Eric J. Schelter
4:30pm - 5:30pm
Room 209 Havemeyer Hall
New York, NY 10027
Hosted by Gerard Parkin
Rare earth elements are essential in renewable energies technologies including in permanent magnets for wind turbines, hybrid and electric vehicles, energy efficient lighting phosphors and many others. But the separations chemistry at the heart of obtaining pure rare earth materials still relies on inefficient liquid-liquid extraction, which presents an unsustainable environmental burden. We have identified hydroxylamines as superior ligands for exploring new directions in rare earths chemistry. In particular, a tripodal ligand, H3TriNOx, was developed and its coordination chemistry established. The RE(TriNOx) RE = La–Lu, Y series led to identification of an unusual solubility dependence of the resulting complexes. These observations have afforded a new method for separating RE elements, in particular, for their recycling from consumer materials. In a related area, we have been working to develop the coordination chemistry and organometallic chemistry of cerium and to understand the physicochemical characteristics that underlie the stability of complexes in the cerium(IV) oxidation state. We have applied this knowledge to isolate some of the first examples of cerium-ligand multiply-bonded compounds. And, we have shown that visible light provides another probe to interrogate Ce(III/IV) redox cycling, which can be directed into new stoichiometric and catalytic photoredox chemistry on organic substrates. The results of these studies and their implications for new one-electron chemistry with cerium will be presented.
Thursday, September 29, 2016 at 4:30pm
Room 209 Havemeyer
Tea and cookies will be served prior to the lecture at 4:00pm in the Miller Room 328 Havemeyer.
Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, NY 10027, USA | 212-854-2202 | http://chem.columbia.edu/