Perspective: Dynamics of confined liquids.

Liquids confined on nanometer lengthscales are ubiquitous in chemistry, occurring in systems ranging from mesoporous catalysts to the crowded interior of a cell. Understanding how the properties of the liquid in these environments differs from that in the corresponding bulk is key to interpreting measurements, developing methods for theoretical predictions, and controlling chemical pathways. This area has received significant attention in recent years, resulting in notable progress. In this perspective, we discuss the advances in understanding the dynamics of confined liquids as well as the nontrivial remaining challenges.