Upcoming Seminars & Events

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Professor Ming Chen

Professor Ming Chen
Department of Chemistry
Auburn University

"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.

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 Shelley D. Minteer

Professor Shelley D. Minteer
Department of Chemistry
College of Science
University of Utah

Abstract

"Electrochemical Alternatives to Haber-Bosch Ammonia Production"

The Haber-Bosch process, responsible for producing NH3 from H2 and N2, ranks as one of the most important discoveries in the history of chemistry. Its industrial application in synthetic fertilizers contributed to the continuously increasing population and their quality of life. The Haber-Bosch process, however, is a very energy-intensive process with high temperature (500 °C) and pressure (20 MPa) required for efficient NH3 production. Over 1 % of the world's energy sources were consumed in order to produce ~140 megatons of NH3 in 2015. Additionally, 3 % of global CO2 emissions are due to the Haber-Bosch related technology. A renewable strategy for ammonia production would therefore be valuable. In nature, the ability to reduce N2 to NH3 is limited to a group of bacteria and archaea classified as diazotrophs, all of which share an enzyme called nitrogenase. Using methylviologen (N,N'-dimethyl-4,4'-bipyridinium) to shuttle electrons to nitrogenase, N2 reduction to NH3 can be mediated at an electrode surface. The coupling of this nitrogenase cathode with a bioanode which utilizes the enzyme hydrogenase to oxidize molecular hydrogen (H2) results in an enzymatic fuel cell (EFC) that is able to produce NH3 from H2 and N2, while simultaneously producing an electrical current. To demonstrate this, 60 mC of charge was passed across H2/N2 EFCs, which resulted in the formation of 286 nmol NH3 mg-1 MoFe protein, corresponding to a Faradaic efficiency of 26.4 %. Importantly, this EFC produces NH3 and electrical energy in a carbon-neutral manner. A protective Fell protein, which can reversibly lock nitrogenase into a multicomponent protective complex upon exposure to low concentrations of 02, was incorporated into a nitrogenase bioelectrosynthetic cell whereby NH3 was produced using air as a substrate. This marks a significant step forward in overcoming the crippling limitation of nitrogenase's sensitivity toward O2. Finally, this talk will discuss Bioelectrochemical strategies for eliminating the ATP-dependence of this reaction.

Shelley D. Minteer

Prof. Shelley Minteer is the Dale and Susan Poulter Endowed Chair of Biological Chemistry and Associate Chair of Chemistry at the University of Utah. Prof. Minteer is also the director of the NSF Center for Synthetic Organic Electrochemistry. Prof. Minteer’s research focuses on improving the abiotic-biotic interface between biocatalysts and electrode surfaces for enhanced bioelectrocatalysis. These biocatalysts include microbial cells, organelles, redox proteins, and oxidoreductase enzymes. The Minteer group utilizes a variety of electroanalytical techniques (linear polarization, cyclic voltammetry, differential pulse voltammetry, differential pulse amperometry), as well as a variety of biological and spectroscopic techniques to accomplish these goals.

Professor Shelley D. Minteer

Professor Shelley D. Minteer
Department of Chemistry
College of Science
University of Utah

Abstract

"Catalytic Cascades for Energy Conversion Devices"

Over the last decade, there have been major developments in materials engineering for bioelectrodes (i.e. bioanodes and biocathodes in biofuel cells), including the engineering of nanomaterials and nanostructured electrodes for increasing electrochemically active surface areas and increasing the rate of direct electron transfer. However, materials engineering does not solve all problems in bioelectrocatalysis. This talk will detail the use of bioengineering to improve the performance (current density, power density and/or efficiency) of bioelectrodes. Enzymes have evolved to function in a particular environment in a living cell, but operating at the biointerface in a bioelectrode is a very different microenvironment. This talk will include a discussion of the use of recombinant enzymes that can be tailored to the bioelectrode application and their microenvironment. The talk will also discuss the use of these recombinant enzymes in the formation of minimal catalytic cascades for deep or complete oxidation of biofuels and substrates/ analytes. This presentation will also discuss the use of bioscaffolding for improving the performance of these catalytic cascades through controlling the proximity of sequential catalytic active sites.

