Chemical Bonding Via Anion Photoelectron Imaging Spectroscopy
$413.2K Funding
1 People
In this project funded by the Chemical Structure, Dynamics and Mechanisms -A(CSDM-A) program of the Chemistry Division, Professor Andrei Sanov at the University of Arizona is using sophisticated laser techniques combined with a technique called photoelectron imaging to study chemical bond­ing. This research targets isolated molecules, as well as molecules undergoing chemical change or interacting with neighboring species. The broad objective is to uncover the prin­ci­ples and mechanisms by which all chemical matter binds together in progressively larger systems: from atoms to mol­e­cu­les, from molecules to molecular clusters and macromolecules, from mono­mers to poly­mers, and beyond. The nature of chemical bonding is defined by electrons and it is their behavior that controls the outcomes of chemical reactions. By capturing images of electrons ejected from molecular anions (molecules with an extra electron) interacting with laser light, Professor Sanov and his research group identify the funda­mental interactions involved in the formation and dissociation of chemical bonds. This research defines a pedagogical framework for introducing students to quantum concepts. The program provides continuing training for undergraduate and graduate students, preparing them for advanced careers in academia, government labs, and industry. Quantum concepts have relevance to careers in computing, sensing, and cybersecurity. Prof. Sanov is continuing to develop photoelectron imaging (which he also refers to as "quantum photography") as a teaching tool for quantum concepts. The project focuses primarily on transient species, such as radical and diradical reactive intermediates, as well as complex reactive pathways involv­ing seve­ral electronic states and/or spin-forbidden transitions. Examples of the specific systems studied include transient diradicals and the radical species of organic heterocyclics with important roles in atmospheric chemistry and combustion processes. In the experiments, the radical and diradical species are accessed by photodetaching electrons from the corresponding molecular anions. The freed electrons carry information about both the initial state of the anion and the final state of the resultant neutral molecule. This information is recorded spectroscopically, by imaging the photodetached electron distributions, generated in interactions of the mass-selected target anions with visible or ultraviolet laser pulses. Additional structural and dynamical insights are obtained from the quantum-state distribu­tions of the nascent products observed in photodissociation reactions and in interactions of anions with solvent molecules. The results are interpreted with the help of electronic-structure calculations, enabling a comparison of observed quantum states with theoretical models. The broader impacts of this work include potential societal benefits resulting from increased knowledge of the structures and thermochemistry of reactive intermediates and an improved understanding of the general mechanisms of chemical bonding and reactivity. The project provides opportunities for the training of students in the design, construction, and operation of advanced instrumentation and complex theoretical analyses.
Photo of A Sanov(sanov)
A Sanov
Chemistry & Biochemistry - Science