Improvement of α-amino Ester Hydrolase (AEH) Via Rational Design, Computational Design, and Machine Learning (ML) Current batch enzymatic processes to important semi-synthetic beta-lactam antibiotics, such as amoxicillin and cephalexin, suffer from yield and selectivity limitations, owing to primary and secondary hydrolysis side reactions (see Figure). Through continuous flow and reactive crystallization of the beta-lactam product, we sought to suppress primary hydrolysis and prevent secondary hydrolysis. Indeed, we found higher yields than in homogenous batch reactions. Type of Event: Organic Seminar Read more about Improvement of α-amino Ester Hydrolase (AEH) Via Rational Design, Computational Design, and Machine Learning (ML)
Frequency Combs as the Route to the Spectroscopic Trifecta: High Time Resolution, High Frequency Resolution, and High Sensitivity Many consequential chemical processes take place on ultrafast timescales, including molecular vibrations and bond breaking. Measurements that follow ultrafast molecular dynamics in real time are changing our understanding of these processes. We are designing new tools to study ultrafast molecular dynamics and quantum mechanics with the sensitivity enough to study the molecules in molecular beams and the spectral resolution sufficient for vibrational and rotational resolution. Type of Event: Departmental Colloquium Physical Seminar Read more about Frequency Combs as the Route to the Spectroscopic Trifecta: High Time Resolution, High Frequency Resolution, and High Sensitivity
Multi-Dimensional Separations for Bacteria Identifications and Investigations of Antimicrobial Resistance Bacterial infections are a major global health concern, with an estimated 1 in 8 deaths attributed to bacterial infections in 2019 alone. When a patient with a suspected infection arrives in a clinical setting, the first step to developing a treatment strategy is to identify the causative pathogen, followed by determination of antimicrobial therapeutics that are appropriate and effective. Type of Event: Departmental Colloquium Analytical Seminar Special Seminar Read more about Multi-Dimensional Separations for Bacteria Identifications and Investigations of Antimicrobial Resistance
Automatic Differentiation of Explicitly Correlated MP2 For a long time, explicitly correlated (F12) methods have offered a solution to the slow convergence of the one-electron basis set. Although there have been numerous studies in which F12 methods have improved the accuracy of single-point energies, most of these methods have not been extended to gradients and Hessians. One such method is the highly robust explicitly-correlated second-order Moeller-Plesset perturbation theory within the 3C(FIX) Ansatz [MP2-F12/3C(FIX)]. Type of Event: Physical Seminar Read more about Automatic Differentiation of Explicitly Correlated MP2
Emerging Chemistry of Main Group Element-Based Dithiolene Complexes While transition metals have played a dominant role in the development of dithiolene chemistry, their main-group element-based counterparts have received considerably less attention. This laboratory recently reported the first structurally characterized lithium dithiolene radical, via reaction of the anionic N-heterocyclic dicarbene with elemental sulfur. This radical provides an effective synthetic platform to access the largely unexplored main group element-based dithiolene chemistry. Type of Event: Inorganic Seminar Read more about Emerging Chemistry of Main Group Element-Based Dithiolene Complexes
Imaging Biological Tissues at High Chemical and Spatial Resolutions Using Mass Spectrometry Imaging mass spectrometry is a powerful analytical technique for analyzing the spatial lipidome. This technology enables the visualization of molecular pathology directly in tissues by combining the specificity of mass spectrometry with the spatial fidelity of microscopic imaging. This label-free methodology has proven exceptionally useful in research areas such as cancer diagnosis, diabetes, and infectious disease. Type of Event: Analytical Seminar Read more about Imaging Biological Tissues at High Chemical and Spatial Resolutions Using Mass Spectrometry
Potential PFAS Degradation Technique: Exploring Plasma-Mediated Chemistry PFAS (per- and polyfluoroalkyl substances) have been used in a variety of applications over the past 70 years, ranging from firefighting foam to nonstick cookware. The strong carbon-fluorine bond is what gives these substances their desirable chemical characteristics, but this is also the cause of their greatest drawback. They are known as “forever chemicals,” highly persistent chemicals that do not occur in nature, and many of which have been found to negatively affect human health. Type of Event: Physical Seminar Read more about Potential PFAS Degradation Technique: Exploring Plasma-Mediated Chemistry
Instrumentation and Precursor Development for Infrared Helium Nanodroplet Isolation Spectroscopy Helium nanodroplet isolation spectroscopy is a technique useful for studying highly reactive, open shell systems due to its low temperature, fast adiabatic cooling, and minimally perturbative matrix. The technique is particularly good at studying pre-reactive complexes with low activation barriers and small, hydrocarbon systems where rotational resolution is maintained due to the superfluid nature of the droplets. These types of systems are relevant to understanding combustion, astrochemistry, and atmospheric chemistry. Type of Event: Physical Seminar Read more about Instrumentation and Precursor Development for Infrared Helium Nanodroplet Isolation Spectroscopy
Kinetic Monte Carlo Simulations for Heterogeneous Catalysis Monte Carlo simulations are a broad, popular class of algorithms that solve chemical problems by changing the position of atoms in a molecule by small, random displacements over a period of time. The kinetic Monte Carlo approach improves on its earlier counterparts by allowing all of the atoms to move dynamically and by grouping these molecular vibrations such that they are treated simultaneously until there is a change in the overall geometry of the system. This allows for kinetic Monte Carlo simulations to last for over a second, while other Type of Event: Physical Seminar Read more about Kinetic Monte Carlo Simulations for Heterogeneous Catalysis
In-Source High-Resolution Spectroscopy Using an Integrated Tunable Raman Laser Raman Spectroscopy is a powerful technique that can probe states not visible in absorption spectroscopy. One limitation for the resolution of a stimulated Raman scattering experiment is the linewidth of the stokes pump. This proposed method uses a diamond based Fabry-Perot Cavity to generate a narrow linewidth stokes pump leading to increased resolution. Then this laser is used to perform spectroscopy in an Ion-Trap to observe sub-doppler measurements in atomic transitions. Type of Event: Physical Seminar Read more about In-Source High-Resolution Spectroscopy Using an Integrated Tunable Raman Laser