Past Seminars & Events

Professor Jenny Yang
Department of Chemistry
University of California, Irvine
Abstract

Electrochemical CO2 Capture, Concentration, and Conversion

CO2 capture, concentration, and utilization are all important processes for a circular carbon economy. Developing selective catalysts for concentration CO2 reduction without concomitant hydrogen evolution is a challenge. I will discuss our thermodynamic and kinetic strategies for suppressing the hydrogen evolution reaction under reductive conditions. I will also discuss our work in developing oxygen- stable systems for electrochemical CO2 capture and concentration using secondary hydrogen- bonding interactions. Lastly, I will discuss our work on integrating CO2 capture and conversion into catalytic systems that can take dilute streams of CO2 directly into products.

Jenny Yang

Professor Jenny Y. Yang is a Professor of Chemistry at the University of California, Irvine (UCI). She received her B.S. degree in Chemistry at UC Berkeley and her Ph.D. with Prof. Daniel G. Nocera at MIT. She was a postdoctoral associate at the Pacific Northwest National Laboratory (PNNL) with Dr. Daniel L. DuBois. She continued as a scientist at PNNL and then at the Joint Center for Artificial Photosynthesis before starting as an Assistant Professor at UCI. Her research is focused on inorganic synthesis and electrochemical processes relevant catalysis and separations.

Hosted by Professor Gwendolyn Bailey

Professor Frank A. Leibfarth
Department of Chemistry
University of North Carolina at Chapel Hill
Abstract

Modern Approaches to Functional and Sustainable Thermoplastics

Plastics are the largest synthetic consumer product in the world, with an annual production of over 360 million metric tons annually. Despite the structural diversity enabled by modern advances in polymer synthesis, greater than 60% of world plastic production remains dominated by polyolefins. These high-volume, low- cost engineering thermoplastics are made from a small sub- set of petroleum derived monomers and demonstrate diverse thermomechanical properties, attractive chemical resistance, and excellent processability. Creating sustainable materials that compete with the performance and value proposition of polyolefins is a grand challenge for the field of polymer science. The goal of research in the Leibfarth group is to develop synthetic methods that transform readily available starting materials into functional and sustainable thermoplastics with molecular-level precision. This goal informs our two complementary approaches that seek to 1) leverage chemo- and regioselective C–H functionalization of polyolefins to enhance the properties of these venerable materials and 2) develop stereoselective polymerization methods that engender emergent polymer properties from simple chemical building blocks. These concepts have resulted in platform synthetic methods that enhance the thermomechanical, adhesion, and transport properties of polyolefins while also uncovering mechanistic insights that broadly inform synthetic method development.

Frank A. Leibfarth

Professor Frank Leibfarth attended the University of South Dakota, where he was a Goldwater Scholar and graduated in 2008 with degrees in Chemistry and Physics. He received his PhD from the University of California Santa Barbara under the direction of Professor Craig J. Hawker in 2013 and completed a postdoc fellowship at MIT under the direction of Professor Timothy F. Jamison. He began his independent career in 2016 at the University of North Carolina, where he is an Associate Professor in the Chemistry Department. His research focuses on the synthesis of materials for contemporary challenges in sustainability, including plastics recycling and water purification. The work of Professor Leibfarth’s group has been recognized by the Beckman Young Investigator award, the Popular Science Brilliant Ten recognition, and the Sloan Research Fellowship, among others. At UNC, Prof. Leibfarth has been recognized by the Tanner Award for Excellence in Undergraduate Teaching and as the Winter 2021 commencement speaker.

Hosted by Professor Marc Hillmyer

Professor William M. Wuest, Ph.D.
Georgia Research Alliance Distinguished Investigator
Professor of Chemistry
Emory University
Abstract

Slaying Superbugs One Natural Product at a Time

The importance of natural products as anticancer and antibiotic compounds is undisputed due to their wide application as potent and effective pharmaceuticals. In contrast to broad-spectrum agents, the development of species-specific, “narrow- spectrum” antibacterials would be of interest to the medical community serving as novel therapeutics and also to microbiologists as chemical probes to deconvolute complex bacterial communities. Over the past decade our group has looked to Nature for inspiring chemical scaffolds and has leveraged diverted total synthesis (DTS) to study bacteria. The talk will highlight recent efforts from our lab using DTS in antibiotic discovery and development; covering antibiotic synthesis, biological evaluation, and target identification.

