Molecular Networks: Bonding and Long-Range Interactions in Anionic Environments

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With support from the Chemical Structure, Dynamics and Mechanisms-A (CSDM-A) program of the Chemistry Division, Professor Andrei Sanov and his team at the University of Arizona will study the binding of electrons to molecules and the cooperative interactions induced by the addition of excess electrons to extended molecular networks. Such interactions are ubiquitous in environmental and biological chemistry and play defining roles in shaping our world. By capturing laser-generated images of the electrons, the project aims to attain a unified molecular/supramolecular view of the essence of chemistry: the behavior of electrons in stable molecules and in systems undergoing chemical change. Professor Sanov will develop educational activities inspired by this research, placing emphasis on science literacy and math-intensive education at the introductory and advanced curriculum levels. These activities will include hands-on research exposure and modeling projects that integrate research elements into the general chemistry, mathematical physics, and physical chemistry coursework.This project in the Sanov laboratory at the University of Arizona will focus on chemical interactions in cluster anions, with an emphasis on charge delocalization and the interplay between covalent and noncovalent forces. Since describing a complex system must start with understanding its building blocks, a two-pronged approach is to be used. First, the intramolecular covalent bonding will be examined, including the effects of interactions with the surroundings on the intramolecular bonding structures. Second, the cooperative effects in molecular networks controlled by long-range covalent and noncovalent forces will be targeted. The synergy between the two prongs is important, for the first is aimed at the building blocks of chemical matter, while the second considers how they fit together in larger structures, transcending the molecular view. The project will utilize photoelectron imaging spectroscopy in conjunction with theoretical modeling. The photoelectron spectra and angular distributions will be used to characterize the chemical bonding and inter-molecular forces in cluster anions. The work will advance from stable bonds to radical and diradical interactions in non-equilibrium transient species, and to weak covalent interactions and solvation forces in clusters and larger molecular networks. The results will be interpreted with the help of electronic-structure calculations. The broader impacts include potential societal benefits from increased knowledge of the structures and thermochemistry of reactive intermediates and an improved understanding of the general mechanisms of chemical bonding, charge-sharing, and reactivity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.