Atropisomer-based construction of a new perylene diimide macrocycle as visible-light photocatalyst for selective sulfide oxidation

By using a perylene diimine (PDI) syn-atropisomer as highly preorganized precursor, we successfully constructed a visible-light-active organic macrocycle PDI-M. The formation of macrocyclic structure effectively avoids self-aggregation of PDI cores and enhances the absorption in visible region. As a photocatalyst, PDI-M exhibits excellent activity on aerobic selective oxidation of sulfide into sulfoxide under visible light irradiation at room temperature. Mechanism studies show that both superoxide and singlet oxygen act as reactive oxygen species. This work provides a typical case toward the maximum utilization of photosensitive groups under mild conditions.