Essential Elements

Department of Chemistry and Biochemistry
Organic/Inorganic/Materials Seminar Series

Professor Jonathan Kuo, Penn State
January 31, 2025
3:00 pm, WIL 110
Hosted by ADSE

Comparing Metalloenzymatic Active Sites to Synthetic Model Complexes: Expanding Views on Supporting Ligands

Organic ligands alter the electronic structure and properties of the transition metals that they bind to. But what other functions can be programmed into metal/ligand complexes? In this talk, we will discuss how dynamic ligand features “unlock” key steps in (a) aerobic oxygenation and (b) electrophilic olefin activation. These dynamic features replicate dynamics present in enzymatic active sites. Recently, comparisons to enzymatic active sites have drawn us to host-guest-type ligand-metalate complexes – where the supporting ligand is designed to bind polyatomic metal anions [MO4]2– or [MCl4]2– via hydrogen bonding.

Department of Chemistry and Biochemistry
Physical Chemistry Seminar Series

Professor Shaowei Li, University of California San Diego
January 27, 2025 — 2:00pm, Tykeson 140
Hosted by: George Nazin

Title: On-Demand Control of Single-Molecule Chemistry through Vibrational Characterization and Manipulation

Chemical processes hinge on the dynamic rearrangement of nuclei within molecules. Controlling these motions with precision has been a long-standing goal in chemistry. My lab focuses on achieving this by manipulating interactions between individual molecules and their nanoscale environment. We engineer the potential energy surface at this scale to control molecular properties such as structure and reactivity. Using vibrational characterization techniques with scanning tunneling microscopy (STM)—including inelastic electron tunneling spectroscopy, action spectroscopy, and our recent advancement in single-molecule infrared absorption spectroscopy—we analyze molecular responses to the variation in the nano-chemical environment by examining their fingerprinting vibrational modes at the sub-molecular scale. By precisely tuning the junction geometry, material, and the interaction between the molecule and other surface entities, we can selectively influence specific bonds, paving the way for bond-selective control in chemistry.

Department of Chemistry and Biochemistry
Physical Chemistry Seminar Series

Professor Jean K. Chung, Colorado State University
January 13, 2025 — 2:00pm, Tykeson 140
Hosted by: Andrew Marcus

Title: Lipid Membrane Structure in Catalysis and Reactivity

The cellular membrane not only defines the boundary of the cell, but also mediates the communication with the environment and organizes vital processes in space and time. In the inflammation process, liberating polyunsaturated fatty acids from phospholipids. The fatty acids are then oxidized by lipoxygenase, which leads to the overall oxidation of the membrane that underlies aging and a host of diseases. Here, we explore how the structural integrity of the cell membrane is linked to both the hydrolysis of phospholipids by phospholipase A2 and lipid peroxidation by lipoxygenase. We use model membrane systems, such as lipid vesicles and supported lipid bilayers combined with fluorescence spectroscopy and imaging to investigate the reactions involved in membrane breakdown.