UCLA

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Elizabeth Young
2023-11-08 16:00 - 17:30 (America/Los_Angeles) | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Flyer: Prof. Elizabeth Young Flyer
Title: From Photodynamic Therapy to Photovoltaics: Photophysics of Pd(II)biladiene and Charge Carrier Dynamics in Thin Films of Light Harvesting Sb2S3
Abstract: Solar light harvesting and interconversion of solar energy into either electricity or driving force for small molecule activation reactions are critical to the production of energy and other processes that our society requires to function. In this talk, I will discuss two project united by photochemistry, each with their own application. In the first vignette, I will discuss a porphyrinoid complex, called a Pd(II)biladiene, This Pd(II)biladiene moiety was designed for use as a photosensitizer drug for photodynamic therapy. Up until this point, the excited-state dynamics of such biladiene complexes have been virtually unexplored. During our work on this moiety, we discovered that while excitation into the lowest-energy absorption feature of the Pd(II)biladiene complexes produces expected photophysics, interestingly, excitation into higher-lying excited states resulted in an additional, unexpected lifetime. I will discuss our work to propose the cause of this unexpected behavior. In the second vignette, I will discuss our recent work on stibnite (Sb2S3), which can be employed as the photoactive layer in next generation thin-film solar cells. Sb2S3 is of particular interest due to the suitable band gap of 1.7 eV and high absorption coefficient (1.8 × 105 cm–1 at 450 nm). I will present our work using transient absorption spectroscopy to directly observe carrier diffusion, electron transfer, hole transfer and charge recombination through uniform ultra-thin (< 3 nm) layers of insulating or transport materials deposited by atomic layer deposition (ALD) that are coupled to photo-active materials. Our results will be used to correlate the structure and function of material thickness and transport type to develop a fundamental, detailed, quantitative understanding of photo-induced ET dynamics through thin films of materials.

Physical Chemistry Seminar 228: Franz Geiger
2023-11-06 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Geiger Flyer
Title: Photonic Electrochemistry
Abstract: Water’s oxygen is the electron source in the industrially important oxygen evolution reaction, but how water interacts with an electrode remains enigmatic. While much microscopic insight into the Stern layer comes from atomistic simulations or joint theory-experiment approaches, water’s strong absorber problem has clouded our view of how water aligns in response to applied potentials. Here, we employ nonlinear optics with a non-resonant pulse triplet at Ni:NiOx electrodes during cyclic voltammetry at pH 13 to quantify 𝒩water↓, the Stern layer water molecules pointing their oxygen atoms towards the electrode, and Ftot, the total interfacial potential. 𝒩water↓ varies sigmoidally with applied potential, U, but linearly with Ftot. While there is no net alignment at U=0.4 V, 3/4 of a water monolayer align at U=0.6 V and Eflip, the energy associated with water flipping, matches liquid water’s cohesive energy. At U=0.8 V, all Stern layer water molecules (1 x 10^15 cm^-2) align and Eflip matches the cohesive energy of ice. The current density is exponentially sensitive to 𝒩water↓ and Eflip. Our experiments provide new benchmarks for electrical double layer models and a diagnostic tool for molecular electrochemistry.

Dickerson Biochemistry Seminar – Jorge Torres and Roy Wollman
2023-11-03 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. Joel Smith
2023-11-02 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Smith Flyer
Title: Dearomative Alkaloid Synthesis
Abstract: Biologically active alkaloids continue to serve as a means of biomedical discovery in addition to serving as forcing functions for the invention of new chemical transformations. Structurally, many of these natural products and rationally designed drugs also contain one or more piperidine rings, making it the most common nitrogenous heterocycle amongst approved small-molecule therapeutics. Thus, the concise redox-economic construction of these heterocycles in the context of target-oriented synthesis has become a recent research focus in our lab. In particular, leveraging controlled and selective dearomatization reactions has enabled the concise synthesis of several natural products and approved pharmaceuticals from simple feedstock pyridines. Our lab’s recent synthetic efforts related to alkaloids from the lupin, ergoline, aspidosperma, morphinan and manzamine families of alkaloids will be discussed, articulating the breadth of targets that can be accessed by this strategic approach. In addition, both fundamental and translational opportunities afforded by our work in this area will be highlighted.

