UCLA

Chem 278: Prof. Hailiang Wang
2020-10-14 16:30 (America/Los_Angeles)
“Heterogenized Molecular Catalyst Materials for Electrochemical Carbon Dioxide Conversion”
Abstract: Sustainable energy utilization and carbon emission reduction are critical challenges for the world. Solving these challenges requires precise control of many important chemical reactions with sluggish kinetics and myriad possible reaction pathways and associated products. There is a critical need for selective, active, durable and low-cost catalysts. This talk presents our research efforts aimed at bridging the gap between homogenous catalysis and heterogeneous catalysis to realize materials with new or improved electrocatalytic properties for the carbon dioxide reduction reactions. We have developed heterogenized metal-complex electrocatalysts allowing for mechanism-based optimization at the molecular level. We have discovered interesting phenomena including ligand-mediated electron transfer, beyond two-electron reduction via a domino process, and reversible restructuring under reaction conditions. We have also designed reactors to enhance electrochemical performance, study surface/interface phenomena, and perform thermodynamically challenging reactions.

Chem 218 Student Exit Seminar: Chuanzhen Zhao
2020-10-15 12:00
“Implantable and Wearable Bioelectronics: Eavesdropping on Chemical Signaling”
Advisors: Prof. Paul Weiss and Prof. Anne Andrews

Exploring Fluoro: Five years of the Sletten Group
2020-10-15 14:00
Abstract: The Sletten Group works in three different areas which all encompass “fluoro” to control and detect chemistries in living systems. These include 1) fluorous nanoemulsions as versatile scaffolds for drug delivery, 2) fluoroarenes as chemical reporter groups for non-covalent bioorthogonal chemistry, and 3) fluorophores for the shortwave infrared region of the electromagnetic spectrum for real-time multiplexed imaging. This talk will briefly highlight recent advances in fluorous nanoemulsions and fluoroarene chemical reporters before focusing on the development of bright fluorophore for the near and shortwave infrared regions of the electromagnetic spectrum, which enable high-resolution, real-time, multicolor imaging in mice.

Chem 268: David Eisenberg
2020-10-16 15:30

Chem 228: Prof. Jay Foley
2020-10-19 16:00
“Refractions in the plastic pulse: Controlling light and heat with hybrid nanostructures”

NSF Center for Integrated Catalysis Webinar Series
2020-10-20 13:00
The NSF Center for Integrated Catalysis is delighted to announce that it will be hosting a monthly webinar series. The second day of this series will be held on Tuesday, October 20th at 1:00 PM. We are pleased to invite all students, postdocs, faculty, and staff.

Midstream Presentation: Zachary Edward Hemminger
2020-10-20 16:00
Zachary Edward Hemminger
Wollman Group
“Scaling up Spatial Transcriptomics using dredFISH”

Chem 278: Dr. Julia Stauber
2020-10-21 16:30
“An Organometallic Approach to the Assembly of Atomically Precise Nanomaterials”
Abstract: There is significant interest in the ability to build atomically precise nanocluster molecules with complex three-dimensional structures resembling the intricate molecular architectures found in natural systems. We have developed a platform to access a class of robust, well-defined, three-dimensional hybrid nanomolecules with high tunability using air-stable, organometallic gold(III) dodecaborate clusters. These clusters serve as templates for further diversification with a wide array of thiol-containing substrates including alkanes, arenes, alcohols, amines, peptides, and sugar molecules. The conjugation reactions proceed rapidly with high chemoselectivity to produce a library of nanocluster assemblies that exhibit high structural stability under biologically relevant conditions due to their full covalency. Glycosylated nanomolecules displayed increased binding affinity to target proteins when compared with the binding of the free sugar molecules, showcasing how this strategy allows for the generation of precise multivalency for molecular recognition.

Chem 218 Student Exit Seminar: Borna Zandkarimi
2020-10-22 12:00
“Rewriting the Rules of Heterogeneous Catalysis for Supported Subnanometer Metal Cluster Catalysts”
Advisor: Professor Anastassia Alexandrova

Boehringer-Ingelheim Seminar: New Reactions from the Process Development of a BACE-1 Inhibitor
2020-10-22 14:00
Abstract: The process development of a BACE-1 inhibitor is described. In order to address major safety and scalability limitations in the Discovery synthesis, two novel reactions were developed. The discovery, development, and scale-up of these reactions will be described. Several additional methodologies which emerged during process research will also be presented.

