CAS: Synthetic Entries to ETM with M-Ligand Multiple Bonds and Their Role in Stoichiometric and Catalytic Carbon-Hydrogen Activation and Functionalization of Volatile Alkanes

With the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Professor Daniel J. Mindiola of the University of Pennsylvania will study the fundamental reactivity of the most abundant and volatile hydrocarbons such as methane, ethane, and propane under mild conditions and with zero emission of carbon dioxide. The project will establish new strategies to convert natural resources such as methane and ethane, the main components of natural and shale gases, into more value-added materials using earth-abundant base metals such as titanium, vanadium, and niobium, among others.

One main target is to convert these alkanes into olefins; molecules that are industrial building blocks due to their use in the design of polymers, adhesives, detergents, and many other value-added chemicals that are routinely used commercially and in the household. Because of their volatility and limited storage capacity available, these natural resources are routinely being flared at staggering rates, so their combustion as well as their direct release into our atmosphere play a tremendous role in our fragile environment.

Our main objective will be to selectively and controllably activate these alkanes using compounds that contain highly polar metal-carbon or metal-nitrogen multiple bonds, especially under mild conditions (room temperature), which is in contrast to industrial processes that tend to crack these alkanes under energy-intensive conditions. The research will also explore methods to construct well-defined metal-oxide, -sulfide or heavier chalcogenide (Se and Te) analogues, and to use these as supports for other metals ions to mimic how metal-oxide supports are used in conjunction with metal catalysts.

Dr. Mindiola has been active with the ACS (American Chemical Society) and the ACS Scholars Program for nearly 20-years in order to promote diversity in the physical sciences. He is actively involved in promoting the science of methane and other “mysterious” hydrocarbons at the university level as well as in elementary and middle schools nationwide.

His research group will also develop podcasts explaining their research projects but aimed to a broader audience. These short clips organized by students and postdoctoral associates will be available to the public through the YouTube group channel “MindiScience” with the aim to educate the community about flaring, catalysis, natural and shale gases, and their rich chemistry.

The Mindiola research team will study the chemistry of early-transition metals ions composed of Ti, V, and Nb, and how these can promote the dehydrogenation of volatile hydrocarbons, selectively and under mild conditions, into olefins containing these unsaturation at the terminal positions. The PI’s research team will investigate these reactions via the development of metal-carbon, nitrogen, phosphorus, and chalcogen multiple bonds, and their reactivity with the alkanes.

Using a combination of synthesis, reactivity, and mechanistic studies, the Penn team will explore optimized conditions for higher catalytic turnover using these base metal complexes. One specific reaction being targeted is the room temperature conversion of methane into an olefin using a well-defined metal complexes that can dehydrogenate the parent hydrocarbon into a parent Schrock-like carbene.

Mindeola and co-workers also plan to synthesize archetypes of group 4 transition metal bischalcogenides and heterobimetallics. If successful, such chemistry is expected to have both real practical impact in making available valuable olefin building blocks and in providing an important contribution to sustainable chemistry.

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.