UCLA

Chem 268 - Margot Quinlan
2021-10-01 15:30 (America/Los_Angeles)

Chem 228: Prof. Bin Zhang
2021-10-04 16:00
“Phase Separation in Genome Organization”

Chem 278: Prof. Rong Tong
2021-10-06 16:00
“Stereoselective Ring-Opening Polymerization to Synthesize Functionalized Polyesters”
Abstract: Polymers are all around us – from our daily use to biopolymers and therapeutics. Inspired by recent advances in chemistry, molecular pharmaceutics and biotechnology, on-demand and triggerable “smart” systems offers opportunities from precisely synthesis of polymers to delivering drugs in dose-, spatial- and temporal- controlled manners. This seminar will mainly discuss our ongoing efforts in controlling synthesis of degradable polyesters by external stimuli such as light and electricity. I will focus on the chemical synthesis of stereoregular, high-molecular-weight polyesters with various pendant functional groups. Our synthetic strategies allow for the preparation of various syndiotactic and stereoblock copolymers from racemic monomers. The mechanistic exploration of such triggerable polymerizations inspired us to develop a scalable synthetic method to prepare stereosequence-controlled copolymers with improved toughness and shape memory properties.

Chem 268 - David Eisenberg and Carla Koehler
2021-10-08 15:30

CANCELLED - Chem 228: Prof. Mark Wilson
2021-10-11 16:00
“TBA”

CIC Careers in Green Chemistry Seminar Series
2021-10-14 13:00
The Center for Integrated Catalysis is hosting a new seminar series called the “Careers in Green Chemistry.” With these webinars, we aim to bring speakers from a wide variety of careers, linked through green chemistry, to come talk about their current job as well as the career path that led them to that position. We are pleased to invite all students, postdocs, and faculty.

Chem 228: Prof. Lan Cheng
2021-10-18 16:00
“Relativity throughout the periodic table: scalar relativity, spin-orbit, and spin-vibronic interactions”

Chem 278: Dr. Samantha Yruegas
2021-10-20 16:00
“Hydrocarbon Upgrading with Boron and Earth-Abundant Metals”
Abstract: The products of fossil fuels, specifically hydrocarbons, are ubiquitous in our daily lives, making up everyday objects from the plastic container that holds your lunch to the fuel that enables us to interconnect the globe. These products are at the core of our modern society, however the development of new boron-carbon and carbon-carbon bonds in these motifs is fundamentally challenging. The first part of my presentation will explore methodology for generating boron-containing aromatics. With both limited routes and the restricted amount of commericially available reagents, significant progress is necessary to expand the library of known boracycles. Boroles, highly reactive four π-electron heterocycles, are a family of compounds with the potential to serve to as effective reagents to produce unique boracyclic architectures with extended conjugation. The second part of my presentation will focus on upgrading di- and tri-substituted olefins into higher molecular weight products for lubricant production. We found that nickel catalysts with electron-deficient ligands result in a highly electrophilic nickel center that enables efficient olefin dimerization. In the same area, efforts towards sustainable catalysts for the dimerization of commodity dienes to higher value products using surface organometallic chemistry will be described. We have developed a series of silica-supported α-diiimine and pyridine(imine) iron precatalysts that maintain the activity and selectivity of their molecular analogues and can be recycled over multiple uses with minimal erosion in performance.