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Professor Prashant Jain
2023-11-01 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Prashant Jain Flyer
Title: “The Chemical Potential of Light”
Abstract: The interaction of light with molecules can be used to access new modes of chemical reactivity; however, this interaction is often difficult to exploit in a universal manner. I will describe how plasmonics is proving to be a general strategy for interfacing photons with molecules and activating chemical transformations and even inducing emergent chemistry. In my laboratory, catalysts based on plasmonic nanoparticles are allowing light to be used as a redox equivalent in chemical reactions, for promoting non-equilibrium chemical processes, for modifying product selectivity, for photosynthesizing fuels, and for boosting electrochemical conversions. I will provide a deeper view of the excited-state structures, species, and mechanisms that underlie these phenomena at the nanoparticle–solution interface.

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Prashant Jain
2023-11-01 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Hannah Shafaat
2023-10-30 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Shafaat Flyer
Title: Model Metalloenzymes to Catalyze the Reactions of Early Life
Abstract: Metalloenzymes catalyze the challenging chemical reactions that lie at the core of vital life processes, from carbon and nitrogen fixation to photosynthesis and respiration. Native metalloenzymes use only earth-abundant transition metals and operate under mild conditions, accessing reactivity that remains largely out of reach for synthetic systems. Given the importance of these fundamental processes in the context of energy, environment, sustainability, and human health, gaining molecular-level understanding into how metalloenzymes work is of the utmost importance. To this end, we are developing protein-based models as structural, functional, and mechanistic mimics of naturally occurring metalloenzymes. Targets to be discussed in this presentation include hydrogenase, carbon monoxide dehydrogenase (CODH), and acetyl coenzyme A synthase (ACS). These nickel-containing enzymes are implicated in chemoautotrophic origins of life and play key roles in the metabolisms of ancient bacteria and archaea. However, while these enzymes are highly functional within their cellular environment, most are costly to isolate, sensitive to external conditions, and generally poorly suited for large-scale application. Additionally, the multimetallic active sites and auxiliary cofactors obscure distinguishing spectroscopic features and render detailed analyses challenging. As a result, the molecular mechanisms of catalysis remain relatively poorly understood, thwarting efforts to build biomimetic synthetic systems that act with the efficacy of native enzymes. By combining functional studies of our model proteins with diverse spectroscopic techniques and computational investigations, we can obtain a comprehensive understanding of how the electronic and geometric structures dictate reactivity in each system. Reconstructing functional metalloenzymes “from the ground up” offers direct insight into the fundamental chemical principles driving the natural systems. Looking forward, we hope to apply these principles towards engineering effective systems for energy conversion reactions while learning about fundamental chemical transformations that may underlie the evolution of prebiotic processes into early life.

Chem 248 Organic Chemistry Student Seminar: Daniel Turner
2023-10-30 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Dickerson Biochemistry Seminar – Ellen Sletten and Danielle Schmitt
2023-10-27 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: Dr. Liela Romero
2023-10-26 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Romero Flyer
Title: Highly Selective Catalytic Platforms for Reduction and Interhalogenation Chemistry: Our Early Explorations in ZrH and Lewis Base Catalysis
Abstract: Research in the Romero group is centered on the development and mechanistic study of novel catalytic reactions, with applications in natural product synthesis and drug discovery. To this end, we are exploring new avenues for the catalytic halo- and hydrofunctionalization of simple π-systems. The first research program regards our efforts to develop a unified strategy for the interhalogenation of alkenes and alkynes via Lewis base activation of sulfinyl halides. This approach furnishes vicinal dihalides with pronounced chemo-, regio-, and stereocontrol. Notably, when 1–3 mol% of a chiral Lewis basic catalyst is employed, a novel enantioselective bromochlorination of chalcones is realized. The second part of this seminar will focus on the development of a general platform for zirconocene hydride catalysis utilizing hydrosilanes as mild reductants. This catalytic system enables a variety of chemoselective and redox-economic functional group interconversions, including the catalytic semi-reductive diversification of amides and esters, as well as the hydrofunctionalization of alkynes.

