October 2024 |
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 | Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Title: Light at Elevation—Photochemical Approaches to Natural Products
by Professor Jon Rainier, University of Utah Abstract: Discussed will be the development and use of photochemical methodology in the synthesis of the Ergot, Discorhabdin, and Ansalactam classes of natural products. |
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 | Organic Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Exploring Ways to Harness N-Heterocyclic Carbenes and Triarylboranes in Organometallic and Synthetic Chemistry
bt Yoichi Hoshimoto Center for Future Innovation (CFi), Department of Applied Chemistry, Faculty of Engineering, Osaka University, Japan Abstract: Our team recently demonstrated a strategy to separate H2 from a gaseous mixture of H2/CO/CO2/CH4 that can include an excess of CO and CO2 relative to H2 and simultaneously store it in N-heterocyclic compounds that act as liquid organic hydrogen carriers (LOHCs), which can be applied to produce H2 by subsequent dehydrogenation.1 Our results demonstrate that LOHCs can potentially be used for H2 purification in addition to their well-established use in H2 storage. Moreover, this work demonstrates a new aspect of main group catalysis beyond its application as a simple alternative to well-established transition metal-catalyzed processes, i.e., the main group–catalyzed hydrogenation of unsaturated molecules (e.g., carbonyl compounds) 2 under mixed gas conditions. Recent progress on our original triarylborane catalysis will also be mentioned in my lecture. 3,4 
References [1] T. Hashimoto, T. Asada, S. Ogoshi, Y. Hoshimoto, Sci. Adv. 2022, 8, eade0189. [2] M. Sakuraba, S. Ogoshi, Y. Hoshimoto, Tetrahedron Chem 2024, 9, 100059. [3] Y. Hoshimoto, T. Kinoshita, S. Hazra, M. Ohashi, S. Ogoshi, J. Am. Chem. Soc. 2018, 140, 7292. [4] Y. Hisata, T. Washio, S. Takizawa, S. Ogoshi, Y. Hoshimoto, Nat. Commun. 2024, 15, 3708.
Host: Matthew Sigman |
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Understanding Phosphate Chemistry for Nuclear Waste Tank Clean Up
by Ege Uyar, University of Utah Abstract: The Hanford Site in Richland, WA was the primary plutonium production facility for the United States between 1940-1989. During this time, the bismuth phosphate and PUREX processes were employed for Pu separation and purification from irradiated nuclear fuel. These methods utilized phosphoric acid or phosphate containing extracting ligands to precipitate or purify Pu through phase transfer. [1] The resulting waste from these separation methods are highly radioactive and contain large amounts of phosphate. This waste is currently stored in corrosion resistant tanks at the Waste Tank Farm at the Hanford Site, awaiting clean up via solubilization and transport to another waste treatment facility. This important clean up activity is hampered by the low solubility of PO43- and F- species in the primary phosphorous containing mineral that crystallizes in the tanks, natrophosphate (Na7(PO4)2F.19H2O). [2,3] One approach to aid cleanup is to control the phosphate solubility by developing a fundamental understanding of how different cations and anions may interfere with the nucleation process. Molecular level insight about phosphate nucleation can be obtained from molecular simulations that can be meticulously parameterized to reproduce the physicochemical properties across a wide range of solution compositions. In this talk I will review the phosphate chemistry occurring in the Hanford tank wastes and the theoretical basis for parameterizing accurate force fields for phosphate containing solutions. Initial studies of the aggregation behavior of sodium phosphate solutions will be discussed.
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Jadon Koegel Abstract: The selective partitioning of metals from complex aqueous mixtures via liquid-liquid extractions remains one of the preferred methods by which metals from mining, electronic, and industrial waste are purified. Here, metals of interest in a two-part aqueous-organic system are selectively complexed by a surface-active extracting ligand. Previous research has indicated that the liquid-liquid complexation reaction occurs at the aqueous-organic interfacial boundary. This work has yet to indicate, however, whether this mechanism and the energetics that drive it are perturbed in the presence of the phase boundary relative to the bulk solution. Through a combination of molecular dynamics and electronic structure calculations, it is possible to simulate and study the complexation mechanism and the interface at which it occurs. In such a computational model it is important that thorough configurational sampling of the complete reaction pathway occurs within a physically accurate model environment. In this talk, extraction of Li by TBP is taken as a representative reaction to demonstrate how the computational objectives above may be accomplished. An iterative feedback loop between configurational sampling of the reaction pathway using molecular dynamics and calculation of relative energetics using electronic structure methods will be introduced using both free energy biased sampling methods and novel cluster/continuum modeling. |
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Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Photoexcited Coupled Electron- and Phase-Transfer Reactions
by Parinaz Nasehi, University of Utah Abstract: Coupled electron- and phase-transfer (CEPhT) reactions are a fundamentally interesting system to understand how solvation shell exchange and electron transfer take place (i.e., sequentially or concerted) as a function of the interfacial structure, reaction kinetics, and relaxation dynamics. Beyond their basic science relevance, CEPhT reactions are important for applications such as electrodeposition, corrosion resistance, battery technology, and photocatalysis. In this seminar, we will use optically-triggered CEPhT at the surface of alkane-functionalized titania nanoparticles as a model system to understand their dynamics at the nanoscale. Ultraviolet photoexcitation of functionalized titania nanoparticles leads to the transfer of an electron to ferrocenium ions in a bulk aqueous phase, and the insertion of neutral ferrocene into the nonpolar alkane layer coating these TiO2 particles. With kinetic absorbance spectroscopy, we measure the rate of CEPhT and compare it to predictions based on electron tunneling rates. The molecular-scale properties of these interfaces are critical to the rate of CEPhT, as evidenced by its dependence on the length of the alkyl layer and the presence of co-solvents. Future work to measure the ultrafast rate of electron transfer in these systems will further elucidate the role of electron transfer in the overall kinetics. |
