Constructing Metal-Carbon Multiple Bonds for Dehydrogenation and Dehydrocoupling Reactions Involving Volatile Hydrocarbons

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

With funding from the Synthesis Program of the Chemistry Division, the research team of Dr. Daniel Mindiola at the University of Pennsylvania is investigating the synthesis of earth-abundant (i.e., "base") metal complexes containing titanium, niobium, and vanadium. The complexes are studied for their ability to convert, catalytically and under mild conditions, alkanes into alkenes (i.e., compounds with carbon-carbon double bonds). Alkenes are building blocks in industry and are useful in the construction of polymers or other commodity chemicals indispensable to pharmaceuticals and petrochemicals. The research team is also investigating how to convert natural gas or volatile natural resources into liquid fuels since these are much easier to transport and store. The team is also investigating ways to convert nitrogen from our atmosphere into chemical fuels and important reagents such as ammonia or ammonium salts. This is done under mild conditions, also using well defined base metal catalysts. The catalysts that the team is synthesizing function under conditions that are milder (70-80 degree C) than cracking conditions used in the petrochemical industry (>800 degree C). Dr. Mindiola has been active with the ACS (American Chemical Society) serving as Chair of the ACS Scholars Program Subcommittee on Minority Affairs among many other activities to promote diversity in the physical sciences. He is actively involved in promoting science at the university level as well as in elementary and middle schools in the region by conducting demonstrations aimed at understanding natural resources such as nitrogen and natural gas. Dr. Mindiola is investigating how base, early transition metals such as Ti, V, and Nb can promote the transfer dehydrogenation of volatile and linear hydrocarbons, selectively, into olefins and terminal olefins in the case of C4 and above. The research team is investigating mild conditions to perform such transformations by taking advantage of the reactive nature of metal-carbon multiple bonds. Through synthetic and mechanistic studies, the team is exploring optimization of conditions for higher catalytic turnover and selectivity. One particular reaction is the room temperature conversion of methane into an olefin using a well-defined Ti alkylidene or robust dinuclear systems. Dr. Mindiola is also exploring the catalytic room temperature conversion of atmospheric nitrogen into ammonia and ammonium salts using base metal niobium precursors that are simple to prepare and handle, and which have yielded intermediates that provide clues into how these systems bind, activate, and split the N-N triple bond. Dr. Mindiola is heavily involved with the American Chemical Society through committees and subcommittees aimed at promoting diversity in the physical sciences. He is also actively involved at the university level and in his community promoting science and educating society about natural gas and other greenhouse gases. 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.