UCLA

UCLA Boehringer-Ingelheim Lecture
2024-10-17 15:00 - 17:00 (America/Los_Angeles) | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

UCLA SPACE Institute: Chemistry and Materials for Space Science and Technology
2024-10-18 13:00 - 19:30 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Inorganic Chemistry Student Exit Talk: Shuaijing Du
2024-10-22 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Shuaijing Du of the Duan Research Group
Flyer: Shuaijing Du Student Exit Talk Flyer
Title: Introducing Chirality into Hybrid Superlattices
Abstract: I will present recent results on two different projects, with the common theme of introducing chirality into hybrid superlattices. 1: Modular assembly of a library of hybrid superlattices. Hybrid superlattices, composed of two-dimensional atomic crystals (2DACs) and self-assembled molecular layers, provide a platform for synergizing the rich physical properties of solid-state 2DACs with customizable molecular functionalities. In this project, we develop a modular electrostatic co-assembly approach for synthesizing over 50 hybrid superlattices from a diverse set of 2DACs and molecular building blocks. We demonstrate that in addition to amines, chiral amino acids and coordination complexes can also assemble with exfoliated MoS2 into hybrid superlattices, incorporating optical chirality into the hybrid superlattices. 2: Construction of chiral hybrid superlattices with monoatomic platinum layers. Compared with layered materials such as graphite and transitional metal dichalcogenides with highly anisotropic in-plane covalent bonds, freestanding metallic two-dimensional (2D) films with atomic thickness are intrinsically more difficult to achieve. This study introduces stabilized monoatomic Pt layers by forming a chiral hybrid superlattice structure with self-assembled chiral carboxylic acid ligand layers. Circular dichroism (CD) spectra of the chiral hybrid superlattices show clear CD signals distinct from the chiral carboxylic acids themselves.

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Jack Norton
2024-10-23 16:00 - 17:30 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Jack Norton Flyer
Title: Applications of Catalytic H• Transfer from H2
Abstract: Transition-metal hydride complexes with en-he bonds stronger than 56 kcal mol’ can often be generated from hydrogen, and may thus be able to catalyze the transfer of H from that gas. Hydrides with unusually weak M-H bonds, such as HV(CO),(dppe), can carry out stoichiometric cyclizations of enamines that contain a remote C=C, converting them to pyrrolidines. The reaction of a Co(Il) salen complex with an olefin in the presence of NaBH, and ‘BuOOH also appears to form a radical by H• transfer, and these radicals can be trapped by TEMPO. The photochemical oxidation of these TEMPO adducts to carbocations (Knowles, Angew. Chem. Int. Ed. 2016, 55, 9969) allows the interception of these cations by many different nucleophiles, giving Markovnikov hydrofunctionalization products. A particularly valuable application of this reaction is in the net hydrofluorination of olefins.

Distinguished Lecture Series/Donald J. Cram Lecture - Prof. David Leigh
2024-10-24 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Chem 248 Organic Chemistry Student Seminar: Ryan Lai
2024-10-28 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Matthew Sheldon
2024-10-28 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Inorganic Chemistry Student Exit Talk: Yessica Nelson
2024-10-30 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Yessica Nelson Student Exit Talk Flyer
Title: Tailoring Boron Clusters: The Impact of Vertex-Differentiated closo-Dodecaborates in Emerging Applications
Abstract: My presentation will highlight recent advancements in the vertex-precise manipulation of polyhedral boron clusters. Specifically, our work centers on developing methods to selectively functionalize the [B₁₂H₁₂]²⁻ cluster, a quintessential three-dimensional aromatic boron-based system, with high precision at individual boron vertices. I will demonstrate how multiple orthogonal strategies can be applied to precisely position various reactive functional groups on this cluster, enabling the creation of novel molecules that serve as key building blocks for extended solids, polymers, and materials with applications ranging from energy storage systems to biologically relevant imaging agents. Our approach allows the functionalization of the –OH, –SH, and –SeH groups as versatile synthetic handles. In some cases, these modifications can be achieved electrochemically, minimizing waste and simplifying purification processes.

Houk-Jung Organic Colloquium: Prof. Grace Han
2024-10-31 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Dickerson Biochemistry Seminar Series – Steve Clarke and Carla Koehler
2024-11-01 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Allison Clark
2024-11-04 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Anna Krylov
2024-11-04 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Samanvaya Srivastava
2024-11-06 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Samanvaya Srivastava Flyer
Title: Complex Coacervate Microemulsions
Abstract: This presentation will discuss our progress in creating stable membraneless water-water emulsions comprising complex coacervate microdroplets. Complex coacervation is a liquid-liquid phase separation phenomenon driven by the electrostatic association of oppositely charged multivalent macromolecules in water, creating coacervate microdroplets enriched with charged moieties. These aqueous membraneless microdroplets possess numerous attributes desired in colloidal reactors and protocell models. However, the membraneless coacervate-water interface that facilitates many of the bio(techno)logical functions of the coacervate microdroplets also promotes their coalescence, resulting in rapid coarsening and sedimentation. We will discuss our recently discovered strategy to stabilize complex coacervate microdroplets without introducing membranous sheaths around the droplets by utilizing the assembly of anionic comb polyelectrolytes at the water(coacervate)-water interface. We will demonstrate the tunability of microdroplet size, its months-long stability, and its ability to withstand high ionic strength environments. Selective sequestration of charged (bio)molecules (proteins and enzymes) into the crowded environments of stabilized coacervate microdroplets will be argued to affect a significant (up to 10-fold) and sustained acceleration of enzyme-mediated bioreactions. Aided by the low cost of the constituent polymers and the simplicity of the formulations, we will argue that the stabilized coacervate emulsions serve as efficient enzyme-encapsulants in economical, large-scale flow bioreactors.

