Ligand Controlled Redox Catalysis with Late Transition Metal Complexes

With support from the Chemical Catalysis program in the Division of Chemistry, Professor T. Brent Gunnoe of the University of Virginia will study the development of new catalysts for the conversion of chemicals derived from natural gas and petroleum into value-added products. Many starting materials for the chemical industry are hydrocarbons derived from fossil sources (primarily natural gas and petroleum), which must be chemically converted into higher value materials.

The chemical industry's energy consumption for this process is substantial and accounts for approximately 10% of total global energy use and greater than 5% of global carbon dioxide emissions. While there are opportunities to dramatically increase the energy efficiency of large-scale chemical processes, there are also substantial scientific challenges to realizing this goal.

In this project, Professor Gunnoe's group aims to develop a fundamentally new understanding of how to perform selective and energy-efficient catalytic chemical transformations that are essential to the goal of using natural gas and other fossil resources in a more environmentally benign manner. The project will provide a foundation for Professor Gunnoe to work with primarily undergraduate institutions (PUIs) to expand a program to increase interest among students from diverse backgrounds in careers as scientists and engineers, especially in the energy arena.

In this program, graduate students will visit PUIs to deliver short courses based on their research, and undergraduate students will participate in summer research internships in Professor Gunnoe's laboratory.

With support from the Chemical Catalysis program in the Division of Chemistry, Professor T. Brent Gunnoe of the University of Virginia will study the development of new catalysts for the conversion of chemicals derived from natural gas and oil into higher value products. The project will focus on the development of new catalysts, based on Co, Rh, Ir and Pt for the functionalization of hydrocarbons (arenes, alkanes and olefins).

A key goal will be to advance a fundamental understanding of ligand design to control redox chemistry necessary to achieve efficient C–H functionalization, especially under oxidizing conditions such as acidic media. This broad goal is to be achieved through two primary objectives: (i) to understand the impact of "capping arene" ligands on redox reactions, including catalytic hydrocarbon oxidation, using Co, Rh and Ir complexes.

The Gunnoe group will quantify how the capping arene ligand structure, including arene functionality and positioning of "capping arene" group relative to the transition metal and arene substituents, impacts metal-based redox transformations as applied to catalytic olefin hydrogenation, olefin oxidation, and hydrocarbon C–H activation and functionalization; and (ii) to understand the effect of new Z-type ligands on redox reactions, including catalytic C–H activation and functionalization, using Rh, Ir and Pt complexes. The Gunnoe group will determine the ability of the Sb group to control transition metal electronic structure, shuttle reactive groups to/from the transition metal, and to directly activate hydrocarbon substrates in concert with the transition metal.

These studies will be applied to catalytic hydrocarbon C–H functionalization. The targeted outcome of these efforts is to gain an improved understanding of ligand design to optimize rates of C–H activation, especially under oxidizing conditions such as in acidic media, to develop new strategies and processes for the oxidative functionalization of metal-coordinated olefins, and to access new catalysts for C–H functionalization, including partial oxidation of hydrocarbons using air-recyclable oxidants.

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.