16th Biannual: John Eisch Lectureship In
Thursday, Dec. 7, 2023
Smart Energy Building, Fountain Room
Professor Polly L. Arnold
Chemical Sciences Division Director, Lawrence Berkeley National Laboratory and Berkeley College of Chemistry, University of California, Berkeley
F-Block Dinitrogen Chemistry; from Rarity to Catalysis in a Few Simple Steps
Chemists have spent more than a century trying to copy nature to make catalysts that
can convert atmospheric dinitrogen (N2) to ammonia (NH3), or directly to amines (NR3) under mild conditions. Hundreds of complexes based on metals from the d-block are now known to bind N2, and a few catalysts for N2 conversion to ammonia or tris(silyl)amine have been developed. However, the picture for the metals at the bottom of the periodic table, the f-block, many of which have been deemed “critical elements” for technology, is completely different. The binding of dinitrogen to any f-block metal cation was considered impossible until the turn of the millennium, but a small, yet growing number of weakly-bound N2 complexes are now being reported. Studies of these weak binding interactions contribute to the fundamental understanding of bonding and electronic structure in these large and energy-relevant elements.
We will show what we have learned about N2 binding to f-block centers over the last decade, and our recent development of the first molecular f-block complexes that can catalyse the reduction and functionalization of dinitrogen, first using actinide, and now earth abundant lanthanide cations. We will also discuss the importance of structural control by the molecular framework in enabling the first catalytic conversion of dinitrogen into a secondary silylamine by any metal.
- Information about Professor Polly L. Arnold
Polly L. Arnold is a professor of chemistry at the University of California, Berkeley, and
director of the Chemical Sciences Division at Lawrence Berkeley National Laboratory.
After earning an MA in chemistry at the University of Oxford and a DPhil in chemistry at the University of Sussex, she moved to MIT as a Fulbright Scholar with Professor Kit Cummins. She returned to the UK to a faculty position at Nottingham, then moved to the University of Edinburgh in 2007, where she subsequently held the Crum Brown Chair of Chemistry. She moved to Berkeley in 2019.
Her group focuses on exploratory synthetic chemistry of the f-block ions. The development of new catalysts from the earth abundant lanthanides, and reactivity studies of the radioactive actinides, provide fundamental contributions to our understanding of electronic structure and bonding at the bottom of the periodic table. This knowledge improves the extraction and recycling of the technology-critical rare earth ions and our curation of radioactive civil nuclear wastes.
Arnold has lectured worldwide on her science and on diversity in STEM matters, and has advised both government and industry. In 2017, she was awarded the Lord Kelvin Prize, Scotland’s senior research prize in the physical sciences. She was also appointed Officer of the Order of the British Empire in 2017 for services to chemistry and to women in science, technology, engineering and mathematics.
She was elected a Fellow of the Royal Society in 2018 for substantial contributions to the
improvement of natural knowledge. Last year, she was also selected by the American Chemical Society as one of twelve LGBT in STEM trailblazers.
- Information about Professor John J. Eisch
John Joseph Eisch joined the Department of Chemistry at Binghamton University in 1972, as chair and professor of chemistry, with the mandate of fostering the national reputation of its graduate teaching and research. Over the next six years as chair, he guided the recruiting of six senior and junior faculty with this goal in mind, while expanding his own research in organometallic chemistry to a yearly group of eight to 12 graduate and postdoctoral students, with support from federal and industrial resources. In 1983, his composite achievements were recognized by his promotion to the SUNY-wide rank of distinguished professor of chemistry. Further recruiting, notably during the chair tenure of professors Eugene Stevens, Alistair Lees, Wayne Jones and currently, Eriks Rozners, expanded the scope of advanced research into areas of immediate importance, such as nano materials, homogeneous catalysis, analytical sensors, biological transformations and energy storage.
