Multilevel Supramolecular Assembly with Three‐Step Sequential Energy Transfer for Selective Generation of Sulfides and Sulfoxides by Photoredox Thiol‐Ene Cross‐Coupling Reactions

Abstract

Abstract Photosynthesis in natural systems involves a series of steps for energy transfer, but replicating this process in artificial light‐harvesting systems (ALHS) with three or more steps is still difficult. This work presents a set of ALHS that exhibit an intricate three‐step energy transfer mechanism. The ALHS are meticulously fabricated by utilizing cyano‐substituted diphenyl ethylene derivative (DCMI), cucurbit[7]uril (CB[7]), and sulfobutylether‐β‐cyclodextrin (SBE‐βCD) through host–guest and electrostatic interactions in water to create a multilevel molecular assembly serving as energy donors. Three distinct types of fluorescent dyes, namely rhodamine B (RhB), sulforhodamine 101 (SR101), and cyanine 5 (Cy5), are employed as energy acceptors. The DCMI‐2CB[7]@SBE‐βCD+RhB+SR101+Cy5 system demonstrates an effective three‐step sequential energy transfer process, which involves the transfer of energy from DCMI‐2CB[7]@SBE‐βCD to RhB, SR101, and Cy5 in a consecutive manner, resulting in a substantial energy transfer efficiency. Remarkably, within the multi‐step energy transfer system, the generation of reactive oxygen species (ROS) exhibit a progressive augmentation. Furthermore, to fully utilize the harvested energy and obtained ROS, the ALHS with multistep sequential energy transfer further promotes the visible‐light induced photoredox thiol‐ene cross‐coupling reaction between thiophenol and styrene to selectively obtain sulfides and sulfoxides in water with high yields.