Determining Mechanisms and Energetics of Alkane Activation and Coupling by Transition Metal Ions

University Of Massachusetts Amherst, Amherst MA

Investigators

Abstract

WIth support from the Chemical Structure, Dynamics, and Mechanisms Program-A of the Chemistry Division, Professor Ricardo Metz of the University of Massachusetts, Amherst will study how transition metal ions and metal cluster ions react with methane and ethane and catalyze their conversion to more industrially useful chemicals. Natural gas is mostly methane. At room temperature methane remains a gas, even under pressure. This limits its usefulness as a transportation fuel. These studies will look at the fundamental reactions involved in converting methane to larger hydrocarbons that are liquids at room temperature and thus are better fuels for vehicles. The broader impacts of this work include potential benefits from improved catalysts as well as training graduate and undergraduate students in techniques such as laser spectroscopy and mass spectrometry. Most fundamentally, students engaged in this research will assimilate skills in problem solving, experimental design, the collection and analysis of data, and in communicating their results. Professor Metz will also help to introduce eighth-grade girls to science research through the Eureka! program. The research studies being conducted under this award will use a variety of techniques to characterize the reactants, intermediates and products of the reactions of transition metal ions and cluster ions with one or more methane or ethane molecules. Kinetics studies are targeted at measuring the rates of the reactions and correlating reactivity with properties of the frontier molecular orbitals of the ions. Vibrational spectroscopy will be employed to identify both reaction products and stable intermediates. Taken together, these studies are expected to contribute to enhanced fundamental understanding of the mechanisms of C-H bond activation and C-C coupling by transition metals, with the ultimate goal of improving methods for C-H/C-C bond activation in relatively unreactive principal components of natural gas streams. Complementary ion photofragment imaging studies of metal-alkyl ions will be utilized to determine precise covalent bond strengths, measure photodissociation dynamics and to examine spin-forbidden processes. 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.