Boehringer-Ingelheim Seminar: Selective Catalytic Functionalization of C-H Bonds
2020-10-22 16:00
Abstract:The selective introduction of functional groups at the positions of typically unreactive C-H bonds has been a longstanding challenge in catalysis. To this end, our group has developed practical methods for the catalytic functionalization of C-H bonds with main group reagents.(1-4) These studies have led us to a general strategy of installing a single transient functional group to form a range of products from one C-H bond functionalization reaction. This research has led us to seek next-generation catalysts for the functionalization of C-H in complex molecules, new classes of reactions for functionalization of these bonds, and new strategies, such as the construction of artificial metallenzymes to control the site at which such reactions occur.
This lecture will present recent directions of research in our group toward discovering selective reactions of both small and complex molecules with large and small catalysts. The design and selection, as well as the intimate mechanism, of catalysts and catalytic reactions for selective functionalization processeswill be presented.

Chem 268: Guillaume Chanfreau and Cathy Clarke
2020-10-23 15:30

Chem 228: Prof. Christine Isborn
2020-10-26 16:00
“Simulating linear and nonlinear optical spectra for chromophores in the condensed phase”

Teaching opportunities after grad school in primarily undergraduate institutions
2020-10-27 12:00
Panelist:
Prof. Jennifer Casey
Dept. of Chemistry and Biochemistry
University of California, Los Angeles
&
Prof. Jay Foley
Dept. of Chemistry
William Paterson University
&
Prof. Jacob Olshansky
Dept. of Chemistry
Amherst College

Midstream Presentation: Evan Maltz
2020-10-27 16:00
Evan Maltz
Wollman Group
“Phenotypic Consequences of Gene Expression Variability”

Chem 278: Prof. Yuzhang Li
2020-10-28 16:30
“Imagining, Building, and Understanding the Next Generation Battery”
Abstract: Electrochemical energy conversion and storage is critical for vehicle electrification and storing clean energy from intermittent sources (i.e. wind, solar) on the grid. Towards these goals, my group pursues the broad spectrum of stages necessary for technological innovation: (1) developing new tools to discover fundamental understandings, (2) designing and synthesizing unique materials to address intrinsic failure modes, and (3) patenting the technology for real world applications. In this talk, I will first discuss a graphene cage design strategy to stabilize the silicon anode for high-energy Li-ion battery chemistries. Next, I will introduce the powerful cryogenic-electron microscopy technique that we have pioneered for atomic-resolution studies on sensitive and reactive battery materials. Using this technique, new discoveries at the nanoscale are correlated with macroscopic battery performance, further expanding our understanding of battery failure mechanisms and providing insight for future materials design.

Some Simple Concepts and Their Consequences in Covalent Mechanochemistry
2020-10-29 16:00
Abstract:The potential to use mechanochemistry, either in isolated polymers or in polymeric materials, to trigger a programmed, desirable covalent molecular response was first revealed only a decade or so ago. Since that time, covalent polymer mechanochemistry has undergone a renaissance in which it has been extensively explored by a number of research groups and for a variety of purposes including (but not limited to) biasing and probing reaction pathways, trapping transition states and intermediates, catalysis, release of small molecules and protons, stress reporting, stress strengthening, and soft devices. Increasingly creative mechanophore designs and new properties continue to emerge at an ever-accelerating pace.
The precision with which mechanophores can be predictively designed has increased as quantitative experimental and computational studies have provided insights into structure-activity relationships. Additional benefits will be realized as these quantitative relationships are mapped onto existing, intuitive physical organic frameworks. This talk will present quantitative studies of mechanochemical reactions and their mechanisms, highlighting opportunities for classical physical organic principles and the new chemistry empowered by mechanochemistry to enrich each other.

Chem 268: Margot Quinlan and Todd Yeates
2020-10-30 15:30

Midstream Presentation: Matthew Paul Agdanowski and Janine Fu
2020-11-03 16:00
Matthew Paul Agdanowski
Yeates Group
“The Development of an Imaging Scaffold for RNA Structural Analysis via Cryo-EM”
and
Janine Fu
Loo Group
“Targeting acyl-lysine modifications in the Rhodopseudomonas palustris proteome via diagnostic ions”

Chem 278: Dr. Jiao Deng
2020-11-04 16:30
“Ambient Electrochemical Functionalization of Methane with d0 early transition metal-oxo species”
Abstract: The abundant yet widely distributed methane (CH4) resources demands an efficient conversion of CH4 into liquid chemicals at ambient conditions with minimal infrastructure support. In the existing approaches of metal-catalyzed reactions and catalysis based on free-radical chain mechanism, the reactivities of the former metal species seem insufficient to achieve ambient activation of CH4 and the latter radical species are uneasy to be sustainably replenished. This talk will show that a controlled electrochemical generation of oxygen radicals on the ligands binding to d0 early transition metal centers is capable to address the above-mentioned challenge, given the electrochemical redox process provides a sustained method of replenishing radical species at ambient conditions without sacrificing their high reactivities. This proposed mechanism represents a new scalable approach that helps mitigate the flaring or direct emission of natural gas at remote locations.