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Inorganic Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher)
11:50 AM Synthesis, characterization and reactions of pentadienyl transition metal compounds
by Dr. David Wilson, Dow Chemical Abstract: TBA Host: Tom Richmond
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 | Analytical Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Single-Entity Crystallization and Memristor Functions Enabled by Nanoscale Charge Transport
by Gangli Wang, Georgia State University Abstract: Crystallization of biomacromolecules is technically challenging but important not just for structural determination in fundamental studies, but also for pharmaceutical industry and other applications. In stark contrast to the classical ensemble trial-error approaches, we present a single-entity method named NanoAC, capable of synthesizing protein crystals one at a time under active controls kinetically and thermodynamically. True atomic resolution at up to 1.20 Å is determined by X-ray crystallography consistently. The method efficacy and generalizability are demonstrated with insulin and lysozyme as prototype, in H2O and D2O, along with common precipitants such as the gradients of pH and ionic strength. Quantifiable electrical signal feedback, such as changes in current amplitudes and noise level, are correlated with optically resolved features during nucleation and other phase transitions as multi-modal signatures for the in-situ control. The enabling mechanism is the dynamic ion transport restrained at nanoscale interfaces, which is the same physicochemical origin in many energy conversion, separation and electrochemistry processes. By derivatizing single nanopipettes and anodized aluminum oxide membranes containing densely organized nanochannels with redox polymer PEDOT:PSS, we further show how electron transfers can be leveraged to tailor ion transport dynamics in rectification, memory effects and state switching properties to achieve advanced memristor and neuromorphic computing functions. Short Bio: Dr. Gangli Wang is currently a Professor of Chemistry at Georgia State University. He is the director of Atomic-C2E, an DOE SFEE research center (Science Foundation for Energy Earthshot). He is affiliated with GSU Imaging Hub and Neuron Institute. Gangli got his B.S. and M.S. degrees from Peking University in 1996 and 1999 respectively. He received his Ph. D. degree under the direction of Dr. Royce Murray at the University of North Carolina at Chapel Hill in 2004. After a postdoc training with Dr. Henry White at the University of Utah, he started his independent career in the Department of Chemistry at GSU in 2007. The main research thrusts in GWang’s group are centered around fundamental nanoelectrochemistry, aiming for better energy and biomedical applications. The research in GWang’s group has been primarily supported by DOE, NIH and NSF. Host: White/Luo |
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 | Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Title: TBA
by Professor Vahe Bandarian, University of Utah Abstract: TBA |
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November 2024 |
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 | Analytical Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Title: TBA
by Brandon Ruotolo, University of Michigan Abstract: TBA Host: Gabe Nagy |
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 | Organic Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Ring strain release for the synthesis of heterocycles and natural products
by Kostiantyn O. Marichev, Georgia State University Abstract: Cycloaddition reactions have been recognized as a robust method to construct carbocyclic or heterocyclic systems in a highly convergent manner through a concerted or stepwise mechanism since the original discovery of the Diels-Alder reaction. N-Heterocyclic compounds are considered “privileged structures” in pharmaceutical and medicinal chemistry for their core structure being present in many biologically active molecules and building blocks. Hence, the development of efficient methods to achieve such heterocycles from low-cost starting materials has attracted considerable attention over the past decades. Our group is involved in exploring strain ring systems, pyridine, quinoline, isoquinoline, and other azine derivatives as potent precursors for the synthesis of such molecular frameworks because of their easy access. We have recently discovered dearomatization/rearomatization strategy as a new methodology for cycloaddition reactions of reactive azinium ylides with dipolarophiles for the construction of new heterocyclic systems. Host: Andrew Roberts |
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Kinetics of Crystallization
by Jon Aronoff Abstract: Predicting the crystal structure that a molecule will form is a longstanding problem that has implications in industries ranging from pharmaceuticals to agriculture. There are millions of ways to arrange a given molecule in a spatial lattice, but only a select few of these arrangements are experimentally observed. Many methods of Crystal Structure Prediction (CSP) consider only the thermodynamically stable polymorphs and rely on the assumption that the polymorph with the lowest energy will always form. Kinetic factors are known to contribute to the observed polymorphs; however, modeling the underlying mechanisms of these kinetic processes is difficult and numerically expensive. This work uses molecular dynamics simulations with a simple model that reproduces the behavior of chiral organic molecules to probe the kinetic growth of an enantiopure seed and attempt to discern between molecules that crystallize well and those that do not. |