Eisch received the BS degree in chemistry, summa cum laude, from Marquette University in 1952; earned the PhD degree in 1956, with Henry Gilman, at Iowa State University; and served as Union Carbide Research Fellow with Karl Ziegler at the Max-Planck-Institut für Kohlenforschung, Mülheim, Germany (1956–57). After junior professional appointments at St. Louis University and the University of Michigan, he became ordinary professor and department head at the Catholic University of America (1963–1972). He retired from his professorial career of 57 years in 2014, the latter 42 years of which were spent at Binghamton University.
The Eisch Group initially had concentrated on the preparation and organic synthetic uses of organometallic reagents of Li, Na, Mg, B and Al, but we were struck by the lack of definitive molecular mechanistic studies in previous work. In ensuing research encompassing reaction kinetics, trapping of any intermediates, IR, UV and X-ray crystallographic measurements, both heterolytic and homolytic C-M cleavages could be involved, as well as 4-centertrapesoidal transition states. Reviews are available in a) “Fifty Years of Ziegler- Natta Polymerization: From Serendipity to Science,” Organometallics, 2012, 31, 4917–4932 and b) Dalton Transactions, (DOI: 10:1039/c4dt010362) “Emergence of Electrophilic Alumination as the Counterpart of Established Nucleophilic Lithiation.” The original seven articles dealing with the reactions of RLi with the azomethyne groups have been recently published by the Eisch and the Rheingold Crystallographic Group in the European Journal of Organic Chemistry.
Over the years, the research involved the fruitful collaboration of more than 200 students as master’s, doctoral, postdoctoral or baccalaureate associates. The results have been reported in more than 410 scientific publications, in some 280 invited lectures worldwide, in the monograph “The Chemistry of Organometallic Compounds” (Macmillian, 1967) and in the edited series, “Organometallic Syntheses” (four volumes, J. J. Eisch and R. B. King, authors and editors). He has been an industrial consultant on organometallic chemistry and an expert witness in several patent litigations on Ziegler-Natta polymerization catalysis.
One of the significant discoveries of our studies is that the reaction of organic carbanionic reagents is not a one-step nucleophilic C alpha attack (i) but a two-step electrontransfer and electron-coupling process (ii)(iii).
- Previous Lectureship Recipients
Stephen L. Buchwald - MIT
“Palladium-Catalyzed CarbonNitrogen and Carbon-Carbon Bond-Forming Reactions: Progress, Applications and Mechanistic Studies”
David W. C. MacMillan - Princeton University
“The Use of Photoredox Catalysis in New Organic Bond Forming Reactions”
Brian M. Stoltz - California Institute of Technology
“Complex Natural Products as a Driving Force for Discovery in Organic Chemistry”
Eric N. Jacobsen - Harvard University
Bob Crabtree - Yale University
“Organometallic Catalysis for Solar Fuels and Storage”
Phil S. Baran - The Scripps Research Institute
Stephen J. Lippard - MIT
“Understanding and Improving Platinum Anticancer Drugs”
Daniel A. Singleton - Texas A&M Uniersity
“Dynamic Effects and Energy Labeling in Free-Radical Reactions”
Clifford P. Kubiak - University of California, San Diego
“If You Make a Solar Fuel From CO2, What Should It Be?”
Scott E. Denmark - University of Illinois at Urbana-Champaign
"Lewis-base Activation of Lewis Acids: An Evolving Paradigm for Catalysis in Main Group Chemistry"
Professor Gregory C. Fu - California Institute of Technology "Nucleophilic Substitution Reactions: A Radical Alternative to SN1 and SN2 Reactions"
John F. Hartwig - University of California, Berkeley
"Selective, Catalytic Functionalization of C-H Bonds with Small and Large Catalysts"
Professor Vern L. Schramm - Albert Einstein College of Medicine
"Enzymatic Transition States and Transition State Analogues"
Karen Goldberg - University of Pennsylvania
"Molecular Oxygen as a Reagent in Late Transition Metal Organometallic Chemistry"
Kendall N. Houk - University of California, Los Angeles "Pericyclic Reactions: Theory, Mechanisms, Dynamics and Role in Biology"