Shelley D. Minteer

Professor Shelley D. Minteer

Professor Shelley D. Minteer
Department of Chemistry
College of Science
University of Utah

Abstract

"Bioelectrocatalysis for Organic Synthesis"

Over the last decade, electrosynthesis has seen a re-emergence in the field of organic synthesis due to a focus on safety and sustainability. Many organic synthesis reactions require stoichiometric amounts of oxidizing or reducing agents, which frequently have safety and sustainability issues, whereas electrosynthesis utilizes electrical current instead of chemical reagents. However, electrochemistry has been plagued with selectivity issues. This talk will discuss combining biocatalysis with electrochemistry for synthetic organic chemistry applications. The talk will discuss a variety of different strategies for improving the feasibility of bioelectrocatalysis for this application including biphasic electrochemical devices and cofactor regeneration. Finally, the talk will discuss chemical transformations ranging from C-H functionalization to chiral synthesis.

Shelley D. Minteer

Professor Justin DuBois

Professor Justin DuBois
School of Humanities & Sciences
Stanford University

Abstract

Making Functional Groups from C–H Bonds

The evolution of selective methods for C-H bond functionalization has shaped the modern practice of synthetic chemistry. For more than two decades, our lab has invested in the development of C-H oxidation reaction technologies that enable facile production of amines and amine derivatives from readily available starting materials. This lecture will present a brief historic overview of our research in this area and detail recent efforts to advance a state-of-the-art method for single-step C-H amination of complex molecules.

Professor Justin DuBois

Justin Du Bois was born August 23, 1969 in Los Angeles, California. He received his B.S. degree from the University of California, Berkeley in 1992, where he conducted undergraduate research with Professor Ken Raymond. In 1997 he earned his Ph. D. from the California Institute of Technology under the direction of Professor Erick Carreira. Following a two year NIH postdoctoral position with Professor Stephen Lippard at MIT, he joined the faculty at Stanford University as an assistant professor. In 2005, he was promoted to the associate level. In addition, Justin is faculty by courtesy in the Dept. of Chemical & Systems Biology at Stanford University, a founding member of the NSF Center for Selective C-H Functionalization, an executive committee member of the Stanford Institute for Chemical Biology, and the founder of the Center for Molecular Analysis and Design at Stanford University.

Professor Justin DuBois

Professor Justin DuBois
School of Humanities & Sciences
Stanford University

Abstract

Toxins as Targets for Chemical Synthesis and Discovery Biology

We are compelled by both the intricate molecular architectures and unique biological activity of a class of natural products known as bis-guanidinium toxins. These compounds act as selective inhibitors of voltage-gated sodium channels, large membrane protein complexes responsible for initiating and propagating electrical impulses in neuronal and cardiac cells. Our group has endeavored to devise efficient and flexible multi-step syntheses of these targets that can enable structure-activity studies and the development of high-precision tool compounds for manipulating sodium channel function. This lecture will detail such efforts and present recent work to understand how certain organisms evolved resistance to these acute poisons.

Professor Justin DuBois

Professor Justin DuBois
School of Humanities & Sciences
Stanford University

Abstract

Using Chemistry to Study Voltage-Gated Ion Channels

We are interested in understanding the role of sodium channels in nociception, work that may ultimately inform the development of new analgesic medicines. Our studies rely on molecular biology and electrophysiology to measure ionic currents in cells and capitalize on the availability of potent neurotoxins and derivatives thereof as selective reagents for manipulating channel function. This lecture will focus specifically on efforts to 'map' toxin-channel receptor sites and to design tool compounds that target and enable regulation of select channel subtypes.

