College of Science » Chemistry-Seminars

Chemistry Seminar
with Ampofo Darko, University of Tennessee

TBBC 4630
4th floor Thatcher
In-Person Seminar

Title:
Tuning Metal Complexes for Catalysis and Sensing: From Axial Ligand Design to Nerve Agent Detection

Abstract:
Dirhodium(II,II) paddlewheel (Rh^II) complexes mediate a wide range of transformations through the catalytic transfer of carbenes from diazo precursors. The reactivity and selectivity of these reactions are traditionally tuned through modification of the bridging ligands surrounding the metal core, while the axial coordination sites remain an underexplored control element. This presentation will detail our ongoing efforts to probe the benefits of axial coordination by designing Rh^II complexes bearing tethered Lewis basic groups appended to conventional bridging ligands. In our initial studies, thioether donors proved to be the most robust Lewis bases when tethered to oxazolidinate and carboxylate bridging ligands. These novel complexes were evaluated in diazo-mediated cyclopropanation, Si–H insertion, and C–H insertion reactions, and the resulting reactivity trends, supported by spectroscopic and computational analyses, offer new insight into how tethered axial coordination governs carbene transfer chemistry.

Building on this foundation in metal-ligand design for molecular recognition, this talk will also present our complementary work in chemical sensing. We will discuss the development of Rh^II-based chromogenic detectors capable of identifying organophosphate nerve agents through their characteristic hydrolysis by-products, as well as our more recent extension of this platform to copper complexes designed for the selective detection of organophosphates. Together, these projects illustrate a unifying theme in our research: leveraging rational ligand design and metal-ligand interactions to control reactivity and enable molecular recognition across catalysis and sensing applications.

Bio:
Ampofo Darko received his B.S. in chemistry from Guilford College and his Ph.D. from the University of Florida, where he studied tungsten-catalyzed oxidative carbonylation of functionalized amines under the direction of Prof. Lisa McElwee-White. He then performed postdoctoral research with Prof. Joseph Fox at the University of Delaware studying trans-cyclooctenes and their bioorthogonal reactivity with tetrazines. He joined the faculty at the University of Tennessee in 2014, with research interests at the interface of organic and inorganic chemistry. His group is interested in using nature as an inspiration for organometallic catalyst design, cycloaddition reactions, and organocatalysis.

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: Rethinking Plastics: Molecular Strategies for Sustainable Polymers
 
Abstract:
Modern society relies on polymers more than ever, but their production and disposal come at an environmental cost. In this lecture, I will share our work to improve polymer circularity by designing materials for mechanical recycling, creating systems for chemical recycling, and developing sustainable pathways to biodegradable plastics.

Bio:
Geoffrey W. Coates received a B.A. degree in Chemistry from Wabash College in 1989, a Ph.D. in organic chemistry with Robert Waymouth at Stanford University in 1994, and was an NSF Postdoctoral Fellow with Robert Grubbs at the California Institute of Technology. He joined the Cornell University faculty in 1997, where he is now the Tisch University Professor in the Department of Chemistry and Chemical Biology.  
 
The research focus of the Coates Group is the development of new catalysts for the synthesis of macromolecules and small molecules. Professor Coates' research concentrates on developing new methods for reacting commodity feedstocks in unprecedented ways. His current research centers on the development of homogeneous catalysts for olefin polymerization, heterocycle carbonylation, epoxide homo- and copolymerization, the utilization of carbon dioxide in polymer synthesis, and new polymers for energy conversion and storage.
 
Professor Coates has been awarded the A. C. Cope Scholar Award, the ACS Award in Affordable Green Chemistry, the ACS Award for Polymer Chemistry, the ACS Hach Award for Entrepreneurial Success, the ACS Applied Polymer Science Award, and the Carl S. Marvel Creative Polymer Chemistry Award. In 2011 he was inducted into the American Academy of Arts & Sciences and was elected to the National Academy of Sciences and the National Academy of Inventors in 2017. He was awarded the Eni Award in 2022 and the National Academy of Sciences Award for the Industrial Application of Science in 2023. He is the scientific cofounder of Novomer, Ecolectro, and Intermix Performance Materials, and is an Associate Editor of JACS.