Saul Winstein Lecture: Prof. Matthew Sigman
2024-11-07 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Dickerson Biochemistry Seminar Series - Joe Loo and Stefan Petrovic
2024-11-08 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Ellen Matson
2024-11-13 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Ellen M. Matson Flyer
Title: Structure-function Relationships that Dictate Proton Coupled Electron Transfer at the Surfaces of Polyoxometalate Clusters
Abstract:While the dynamics of proton- and electron-transfer at metal oxides have been studied extensively in the field of electrochemical energy storage, researchers have only very recently begun to understand how these process play out on molecular length scales and in the presence of small-molecule substrates. The latter is notable, considering that redox-active metal oxides are widely used in thermal and electrochemical catalytic processes. Further advances in the effective use of metal oxides in electrochemical catalysis will require improved understanding of elementary charge-transfer reaction mechanisms. Our research team has been studying the interfacial reactivity of reducible metal oxides using atomically precise, polyoxometalate clusters as models for extended materials. Polyoxometalates (POMs) consist of three of more redox-active transition metal oxyanions that are linked together by bridging oxide units to form three dimensional structures. These self-assembled clusters are well-positioned to provide insight into the surface chemistry of reducible metal oxides. This talk will focus on the synthesis and characterization of reduced POMs, which have provided our research group with opportunities to investigate factors that dictate mechanisms of H-atom uptake and transfer at metal oxide surfaces. Collectively, our studies inform our understanding of proton-dependent reactivity of metal oxide surfaces, toward the design of materials capable of converting chemical pollutants into energy-rich fuels.

Bristol-Myers Squibb Lecture
2024-11-14 15:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
BMS Seminar Flyer

Dickerson Biochemistry Seminar Series - Rob Clubb and Bill Gelbart
2024-11-15 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Neyci Estefania Gutierrez Valencia
2024-11-18 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Teresa Head-Gordon
2024-11-18 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Timothy Su
2024-11-20 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
Flyer: Prof. Timothy Su Flyer
Title: Sila-Diamondoids: Atomically Precise Clusters of Crystalline Silicon
Abstract: This talk will describe the synthesis, derivatization, and quantum transport properties of silicon diamondoids—atomically precise clusters of crystalline silicon. First, we describe strategies for the functionalization of the fundamental silicon diamondoid cluster, sila-adamantane. Mechanistic insights support that an aluminate-stabilized silylium at the 2-position of sila-adamantane is the terminal intermediate in its isomerization synthesis; we can intercept this intermediate to install halides at the 2-position. In addition, we can tetra-substitute sila-adamantane at its bridgehead positions with the same or different functional group, or precisely edit the skeletal structure of the adamantyl core by installing up to four Ge atom dopants at the bridgehead positions. We can extend this strategy to access, for the first time, the all-germanium adamantane. We have also developed radical-mediated approaches to catenate these clusters together to make supermolecules out of sila-diamondoid superatoms. As sila-adamantane represents the ultimate limit of miniaturization for nanocrystalline silicon, these regioselective approaches allow us to probe structure-property relationships in cluster models of silicon semiconductors at an atomically exact level. To showcase this, we show how the symmetry and dimensionality of sila-adamantane gives rise to unusual quantum interference effects in conductive single-molecule junctions studied with the scanning tunneling microscopy break-junction (STM-BJ) technique that may be controlled by chemical substitution. Finally, we exploit this phenomenon to create single-molecule conductance switches where we can mechanically toggle between different conductive pathways through the diamondoid cluster.

Houk-Jung Organic Colloquium: Prof. Jeff Martell
2024-11-21 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Dickerson Biochemistry Seminar Series - Rosalie Lawrence and Avi Samelson
2024-11-22 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Benjamin Janda
2024-11-25 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Judy Kim
2024-11-25 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Chem 248 Organic Chemistry Student Seminar: Braden Chaffin
2024-12-02 15:00 - 16:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Physical Chemistry Seminar 228: Prof. Brad Chmekla
2024-12-02 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

Jeffrey I. Zink Inorganic Chemistry Seminar Series – Prof. Eugene Chen
2024-12-04 16:00 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222

OCDS Sponsored Seminar - Jessica Kisunzu
2024-12-05 16:00 - 17:00 | Mani L. Bhaumik Centennial Collaboratory, 607 Charles E. Young Dr., East, Los Angeles, CA, 90095, United States

Dickerson Biochemistry Seminar Series - Danielle Schmitt and Jose Rodriguez
2024-12-06 15:30 - 17:00 | Collaboratory Yoo Seminar & Conference Hall YH4222
