Molecular clusters in confined spaces

Confinement chemistry is a growing field with many potential applications in the synthetic, catalytic and especially pharmaceutical industries. Confinement of materials can reveal novel properties as compared to their bulk. They can also give insight into the nucleation and crystallization processes at the nanoscale. In this review, we focus on enclosed molecular clusters, from small aggregates to nucleation effects and ultimately crystallization within confining matrices such as metal-organic frameworks (MOFs), discrete cages, nanopores and droplets ranging from 5 A to 2 mm. This review aims to impact on the discovery of new drug solid forms, drug delivery, crystal engineering, water harvesting, and gas capture among other topics.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).