Chemistry Departmental Seminar – Prof. Henry S. La Pierre
About the event
Speaker: Prof. Henry (Pete) S. La Pierre, Associate Professor – School of Chemistry and Biochemistry, Georgia Institute of Technology
Title: Electron (De)Localization in High-Valent Lanthanides and Actinides
Abstract: In this talk, I will present my group’s synthetic studies to isolate and characterize both molecular complexes and extended solids of tetravalent lanthanide ions. Through the discussion of the spectroscopic, structural, and thermomagnetic properties of these systems, I will summarize the key consequences of the competition of between crystal field splitting and spin orbit coupling in the properties of high-valent lanthanide and actinide systems. I will then extend these studies as motivation our synthesis of high-valent mid-actinide (U, Np, Pu) complexes. The redox chemistry and atom/group transfer chemistry of these systems will be presented along with initial electronic structure analyses.
Bio: Dr. Henry (Pete) S. La Pierre is an Associate Professor in the School of Chemistry and Biochemistry at the Georgia Institute of Technology. His group studies how collective magnetic, physical, and chemical properties arise from electron (de)localization phenomena in f-element systems. These studies include the development of solid-state and solution methodologies for the synthesis of novel lanthanide and actinide (Th – Am) materials and complexes. These synthetic efforts are paired with synchrotron and neutron spectroscopies and physical property studies to break down the challenge of understanding the electronic structure of f-element systems. These materials and complexes present unique valence electronic structures due the near degeneracies engendered in these systems and strong electron correlation. Our efforts to-date have focused on the synthesis and analysis of systems governed by one of three phenomena: multi-configurational electronic structures (ground state degeneracy including hybridization with ligand/band states), mixed-valence metal ions (i.e. mixed f/d occupancy and mixed-oxidation states), and magnetic super-exchange (i.e. exchange coupled systems). Understanding and controlling the manifestation of these phenomena in molecular systems is crucial for understanding the interplay of these phenomena underpinning topological insulators such as SmB6 and PuB6 and superconductors such as CeCoIn5 and PuCoGa5. In turn, the group has employed this expanded fundamental understanding of f-element electronic structure and redox chemistry to construct components of quantum information technologies (e.g. quantum bits (qubits)) and single-molecule magnets.
Dr. La Pierre completed his undergraduate studies at Harvard University, where he worked with Prof. Jared Shaw at the Broad Institute on the synthesis of antibiotics and with Prof. Masahiro Murakami at Kyoto University on main group organometallics. His graduate work, with Professors John Arnold, Robert Bergman, and Dean Toste at UC-Berkeley, focused on the development of a Z-selective alkyne semihydrogenation catalyst. Following graduation, he studied ligand control of reactive low- and high-valent uranium complexes as a postdoctoral scholar with Prof. Karsten Meyer at FAU Erlangen-Nuremberg. He then worked as a Director’s Postdoctoral Fellow at Los Alamos National Laboratory with Dr. Stosh Kozimor on ligand K-edge X-ray absorption spectroscopic studies of transuranic complexes. In addition to receiving the Beckman Young Investigator award in 2018, Dr. La Pierre received the NSF CAREER Award, the Alfred P. Sloan Research Fellowship, and the Ralph E. Powe Junior Faculty Enhancement Award. His group’s research is also supported by the ACS Petroleum Research Fund, the DOE Heavy Element Chemistry Program, and the DOE Quantum Information Science Program.