William M. Wuest

Professor Wuest was born on Long Island, NY in 1981. He received his B.S. magna cum laude in Chemistry/ Business from the University of Notre Dame in 2003. As an undergraduate, he investigated intramolecular hydroamination reactions under the tutelage of Professor Paul Helquist. Bill then moved to Philadelphia, PA to begin his graduate studies at the University of Pennsylvania working with Professor Amos B. Smith, III. His graduate work focused on both the total synthesis of peloruside A and the development of Anion Relay Chemistry (ARC) culminating with a Ph.D. in 2008. Bill then traveled to Harvard Medical School as a Ruth Kirschstein-NRSA Postdoctoral Fellow in the laboratory of Professor Christopher T. Walsh, where he investigated unusual enzymatic transformations in the construction of non-ribosomal peptide natural products. 

In July of 2011, Bill began his independent career as an Assistant Professor at Temple University, was named the Daniel Swern Early Career Professor of Chemistry in 2016, and received tenure in 2017. He moved to Emory University as an Associate Professor of Chemistry with tenure and also as the inaugural Georgia Research Alliance Distinguished Investigator that same year. In 2021 he was promoted to his current position of Professor of Chemistry. His research focuses on the modification of natural products through total synthesis in an effort to develop innovative, pathogen- specific therapeutics. Bill is the recipient of a number of awards including the NIH ESI Maximizing Investigators Research Award (MIRA), NSF CAREER Award, the 2017 ACS Infectious Diseases Young Investigator Award, the 2020 David W. Robertson Award from the ACS Division of Medicinal Chemistry, the New Investigator Award from the Charles E. Kaufman Foundation, the Thieme Journal of Chemistry Award, the Young Investigator Award from the Center for Biofilm Engineering at Montana State University, and the Italia- Eire Foundation Distinguished Teacher of the Year Award from the College of Science and Technology at Temple University. He has also been selected as an Alan Leshner Public Engagement Fellow by the AAAS, a Scialog Fellow by the RCSA, and a SVPR Faculty Leadership Fellow by the Office of Research at Emory.

Hosted by Professor Erin Carlson

Professor Kay M. Brummond
Department of Chemistry
University of Pittsburgh
Abstract

The Asymmetric Rh(I)-Catalyzed Pauson–Khand Reaction

In the fifty years since its discovery, the Pauson–Khand reaction (PKR) has transformed the design and synthesis of ring-fused cyclopentenones—an unsaturated motif of immense value for building complex molecular compounds. Moreover, the PKR is frequently used in natural product synthesis owing to the predictable and high diastereoselectivity afforded by this cyclocarbonylation reaction. And yet, the scope of the asymmetric PKR remains limited. The focus of this presentation will be on our group’s discoveries leading to the expansion of the scope of the Rh(I)-catalyzed asymmetric PKR through catalyst-controlled reactivity modes and the application of our findings to medicinally important targets.

Kay M. Brummond

Professor Brummond is an organic chemist and a Professor of Chemistry at the University of Pittsburgh. She received her BS degree from the University of Nebraska-Lincoln (1985), her PhD in organic chemistry from The Pennsylvania State University (1991), and she performed her postdoctoral studies in organic chemistry at the University ofRochester (1991–1993). Her first faculty appointment was in the Department of Chemistry at West Virginia University in 1993 where she was promoted to Associate Professor with tenure (1999). In 2001, Brummond joined the Department of Chemistry at the University of Pittsburgh as an Associate Professor and was promoted to Professor in 2006. She served as the first female departmental chair in their 160-year history (2014–2017) and as the Associate Dean for Faculty in the Dietrich School of Arts and Sciences (2017–2023). She and her coworkers have published 92 journal articles, reviews, and book chapters. Brummond has delivered 190 presentations as an invited speaker for departmental colloquia and seminars (135) and as a plenary lecturer for symposia and conferences (55). Students and postdocs have presented 71 posters and seminars at national meetings. Thirty-two graduate students have obtained PhD (18, 10 since 2014) and MS (14, 2 since 2014) degrees under her direction, and she has mentored 35 undergraduate students (81 semesters) and 15 postdoctoral fellows. She currently has 8 graduate students in her group, 2 of which are co-advised by Professor Liu at the University of Pittsburgh.

