Tuned amphiphilic assembly in water for 100 % [2 + 2] photocycloaddition and highly efficient isomeric separation

Abstract

Photoresponsive smart materials suffer from elusive reaction pathways and complicated purification processes, which contradicts the principles of green chemistry and atomic economy chemistry. Herein, based on simply tuned self- and co-assembly of an amphiphile in water, a "one stone, two birds" function is achieved in a controllable photoresponsive system, that is quantitative photocycloaddition and efficient E/Z isomeric separation. Self-assembly driven by hydrophobicity refines the photochemical process to a single pathway with remarkable 100 % conversion. The synergy of thermal responsiveness and ion-induced co-assembly enables selective crystallization, facilitating highly efficient E/Z isomeric separation. This study demonstrates the host-guest interactions between open linear oligoethylene glycol chains and cations by single crystal. The tunable transparency and the inherent aggregated emission allow for visible tracking of both the photocycloaddition and separation processes, providing valuable insights into the underlying mechanisms. This work offers a new paradigm for the development of green and controllable photoresponsive systems.