Imaging Electrons to Explore Questions in Chemical Bonding and Chirality
An experiment capable of unravelling complex chemical phenomena should be sensitive, controllable and versatile. Gas-phase anion photoelectron spectroscopy allows for manipulation and intimate interrogation of molecules in well-controlled environments. Combined with velocity map imaging, this versatile technique captures both the energetic and angular information of the photoemitted electrons, and parent molecules, to enable flexible and sensitive investigation into a variety of chemical questions. In my presentation, I will discuss two different research directions from my graduate and postdoctoral work where I utilized this technique.
The first half will be a discussion of the abnormal chemical bonding of beryllium. Despite its small size, with only 4 electrons, beryllium is known to participate in bonding that deviates from periodic trends and evades accurate electronic structure modeling. To improve the robustness of computational methods and provide a path for understanding of this element, experimental benchmarks of the bonding of beryllium are needed, starting with the smallest beryllium-containing molecules. I will discuss my graduate contributions to understanding the behavior of this element through the characterization of bonding between two closed shell atoms, Be and F- in the BeF- anion.
In the second half of my presentation, we will shift gears to studies of chiral anions in the gas phase. Chirality is ubiquitous in nature, and scientists seek to explore this property to better understand life processes and facilitate more efficient chemical processes. Chiroptical studies of molecular chirality in the gas phase are often limited due to weak chiral light-matter interactions. However, a relatively new chiroptical technique, known as photoelectron circular dichroism, bypasses these weak interactions to enable chiral discrimination measurements with chiral sensitivity that well exceeds conventional techniques such as absorption circular dichroism. I will discuss my recent observation of photoelectron circular dichroism in the photodetachment of anions. In this discussion, I will explain the implications of this result for understanding the universal dynamics that govern this chiroptical effect, and the potential for new analytical techniques for chiral discrimination of dilute and complex mixtures.
Hosted by Professor Lu Wang
~Coffee/tea will be served prior to the lecture~