Hosted by Professor Courtney Roberts

Professor Xuhui Huang
Department of Chemistry
University of Wisconsin-Madison
Abstract

Non-Markovian Dynamic Models for Studying Protein Conformational Changes

Protein’s dynamic transitions between metastable conformational states play an important role in numerous biological processes. Markov State Models (MSMs) provide a powerful approach to study these dynamic processes by predicting long time scale dynamics based on many short molecular dynamics (MD) simulations. In the first part of this talk, I will introduce our group’s work on developing the MSM methodology and applying it to simulate the complex conformational changes, that occurs millisecond timescales for RNA Polymerase complexes containing about half a million atoms (e.g., backtracking). MSMs provide a useful approach to study protein conformational changes, but it is challenging to build truly Markovian models due to the limited length of lag time (bound by the length of relatively short MD simulations). In the second part of my talk, I will introduce our recent work on developing non-Markovian dynamic models based on the Generalized Master Equation (GME) theory that encodes the dynamics in a generally time-dependent memory kernel, whose characteristic decay time scale corresponds to the kernel lifetime. We show that GME methods can greatly improves upon Markovian models by accurately predicting long timescale dynamics using much shorter MD trajectories on complex conformational changes.

I will also introduce our Integrative GME (IGME) based on the time integrated memory kernels to avoid huge numerical instability in the memory kernel tensor. Finally, I will present our newly developed deep- learning approach, the Memory Kernel Minimization based Neural Networks (MEMnets), which can accurately identify the slow CVs of biomolecular dynamics. MEMnets is built on the GME theory. Its key innovation is the development of a novel loss function that corresponds to the integrals of memory kernels in encoder deep-neural networks. We show that MEMnets can successfully elucidate the gate opening dynamics of a bacterial RNA polymerase, a process occurring at millisecond timescale. We expect that the GME-based methods hold promise to be widely applied to study functional dynamics of proteins.

Xuhui Huang

Professor Xuhui Huang obtained his Ph.D. from Columbia University in 2006 with Prof. Bruce Berne. He did his postdoc research at Stanford University with Profs. Michael Levitt and Vijay Pande. He was as an Assistant, Associate and Full Professor of the Hong Kong University of Science and Technology (HKUST) between 2010 and Summer 2021. 

Since Fall 2021, he took up the position of the Hirschfelder Endowed Chair Professor in Theoretical Chemistry, and Director of Theoretical Chemistry Institute at University of Wisconsin- Madison. He has received numerous awards, including Biophysical Society Theory & Computation Award for Mid- Career Scientists (2023), Pople Medal from the Asia-Pacific Association of Theoretical and Computational Chemists (2021), American Chemical Society OpenEye Outstanding Junior Faculty Award (2014), and Hong Kong Research Grant Council Early Career Award (2013). He is a founding member of Young Academy of Sciences of Hong Kong (YASHK) and Fellow of Royal Society of Chemistry (FRSC). His group pioneered in elucidating the dynamics of protein conformational changes by developing new methods based on statistical mechanics that can bridge the gap between experiments and atomistic MD simulations.

Hosted by Professor Jiali Gao

Professor Andre K. Isaacs
Department of Chemistry
College of the Holy Cross
Abstract

From Imposter to Impressor: Embracing Complex Identities in STEM

In the wake of the Covid-19 pandemic, along with rapid technological advancements and shifting generational cultures, educators face unprecedented challenges in sparking the curiosity of budding scientists. This seminar is dedicated to navigating these challenges with enthusiasm and compassion, as we explore innovative approaches to teaching that will empower the next generation of learners, with special attention to those from historically excluded groups. The focus extends beyond the conventional methods and embraces cutting-edge technologies and inclusive pedagogy to create an engaging and accessible learning environment.

Andre K. Isaacs

Professor Isaacs is a native of Jamaica, André moved to the US to attend the College of the Holy Cross where he received his B.A. in Chemistry in 2005. He received his PhD from the University of Pennsylvania in 2011 (under the guidance of Professor Jeffery D. Winkler) and worked as a post-doctoral researcher with Professor Richmond Sarpong at the University of California, Berkeley. He is currently an Associate Professor at the College of the Holy Cross. In addition to teaching courses in Organic Chemistry, he conducts research utilizing copper-mediated organic transformations. He uses his social media platform to challenge the normative culture in STEM and to increase visibility of queer and BIPOC scientists. 