Combining Theory and Experiment to Develop Selective Three-Component Fe-Catalyzed Radical Cascade/Cross-Couplings
2020-11-05 16:00
Abstract: Despite advances in high-throughput screening methods leading to a surge in the discovery of catalytic reactions, our knowledge of the molecular-level interactions in the rate- and selectivity-determining steps of catalytic reactions, especially those involving highly unstable and reactive open-shell intermediates, is rudimentary. These knowledge gaps prevent control, suppression or enhancement, of competing reaction channels that can drive development of unprecedented catalytic reactions. In this talk, I will focus on our use of high-level quantum mechanical calculations, rigorously calibrated against experimental data, to interrogate the mechanisms and to guide the development of new catalysts and reagents for currently sluggish or unselective reactions. In particular, I will focus on our use of combined experimental and computational tools to understand and develop new (asymmetric) three-component iron-catalyzed radical cascade/cross-coupling reactions.

Chem 268: Rob Clubb and Carla Koehler
2020-11-06 15:30

Chem 228: Prof. Brenda Rubenstein
2020-11-09 16:00
“Computing with Molecules: Storage and Classical Computation Using Small Molecules and Their Reaction Networks”

Midstream Presentation: Kyle Meador and Natalie Schibrowsky
2020-11-10 16:00
Kyle Meador
Yeates Group
“Design and Assembly of 3D Protein Crystals”
and
Natalie Schibrowsky
Rodriguez Group
“Biochemical and structural analysis of in vivo Cry11Bs crystalline inclusions”

Chem 218: Prof. Vanessa Wood
2020-11-12 12:00
“Structure and Surfaces at the Nanoscale”
Abstract: Liquid-phase and wet-processing techniques offer tremendous opportunities for low-cost manufacturing and enable the concept of large-scale nanotechnology. Today, these approaches have facilitated the massive upscaling of lithium ion battery technology and promise to play a future role in a wide variety of electronic, photonic, and electrochemical systems. Materials and devices made from these approaches often exhibit hierarchical structures and have complex interfaces that are key to their performance. In this talk, I will describe the importance of understanding structure-performance relationships to achieve the full potential of solution processed systems.
To characterize structure and structural dynamics in these complex, multiscale materials, we leverage a wide variety of techniques including electron microscopies, x-ray imaging, diffraction, and scattering, neutron scattering and imaging, and muon spectroscopy. Combining information from characterization with simulation and experiment, we use our findings to understand the origins of performance limitations and develop design guidelines to systematically improve material and devices.
My talk will present several examples, including the role of nanocrystal surfaces in determining their emission linewidths, carrier cooling, and charge transport, and the role of nanoscale structure and surface chemistry on electrolyte infilling in lithium ion batteries and lithium transport. I will address the experimental and computational challenges associated with studying these systems and emphasize ways machine learning techniques and systematic leveraging of size control the nanoscale can be used to overcome these challenges.

Development of New Chemical Platforms for Polymer Synthesis
2020-11-12 16:00
Abstract: Synthetic polymers have permeated nearly every facet of modern life. From the ubiquity of polyolefins to recent advancements in 3-D printing, organic materials continue to shape the world around us. While tremendous accomplishments have been made with relatively few polymer families, the future requires the development of materials with increased control over structure to produce systems that can respond to programmed inputs, as well as the exploration of entirely new polymer compositions. Our group takes a chemistry-focused approach to address these challenges through the strategic application of organic methodologies to design new monomer families and reagents for precision polymer synthesis. This presentation will specifically highlight (1) the utility of enyne chemistry to impart degradability and expedite functionalization of metathesis-derived materials and (2) the development of a new class of living polymerization that is enabled by the unusual reactivity profiles of twisted amide molecules.

Chem 268: Juli Feigon
2020-11-13 15:30

Chem 228: Alex Wiltschko, Ph.D.
2020-11-16 16:00
“Machine learning for scent”

NSF Center for Integrated Catalysis Webinar Series
2020-11-17 13:00
The NSF Center for Integrated Catalysis is delighted to announce that it will be hosting a monthly webinar series. The second day of this series will be held on Tuesday, November 17th at 1:00 PM. We are pleased to invite all students, postdocs, faculty, and staff.

Midstream Presentation: Carter Lantz
2020-11-17 16:00
Carter Lantz
Loo Group
“Mass Spectrometry Analysis of Amyloid Proteins and their Interaction with the Aggregation Inhibiting Compound CLR01”