Chem 218 Student Exit Seminar: Benqian Wei
2023-10-26 12:00 - 13:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Professor Jinyong Liu
2023-10-25 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Jinyong Liu Flyer
Title: “Photodegradation of PFAS: Mechanistic Insights and Technology Development”
Abstract: The list of PFAS pollutants is expanding rapidly. PFAS pollutants have various chain lengths and end functional groups. These structural features substantially impact the molecular reactivity under reductive and oxidative treatment. The efficacy and efficiency of PFAS degradation systems also depend on solution chemistry, such as pH and the source of reducing/oxidizing species. This presentation will summarize our recent findings from treating over 60 legacy and emerging PFAS structures. The structure-reactivity relationship and system performance improvement will benefit the design of remediation systems for most PFAS pollutants.

Special Physical Chemistry Seminar by Prof. Sandeep Sharma
2023-10-25 13:00 - 14:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Sandeep Sharma Flyer

Physical Chemistry Seminar 228: II-Doo Kim
2023-10-23 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Kim Flyer
Title: Innovation in Nanomaterials Synthesis: from Lab to Commercialization
Abstract: Nanoengineering plays a pivotal role in optimizing nanomaterials to achieve enhanced performance and impressive mechanical stability, especially in challenging environments. Recent research has been dedicated to the creation of various novel composite materials, encompassing high entropy and multi-elemental nanoparticles, as well as the integration of stable single-atom catalysts onto robust supporting nanomaterials to ensure highly efficient catalytic performance. Effective catalyst design is essential not only for the advancement of chemical sensors but also for energy devices like lithium-air batteries, water-splitting, and CO2 conversion, and more. These active nanomaterials, including catalysts, must resist agglomeration, maintain high thermal stability during repetitive reactions, and necessitate minimal catalyst content for maximal performance. This presentation delves into diverse applications employing electrospun polymer fibers, metal oxide fibers, and carbon fibers. The presentation also outlines an expedited and optimal process for catalyst attachment onto electrospun nanofiber backbone structures. Lastly, a case study traversing the journey from laboratory research to commercialization spotlights the utilization of custom-made electrospinning equipment, roll-to-roll machines with nozzle arrays spanning 35 cm and 1.2 m widths. As electrospinning relies on solution-based processing, we can create a range of fiber types, including colorimetric, thermochromic, and antivirus fibers. Finally, I will conclude by offering insightful perspectives on innovative material synthesis using electrospinning and highlighting interesting case studies of device application

Dickerson Biochemistry Seminar – Joe Loo and Michael Lawson
2023-10-20 15:30 - 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: Professor Yong Yan
2023-10-18 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Yong Yan Flyer
Title: “Perovskite Semiconductors For Photocatalytic Organic Synthesis”
Abstract: Heterogeneous catalysis is responsible for the vast majority of chemical transformations, yet the direct employment of chiral solid catalysts for asymmetric synthesis is mostly overlooked. Our lab proved that photophysical properties of lead halide perovskites already proved for photovoltaics, also should be of interest in photoredox organic synthesis. Because the key aspects of these two applications are both relying on charge separation and transfer. We demonstrated that perovskites nanocrystals are exceptional candidates as photocatalysts, not only for fundamental organic reactions but also active for elusive asymmetric organic synthesis. Chiral 1-phenylethylamine (PEA)-hybridized perovskite PEA/CsPbBr3 NC photocatalysts exhibit an enantioselective (up to 99% enantiomer excess) avenue to produce N–C axially chiral N-heterocycles, i.e., N-arylindoles from N-arylamine photo-oxidation. Mechanistic investigation indicated a discriminated prochiral binding of the N-arylamine substrates onto the chiral-NC surface with ca. −2.4 kcal/mol enantiodifferentiation. Our perovskite NC heterogeneous catalytic system not only demonstrates a promising strategy to address the long-term challenges in atroposelective pharmaceutical scaffold synthesis but also paves the road to directly employ chiral solids for asymmetric synthesis.

