BOONE, N.C. — Dr. Jefferson Bates, associate professor in the Appalachian State University Department of Chemistry and Fermentation Sciences, is the lead author of a new paper published in Inorganic Chemistry. The work, titled “Symmetry Breaking in a Triferrous Extended Metal Atom Chain,” provides a thorough analysis of the electronic structure of a novel transition metal compound synthesized by collaborators at Furman University with potential single-molecule magnet behavior. Single-molecule magnets are an exciting class of molecules that have applications in quantum computing and spin-based electronics.
Extended metal atom chain (EMAC) complexes are typically designed so that metal-metal bonding can be carefully explored, according to Dr. Bates. Despite hundreds of known EMACs, the complex of interest in their study is the first iron EMAC with short iron-iron bonds and a high-spin ground state that exhibits ferromagnetic couplings between adjacent irons. Though the compound was reported in 2020, full characterization of this compound required advanced computational analysis to compare with available experimental data.
Bates shared, “Density functional theory (DFT) is a powerful computational tool that yields deep insight into the behavior of the electrons in chemical compounds such as EMACs. This compound exhibits structural features that are dependent on temperature, as well as a tendency to align the spins of each iron in parallel, which we were able to elucidate and rationalize with careful computation.”
To study the triferrous EMAC, Bates worked with recent graduate Jack McKeon '24 to perform the needed calculations through high-performance computing available on campus. “We utilized basic DFT calculations, which are fast on modern computers, as a platform for understanding where higher-level, more computationally demanding methods were needed. This approach yielded a clear picture of the structural and magnetic properties of this novel compound,” said Bates.
The results reported in Bates’ paper illustrate the important impact of the coordination environment around the irons, and how the iron ions bond with one another. Their results confirmed a high-spin ground state that is susceptible to a geometric distortion as the temperature of the sample is cooled, thereby rationalizing the discrepancy between solution and solid phase measurements reported in the experimental literature. A small energy gap between different magnetic spin states, in addition to the ferromagnetic coupling between the irons predicted by DFT, ultimately points to a good candidate for single-molecule magnetism. The insights provided therein will help guide the rational design of future compounds in order to optimize their magnetic properties.
Bates and McKeon published the paper in collaboration with Dr. Gary Guillet, associate professor in the Department of Chemistry at Furman University. Their work is currently supported by the National Science Foundation through a Research in Undergraduate Institutions (RUI) grant from the Division of Chemistry, for which Bates is a co-principal investigator.
Bates earned his master's and doctoral degrees in physical chemistry with a concentration in chemical and material physics from the University of California Irvine before joining App State's Department of Chemistry and Fermentation Sciences in 2017. His research interests include theoretical chemistry and density functional development, as well as applied quantum calculations for inorganic chemistry. At App State, Bates teaches general and physical chemistry courses and has served as faculty mentor to the American Chemical Society sponsored Chemistry Club since 2018.
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About the A.R. Smith Department of Chemistry and Fermentation Sciences
The A.R. Smith Department of Chemistry and Fermentation Sciences offers a Bachelor of Arts in chemistry, a Bachelor of Science in chemistry with eight different concentrations and an interdisciplinary Bachelor of Science degree in fermentation sciences. The department’s programs prepare students to attend graduate and professional schools, as well as for employment in the pharmaceutical and fermentation industries and other business sectors. Learn more at dcfs.appstate.edu.
Written by Dr. Jefferson Bates
Edited by Lauren Gibbs
October 21, 2024
BOONE, N.C.