“…Nature uses confined and compartmentalized environments such as organelles to carry out chemical reactions under mild conditions with precise control of kinetics and selectivity. Over the last few decades, this has served as an inspiration to develop artificial nanoreactors based on directed self-assembly of small molecules through noncovalent interactions. − Within this context, photochemistry can benefit from confined spaces, , for example, when performed in mesoporous inorganic materials, microemulsions, micelles, , vesicles, polyelectrolyte nanoparticles, foams, and gels. , The confinement may improve photochemical processes by influencing key aspects such as light absorption and the lifetime of redox intermediates. , Among the above-mentioned confined media, physical or supramolecular gels are typically made of low molecular weight (LMW) compounds, so-called gelators, self-assembled through noncovalent interactions (e.g., hydrogen bonding, van der Waals, charge transfer, dipolar, p-p stacking), which usually provides reversible gel-to-sol phase transitions as a response to external stimuli. The solid-like appearance and rheological behavior of these materials result from the immobilization of the liquid (major component) into the interstices of a self-assembled matrix (minor component) through high surface tension and capillary forces, making the liquid pools different from homogeneous solutions .…”