Hosted by Professor Lee Penn

Professor Andre K. Isaacs
Department of Chemistry
College of the Holy Cross
Abstract

A Click Chemistry Approach to Nitrogen Heterocycles

My research interest is centered on a very reliable organic reaction - the copper-catalyzed cycloaddition of sulfonyl azides and terminal alkynes (CuAAC). Differential fragmentation of the resulting 1,2,3-triazole generates ketenimines or rhodium carbenoids which readily engage
with a variety of nucleophiles to provide access to heterocycles of interest to the synthetic community. We’ve demonstrated the utility of click chemistry in the synthesis of N-Heterocycles such as indolizines, dihydroisoquinolines and as an approach to beta-lactams.

Andre K. Isaacs

Professor Isaacs is a native of Jamaica, André moved to the US to attend the College of the Holy Cross where he received his B.A. in Chemistry in 2005. He received his PhD from the University of Pennsylvania in 2011 (under the guidance of Professor Jeffery D. Winkler) and worked as a post-doctoral researcher with Professor Richmond Sarpong at the University of California, Berkeley. He is currently an Associate Professor at the College of the Holy Cross. In addition to teaching courses in Organic Chemistry, he conducts research utilizing copper-mediated organic transformations. He uses his social media platform to challenge the normative culture in STEM and to increase visibility of queer and BIPOC scientists. 

Hosted by Professor Jessica Lamb

Professor Robert M. Waymouth
Department of Chemistry
Stanford University
Abstract

New Catalysts and Processes for Organocatalytic Polymerization: From Catalysis to Functional Materials

We have developed a family of versatile organic catalysts for the living polymerization of lactone and carbonate monomers that have been integrated into efficient flow reactors for the programmed synthesis of block copolymer libraries. These synthetic methods spawned the development of a new concept for gene delivery based on a class of dynamic oligomeric cationic materials that are designed to self- assemble with polyanionic nucleotides to form coacervate nanoparticles. Charge-Altering Releasable Transporters are structurally unique oligomers that operate through an unprecedented mechanism, serving initially as oligo(α-amino ester) cations that complex, protect and deliver mRNA, and then change physical properties through a degradative, charge-neutralizing intramolecular rearrangement, leading to intracellular release of functional mRNA and highly efficient protein expression, both in cell culture and in animals. Selected applications of in-vivo mRNA delivery for cancer and COVID vaccination will be described.

Robert M. Waymouth

Professor Robert Waymouth is the Robert Eckles Swain Professor of Chemistry at Stanford University. He received B.S. in Mathematics and B.A. in Chemistry from Washington and Lee University and his Ph.D. in Chemistry at the Caltech in 1987 with Professor R.H. Grubbs. He was a postdoctoral fellow with the late Professor Piero Pino at the ETH in Zurich in 1987 and joined the faculty at Stanford as an Assistant Professor in 1988. He received the Alan T. Waterman Award from the NSF in 1996, the Cooperative Research Award in Polymer Science in 2009, and EPA’s Presidential Green Chemistry Challenge Award in 2012, the ACS Polymer Chemistry Award and the Herman F Mark Award. He has won several university teaching awards, including the Walter J. Gores Award, the Phi Beta Kappa Teaching Award, and is currently a Bass Fellow in Undergraduate Education. His research interests are at the interface of Inorganic, Organic and Polymer Chemistry, in particular the development of new concepts in catalysis for the selective synthesis of both macromolecules and fine chemicals. Particular areas of interest include catalytic polymerization reactions, selective oxidation catalysis, the development of organocatalytic polymerization strategies and the design of functional macromolecules for applications in sustainable materials, biology and medicine.

