In this talk, I will discuss some of our recent efforts to understand how simple reactions that rearrange charge are altered when embedded in complex, fluctuating environments. In the first part, I show how liquid-vapor interfaces can modulate aqueous chemistry. Specifically, I will discuss how the facile charge separation of N2O5 occurring via interfacial hydrolysis leads to efficient gaseous uptake into aqueous atmospheric aerosols, offering an irreversible sink of NOx compounds in the nighttime air. In the second part, I will show how strongly anharmonic lattices can effectively dissociate excitons. Specifically, I will discuss how photo-generated electrons and holes in the lead halides are slow to radiatively recombine due to polaronic effects that result from the uncharacteristically soft, polar perovskite lattices. In both cases, our progress is enabled and enriched by novel simulation tools and theory.