Construction of aggregation-induced emission photosensitizers based on supramolecular polymers for enhanced photocatalytic oxidative coupling of amines

Abstract

In this study, we have developed and produced a derivative of tetraphenylethene (TPE–Epy) and demonstrated its ability to undergo self-assembly with cucurbit[8]uril (CB[8]) via host–guest interactions, which lead to the formation of supramolecular polymers (TPE–Epy–CB[8]) exhibiting aggregation-induced emission when placed in an aqueous solution. The photophysical properties of TPE–Epy are enhanced when it is encapsulated within the CB[8] cavity of supramolecular polymers, which can be used as photosensitizers. This is attributed to the host–guest interactions between TPE–Epy and CB[8], which restrict the intramolecular motion of TPE–Epy. Consequently, the supramolecular polymers exhibit a high efficiency in generating reactive oxygen species (ROS). Significantly, owing to its notable effectiveness in generating ROS, TPE–Epy–CB[8] exhibits promising potential as a highly effective photocatalyst for facilitating the photocatalytic oxidative coupling reaction of amines to imines. This reaction can produce up to 90% of the desired product when conducted in an aqueous solution.