Professor Justin DuBois

Professor Jahan Dawlaty

Professor Jahan Dawlaty
Department of Chemistry
University of Southern California

Abstract

"Revealing Complexities of the Electrode-Electrolyte Interface Using Vibrational Spectroscopy"

Controlling the chemical microenvironments at an interface is a central goal of surface chemistry and more specifically electrochemistry. The interface is known to behave quite differently from the bulk, both in its physical and chemical properties. A quantity of central importance in electrochemistry is the interfacial electric field, which is closely related to the double layer structure. The interfacial fields act as polarizing agents for catalyzing reactions and are important for selectivity, ion transport, and lowering charge transfer barriers. We use vibrational Stark shift spectroscopy to measure such fields in an array of complex environments including the interface between electrodes and solvents, surfactants, and ionic liquids. Using these vibrational probes, we answer questions such as: How is the dielectric solvation different at the interface? How is proton transfer affected by the solvent and the interfacial field? How can one tailor and engineer the interfacial fields for specific purposes? These are some of the fundamental questions that we will focus on answering and will highlight their relevance to modern challenges in electrochemistry.

Jahan Dawlaty

Jahan Dawlaty is an experimental physical chemist at the University of Southern California. Dr. Dawlaty received his undergraduate degree in chemistry from Concordia College in Minnesota and his Ph.D. in physical chemistry from Cornell University, where he worked at the interface of materials and spectroscopy both in the chemistry and electrical engineering departments with John Marohn and Farhan Rana. He joined UC Berkeley for his postdoctoral work with Graham Fleming. He started his independent career at the University of Southern California in 2012. He applies spectroscopic methods to fundamental molecular problems of relevance to catalysis. He has worked on measuring and modeling interfacial electric fields at electrochemical interfaces, excited state proton dynamics in molecular and material systems, and lattice dynamics in hydrogen bonded solids. He has received the NSF CAREER award, the AFOSR Young Investigator Award, the Cottrell Scholar Award, and the Journal of Physical Chemistry Lectureship Award among others. He has served as a guest member in the Annual Reviews of Physical Chemistry editorial meeting, and a guest editor for the Journal of Chemical Physics. He is interested in chemical education, with special emphasis on modernizing the pedagogy of chemical thermodynamics and kinetics.

Professor Jonathan Owen

Etter Memorial Lectureship

Professor Jonathan Owen

Department of Chemistry

Columbia University

Abstract

"The mechanisms governing colloidal Quantum Dot size and size distributions"

The size and shape homogeneity of modern colloidal semiconductorbnanocrystals or ‘Quantum Dots’ (QDs) result in their characteristically narrow photoluminescence linewidths. This narrow and tunable luminescence is driving the cutting edge in display technologies and can increase the luminous efficacy of commercially viable solid state lighting devices by > 25%. The spectral tunability and linewidth are due to the extraordinary size and size distributions achievable using modern colloidal synthesis. Despite many years of research in that regard, however, the optimization of QD luminescence remains an empirical process of trial and error. Accurate mechanistic pictures that can be used to design improved syntheses are lacking. To address this discrepancy our group studies the kinetics of colloidal nanocrystal nucleation and growth using in situ x-ray scattering and optical absorption methods. We have demonstrated the surprising finding that size and size distributions are primarily governed by the reactivity of nanocrystals toward monomer attachment rather than the conventional
"burst of nucleation" and diffusion limited growth hypothesis that has dominated synthetic design for the last 40 years.

Jonathan Owen

Jonathan Owen obtained a BS from the University of Wisconsin-Madison in 2000, a PhD from Caltech in 2005 and was a postdoctoral researcher at UC Berkeley until 2009. In 2009 he joined the faculty at Columbia University where he is currently Associate Professor of Chemistry. His group studies the coordination chemistry of colloidal semiconductor nanocrystals, as well as the mechanism of nanocrystal nucleation and growth. He has received several awards for his work including: The 3M Nontenured Faculty Award (2010); The Early Career Award from the Department of Energy (2011); The DuPont Young Faculty Award (2011); A Career Award from the National Science Foundation (2012); The Award in Pure Chemistry from the American Chemical Society (2016)