Past Seminars & Events

Sustainable & Green Chemistry Committee Open House

The newly formed Sustainable & Green Chemistry Committee will be holding an open house on Friday, September 30th from 3-5 pm.

Committee Website

Professor Ming Chen

Professor Ming Chen
Department of Chemistry

Auburn University

Abstract

"Enantioselective C-C Bond Formation via Asymmetric Catalysis"

The seminar will focus on the development of enantioselective C-C bond formation reactions using asymmetric catalysis. Applications in the context of complex molecule synthesis will also be discussed.

https://www.auburn.edu/cosam/faculty/chemistry/chen/research/index.htm
https://www.auburn.edu/cosam/faculty/chemistry/chen/research/publications.htm

Ming Chen

Dr. Chen’s research interests mainly focus on synthetic organic chemistry. Specifically, he is interested in catalytic asymmetric processes that employ transition-metal complexes as well as organic catalysts to produce enantioenriched molecules from readily available achiral feedstock chemicals. Synthetic applications toward the total syntheses of bioactive natural products and medicinal agents are also being pursued.

Professor Renee Frontiera

Professor Renee R. Frontiera
Department of Chemistry
University of Minnesota

Abstract

Spectroscopic Probes of Plasmon-Driven Chemical Reactions

            Plasmonic materials are highly promising catalysts for driving energetically unfavorable chemical reactions with sunlight, due to their large optical cross sections and ability to generate a number of hot holes and electrons. However, the efficiencies of most plasmon-driven processes are quite low, likely due to the lack of mechanistic understanding of the underlying physical processes. Plasmons can concentrate electromagnetic fields, can generate highly energetic electrons and holes, and can heat up local environments. An understanding of the energy partitioning into each of these processes is crucial to the design of plasmonic photocatalysts which are optimized for chemical selectivity. Here I’ll discuss our development of ultrafast surface-enhanced Raman spectroscopy (SERS) to probe the contributions of plasmon-generated hot electron transfer, heating, and vibrational energy transfer on timescales relevant to photocatalysis. Specifically, we are able to quantify plasmon-driven charge transfer processes by monitoring the rate and yield of reduced molecular adsorbates, as well as monitoring energy transfer and heating processes through ultrafast Raman thermometry. These efforts in developing a fundamental understanding of plasmon-mediated processes in molecules will ultimately aid in the rational design of cost-effective plasmonic materials capable of driving industrially relevant chemistries using solar radiation.

Renee Frontiera seminar graphic

Renee Frontiera

Renee R. Frontiera is the Northrop Professor of Chemistry at the University of Minnesota. Her research group uses Raman spectroscopic techniques to examine chemical composition and chemical reaction dynamics on nanometer length scales and ultrafast time scales. She received her Ph. D. in 2009 from the University of California – Berkeley in Richard Mathies’ group, and did her postdoctoral research with Richard Van Duyne. Her research group at the University of Minnesota was founded in 2013, and she is the recent recipient of an NSF CAREER award, a DOE Early Career award, and an NIH Maximizing Investigators’ Research Award (MIRA). She was named one of Chemical & Engineering News’s “Talented 12”, and has won a Journal of Physical Chemistry Lectureship, the American Physical Society’s “Future of Chemical Physics” lectureship, and a Camille Dreyfus Teacher-Scholar award.

 

 

 

Dr. Gregory Hughes

Dr. Gregory Hughes
Senior Principal Scientist

Discovery Process Chemistry Department

Merck

Abstract

The development of a scalable approach to Islatravir

The development of increasingly capable tools for protein engineering has led to a number of novel enzymatic catalysts for industrial applications. These new tools have been applied in a number of chemical manufacturing sectors, with the pharmaceutical industry finding these tools to be particularly impactful. Early applications of biocatalysis involved the replacement of stoichiometric reagents with enzymatic alternatives. As chemists became more confident in the reliability of protein engineering, they were inspired to imagine more efficient routes that elimated multiple unit operations, along with the waste and costs associated with those operations. More recently, enzymatic cascades have been developed which allow multiple chemical steps to be performed in a single vessel, often without protecting groups. This approach has led to an even more dramatic reduction in time cycles, energy, solvents and waste. In this talk, the development of a biocatalytic cascade inspired by a natural nucleoside salvage pathway will be presented. This approach was developed for the production of Islatravir, a clinical candidate for the treatment of HIV.