TFR Chemistry Seminar
with Aurora Clark, University of Utah

TBBC 4630
4th floor Thatcher
In-Person Seminar

Title: TBA
by Aurora Clark, University of Utah

Abstract: TBA

TBBC 4630
4th floor Thatcher
In-Person Seminar

Title: Spectroscopy and Scattering Experiments on Flat Liquid Jets

Abstract:
The dynamics of photoexcited solute molecules and the properties of liquid interfaces are studied by carrying out spectroscopy and scattering experiments on flat liquid water jets. In one set of experiments, solute dynamics are probed using time-resolved photoelectron spectroscopy in which molecules are photoexcited with a femtosecond UV pulse and photoionized with a time-delayed femtosecond XUV pulse (at 21.7 eV). The time-dependent photoelectron spectra provide a unique probe of the relaxation of photoexcited neutral and anionic species in aqueous solution. Results will be presented for several negative ions including phenolate,1 bromophenolate, 2 and nitrophenolate. These experiments probe the competition among the various relaxation pathways including internal conversion, dissociation, and electron ejection.
In complementary experiments, the liquid interface is explored in molecular beam scattering experiments from flat liquid jets of cold salty water (-50 °C, 8 m LiBr). In contrast to cylindrical jets, flat jets provide a large target area and well-defined surface normal, both of which are highly advantageous for scattering experiments. Product angular and translational energy distributions for rare gas and molecular scatterers will be presented.3, 4 The competition between impulsive scattering (IS) and thermal desorption is measured, and the energy loss in the IS channel is characterized using a soft-sphere model. Results are sensitive to both the scatterer identity and its collision energy. Possible effects of surface roughness on the product angular distributions will be discussed.

[1] Kang, D. H.; Basu, J.; Haldar, N.; Koga, M.; Neumark, D. M. Photo-relaxation dynamics of phenolate anions by extreme ultraviolet time-resolved photoelectron spectroscopy in liquid jets. Phys. Chem. Chem. Phys. 2026, 28, 7754-7765.|
[2] Kang, D. H.; Basu, J.; Haldar, N.; Neumark, D. M. Time-resolved extreme ultraviolet photoelectron spectroscopy of 4-bromophenotate anions in a liquid jet. Faraday Disc. 2026, DOI: 10.1039/d1036fd00059b.
[3] Yang, W.; Foreman, M. M.; Ly, T. C.; Wilson, K. R.; Neumark, D. M. Molecular beam scattering of neon from flat jets of cold salty water. Chem. Sci. 2025, 16, 11608-11618.
[4] Foreman, M. M.; Yang, W. L.; Ly, T. C.; Wilson, K. R.; Neumark, D. M. Selectivity in gas-liquid interactions: Molecular beam scattering of CD4 and ND3 from an aqueous flat liquid jet. J. Chem. Phys. 2026, 164, 014707.

Parry Lectureship Seminar at the University of Utah
with David Cahen, Weizmann Institute

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: Durable Materials: a Chemical Challenge for Sustainable Energy  &  Electronics

Abstract:
Achieving true sustainability by mid-century requires more than transitioning to renewable and low-carbon forms of energy; the materials that enable these technologies must themselves be sustainable. This presents a fundamental scientific challenge. Many of the materials used today for solar-energy conversion, batteries, hydrogen production, and the conversion of CO₂ into fuels and chemicals rely on resources, processing methods, or device architectures that are not inherently compatible with long-term sustainability. Moreover, sustainability demands long operational lifetimes, a requirement that challenges conventional approaches to manufacturing and consumption and renews the importance of designing materials and devices that can be repaired, regenerated, or healed.

Meeting this challenge requires moving concepts that can appear to belong to science fiction, i.e., materials capable of repairing or healing themselves into scientific and technological reality. Biology provides the most sophisticated examples of autonomous repair, but related phenomena can also be found across chemistry and materials science. Beginning with biological systems and established examples in chemistry, this lecture will trace the progression toward modern inorganic materials capable of repair, self-repair, and self-healing. Examples range from bio-solar systems and concrete to silicon photovoltaics, organic and ionic materials such as AgI, and inorganic light-to-electricity conversion materials including CuInSe₂ and lead-halide perovskites.

These examples raise fundamental questions: What enables a solid to recover from damage? Which structural, chemical, electronic, and ionic properties determine whether degradation is reversible? And can these principles be identified well enough to guide the discovery of new self-repairing energy materials? To address these questions, we examine what can be learned systematically from known compounds by identifying experimentally measurable descriptors associated with repair and healing and using these descriptors for data-driven materials exploration. Initial results illustrate how combining physical insight, experiment, and data mining may reveal design principles for a new generation of resilient materials.

Ultimately, the goal is to move beyond simply making energy technologies more efficient and toward materials that are long-lived, repairable, and intrinsically more sustainable, thus materials designed not merely to resist failure, but, where possible, to recover from it.

This work was supported in part by the Weizmann Institute of Science Institute for Environmental Sustainability.
The lecture will distinguish between repair, self-repair/self-healing, and autonomous self-healing and discuss their implications for materials design.

Biological Chemistry Seminar at the University of Utah
with Yangguang Ou, University of Vermont

TBBC 4630
4th floor - Thatcher
In-person seminar

Title:
TBD

Abstract:
TBD

Biological Chemistry Seminar at the University of Utah
with Danzhou Yang, Purdue University

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD

Biological Chemistry Seminar at the University of Utah
with Kristin Koutmou, University of Michigan

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD

Chemistry Seminar at the University of Utah
with Chia-en Chiang, University of California-Riverside

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD

Chemistry Seminar at the University of Utah
with Vicki Wysocki, Georgia Tech

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD

Ted Eyring Lectureship Seminar at the University of Utah
with Joaquín Rodríguez-López, University of Illinois Urbana-Champaign

TBBC 4630
4th floor - Thatcher
In-person seminar

Title: TBD

Abstract: TBD