UCLA

Dickerson Biochemistry Seminar - James Link
2024-03-08 15:30 - 16:30 (America/Los_Angeles) | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Houk-Jung Organic Colloquium 247: Prof. Peter Schultz
2024-03-07 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Alexander Balandin
2024-03-04 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Seminar - Gulcin Pekkurnaz
2024-03-01 15:30 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Houk-Jung Organic Colloquium 247: Prof. Frank Glorius
2024-02-29 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 218 Student Exit Seminar: Zerina Mehmedović
2024-02-29 12:00 - 13:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series - Prof. Chong Liu
2024-02-28 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Flyer: Prof. Chong Liu Flyer
Title: Materials Design for Critical Element Separation
Abstract: The development of renewable energy technologies and next-generation quantum and optoelectronic devices relies on the secured supply of critical elements. Traditional mining and separation methods are disruptive to the environment, consume large quantities of harsh chemicals, and are unable to access dilute resources due to low elemental selectivity. Therefore, the invention of new separation methods and the fundamental understanding of the separation processes are crucial to realizing sustainable mining while broadening minable resources. In this talk, I will first introduce a platform method, electrochemical intercalation, for selective ion separation. I will present several strategies to promote the separation of lithium and lanthanides based on the understanding of complex host behavior upon co-intercalation of competing ions. In the second part, I will introduce our efforts in developing methods to construct (sub)nanometer solid ionic channels and probe the water and ion transport behavior in confinement.

Physical Chemistry Seminar 228: Matthew Sheldon
2024-02-26 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Prof. Matthew Sheldon Flyer
Talk Title: Plasmonic Platforms for Polaritonic Chemistry
Abstract: We are developing experimental platforms to probe vibrational strong coupling (VSC) between molecules and resonant infrared (IR) nanophotonic architectures, in order to understand how this coupling can fundamentally control chemical reactivity, as well as enable new classes of light-matter interaction. This method of altering the potential energy surface of a chemical process via coherent, electromagnetic perturbation of vibrating bonds has also been termed “polaritonic chemistry”. We employ a combined experimental strategy leveraging expertise in (1) the design of IR “metasurfaces” composed of plasmonic metal substrates that provide tailorable VSC to molecules within their optical near-field; and (2) multiple continuous wave (CW) spectroscopic techniques that enable analysis of several non-equilibrium, dynamic electronic effects in the metal substrate. Taken together, these tools allow studies into new regimes of spectral bandwidth (e.g. simultaneous multi-mode coupling), coupling strength, and time domains (e.g. studies of long lived and steady-state phenomena) that have been inaccessible using conventional optical cavities and time-resolved spectroscopies performed to date. Vibrational strong coupling is fundamentally interesting because it is a coherent interaction between radiation and molecular motion. The direct manipulation of a molecular process using externally controlled forcefields to obtain a desired outcome, i.e. “coherent control” or “quantum control”, has been a long-standing goal connected to the central aims of chemical science. Thus, this presentation will discuss the limits of chemical analysis and chemical control at interfaces leveraging a framework based on coherent interactions between controllable features of the engineered surface geometry and the molecular systems under study.

Dickerson Biochemistry Seminar - Shashank Shekhar
2024-02-23 15:30 - 16:30

Houk-Jung Organic Colloquium 247: Dr. Eugene Kwan
2024-02-22 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Special Inorganic Chemistry Seminar - Dr. Alec Follmer
2024-02-22 14:00 - 15:30 | Young Hall 2033
Flyer: Dr. Alec Follmer Flyer
Title: Controlling C-H Bond Activation: Structural and Dynamic Regulation of Reactive Intermediates in Cytochrome P450 Catalysis
Abstract: From metabolism and detoxification to the biosynthesis of steroids and natural products, cytochromes P450 (P450s) are heme-containing enzymes that utilize O2 for the activation of C–H bonds and serve ubiquitous roles in nearly all biological systems. Their enzymatic activity, however, requires the formation of highly reactive intermediates within their active sites that can lead to the generation of potentially harmful reactive oxygen species and/or deleterious effects to the protein itself. Accordingly, many P450s have evolved structural and dynamic mechanisms to regulate their catalytic activity that involve complex rearrangements of their protein scaffolds. Despite a general understanding and appreciation of this regulation, the specific mechanisms and the extent to which they can be generalized remains unclear. Here, I will highlight several new key insights into how the reactivity of P450s is the controlled by allosteric interactions far from the active site that were discovered using a combination of structural, spectroscopic, and computational methods. Together these studies provide a new perspective on the importance that conformational dynamics play in the regulation of P450 activity.

