ChemAIMS Seminar: Professor Polly Arnold, UC Berkeley
About the Seminar
A new class of earth abundant metal catalysts for dinitrogen conversion at ambient conditions
We have been studying the reactions of f-block complexes with N2, a molecule that would traditionally not be expected to bind to f-block cations. Dinitrogen, 78 % of the earth's atmosphere, holds a unique position amongst small molecules, in that there is only one industrial process that uses it as a feedstock, the Haber Bosch process. Chemists have spent more than a century trying to make catalysts that can convert N2 under mild conditions to useful products such as fertilizers or energy carrier replacements for fossil fuels. Small scale conversions of N2 that operate under ambient conditions could offer food and energy justice to remote populations.
The few homogeneous catalysts for N2 conversion to ammonia or tris(silyl)amine focused entirely on electron rich metals inspired by nature such as molybdenum until recently. We will discuss a new system, using electron deficient, and earth abundant metals formed into a metallacyclic cage with aromatic ligands, that traps dinitrogen, and funnels electrons and electrophiles to the N atoms, both demonstrating the first nitrogen reduction catalysis by electropositive metal complexes, and enabling the first selective formation of bis(functionalized)amines by any catalyst.
Francis Lam, [a] Anthony Wong, [a] Matthew Hernandez, [a] Jaden Lara, [a] Shahbaz Ahmad, [d] Francesca Pike, [e] Laurent Maron, [b] R. David Britt, [c] Nikolas Kaltsoyannis, [d] Polly L Arnold. [a] * pla [at] berkeley.edu (pla[at]berkeley[dot]edu)
[a] Department of Chemistry, University of California, Berkeley, California 94720, USA and Lawrence Berkeley National Laboratory, California 94720, USA
[b] Department of Chemistry, University of Toulouse, France.
[c] Department of Chemistry, University of California, Davis, California, USA
[d] Department of Chemistry, University of Manchester, Manchester, United Kingdom
About the Speaker
Polly is a professor of chemistry at the University of California, Berkeley and director of the Chemical Sciences Division at Lawrence Berkeley National Laboratory.
After UG and PG degrees at Oxford and Sussex, she was awarded a Fulbright Scholarship for a postdoc at MIT. She returned to the UK to a faculty position first at Nottingham then Edinburgh, where she held the Crum Brown Chair of Chemistry. She moved to Berkeley in 2019.
Her group studies exploratory synthesis and catalysis with the earth abundant lanthanides, and reactivity studies of the actinides, providing fundamental contributions to our understanding of electronic structure and bonding in the f block.
Polly has lectured worldwide on her science, and on diversity in STEM matters, and advised government and industry. She was appointed Officer of the Order of the British Empire in 2017 and elected a Fellow of the Royal Society in 2018. Last year she was also selected by the American Chemical Society as one of twelve LGBT in STEM trailblazers.