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Jonathan Rivnay

Department of Biomedical Engineering and Simpson Querrey Institute

Northwestern University, Evanston, IL

Abstract: Direct measurement and stimulation of ionic, biomolecular, cellular, and tissue-scale activity is a staple of bioelectronic diagnosis and/or therapy. Such bi-directional interfacing can be enhanced by a unique set of properties imparted by organic electronic materials. These materials, based on conjugated polymers, can be adapted for use in biological settings and show significant molecular-level interaction with their local environment, readily swell, and provide soft, seamless mechanical matching with tissue. At the same time, their swelling and mixed conduction allows for enhanced ionic-electronic coupling for transduction of biosignals. Structure-transport properties allow us to better understand and design these active materials, providing further insight into the role of molecular design and processing on ionic and electronic transport, charging phenomena, and stability for the development of high-performance devices. Such properties stress the importance of bulk transport processes and serve to enable new capabilities in bioelectronics. In this talk I will discuss the design of new organic mixed conductors and future design rules for performance and stability. I will demonstrate how such materials properties relax design constraints and enable new device concepts and unique form factors, allowing for flexible amplification systems for electrophysiological recordings, and electroactive scaffolds to modulate tissue state and/or cell fate. New materials design continues to fill critical need gaps for challenging problems in bio-electronic interfacing.

Faculty Host: Dr. John Anthony

Abstract: Despite the clinical success and proven efficacies of the conventional platinum-based drugs cisplatin, carboplatin, and oxaliplatin, these drugs suffer from a number of challenges that limit their more widespread therapeutic potential. These limitations, including toxic side effects and susceptibility to cancer drug resistance mechanisms, have prompted researchers to explore alternative metal complexes as anticancer agents. In this presentation, an overview of our work on the development and understanding of rhenium-containing organometallic complexes as potential drug candidates is discussed. We will disclose our discovery that a wide range of rhenium(I) tricarbonyl complexes exhibit potent in vitro anticancer activity via diverse biological mechanisms of action. Furthermore, several classes of rhenium(I) tricarbonyl complexes that we have investigated undergo photochemical processes that can be harnessed to trigger cancer cell death selectively upon irradiation or can be used for imaging applications. For this class of compounds, we have carried out detailed biological studies to determine their mechanisms of action. Our results indicate that subtle structural modifications of these compounds can lead to significant changes in their biological properties. Lastly, in vivo studies will be presented, demonstrating that the potential of these compounds as anticancer drug candidates exists beyond in vitro cellular experiments.

University of Alabama

Abstract: We aim to apply bioinorganic and organometallic chemistry to problems that relate to green chemistry and sustainability. We are exploring how protic and electron donor groups impact catalysis. We have pursued reactivity inspired by the need for energy storage, specifically carbon dioxide reduction. Recently, we designed new pincer ligands using N-heterocyclic carbene (NHC) and pyridinol rings that can change their properties by protonation and deprotonation, rather than lengthy synthesis. The most active transition metal catalysts with these pincers use methoxy groups which balance electron donor ability with stability. This has allowed for formation of ruthenium, cobalt, and nickel complexes that perform catalytic and light driven carbon dioxide reduction. We have also demonstrated that the OH derivatives can be switched on or off for catalysis with acid concentration. One of our ruthenium complexes is record setting in terms of reaction rates and selectivity. CO₂ reduction is of fundamental importance to the impending global energy crisis, and carbon dioxide reduction (when coupled with water oxidation) can allow for a sustainable method of energy storage in solar fuels. Furthermore, we have studied our hydroxyl substituted bipyridine ligands as a part of ruthenium based anticancer metallo-prodrugs. The ruthenium complexes are light activated and show selective toxicity towards cancer cells.  

Bio: Elizabeth T. Papish was born and raised on Long Island, NY. She studied chemistry at Cornell Univ. (BA, 1997) and Columbia Univ. (PhD, 2002). She has taught at Franklin & Marshall College (2002-3), Salisbury Univ. (Asst. Prof. 2003-2007), Drexel Univ. (Asst. Prof. 2007-2012, Assoc. Prof. 2012-2013), and at the Univ. of Alabama (Assoc. Prof. 2013-2019, Full Prof. 2019-present). Her research group studies bioinorganic and organometallic chemistry with an emphasis on designing new organic ligands for the use of transition metal complexes in energy related catalysis applications and for metal-based therapies for health applications. She is the recipient of an NSF CAREER award (2009) and has been honored with the "Outstanding Research Mentor of the Year Award" at Salisbury Univ. in 2007 and with the "College of Arts and Sciences Teaching Award" for excellence in teaching and mentorship from Drexel Univ. in 2012.  In 2013, Papish and her student received the "Division of Inorganic ����vlog�ٷ���� Award for Undergraduate Research" from the American Chemical Society. Her research is currently supported by NSF and NIH.

