Through this award, funded by the Chemical Structure, Dynamics, and Mechanisms - A Program of the Division of Chemistry, Prof. Andrei Sanov from the University of Arizona will investigate the electronic structure of stable isolated molecules, as well as that of molecules undergoing chemical change or interacting with neighboring species. This goal will be achieved through targeted applications of photoelectron imaging and photofragment spectroscopy to molecular and cluster anions. The combination of these experimental techniques focuses on both the electron emission and anionic fragmentation processes, as both pathways are essential for unraveling the complete picture of negative-ion chemistry. The experiments will specifically target heterocyclic organic radicals, diradicals (carbenes), and strong electron acceptors (such as organocyanides). In addition, the fundamental understanding of photodetachment processes will be advanced by contrasting the experimental observations with predictions of theoretical models that describe photoelectron angular distributions. The interactions with neighboring molecules will be studied using cluster anions as well-defined microscopic solvation environments, recognizing that the reactivity of negative ions is strongly affected by intermolecular interactions.Chemical bonding is controlled by electrons, as it is their behavior that determines molecular structures and controls the outcomes of chemical reactions. Negative ions play important roles in many natural and technological processes and their unique properties are vital to understanding the chemistry of solutions, bio-, environmental, and astrochemistry. Furthermore, the process of removing the electron from the negative ion provides access to important neutral species, such as atmospheric and combustion radicals and other reactive intermediates. This research will provide knowledge relevant to several areas of physical sciences, such as combustion and electronic devices. The methods used in this study provide conceptual views of bonding that ultimately hold all matter together and define a new approach for introducing students and the general public to important concepts in physics and chemistry. These pursuits will allow student participants to acquire specialized training in experimental physical chemistry, preparing them for advanced careers in science, industry, and education.