Cavity Quantum Electrodynamics Enables para- and ortho- Bromination of Nitrobenzene

Coupling molecules to a quantized radiation field inside an optical cavity has shown great promise to modify chemical reactivity. In this work, we show that the ground state selectivity of the electrophilic bromination of nitrobenzene can be fundamentally changed by strongly coupling the reaction to the cavity, generating the \textit{ortho}- or \textit{para}-substituted products instead of the \textit{meta} product. Importantly, these are products that are not obtained from the same reaction outside the cavity. A recently developed \textit{ab initio} approach was used to theoretically compute the relative energies of the cationic Wheland intermediates, which indicate the kinetically preferred bromination site for all products. Performing an analysis of the ground state electron density for the Wheland intermediates inside and outside the cavity, we demonstrate how strong coupling induces reorganization of the molecular charge distribution, which in turn leads to different bromination sites directly dependent on the cavity conditions. Overall, the results presented here can be used to understand cavity-induced changes to ground state chemical reactivity, from a mechanistic perspective, as well as to directly connect frontier theoretical simulation to state-of-the-art, but realistic, experimental cavity conditions.