Physical Chemistry Seminar 228: Rodrigo Noriega
2023-10-16 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Noriega Flyer
Title: Study and Regulation of Biomolecular Interactions at Electrified Interfaces
Abstract: We seek to understand the role of electrostatic interactions in molecular recognition mechanisms that are sensitive to structure but not sequence. An interesting model system for these multifaceted interactions is Loquacious-PD (Loqs-PD), a co-factor protein with two RNA binding motifs that recognize double-stranded RNA (dsRNA) regardless of their terminus structure. Loqs-PD regulates the terminus-dependent binding of the endonuclease enzyme Dicer-2 and is crucial to the efficient processing of sub-optimal dsRNA targets with a 3’ overhang terminus for gene silencing in Drosophila melanogaster.
To identify the effects of electrostatics and local dynamics on the formation and stability of dsRNA:Loqs-PD complexes, we study their binding and dynamics at electrified interfaces with a combination of mid-infrared surface plasmonics, time-resolved ultrafast fluorescence, and in situ electrochemical experiments at the surface of a degenerately doped wide-gap metal oxide. In this way, we distinguish distinct stages in the binding event between an RNA-binding protein and its target and follow dynamic events over multiple time scales. Time-resolved fluorescence measurements show a high affinity interaction that is strongly affected by electric fields, while mid-infrared surface plasmon observations detect a lower affinity interaction with a reduced (but still substantial) sensitivity to electric fields. In both cases, fluctuations are dependent on protein binding and the presence of electric fields.
Multi-stage binding process that arise from non-specific interactions are common between nucleic acids and proteins, and studies that employ complementary observations under controlled perturbations are a powerful tool to interrogate the link between molecular recognition and biochemical function.

SoCal TheoChem 2023
2023-10-14 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Explore theoretical and computational chemistry with talks and poster sessions. Organized by Profs. Anastassia Alexandrova and Benjamin Schwartz at UCLA. Featuring speakers from UCLA, California State University Northridge, UC Riverside, UCSD, and Caltech. Abstract submissions are now being accepted. Free attendance, register by September 14 at http://www.chem.ucla.edu/~ana/SoCalTheoChem/.

Dickerson Biochemistry Seminar – David Eisenberg and Bill Gelbart
2023-10-13 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: Steven D. Townsend
2023-10-12 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Townsend Flyer
Title: Preventing Premature Birth and Breaking Strong Bonds with Carbohydrates
Abstract: Abstract: Carbohydrates are the most abundant organic molecules on earth and are critical to a myriad of biological processes. The Vanderbilt Laboratory for Glycoscience uses a blend of synthetic organic chemistry and microbiology to elucidate the biological roles of carbohydrates, with a foci on advances in chemical synthesis and learning new mechanistic concepts. Our discussion will be divided into two categories: (1) the synthesis of structurally and biologically compelling complex carbohydrates, and (2) application of the host defense properties of human milk.

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Timothy Johnstone
2023-10-11 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Prof. Timothy Johnstone Flyer
Title:“Synthesis, Isolation, and Exploration of the Chemistry of Kinetically-Stabilized Pnictine Oxides”
Abstract: The light pnictine oxides R 3 NO, R 3 PO, and R 3 AsO comprise a well-characterized class of monomeric molecules with a tetrahedral geometry about the pnictogen center. In contrast, the preparation of the corresponding Sb and Bi species has long proved challenging. For the heavier pnictogens, reduced orbital overlap with oxygen increases charge separation, which in turn increases the electrophilicity of the pnictogen and the nucleophilicity of the oxygen. Furthermore, the heavier pnictogens have an increased propensity to expand their coordination spheres. Consequently, stibine oxides and bismuthine oxides occur as oligomeric/polymeric materials. We have recently employed a kinetic stabilization strategy to isolate the first example of an unperturbed monomeric stibine oxide. We have examined the electronic structure of the newly isolated stiboryl functional group using a variety of physical and theoretical techniques. These investigations have guided our exploration of the reactivity of this previously inaccessible unsaturated (heavy pnictogen)–oxygen bond

