CAREER: Valence Orbital Control in f-Block Complexes

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

With this CAREER Award, the Chemical Synthesis Program of the Chemistry Division supports the research of Professor Henry S. La Pierre at the Georgia Institute of Technology to establish the synthetic chemistry, magnetism, and spectroscopy of compounds in which lanthanide atoms have unusual high or low charge. The chemical elements that drive the nuclear age are from the bottom of the periodic table and include the actinide and lanthanide elements. Together these are known as the f-elements. Today, the f-elements and their chemical complexes play key roles in energy production, conversion, and use. In addition, these elements are driving large-scale technological developments in areas including lighting, hard magnets, and electronics. While the f-elements have been intensively studied over the years, fundamental chemical control of their bonding is incomplete. In this respect knowledge that can expand our ability to utilize unusual bonding features of the f-elements is very important. These species are a foundation, for new lanthanide-based technologies in applications including quantum information science and quantum materials. The graduate and undergraduate students who carry out this research will be trained in a wide range of physical and synthetic techniques. They will also participate in an outreach program to the community to increase access to scientific careers among economically disadvantaged and underrepresented minority students. This project establishes the synthetic chemistry and ligand design to control and exploit multi-configurational and mixed-valence ground states in lanthanide complexes. These goals require the development of synthetic methodology to regulate the accessible oxidation states in the lanthanides: in particular, to expand the scope of accessible tetravalent and divalent lanthanide complexes. This synthetic methodology, in conjunction with physical characterization and reactivity studies, provides fundamental insight into how multi-configurational and mixed-valence phenomena emerge in lanthanide materials and how these phenomena influence thermodynamics, kinetics, and magnetism. In particular, X-ray absorption spectroscopy, electron paramagnetic resonance, and magnetic probes are employed to elucidate the electronic basis of the stabilization of the tetravalent oxidation state and the ligand field considerations which lead to mixed-valent ground states in tri- and divalent lanthanides. Determination of these fundamental physical and chemical properties may enable important f-element-based technological advances. This support also establishes an educational and outreach program to increase awareness of and access to scientific careers among economically disadvantaged and underrepresented minority communities the Atlanta Metro area. 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.