Understanding and Exploiting Redox in Conjugated Polymers: From Improved Polymer Conductivity, to Photoinduced Charge Transfer, to Next Generation Polymer Binders for Lithium Ion Batteries
2021-10-21 16:00
Semiconducting polymer have the potential to be use in an exciting array of devices, but their intrinsic conductivity is
low due to their large band gaps. Chemically doping conjugated polymers is an effective way to increase conductivity
and involves introducing treating the polymer with a strong electron acceptor or donor that can undergo charge
transfer (i.e. redox) with the polymer. The charge transfer reaction creates delocalized electrical carriers on the
polymer chain (usually positive polarons a.k.a. holes) while the dopant molecules remain in the film and serves as a
counterion. Unfortunately, strong electrostatic attraction between counter-ions and most dopants will localize the
polarons and reduce their mobility. Here, we first explore a new family dopants based on substituted icosahedral
dodecaborane (DDB) clusters that provide a unique combination of high oxidizing potential and large size. By tuning
the cluster redox potential, we can understand the role of energetics in polymer conductivity, and the large size helps
reduce electrostatic interactions, resulting in polymer films with highly delocalized polarons and thus high
conductivity. A combination of molecular substituent tuning, electronic spectroscopy, and X-ray scattering are used
to under chemical-structure-function relationships. We next consider applications for doped conjugated polymers, in
this case focusing on electrochemically doped polymers and their application as binders in lithium ion batteries.
Battery binders are usually chosen only for chemical inertness, but the use of conjugated polymer binder can
increase overall conductivity and thus rate capabilities. By tuning the polymer redox to match the electrode material,
highly conductive doped binders can be produced, and by tuning the side chains, ionic conductivity can be mixed with
electronic conductivity, both of which are needed for fast battery operation. Finally, we end by examining self-
assembling amphiphilic conjugated polymers, and consider both photo-doping and chemical doping of these unique
water soluble polymers.

Chem 268 - Juli Feigon
2021-10-22 15:30

Chem 228: Dr. Oliver Bruns
2021-10-25 11:00
“Biomedical Imaging beyond the Visible – Fluorescence Imaging in the Shortwave-Infrared”

Chem 278: Dr. Allegra Aron
2021-10-27 16:00
“Finding Metal-Binding Molecules: Native Electrospray-based Metabolomics”
Abstract: Metals are required for life, and microbes have evolved a number of small molecules to compete for, acquire, and utilize metals. Metal-binding compounds are important in a number of fields – these compounds can alter the growth of the microbial communities, enhance plant yields, control harmful pathogens, deliver metals in diseases of deficiencies, or can be used for bioremediation. Systematic methods for the discovery of metal-small molecule complexes from biological samples remain limited. In this talk, I describe a native electrospray ionization mass spectrometry-based method, in which post-column metal-infusion and pH adjustment is combined with ion identity molecular networking, a rule-based informatics workflow performed using the Global Natural Products Social Molecular Networking (GNPS) platform. This method has been used to identify metal-binding molecules in complex samples based on defined mass (m/z) offsets of ion features with the same chromatographic profiles. As this native metal metabolomics approach can be easily implemented on any liquid chromatography-based mass spectrometer, this method has the potential to become a key strategy for elucidating and understanding the role of metal-binding molecules in biology.

Boehringer-Ingelheim Seminar: Catalysis Innovation in Chemical Development: Effective Applications to BI Projects
2021-10-28 13:30
Abstract: Catalysis has become an indispensable, frequently applied tool for devising convergent, innovative, asymmetric and economical synthesis of APIs in the pharmaceutical industry. BI-Catalysis group, established in Ridgefield in 2008, contributed to the development of novel processes in many BI projects at all stages of research and development through close collaboration with all BI sites. In addition to the screening function of commercially available ligands, an innovative family of tunable BI-ligands was developed and emerged as privileged
ligands for applications to asymmetric catalysis. Screening capacity of catalytic reactions and selected examples from BI projects will be presented.

Boehringer-Ingelheim Seminar: New Developments in Electrochemical Synthesis
2021-10-28 16:00
Abstract: Owing to its many distinct characteristics, electrochemistry represents an attractive approach to discovering new reactions and meeting the prevailing trends in organic synthesis. In particular, electrocatalysis—a process that integrates electrochemistry and small-molecule catalysis—has the potential to substantially improve the scope of synthetic electrochemistry and provide a wide range of useful transformations. Despite its attractive attributes and extensive applications in energy-related fields, electrocatalysis has been used only sparingly in synthetic organic chemistry. Thus, there exists a clear impetus for inventing new catalytic strategies to improve the scope of synthetic electrochemistry and provide new platforms for reaction discovery and synthetic innovations. Toward this end, we developed a new catalytic approach that combines electrochemistry and redox-metal catalysis for the functionalization of alkenes to access a diverse array of vicinally functionalized structures. This talk details our design principle underpinning the development of electrocatalytic alkene difunctionalization and hydrofunctionalization with a particular emphasis on enantioselective electrocatalysis. In addition, our recent forays into electroreductive chemistry will be discussed, in which we harness the power of deeply reducing potentials to achieve previous challenging organic transformations.