Gregory Hughes

Dr. Hughes completed his undergraduate studies the University of New Brunswick in 1994 and then a PhD in organic chemistry at the University of Toronto. After completing his graduate studies in 2000, Dr. Hughes accepted a postdoctoral fellowship at the Massachusetts Institute. In 2002, he started at Merck Frost joining a newly formed satellite Process Chemistry group. In 2008, Dr. Hughes relocated to Merck’s Rahway site managing a number of enabling technology groups including the catalysis, automation, flow chemistry and biocatalysis groups. In 2013, Dr. Hughes assumed a position as VP of Business Development and Alliance Management at Codexis. In 2016, Dr. Hughes returned to R&D at Merck, a Principal Scientist in the Process Chemistry organization. In Jan 2022, Dr. Hughes moved into a Senior Principal Scientist position within the Discovery Process Chemistry department.

Professor Aaron Massari

Professor Aaron Massari
Director of Graduate Studies

Department of Chemistry

University of Minnesota

Abstract

"Two dimensional IR spectroscopy: A game of molecular telephone"

Infrared spectroscopy is often used as an analytical tool to determine what functional groups are present on a solute. Beyond telling us what molecules are present, vibrations can also be used as a probe of their surroundings; they can communicate their interactions with other vibrations on the same molecule or with the surrounding solvent bath. With the right measurement tool, their stories can be heard. The question becomes: are they telling us the whole story or even the true story of their experiences, or are we losing the message in translation? Our group uses two dimensional IR spectroscopy to eavesdrop on communications between molecular vibrations. From these measurements, we determine the time scales of molecular dynamics experienced by vibrations on organometallic catalysts and semiconducting nanoparticles. With the help of experimental design and MD simulations, we explore the fidelity of our interpretations to separate fact from fiction.

Aaron Massari

Aaron received his BS in Chemistry from Arizona State University in 1999, doing undergraduate research with Prof. J. Devens Gust, a synthetic chemist of all things. He went on to get his PhD at Northwestern University working with Prof. Joe Hupp, an electrochemist of all things. And he was then an NIH Ruth Kirschstein Fellow working with Prof. Michael Fayer at Stanford, finally a spectroscopist. He began his independent career at the U of MN in 2006.

Professor Ian Tonks

Professor Ian A Tonks
Department of Chemistry
University of Minnesota

Abstract

Complex Amination Reactions Promoted by Titanium:
Harnessing an Overlooked Element for New Transformations

Titanium is an ideal metal for green and sustainable catalysis—it is the 2nd most earth-abundant transition metal, and the byproducts of Ti reactions (TiO2) are nontoxic. However, a significant challenge of utilizing early transition metals for catalytic redox processes is that they typically do not undergo facile oxidation state changes because of the thermodynamic stability of their high oxidation states. Several years ago our group discovered that Ti imidos (LnTi=NR) can catalyze oxidative nitrene transfer reactions from diazenes via a TiII/TiIV redox couple. We are using this new mode of reactivity to develop a large suite of practical synthetic methods. In this talk, our latest synthetic and mechanistic discoveries related to Ti nitrene transfer catalysis and other amination reactions will be discussed, including new catalyst design strategies for selective construction of pyrroles via [2+2+1] cycloaddition of alkynes with Ti nitrenes and alkynes, as well as new methods for catalytic oxidative amination, N-N oxidative coupling of pyrazoles, and more.