Hosted by Professor Jessica Lamb

Professor T. Grant Glover
Chemical and Biomolecular Engineering
University of South Alabama
Abstract

The Role of Mass Transfer and Thermodynamics in Metal-Organic Framework Based Gas Separations

As global demand for CO2 mitigation and clean drinking water accelerates, reticular materials, such as metal-organic frameworks and covalent organic frameworks, will play an increasing role in solving these challenges. Although many novel porous materials have been developed over the last 20 years, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) are uniquely suited to solve complex problems because they can be synthesized with atomic-scale precision and in a nearly infinite number of structural combinations. Beyond drinking water and CO2 mitigation, these materials have been examined for a variety of other globally relevant applications including, CH4 storage, olefin/paraffin separations, catalysis, toxic gas filtration, space life-support, and others. All of these proposed applications raise numerous questions about the thermodynamics and mass transfer of gases in these materials and how to best tailor them to provide precision control over the material’s adsorption isotherms and diffusion rates. Defects in the crystal structures add additional complexities, some of which can be addressed by pairing molecular simulations and experiments. This seminar will discuss some of these applications and illustrate the connection between MOF structure, mixed-gas adsorption isotherms, and diffusion. These concepts will be discussed in the context of the adsorption of CO2 in humid gas streams and atmospheric water harvesting.

T. Grant Glover

Since 2012 Prof. Glover has operated an externally funded research group focused on understanding mixed-gas adsorption, mass transfer in porous materials, and absorption in ionic liquids. In 2017 he received the Russ and Robin Lea Faculty Innovation Award, and the South Alabama College of Engineering Excellence in Research Award. He has published numerous journal publications, government reports, and patents detailing gas adsorption and porous materials development, and he is the editor of the 2018 book Gas Adsorption in Metal-Organic Frameworks: Fundamentals and Applications published by CRC Taylor & Francis. His current research projects examine CO2 capture from flue gas, direct CO2 capture from air, atmospheric water harvesting, CO2 capture with task-specific ionic liquids, and CO2/H2O binary adsorption measurements for novel materials design. Prof. Glover is the program director of the University of South Alabama’s newly implemented Ph.D. in Chemical and Biomolecular Engineering, which he spearheaded from conception through final state approval. Before his academic appointment, Prof. Glover worked for SAIC/Leidos as a Defense Department contractor where he executed experiments studying the filtration of acutely toxic compounds from air, managed a pilot scale test facility, and supervised novel adsorbent materials research for chemical defense. During his time at SAIC/Leidos he received the Living Our Values Award and the SAIC Division Level Employee of the Year Award. Prof. Glover holds a B.S. degree from the Georgia Institute of Technology, a Ph.D. from Vanderbilt University under the direction of Prof. Douglas LeVan, and completed a post-doctoral fellowship with Prof. Omar M. Yaghi at the University of California, Los Angeles.

Hosted by Professor Lee Penn

Professor Rajarshi Chakrabarti
Department of Chemistry
Indian Institute of Technology Bombay
Abstract

Statistical Mechanics of active polymers: from dilute to dense phase

Colloidal chains driven by local chemical reactions [1] or in a bath of bacteria [2] show unusual scaling behavior, not observed in equilibrium. In the first part of the talk, I will briefly discuss some analytically solvable models for a single active polymer chain or a passive polymer chain in active baths [3-5]. These models can actually predict experimentally observed superdiffusive motion of the tagged monomer of a colloidal chain in an active bacteria bath. These models also predict swelling of active chains in passive baths and passive chains in active baths, longtime enhanced diffusion as seen in experiments [1-2]. To understand the motion of active shape- deforming agents, a collection of rings made of active Brownian particles (ABPs) [3, 4] for different packing fractions and activities is investigated using computer simulations. This will be the topic for the second part of my talk. Our computer simulations reveal that active rings display a novel dynamic clustering [5] instead of the conventional motility- induced phase separation (MIPS) [6] as observed in case of collection of ABPs. Surprisingly, increasing packing fraction of rings exhibits a non-monotonicity in the dynamics due to the formation of a large number of small clusters. The conformational fluctuations of the polymers suppress MIPS exhibited by ABPs. This demonstrates a complex interplay between activity, topology, and connectivity.

Rajarshi Chakrabarti

Professor Rajarshi Chakrabarti received his Ph.D. in Theoretical Chemistry from the Indian Institute of Science, Bengaluru. After two postdoctoral stints at the University of Illinois at Urbana Champaign and the University of Stuttgart, he joined the Department of Chemistry, Indian Institute of Technology Bombay, as an Assistant Professor in 2013 and became a full Professor in 2021. His research interests are broadly in the area of Statistical Mechanics and Soft and Living Matter. Currently, he is serving as an Editorial Board Member of Journal of Physics A: Mathematical and Theoretical. Research Website: rajarshichakrabarti.wixsite.com/rajarshichakrabarti

Hosted by Professor Sapna Sarupria.