Faculty Host: Dr. Aron Huckaba

Faculty host: Dr. Anne-Frances-Miller

Bio: Hannah Shafaat received her B.S. in ����vlog�ٷ���� from the California Institute of Technology (Caltech) in 2006, where she performed research on spectroscopic endospore viability assays with Adrian Ponce (NASA Jet Propulsion Laboratory) and Harry Gray. She received her Ph.D. in Physical ����vlog�ٷ���� from the University of California, San Diego (UCSD) in 2011, under the direction of Professor Judy Kim, as an NSF Graduate Research Fellow and a National Defense Science and Engineering Graduate Fellow. During her graduate research, she used many different types of spectroscopy to study the structure and dynamics of amino acid radical intermediates in biological electron transfer reactions. After earning her Ph.D., Hannah moved across the ocean to Germany to study hydrogenase and oxidase enzymes and learn advanced EPR techniques as a Humboldt Foundation Postdoctoral Fellow working under Director Wolfgang Lubitz at the Max Planck Institute for Chemical Energy Conversion. Since starting her independent career, Hannah has received the NSF CAREER award in 2015 to support work on hydrogenase mimics, and in 2017, she was awarded the DOE Early Career award to support the group’s research on one-carbon activation in model nickel metalloenzymes. Recently, the group has received support for their research on heterobimetallic Mn/Fe cofactors through the NIH R35 MIRA program for New and Early Stage Investigators. Hannah was also awarded the 2018 Sloan Research Fellowship.

Abstract: Nature has evolved diverse systems to carry out energy conversion reactions. Metalloenzymes such as hydrogenase, carbon monoxide dehydrogenase (CODH), acetyl coenzyme A synthase (ACS), and methyl coenzyme M reductase use earth-abundant transition metals such as nickel and iron to generate and oxidize small-molecule fuels such as hydrogen, carbon monoxide, acetate, and methane. These reactions are highly valuable in the context of the impending global energy and climate crisis. However, due to substantial challenges associated with studies of these native enzymes, much remains unknown about the basic catalytic mechanisms, hindering efforts to harness this chemistry for anthropogenic purposes. To address these limitations and develop a molecular-level understanding of these systems, we have developed robust, protein-derived models as structural, functional, and mechanistic mimics of hydrogenase, CODH and ACS. In this presentation, our recent efforts to install and modulate novel reactivity in rubredoxin, ferredoxin, and azurin scaffolds will be discussed. along with findings from multiple complementary spectroscopic techniques used to probe the catalytic mechanisms. These engineered metalloenzymes provide direct insight into the fundamental chemical principles driving the natural systems.

Faculty host: Dr. Anne-Frances-Miller

**CANCELLED**

Marco Bonizzoni

Department of ����vlog�ٷ���� and Biochemistry, The University of Alabama, Tuscaloosa, AL, USA.

Alabama Water Institute, The University of Alabama, Tuscaloosa, AL, USA.

E-mail: marco.bonizzoni@ua.edu

Abstract: Artificial supramolecular receptors often rely on weak intermolecular interactions for their chemical recognition properties, so they may struggle to work in competitive media, chief among 

which are water solutions. However, aqueous media are very important in analytical, environmental, and biomedical applications, so it is valuable to adapt our supramolecular tools to them. With the right tools, even the weakest noncovalent interactions can be pressed into service in aqueous media. We have been using water-soluble polymers (e.g. dendrimers, hydrogels, conjugated polymers) as scaffolds to build multivalent supramolecular sensors that take advantage of the large number of interactions and of the preorganization of receptor sites afforded by such scaffolds, resulting in improved affinity in buffered aqueous solutions near neutral pH. We have successfully built systems for the detection of interesting guest families, including carboxylate anions, simple saccharides, heavy metal cations, and polycyclic aromatic hydrocarbons. These are examples of a general approach with two key advantages. On the one hand, installing known receptor chemistry on a polymer scaffold affords a modular approach to multivalency with minimal design and synthesis effort. This improves the apparent strength of weaker interactions and allows them to overcome desolvation costs in water. On the other hand, water-soluble macromolecular scaffolds impart solubility to water-incompatible receptor families.

This simple approach is particularly valuable when designing chemical fingerprinting systems (sometimes referred to as an “electronic nose” or “tongue”) that typically require many different receptors, each one poorly selective, and recovers selectivity from judicious interpretation of the ensemble response.