John D. & Edith M. Roberts Lecture - Soumitra Athavale
2023-10-10 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Roberts Lecture Flyer

John D. & Edith Roberts Lecture - Prof. Soumitra Athavale
2023-10-10 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Title: TBD
Abstract: TBD
Flyer Pending

Physical Chemistry Seminar 228: Mitchio Okumura
2023-10-09 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Okumura Flyer
Title: Combs and Mirrors: Spectroscopic Studies of Radical Reactions Important in Air and Space
Abstract: Trace gas phase free radicals play a central role in the chemistry of Earth and planetary atmospheres, as well as the interstellar medium. Laboratory studies of their spectroscopy, reaction dynamics and kinetics are important for accurate modeling of these environments. Experiments require high sensitivity, time resolution, and specificity to detect these reactive intermediates. We have pursued advances in spectroscopic techniques using optical cavities and optical frequency combs to detect free radicals in the Mid-Infrared by direct absorption. I will discuss several examples of cavity ringdown, direct frequency comb cavity-enhanced spectroscopy, and Vernier comb spectroscopy and their applications to atmospheric kinetics. In addition, I will present experiments using Uniform supersonic flows and LIF detection reveal new dynamical effects in low temperature radical kinetics.

Dickerson Biochemistry Seminar – Guillaume Chanfreau and Juli Feigon
2023-10-06 15:30 - 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: Brandon Jolly and Yi Chen
2023-10-04 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Brandon Jolly and Yi Chen Flyer
Speaker: Brandon Jolly
Title: Spatial Control in Multi-step, Multi-catalyst Organometallic Processes
Abstract: Spatial localization is one method in which biology manages its complex network of multi-step and/or multi-catalyst processes. For example, encapsulation of enzymes via compartmentalization allows for the efficient generation and utilization of intermediate species along a biochemical pathway. Much work has been devoted to applying compartmentalization for efficient in vitro enzyme cascades both theoretically and experimentally. However, only recently has attention been given to spatial localization in the context of organometallic catalysis experimentally, with no theoretical insights. Therefore, we developed a kinetic model to evaluate and understand the effect compartmentalization may have on a multi-step organometallic process, such as a typical catalytic cycle. A key design principle born out of this work is that compartmentalization is predicted to benefit organometalic catalysis if diffusion into/out of the compartment is kinetically comparable to, or slower than the catalytic cycle itself, which is tunable via compartment morphology. Next, we then set out to extend the concept of spatial localization in organometallics to multi-catalyst processes. Specifically, electrocatalytic CO2 reduction integrated to Pd catalyzed polyketone synthesis was chosen as a target multi-catalyst system that may benefit from spatial control. Ultimately, we demonstrate the generation and consumption of CO from CO2 reduction to co-polymerization with ethylene in one pot, with external control over %CO incorporation into the polymer via applied current, which is unattainable without spatial control.
Speaker: Yi Chen
Title: Generate Gradient in Electrochemical Microfluidic Systems to Investigate P. Aeruginosa Metabolic Regulation Kinetics on Single Cell Level
Abstract: Comprehending how bacterial metabolism adapts to environmental changes, like oxygen abundance variation, is important in microbial ecology and has potential applications in disease treatment and bacterial infection. Previous research primarily centered on the collective regulatory responses in bulk culture study while single-cell level understanding of bacterial regulation kinetics still remains a challenge. To address the challenge, we developed an electrochemical microfluidic system to generate microscopic oxygen and hydrogen peroxide concentration gradients, simulating the intricate micrometer-scale environments inhabited by bacteria. Particularly, we cultivated P. aeruginosa in the generated oxygen gradient and investigated its metabolic regulation kinetics on single-cell level, specifically with regard to the concentration of adenosine triphosphate (ATP), in response to environmental oxygen spatial variation and temporal oscillation.