Tonks seminar graphic

Ian A Tonks

Ian Tonks is the Lloyd H. Reyerson professor at the University of Minnesota – Twin Cities, and associate editor for the ACS journal Organometallics. He received his B.A. in Chemistry from Columbia University in 2006 and performed undergraduate research with Prof. Ged Parkin. He earned his Ph.D. in 2012 from the California Institute of Technology, where he worked with Prof. John Bercaw on olefin polymerization catalysis and early transition metal-ligand multiply bonded complexes. After postdoctoral research with Prof. Clark Landis at the University of Wisconsin – Madison, he began his independent career at the University of Minnesota in 2013. His current research interests are focused on the development of earth abundant, sustainable catalytic methods using early transition metals, and also on catalytic strategies for incorporation of CO2 into polymers. Prof. Tonks’ work has rbeen recognized with an Outstanding New Investigator Award from the National Institutes of Health, an Alfred P. Sloan Fellowship, a Department of Energy CAREER award, and the ACS Organometallics Distinguished Author Award, among others. Additionally, Prof. Tonks’ service toward improving academic safety culture was recently recognized with the 2021 ACS Division of Chemical Health and Safety Graduate Faculty Safety Award.

 

 

Professor Jason Goodpaster

Professor Jason Goodpaster
Assistant Professor
Department of Chemistry
University of Minnesota

Abstract

Advancements in Machine Learning and Quantum Embedding for Large Scale Simulations

Large, condensed phase, and extended systems impose a challenge for theoretical studies due to the compromise between accuracy and computational cost in their calculations. We present two methods that show exciting promise for treating this compromise: machine learning and quantum embedding. We exploit machine learning methods to solve this accuracy and computational cost trade-off by leveraging large data sets to train on highly accurate calculations using small molecules and then apply them to larger systems. We are developing a method to train a neural network potential with high-level wavefunction theory on targeted systems
of interest that are able to describe bond breaking. We combine density functional theory calculations and higher level ab initio wavefunction calculations, such as CASPT2, to train our neural network potentials. We first train our neural network at the DFT level of theory. Using an adaptive active learning training scheme, we retrained the neural network potential to a CASPT2 level of accuracy. Quantum embedding methodology exploits the locality of chemical interactions to allow for accurate yet computationally efficient calculations to be performed on complex systems. Quantum embedding allows for the partitioning of the system into two regions. One is treated at a highly accurate level of theory using wave function theory methods, and the other is treated at the more computationally efficient level of DFT. We discuss our recent advancements for quantum embedding, specifically for systems with complicated electronic structure such as homogeneous and heterogeneous catalysts. Together, we believe both methodologies can allow for complex systems to be studied at a significantly reduced computational cost.

 Jason Goodpaster

Professor Goodpaster obtained his PhD under the guidance of Thomas F. Miller III at Caltech and continued his postdoctoral studies with Martin Head-Gordon and Alexis Bell at Lawrence Berkeley National Laboratory. He joined the department of chemistry at the University of Minnesota in 2016 where is work focus on the development of quantum embedding theories and machine learning methodologies. He won the NSF CAREER award and The Camille and Henry Dreyfus Machine Learning award in 2020.

Professor William Pomerantz

Promotional Seminar
Professor William C. K. Pomerantz
Department of Chemistry
University Minnesota

Abstract

Organofluorine Chemistry at the Biological interface

Despite being the thirteenth most abundant element in the earth’s crust and most abundant halogen, fluorine remains largely absent from nature’s most essential biopolymers and natural products.  Despite this absence in biology, organofluorine compounds hold significant promise for impacting human health, including for imaging applications (18F PET and 19F MRI), structural biology, drug screening, and drug development. As one innovation in our lab, we develop protein-observed 19F NMR (PrOF NMR) approaches using 19F-labeled side-chains that are enriched at protein-protein-interaction interfaces. We use PrOF NMR for characterizing protein-protein and nucleic acid interactions and drug discovery applications.

Today, I will discuss one recent medicinal chemistry application of PrOF NMR, which has led to potent inhibitors and the first synthetic degraders (PROTACs) of the Bromodomain PHD Finger Transcription Factor, BPTF. BPTF has become increasingly identified as a pro-tumorigenic factor prompting investigations into the molecular mechanisms associated with BPTF function. Despite a druggable bromodomain which engages in protein-protein interactions with acetylated histones, small molecule discovery is at an early stage. Our lab has developed novel screening approaches using PrOF NMR, protein crystallography, and supporting biophysical methods to develop both the first inhibitor of the BPTF bromodomain, and now more potent and selective chemical probes. These molecules have been used in both cell-based assays and in vivo. They have demonstrated the importance of the bromodomain for mediating transcription as well as serving as a mechanism for reducing c-Myc occupancy on chromatin. Most recently they have showed synergistic effects with chemotherapeutic drugs in breast cancer models. Finally, their potential as novel heterobifunctional molecules will also be discussed.  These new inhibitors and degrader are envisioned to serve as useful chemical probes of BPTF function both in normal and pathophysiology. Time permitting, many of the enjoyable collaborations here at UMN will be briefly mentioned including work in 19F MRI, epigenetics, and environmental fate studies.

