals by at least an order of magnitude. The resulting scientific discoveries will broadly impact aqueous natural gas technology, but they will also advance chemical engineering education. The project will accomplish two K-12 educational goals beyond affecting the undergraduate and the graduate-level chemical reaction engineering curricula that the PI teaches: 1) inspire science and mathematics students to pursue careers in chemical engineering, and 2) innovate approaches to remotely involve students with chemical engineering research. The PI has already established a partnership with the Alabama School of Fine Arts, Birmingham, AL where he is mentoring a K-12 senior for the second year towards the completion of his research thesis. The knowledge created will be disseminated through works of art in both the science and the visual arts they generate. Students enrolled in the Alabama School of Fine Arts are commonly gifted in the visual arts, and thus each student the PI advises will express the chemical engineering knowledge they learn by touring exhibitions at the Birmingham Art Walk, the Alabama School of Fine Arts, and the posting of artwork photographs on the PI's laboratory website. The outcomes are anticipated to be innovations that discover the science of natural gas in aqueous systems, a K-12 educational component that broadly outreaches beyond the campus boarders, and ultimately the advancement of natural gas utilization in a broad cross-section of society.Cyclodextrins (alpha-, beta-, and gamma-CD's), both naturally occurring and synthetically prepared organic inclusion compounds, are known to stabilize CH4 in liquid water and to catalyzed CH4 hydrate formation with molecular diffusion often controlling both processes. Molecular-level understanding acquired via the microreaction engineering of inclusion compounds and their complexes in C-H activation/C-C cross-coupling could advance the versatility of natural gas as an economical feedstock for multiphase organic synthesis. The understanding will be learned by i) innovating microsystems with online analytics for continuous multiphase C-C cross-couplings of CH4, ii) discovering the Pd-catalyzed C-C cross-coupling of CH4 stored in hydrates with aryl heteroatoms at organic-liquid water interfaces using alpha-, beta-, and gamma-CD's, iii) discovering the Pd-catalyzed C-C cross-coupling of ionized CH4 with aryl heteroatoms at cold plasma-liquid water interfaces, and iv) elucidating the catalytic cycle(s) that control the C-C cross-couplings. The project couples the PI's decade of experiences studying inorganic inclusion compounds in his doctoral research, innovating science and technology that are enabling the US to secure natural gas in his post-graduate career, researching microchemical systems for organic synthesis in his postdoctoral research, and building his academic laboratory on aqueous methane conversion with discoveries on gas hydrates and hydrophilic organic synthesis.