Jeffrey I. Zink Inorganic Chemistry Seminar Series Prof. Robert Comito
2024-02-21 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Robert Comito Flyer
Title: Bimetallic Main-Group Catalysts for the Synthesis of Advanced Biodegradable Polymers
Abstract: Aliphatic polyesters are biodegradable and biocompatible materials that could replace polyolefins in many applications. However, their synthesis with fine structural control remains challenging, limiting the ability to tailor these materials for specialty and advanced applications. Our laboratory has developed a class of bimetallic main group catalysts for lactone and lactide polymerization distinguished by their electronic and steric tunability. The catalysts are constructed from binucleating bis(pyrazolyl)alkane ligands, which we have prepared by a novel method. Targeting monomer selectivity, stereocontrol, and sequence control we have developed homobimetallic, heterobimetallic, and chiral analogues of these complexes. We show promising evidence for metal-metal cooperativity from significant enhancements in rate compared to monometallic analogues. Through systematic comparison of metal composition and ligand sterics, we have identified a highly selective catalyst for lactone incorporation into polylactide, providing copolymers with a highly alternating structure. We describe an unusual dilithium complex that polymerizes aldehydes with exceptional activity and selectivity, raising opportunities for more sophisticated and adaptable oxygenated polymers.

Special Chemistry Seminar - Rigoberto Hernandez
2024-02-21 14:00 - 15:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Hernandez Seminar Flyer

3D-Networked Nanoparticles for Autonomous Computing

Abstract: Over the last decade, it has become clear that conventional VLSI is reaching key scaling limits. Moreover, the energy efficiency of human-engineered electronic devices is many orders of magnitude lower as compared to biological computational structures. Such inefficiencies, for example, severely limit our ability to move from 2D to 3D architectures in materials systems as is needed to achieve high performance and span the complexity required for applications using big data or artificial intelligence. We therefore need a new class of materials that can enable computing, but which are not bound by the rules of conventional VLSI, and we are inspired by the fact that the brain is an existence proof for such low-energy high-computing materials that do not rely on a von Neumann architecture. We have pursued the use of polymer-networked nanoparticles as a possible alternative. We will summarize our progress on characterizing these materials and report the primitive structures that we have created computationally thus far.

Dickerson Biochemistry Seminar - Ben Montpetit
2024-02-16 15:30 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Houk-Jung Organic Colloquium 247: Prof. Danica Fujimori
2024-02-15 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 218 Student Exit Seminar: Minh Nguyen
2024-02-15 12:00 - 13:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series - Prof. Wenliang Huang
2024-02-14 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Flyer: Prof. Wenliang Huang Flyer
Title: F-Block Metal–Arene Interaction: Dual Reactivity of Metal and Arene
Abstract: The unique metal–arene interactions motivated the advancement of chemical bond theory, and enabled a wide range of applications in synthesis and catalysis. In addition, ligand designs incorporating metal–arene interaction led to breakthroughs in stabilizing unusual oxidation states, and empowering small molecule activation and catalysis. Our group focuses on utilizing f-block metal-arene interactions in synthesis and catalysis. We have synthesized a series of inverse-sandwich f-block metal arene complexes and explored their reactivity. In addition, we have incorporated metal-arene interaction in ligand design and developed tripodal tris(amino)arene ligands capable of supporting multiple oxidation states of f-elements. Our results unveiled that the f-block metal-arene interaction not only enables redox chemistry at the metal site, but also leads to unprecedented functionalization of the arenes.

Physical Chemistry Seminar 228: David Limmer
2024-02-12 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Prof. David Limmer Flyer
Talk Title: Exciton polarons in lead halide perovskites
Abstract: In this talk, I will review some of our recent work concerning the photophysics of the lead halide perovskites. In particular, I will discuss how their soft, polar lattices endow quasiparticle excitations like, polarons and excitons, with a number of anomalous properties. The electron-phonon coupling in this class of materials results in electrons and holes being repelled from each other in bulk materials at elevated temperatures, and generates a strongly size dependent dynamic Stokes shift in nanoparticles. In 2d materials, lattice effects renormalize exciton binding energies, bringing theoretical predictions that neglect them into better agreement with experimental measurements. The results presented are derived from simple Gaussian field theories and validated with quasiparticle path integral molecular dynamics simulations.

Dickerson Biochemistry Seminar - Derrick Morton
2024-02-09 15:30 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Houk-Jung Organic Colloquium 247: Prof. Alshakim Nelson
2024-02-08 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series - Professor C. Michael McGuirk
2024-02-07 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. C. Michael McGuirk Flyer
Title: Exploring Flexibility and Connectivity in Synthetic Porous Frameworks
Abstract: Synthetic permanently porous materials are poised to play a key role in our transition to a more sustainable society. Owing to their structural and chemical modularity, synthetic frameworks, such as metal–organic, covalent, and hydrogen-bonded networks, are uniquely amenable to realizing highly specific functionality for emergent clean energy applications. However, desired performance for many pressing challenges, such as H2 delivery and light alkene purification, continue to elude established framework classes. Thus, the pursuit of synthetic porous frameworks with emergent behaviors and of entirely new classes of frameworks is essential. In this vein, this talk will cover two distinct efforts to diversify function and form. First, recent efforts to harness reversible framework flexibility to enhance usable capacities of hydrogen storage and delivery and for direct purification of propylene will be discussed. Then, the recent discovery of a novel class of frameworks assembled and stabilized through noncovalent chalcogen bonds, called Chalcogen-Bonded Organic Frameworks (ChOFs), will be detailed.

