Guest-Induced Transformations in Metal-Organic Cages

Stimuli-responsive structural transformations are common in artificial coordination assemblies and can help expand the engineering of programmable functional materials. In particular, chemical guests have proven to act as stimuli and signals inducing structural interconversions in Metal-Organic Cages (MOCs). In addition to cages, other related classes of coordination assemblies can express structural reorganization upon chemical binding to produce new MOC constructs, many of which do not form otherwise, and exhibit properties and functions not available before the transformation. This review highlights recent examples of such a class of guest-induced transformations. The connection between changes and host-guest interactions is examined for both neutral and anionic guests, pointing out that in-situ formed molecular cargoes may also exert conversions. Cases of mixtures of MOCs that redistribute upon encapsulation of complementary species are also featured. This review thus aims to provide an update and new methodological insights into guest-responsive MOCs for enhancing their design and applications.