Physical Chemistry Seminar 228: Evgeny Pidko
2023-10-02 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Pidko Flyer
Title: Death and Life of Homogeneous Carbonyl Reduction Catalysts: Navigating Condition Space Towards Superior Catalytic Performance
Abstract: Catalytic hydrogenation chemistry offers a greener and more sustainable alternative to prevalent stoichiometric reduction methodologies in the production of high-value chemicals. In recent years, traditional Ru and Ir catalysts have been complemented by novel first-row transition metal catalysts due to their favorable sustainability, economics, and reduced toxicity. The practical implementation of such catalysts based on e.g. Fe or Mn is often hampered by their limited stability under the catalytic conditions. Understanding the catalytic and deactivation paths for such systems is key to tailoring their properties towards enhanced and sustained catalytic performance. In this lecture, I will discuss the importance and challenges of understanding the chemistry of catalyst deactivation for the development of practical catalytic technologies with the examples of our recent studies on Mn catalysis for selective reduction of carbonyl-containing compounds. While the performance of homogeneous catalysts is typically interpreted based on the molecular structures and electronic properties of the originating organometallic compounds, these catalyst systems are complex and multifunctional. Their behavior is influenced by a wide range of parameters, such as activation procedure, presence of promotors, solvent type, and selected conditions. Insights into the underlying mechanisms and their condition-dependencies can be obtained through a combination of operando spectroscopy, kinetic studies, and automated computational mechanistic analysis. This approach can help navigate this vast condition space and enhance the efficiency and lifespan of 3d metal-based catalyst systems.

Dickerson Biochemistry Seminar
2023-09-29 15:30 - 16:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Introduction of Biochemistry Faculty to First Year Biochemistry Graduate Students

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Titel Jurca
2023-09-27 16:00 - 17:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States
Title: “Building a Toolbox for Sustainable Synthesis and Catalysis”
Abstract: The presentation will focus on three of our current areas of interest:
Mechanochemical synthesis: by leveraging mechanochemical forces via vibratory ball milling or ultrasonic irradiation, we can expedite the synthesis of both conventional, and exotic Schiff base coordination complexes. Critically these reactions can be performed solvent-free or solvent-minimal, and facilitate the formation of target compounds in one-pot and one-step from multiple starting materials in minutes-to-hours compared to conventional multi-day, multi-step processes.
Silane-based reductions: using silanes, high-valent, mid d-block metal halides can be controllably reduced to highly reactive mid-valent synthons (e.g. MoCl3). The reactions are facile, and produce only H2 and recoverable chlorosilanes as byproduct. The resulting products are ideal starting points towards new precursors for ALD and CVD; enabling technologies for coatings, electronic materials, and heterogeneous catalysis.
Monolith-based nanocatalysts: controlled growth of nanocatalysts on contiguous Ni foams. Ni foams afford numerous advantages; among these include ease of handling and facile separability inherent to monolith systems, suitability for continuous flow catalysis, and self-stirring. The application of these materials towards catalytic hydrogenations will be discussed.

Jeffrey I. Zink Inorganic Chemistry Seminar Series: Sundargopal Ghosh
2023-09-20 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Title: “Coordination Chemistry of Diborane(4) and Diborane(6)”
Abstract: The fascinating aspect of metallaborane chemistry is that several classic organometallic complexes that defined fundamental structural and bonding paradigms are mimicked by many isoelectronic metallaborane analogues.[1] In this connection, diborane compounds not only mimics several classic organometallic compounds but also they have been extensively explored for the broad understanding of the chemical bonding and catalysis.[2] For example, we have recently synthesized and structurally characterized a bimetallic diborane(4) which mimics Cotton’s dimolybdenum–alkyne complex [{CpMo(CO)2}2C2H2].[3] Also, we have isolated the first classical diborane(5) [B2H5]-, in which the sp2-B center is stabilized by the electron donation from tantalum.[4] Very recently, we have developed an uncatalysed synthetic pathway to generate the doubly base stabilised symmetrical and unsymmetrical diborane(4) species from the thermolysis reaction of 2-mercaptopyridine with [BH3.THF]. The key results of this work will be described.