Special Physical Chemistry Seminar: Thomas Fay
2024-02-06 12:00 - 13:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Michael Zuerch
2024-02-05 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Seminar - Yinsheng Wang
2024-02-02 15:00 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Jeffrey I. Zink Inorganic Chemistry Seminar Series - Prof. Victor Mougel
2024-01-31 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Victor Mougel Flyer
Title: Bio-inspired Strategies for Small Molecule Electroreduction Across Multiple Scales
Abstract: Enzymatic systems have evolved complex strategies to maximize the efficiency and product selectivity in small molecule activation, including CO2 reduction. Besides unique active sites containing, by definition, earth-abundant elements, enzymes further control catalytic activity through second sphere interactions and a fine control of electron transfer chains. In this talk, we will introduce a series of bio-inspired strategies for the design of electrocatalytic systems for small molecule activations across multiple scales, encompassing the development of both heterogeneous and molecular catalysts. We will highlight a series of earth-abundant metal-based molecular and heterogeneous catalysts inspired by the active sites of enzymatic systems. Particular emphasis will be given to the exploration of bio-inspired strategies for electron transfers and storage, using synthetic Fe4S4 clusters.

Houk-Jung Organic Colloquium 247: Prof. Michelle Arkin
2024-01-31 14:00 - 15:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Bryan Changala
2024-01-29 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Title: “Illuminating Exotic Chemistry and Physics with Single-Quantum-State Spectroscopy”
Abstract: Molecules are amongst the most complex objects that can be controlled and studied at the individual quantum state level. In this talk, I will introduce some of the extraordinary advances made in the last decade by the application of AMO physics tools, including cavity-enhanced optical frequency comb and microwave techniques, to such quantum-state-resolved spectroscopy. These precision light-matter probes have redrawn the limits of molecular complexity that can be characterized and controlled in the laboratory, enabling scientists to address important chemical and physical problems from a fundamental, bottom-up perspective. I will showcase these applications in achieving rovibrational quantum-state spectroscopy of the C60 fullerene (the largest molecule for which this has been achieved); revealing the unexpectedly rich chemistry that occurs in extreme astrophysical environments; and exploring the unique electronic properties of metal-ligand complexes critical to applications in quantum science and metrology.
Dr. Bryan Changala Flyer

Dickerson Biochemistry Seminar - Lalit Deshmukh
2024-01-26 15:30 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Distinguished Lecture Series - David A. Leigh
2024-01-25 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Title: Giving Chemistry Direction
Abstract: In recent years examples of synthetic molecular machines and motors have been developed, all be they primitive by biological standards. Such molecules are best designed to work through statistical mechanisms. In a manner reminiscent of Maxwell’s Demon, random thermal motion can be rectified through ratchet mechanisms, giving chemistry direction.
It is increasingly being recognized that similar concepts can be applied to other chemical exchange processes. Ratchet mechanisms—effectively chemical engines in which catalysis of ‘fuel’ to ‘waste’ is used to drive another chemical process—can cause directional impetus in what are otherwise stochastic systems, including reversible chemical reactions. This is ushering in a new era of non-equilibrium chemistry, providing fundamental advances in functional molecule design and the first examples of molecular robotics, overturning existing dogma and offering fresh insights into biology and molecular nanotechnology.
David Leigh DLS Flyer

Physical Chemistry Seminar 228: Giulia Palermo
2024-01-22 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Prof. Giulia Palermo Flyer
Title: Dynamics and mechanisms of CRISPR-Cas9 through the lens of computational methods
Abstract: The clustered regularly interspaced short palindromic repeat (CRISPR) genome-editing revolution established the beginning of a new era in life sciences. I will report the role of state-of-the-art computations in the CRISPR-Cas9 revolution, from the early refinement of cryo-EM data to enhanced simulations of large-scale conformational transitions. Molecular simulations reported a mechanism for RNA binding and the formation of a catalytically competent Cas9 enzyme, in agreement with subsequent structural studies. Inspired by single-molecule experiments, molecular dynamics offered a rationale for the onset of off-target effects, while graph theory unveiled the allosteric regulation. Finally, the use of a mixed quantum-classical approach established the catalytic mechanism of DNA cleavage. Overall, molecular simulations are instrumental in understanding the dynamics and mechanism of CRISPR-Cas9 and pave the way for a new field of computational studies aimed at deciphering and engineering genome editing systems.