Chem 268 - Guillaume Chanfreau and Joe Loo
2021-10-29 15:30

Chem 228: Prof. Aaron S. Rury
2021-11-01 16:00
“Assessing Hybrid Molecular Platforms for Next Generation Quantum Technologies “

Chem 278: Prof. Jonathan Barnes
2021-11-03 16:00
“Supramolecular Polymers and Crosslinkers to Control Structure, Properties, and Performance in Polymer Networks and Nanomaterials”

Chem 268 - Jorge Torres and Todd Yeates
2021-11-05 15:30

Chem 228: Prof. Nancy Makri
2021-11-08 16:00
“Real-Time Path Integral Methods for Electron-Vibration Dynamics of Large Molecular Aggregates”

Bristol Myers Squibb Seminar:TBA
2021-11-09 13:00, 2021-11-09 16:00

Chem 278: Dr. Rebecca Sherbo
2021-11-10 16:00
“Creating Sustainable Chemicals and Foods from Water, Air and Electricity”

Chem 268 - Rob Clubb
2021-11-12 15:30

Chem 228: Prof. Arthur G. Suits
2021-11-15 16:00
“Quantum Resonances in Molecular Systems at High Energy: Cold Collisions of Hot Molecules and Quantum Roaming Dynamics”

Chem 278: Prof. Lisa Olshansky
2021-11-17 16:00
“Conformational Control over Metal ion Reactivity”
Abstract: Metalloenzymes facilitate some of the most thermodynamically and kinetically challenging chemical transformation known, and in contrast to our industrial methods, they do so under extremely mild conditions. What are they doing that we are not? One aspect of metalloenzyme reactivity that is ubiquitous in nature yet often overlooked in the development of synthetic systems is the role that conformational gating steps play in mediating metallocofactor reactivity. Inspired by these enzymes, research in the Olshansky lab is focused on testing the hypothesis that conformational control represents an efficient means with which to control metal ion reactivity, promote electron and proton transfer steps, and mediate the interconversion of different forms of energy. However, naturally occurring metalloenzymes are extremely complex and studying them directly, it is often impossible to disentangle the interplay between conformation and reactivity, so instead, the Olshansky lab prepares and studies simplified model systems encapsulating this interplay. Through the construction of switchable artificial metalloproteins and coordination complexes, we are working to dissect the kinetic and thermodynamic consequences of conformational control, and we are preparing an array of switchable systems for applications in solar energy conversion, catalysis, and biomedicine.

Chem 218: Student Exit Seminar - Hannah Friedman
2021-11-18 12:00

The 2021 John D. Roberts Lecture - Physical Organic Chemistry on the Brain: Understanding the Nicotine Receptor
2021-11-18 16:00
The remarkable complexity of the human brain is evident at all levels, from anatomical to cellular to molecular. The central molecules of synaptic signaling comprise a diverse array of integral membrane proteins that are resistant to most approaches to high resolution structural characterization. As such, chemistry provides the most powerful tool for unraveling the structures and functions of the molecules of memory, thought, and sensory perception; of Alzheimer’s, Parkinson’s, and schizophrenia. Using the mindset and methodologies of physical organic chemistry, and combining them with molecular biology, electrophysiology, and computer modelling we have probed these complex membrane proteins with a precision and subtlety normally associated with small molecule studies. We have uncovered key interactions that allow agonists to bind, and that distinguish binding of natural ligands vs. substances of abuse, including a key cation-π interaction that enables tight binding of nicotine to specific regions of the brain.

Chem 268 - Steve Clarke and Roy Wollman
2021-11-19 15:30

Chem 228: Samanvaya Srivastava
2021-11-22 16:00
“Polyelectrolyte Complex-Based Robust and Tough Wet Adhesives”

Chem 278: Dr. Miguel Gonzalez
2021-12-01 16:00
“Controlling Chemistry through Confinement”