This talk will describe several case studies where PrOF NMR has been applied for fragment screening, ligand deconstruction, and screening of protein mixtures to develop inhibitors of epigenetic complexes.  New applications towards large and multi-domain proteins will also be highlighted.

William Pomerantz

William C. K. Pomerantz, Associate Professor of Chemistry, University of Minnesota. Prof. Pomerantz received his B.S. in chemistry from Ithaca College in 2002, followed by a Fulbright Fellowship at ETH, Zurich with Professors François Diederich and Jack Dunitz. He obtained a Ph.D. in chemistry under Professors Sam Gellman and Nick Abbott at the University of Wisconsin-Madison and was an NIH postdoctoral fellow under Prof. Anna Mapp at the University of Michigan. He joined the chemistry faculty at the University of Minnesota in 2012. He is a recent McKnight Presidential Fellow and current Merck Professor of chemistry.  His research focus is on developing chemical biology and medicinal chemistry approaches to modulate protein-protein interactions. Protein-Observed Fluorine NMR (PrOF NMR) is one such tool in his lab that is being developed for fragment-based drug discovery, and has been applied towards inhibiting epigenetic protein complexes.  Additional interests include macrocyclic peptide design, fluorinated imaging agents and sensors, and environmental fate studies of polyfluorinated molecules known as PFAS. He has published this research in over 70 peer reviewed research articles.  Aspects of his work have been recognized through an NSF CAREER award, Sidney Kimmel Cancer Scholar award, and a Rising Star in Chemical Biology award. Prof. Pomerantz is currently the global council co-chair for the International Chemical Biology Society and vice chair for the Early Career Board Member for ACS Med. Chem. Lett.  

 

Professor Christy Haynes

Professor Christy Haynes
Distingquished McKnight Professor

Department of Chemistry

University of Minnesota

Abstract

Proactive Design of Sustainable Nanomaterials

Because of their size, engineered nanoparticles display an exciting range of chemical and physical properties, and thus, have great potential for a variety of applications. While the early years of applied nanoscience brought concerns about the potential toxicity of nanomaterials, in the last decade, the research community has largely established that nanoparticles do not display unique toxicity threats. Not only are most engineered nanomaterials unlikely to represent a specific threat to biological or ecological systems, but they actually represent some likely solutions to long-standing biological or ecological challenges. This seminar will explore the proactive design of several engineered nanoparticles for sustainability-promoting applications, including inorganic nanomaterials for energy applications and organic nanomaterials for imaging applications.

Christy Haynes

Prof. Christy Haynes is the Distinguished McKnight University Professor at the University of Minnesota where she leads the Haynes Research Group, a lab dedicated to applying analytical and nanomaterials chemistry in the context of biomedicine, ecology, and toxicology. Professor Haynes completed her undergraduate work at Macalester College in 1998 and earned a Ph.D. in chemistry at North- western University in 2003 under the direction of Richard P. Van Duyne. Before joining the faculty at the University of Minnesota in 2005, Haynes performed postdoctoral research in the laboratory of R. Mark Wightman at the University of North Carolina, Chapel Hill. Among many honors, she has been recognized as an Alfred P. Sloan Fellow, a Searle Scholar, a Dreyfus Teacher-Scholar, and a National Institutes of Health “New Innovator.” In addition to wide recognition for her research contributions, including over 200 peer-review publications, she has been recognized at UMN as an Outstanding Postdoctoral Mentor and the Sara Evans Faculty Woman Scholar/Leader Award. Professor Haynes is currently the Associate Head of the Department of Chemistry, the Associate Director of the National Science Foundation-funded Center for Sustainable Nanotechnology, and an Associate Editor for the journal Analytical Chemistry.

