Photosensitive hyper-cross-linked polymers derived from three-dimensional ringlike arenes: Promising catalysts for singlet-oxygen generation

Solar energy-driven synthesis of chemicals is of great significance for green and sustainable development, and design of photocatalysts with high efficiency is an interesting topic. Herein, a series of hyper-cross-linked polymers (PS-HCPs) with excellent photosensitivity were synthesized via one-pot polymerization of non-photosensitive arenes with three-dimensional ringlike stereostructures (e.g., hexaphenylbenzene) under AlCl3 catalysis in dichloromethane. They could efficiently convert O2 into singlet oxygen under visible light irradiation and showed excellent activity for catalyzing aerobic photooxidation of benzylamines, sulfides, and benzyl alcohols to corresponding target products in high yields. Especially, PS-HCP-4 derived from hexaphenylbenzene even showed 2 times higher activity for benzylamine photooxidation than the best polymer-based photocatalyst to date. In addition, the resultant PS-HCP catalysts were stable and could be reused for 5 times without obvious activity loss.