CAREER: Accelerated Chemical Reactions in Unique Solvation Environments

With support from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry, Jesse McDaniel of the Georgia Institute of Technology is investigating the acceleration of chemical reactions at interfaces and within specific solvation environments. Developing new chemistries that address a wide range of societal applications requires fundmental understanding of the rates of chemical reactions, which in certain cases can be substantially accelerated by the presence of interfaces or confinement of reactants in small droplets. In all cases, reaction acceleration occurs through interactions at the atomic scale, and molecular simulations using high-performance computers are routinely engaged to characterize reaction mechanisms. Dr. McDaniel and his research group will build on these approaches by pioneering a new framework for calculating and predicting rate acceleration in complex environments. The project aims to improve mechanistic understanding of catalytic rate enhancements at interfaces and heterogenous solvation environments for important C-C bond forming reactions and conversions of fructose and polyalcohols. This has the potential to enable tailored design of reaction environments (e.g. microdroplets, thin films) to optimize the reaction rates/yield. The McDaniel team will partner with regional high school teachers to better integrate software and data science tools within the high school educational curriculum and effectively train the next generation of computational scientists. There are many compelling examples of dramatically accelerated chemical reactions in microdroplets, thin films, and other heterogenous solvation environments. In all cases, the key questions concern the microscopic mechanisms and atomistic interactions through which the reactions are accelerated within these unique contexts. Jesse McDaniel and his research group will investigate these catalytic mechanisms by developing a new computational framework for calculating chemical reaction free energy profiles in complex environments. The new approach will include quantum mechanics/molecular mechanics (QM/MM) with exact long-range electrostatic embedding, coupled with physics-based/neural network (PB/NN) reactive force fields. Both methods will be implemented within a unified software infrastructure to simultaneously optimize accuracy and sampling. The McDaniel group will apply this novel framework to investigate a variety of examples of accelerated chemical reactivity in heterogeneous solvation environments including Claisen-Schmidt condensation reactions within thin films, fructose conversion within ionic liquid/water solutions, and accelerated Friedel-Crafts alkylation within microdroplets. These efforts have the potential to provide for a detailed microscopic understanding of the accelerated chemical 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.