CAREER: Quantum-State Control on Multidimensional Potential Energy Surfaces

College Of William And Mary, Williamsburg VA

Investigators

Abstract

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program in the Division of Chemistry, Nathanael Kidwell of the College of William and Mary will use advanced molecular spectroscopy and dynamics methods to study the bimolecular reaction pathways of hydroxyl radicals (OH) with several classes of hydrocarbons. There exists a knowledge gap arising from the difficulty in identifying the reactive and nonreactive pathways for large molecular systems. The goal of this project is to characterize how the orientation and nuclear motions of the colliding molecules impact which pathway is followed. The research seeks to understand the fundamental interactions and outcomes from bimolecular collisions of OH radicals with hydrocarbons with increasing chemical complexity. These studies will probe the interaction potential between the collision partners without interference from other molecules with the goal of better understanding the roles of OH radicals in oxidation reactions in atmospheric and combustion chemistry. In addition to training students in modern laser technology and analysis approaches, members of the Kidwell research group will engage undergraduate and high school students in vertical profiling of the atmosphere using drone-enabled Raspberry Pi atmospheric sensors. This project will apply laser-based spectroscopy and velocity map imaging techniques to obtain insights into the intermolecular interactions between OH and hydrocarbon/atomic targets with increasing chemical and multistate complexity. In addition to being important chain carriers in oxidation reactions, OH radicals are pivotal reactive intermediates in atmospheric and combustion chemistry modeling. Additionally, hydrocarbons are central to both atmospheric chemistry and combustion chemistry, and their oxidation initiated by OH radical collisions is a critical first step in characterizing their removal. Under single-collision conditions, the targeted molecular complexes will be characterized with isomer-specificity and activated with mode-selectivity to reveal bimolecular collision outcomes. Objectives are to study nonadiabatic effects and topological features on multidimensional reactive and nonreactive potential energy surfaces. The project will provide advanced training and learning opportunities for students to catalyze career success and will foster outreach activities with near-peer instruction. 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.