**CANCELLED**

Abstract: Plastic semiconductors incorporated into transistors have shown enormous potential for flexible, printable electronics as well as bioelectronics that communicate with the body. In my talk I will discuss the background and potential applications of these exotic transistors, as well as novel, state-of-the-art materials systems I have developed to overcome their intrinsic bottlenecks. I will show how these simple, low-cost solutions to organic transistor problems work towards the realization of a broad suite of organic electronic technologies.

Abstract: Process analytical technology (PAT) plays an essential role in understanding and optimization chemical manufacturing routes by furnishing data-dense reaction profiles. However, each PAT tool presents certain limitations with respect to chemical component resolution, reaction compatibility or useful operational domain. High-pressure liquid chromatography (HPLC) represents one of the most versatile analytical tools available for providing detailed reaction progress analysis. Yet this technology introduces a new set of challenges relating to sample acquisition and preparation, especially when trying to utilize HPLC as a real time analytical technology.

Our lab has developed a comprehensive set of automated tools, which allow nearly any chemical process to be visualized in real time by HPLC. This includes reactions performed under inert atmosphere, systems with heterogenous reagents, and complex competition reactions with many components. The combination of excellent resolving power of UHPLC, coupled to the high dynamic range of standard UV/Vis and MSD detectors has allowed this tool to be broadly deployed. This has allowed complex reactions to be visualized in exceptional details with unprecedented ease. This presentation will discuss several case studies to demonstrate the flexibility and fidelity of this new online HPLC technology. Examples will include studying reaction mechanisms, measuring crystallization processes and deployment as an in-process control for reaction automation.

Abstract: Advances in machine learning (ML) are making a large impact in many disciplines, including materials and computational chemistry. A particularly exciting application of ML is the prediction of quantum mechanical (QM) properties (e.g., formation energy, bandgap, etc.) using only the structure as input. Assuming sufficient accuracies in the ML models, these methods enable screening of a considerably large chemical space at orders of magnitude lower computational cost than available QM methods. Despite the promise of ML in chemistry, several key challenges remain in both applying and interpreting the results of ML algorithms. Here, we will discuss our efforts in addressing these issues, including our recent work on opening the black box of ML methods by identifying the domain of applicability, i.e., where a given model is reliable.

Bio: Chris Sutton is an Assistant Professor in the Department of ����vlog�ٷ���� & Biochemistry at the University of South Carolina. Chris received his PhD at the Georgia Institute of Technology under the direction of Professor Jean-Luc Bredas, and then moved to Duke University for postdoctoral research with Professor Weitao Yang. Chris received the Alexander von Humboldt postdoctoral fellowship to work in the Theory Department at the Fritz Haber Institute in Berlin, Germany where Matthias Scheffler was the Director. Chris’ current research is focused on computational materials discovery through a combination of   electronic structure calculations, machine learning, and stochastic sampling techniques to speed up the traditional computational design of materials.

Michael Chabinyc

Materials Department

University of California Santa Barbara

Abstract: Polymers are essential for wearable electronic systems as active and passive materials.  We will discuss the role of molecular structure on the behavior of semiconducting polymers and dielectric elastomers. In both cases, the molecular architecture of polymers controls their ultimate functional behavior. First, we will discuss how relatively small changes in the design of the sidechains of semiconducting polymers can be used to modify donor-acceptor interactions with molecular dopants. These subtle changes control whether charge transfer is complete leading to an electrically conductive state, or partial leading to a poorly conducting charge-transfer state.  Second, we will discuss how polymers with a bottlebrush architecture can be used to form super-soft elastomers useful for pressure sensors. The low mechanical modulus of bottlebrush elastomers, which is comparable to that of hydrogels, allows for the simple formation of capacitive pressure sensors with sensitivity comparable to human touch. Recent results on 3D printing of super-soft materials will also be described.

Biography: Professor Michael Chabinyc is Chair of the Materials Department at the University of California Santa Barbara. He received his Ph.D. in chemistry from Stanford University and was an NIH postdoctoral fellow at Harvard University. He was a Member of Research Staff at (Xerox) PARC prior to joining UCSB in 2008. His research group studies fundamental properties of organic semiconducting materials and thin film inorganic semiconductors with a focus on materials useful for energy conversion. He has authored more than 200 papers across a range of topics and is inventor on more than 40 patents in the area of thin film electronics.  He is a fellow of the Materials Research Society (MRS), the American Physical Society (APS), the National Academy of Inventors (NAI), and the American Association for the Advancement of Science (AAAS).