Professor Ramanathan Vaidhyanathan

Special Seminar
Professor Ramanathan Vaidhyanathan 
Department of Chemistry
Indian Institute of Science Education and Research Pune

Abstract

Covalent Organic Frameworks as Platform for Charge-storage

Covalent Organic Framework (COF) as crystalline organic polymer has rapidly surged since 2005. The modular framework of COF offers room for by-design functional manipulation in an application-specific manner. Their lightweight nature, high surface area, and processability have signified them as a potential candidate for many charge-storage systems. Large micro-mesopores favor rapid diffusion of charged ions, which is guided by the intrinsic electronics of the conjugated framework. Unfortunately, in many cases, due to the inherent defects in the framework, the conjugation does not propagate sufficiently, leading to poor conductivity. To substitute this, conducting carbons are typically added to boost their conductivity, enhancing their charge storage properties. Here we embrace a different approach to achieving this. Our versatile strategy yields a carbon-free conducting COF displaying substantially high energy and power density in a supercapacitor configuration. This presentation will brief our approach and findings.

Figure 1. COF for lightweight rapid charge-discharge storage
Figure 1. COF for lightweight rapid charge-discharge storage

Ramanathan Vaidhyanathan 

Dr. R. Vaidhyanathan obtained his Ph.D. from the Jawaharlal Nehru Centre for Advanced Scientific Research under Prof. C. N. R. Rao and Prof. S. Natarajan. He worked as a postdoc with Prof. M. J. Rosseinsky at the University of Liverpool and as a research associate with Prof. George Shimizu at the University of Calgary. He started his independent research career as an assistant professor in IISER Pune in 2012. Currently, he is an Associate Professor at IISER Pune. His research focuses on developing Advanced Porous Materials such as metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) and their nanocomposites for environmental and energy applications. He has published over 101 papers and has 11 patents filed from IISER Pune. He has been rewarded with several honors, including the C.N.R. Rao Award. National Prize for research in Physical and Inorganic Chemistry (2021), Materials Research Society of India Medal (2019). He serves as an Editorial Board Member of ACS Materials Letters and Nature Scientific Reports. He is an Associate Editor of ACS Chemistry of Materials.

Relevant publications:

  1. Exceptional Capacitance Enhancement of a Non‐Conducting COF through Potential‐Driven Chemical Modulation by Redox Electrolyte, Kushwaha R, Haldar S, Shekhar P, Krishnan A, Jayeeta S, Hui P, Vinod CP, Subramaniam C, Vaidhyanathan R, Adv. Energy Mater., 11, 2003626 (2021).
  2. Facile Exfoliation of Single-Crystalline Copper Alkylphosphates to Single-Layer Nanosheets and Enhanced Supercapacitance, Bhat GA, Haldar S, Verma S, Chakraborty D, Vaidhyanathan R, Murugavel R, Angew. Chem. Int. Ed., 58,16844–16849 (2019).
  3. Tuning the electronic energy level of covalent organic frameworks for crafting high-rate Na-ion battery anode, Haldar S, Kaleeswaran D, Rase D, Roy K, Ogale S, Vaidhyanathan R, Nanoscale Horiz., 5, 1264-1273 (2020).
  4. Chemical Exfoliation as a Controlled Route to Enhance the Anodic Performance of COF in LIB, Haldar S, Roy K, Kushwaha R, Ogale S, Vaidhyanathan R, Adv. Energy. Mater., 9, 1902428 (2019).
  5. Pyridine-Rich Covalent Organic Frameworks as High-Performance Solid-State Supercapacitors, Haldar S, Kushwaha R, Maity R, Vaidhyanathan R, ACS Materials Lett., 4, 490–497 (2019).
  6. 6High and Reversible Lithium Ion Storage in Self-Exfoliated Triazole-Triformyl Phloroglucinol based Covalent Organic Nanosheets, Haldar S, Roy K, Nandi S, Chakraborty D, Puthusseri D, Gawli Y, Ogale S, Vaidhyanathan R, Adv. Energy Mater., 8, 1702170 (2018).