Past Seminars & Events

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 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 2^nd 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 (L_nTi=NR) can catalyze oxidative nitrene transfer reactions from diazenes via a Ti^II/Ti^IV 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.

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
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.

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
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.

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.

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).

Accurate Calibration of the Flory-Huggins C Parameter

Professor Mark Matsen
Departments of Chemical Engineering, Physics & Astronomy
University of Waterloo

Abstract

Mark Matsen obtained his PhD on lyotropic liquid crystals from the University of Guelph (Canada) in 1987. His research interests switched to the theory of block copolymers during postdoc positions at the University of Washington with Michael Schick and then the University of Minnesota with Frank Bates. He then took a faculty position at the University of Reading (UK), first in the Physics Dept (1996-2005) and then in the Mathematics Dept (2005-2013). Matsen is now a faculty member at the University of Waterloo (Canada) jointly in the Chemical Engineering and Physics & Astronomy Depts, where he continues to research block copolymers and polymer melts.

Multiscale Simulation of Flow-Induced Crystallization in Polymers

Professor Gregory Rutledge
Department of Chemical Engineering
Massachusetts Institute of Technology

Abstract

Gregory C. Rutledge is the Lammot du Pont Professor of Chemical Engineering at MIT. He served as Director of the Program in Polymer Science and Technology and Executive Officer in Chemical Engineering. He is a Fellow of AIChE, APS, and PMSE Division of ACS. He received the AIChE Braskem Award, Fiber Society Founders Award, Morton Distinguished Visiting Professorship (University of Akron), and Thinker-in-Residence (Deakin University). His research entails the molecular engineering of soft matter, with publications on process-structure-property relationships for polymers and the fabrication, properties and applications of ultrafine fibers. Prof. Rutledge is an editor for the Journal of Materials Science.

The 21st annual Chemistry Graduate Student Research Symposium is being held June 9, 2022 in Tate Hall and virtually on Zoom.

The symposium primarily consists of research presentations by third-year graduate students in the Chemistry Ph.D. program at the University of Minnesota. Presentations will take place in four concurrent sessions and will be 20 minutes in length with an additional 5 minutes reserved for discussion.

Department of Chemistry Strengthening Climate Event

Mariann Johnson
Mindfulness and Wellbeing Instructor
Earl E. Bakken Center for Spirituality & Healing
University of Minnesota

This experiential and interactive session will provide participants an opportunity to pause and reflect on their personal wellbeing and present mindfulness as an evidence-based tool for reducing stress and enhancing emotional resilience. Research has demonstrated that practicing mindfulness can broaden our perspective and down regulate the stress response, allowing us to be with life’s inevitable challenges more resourcefully. Mindfulness will also be explored as a relational practice; when we are mindful, we are often able to see and respond to others with greater sensitivity, understanding and compassion. The session will also include a mindfulness meditation and provide participants with practical tips for incorporating wellbeing and mindfulness into their everyday lives.

Daniel Gonzalez
Dept. of Organizational Leadership, Policy, & Development
University of Minnesota
Host: Chemistry D&I Grad Student Training Working Group

Abstract

The Latinization of the American Student: The Impact of Systemic Silencing & Implications for the Education Arena

Since 2000 the Latine/Hispanic population has been the largest racial minority within the United States; however, Latine students also have the largest educational opportunity gaps across racial identities. The session will begin with participants discovering the historical context of migration patterns, demographic shifts, and statistical differences related to educational attainment. Then, participants will unpack literature centering Latine student experiences and focus on research-based practices to help transform said experiences. The session will examine narratives illustrating systemic silencing in the education arena while also showcasing recommendations for improvement.

Daniel Gonzalez

Daniel Gonzalez (he/him/his) completed his B.S. and M.S.Ed. in Music Education from The College of Saint Rose in Albany, NY. Since completing his M.S.Ed., he has worked at the University of Southern Mississippi, Western Kentucky University, and currently at UMN in student retention roles within residential life and orientation and transition functions. As a proud first-generation student, low-income background, queer, Puerto Rican, Daniel has witnessed first-hand some of the barriers to success for those that hold similar identities. These experiences ground him in his purpose to create an environment that allows all to access and persist within higher education.