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Perry Martin, University of Utah Abstract: Ruddlesden-Popper (RP) metal halide perovskites have emerged as a promising class of materials in the fields of optoelectronics and thermal storage. Indeed, the optoelectronic and thermodynamic properties of these materials have been extensively studied independently. Due to their twodimensional (2D) structure of alternating layers of organic cations and metal halide octahedra, these materials can undergo structural phase transitions near room temperature that drastically affect their optical properties. Despite this, the connection between the structural dynamics of these materials and their optoelectronic properties has received less attention compared to other areas. As such, correlating changes in optoelectronic properties that stem from subtle structural changes in the 2D perovskite lattice could provide a better understanding of the dynamics these materials undergo. Use of temperature-dependent photoluminescence (PL) spectroscopy and temperature-dependent grazing incidence wide angle X-ray scattering (GIWAXS) allows us to interrogate this relationship directly. Additionally, we can visualize the dynamics of 2D perovskite phase transitions using PL microscopy, which provides insight into how the PL changes based on cation and halide identity as phase transitions occur. |
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 | Second Year Chemistry Education Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) The Mentor’s Perspective: Exploring Inclusivity Within the University of Utah’s Introductory STEM Courses
by Kim Weaver, University of Utah Abstract: Inclusive pedagogical practices aim to engage and inspire students from diverse backgrounds. One such practice, the Learning Assistant (LA) Model, utilizes peer mentoring to foster a welcoming environment in higher education. Developed by the University of Colorado Boulder in 2001, the LA Model promotes curriculum innovation, instructional changes, prospective educator preparation, and the integration of discipline-based educational research. Designed with inclusivity in mind, the LA Model offers peer assistance that diversifies instructional methods, provides equitable support, and enhances accessibility. While existing research often focuses on students’ perceptions of inclusivity within LA Models, this study examines how learning assistants perceive and how could inclusivity be promoted when mentoring students. Inclusivity surveys were administered to learning assistants at the beginning and end of the Spring and Fall 2021 semesters. These LAs served in introductory chemistry, biology, and physics courses at the University of Utah. Four open-ended questions explored the learning assistants’ views on inclusivity, their role in promoting it, how students can foster inclusivity in their courses, and how professors can create inclusive environments. A total of 180 responses were analyzed using qualitative content analysis to identify common themes. This research reports on the identified inclusivity themes and compares their frequency within the study |
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Yexalen Barrera, University of Utah Abstract: Lanthanide-containing diatomic and triatomic molecules were spectroscopically probed using resonant two-photon ionization (R2PI) spectroscopy to determine one of the most relevant thermochemical values, their bond dissociation energies (BDEs). A quasi-continuous optical spectrum was found for several lanthanide nitride (LnN) molecules and two lanthanide cyanides or isocyanides (LnCN or LnNC). The spectra display sharp predissociation thresholds that can be measured to high precision and accuracy. These molecules have a high density of electronic states in the vicinity of the dissociation limit because of their open 4f subshells. Spin-orbit and nonadiabatic interactions couple these states, providing a pathway for rapid dissociation once the ground separated atom limit is exceeded. This allows the BDEs to be measured to high precision and accuracy. Visually, the R2PI spectrum near the dissociation limit can be divided into three regions. Below the dissociation limit, the spectrum displays a high density of states. When the dissociation limit is energetically met, a sharp drop in ion signal is observed. Beyond the dissociation limit, only background signal is found. This seminar will provide a discussion of the experimental method as well as the BDE results for specific molecules. |
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 | Second Year Physical Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) The thermochemistry of actinides with ammonia using Guided Ion Beam Tandem Mass Spectrometry
Gonzalo Perez, University of Utah Abstract: The kinetic energy dependent reaction between atomic Uranium cations (U+) and ammonia was studied in the gas phase using guided ion beam tandem mass spectrometry. Products formed included UNH+, UNH2+, UN+, and UH+. Using the modified line of centers model, 0 K reaction thresholds were extracted and used to determine experimental bond energies for each of these species. Experimental bond energies are of great interest as they can be used as benchmarks for theoretical methods and the evaluation of other potential reactions. A theoretical exploration of the potential energy surfaces for formation of all products observed here was also conducted at the B3LYP/cc-pVDZ-PP level of theory and elucidated the mechanism for the reactions. |
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 | Analytical Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Title: TBA
by Zeev Rosenzweig, UMBC Abstract: TBA Host: Bischak |
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 | Biological Chemistry Seminar at the University of Utah
TBBC 4630 (4th floor Thatcher) Title: TBA
by Ed Lyman, University of Delaware Abstract: TBA Host: Jessica Swanson |
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Physical Chemistry Seminar at the University of Utah
Ed Lyman, University of Delaware
TBBC 4630 (4th floor Thatcher)
4:00 PM - 5:00 PM Title: TBA
by Ed Lyman, University of Delaware Abstract: TBA Host: Jessica Swanson |
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