Perylene diimide-based hyper-cross-linked polymers for visible-light-driven selective organic sulfide oxidation

Abstract

Hyper-cross-linked polymers (HCPs) feature excellent pore structures, ultra-high stability, and ease of preparation, making them promising candidates for visible-light-driven selective organic sulfide oxidation. Developing new HCPs of good performance is of great significance in the endeavor. Perylene diimide (PDI) exhibits excellent visible light absorption properties due to its high planar conjugated structure, showing potential as a monomer for photocatalytic HCP synthesis. In this study, we report the construction of two HCPs, named NUT-18 and NUT-18-Me, employing the Friedel-Crafts alkylation reaction using PDI derivatives as monomers. Both HCPs possess high specific surface area (reaching up to 811 and 828 m²/g) and photoactivity. Consequently, NUT-18 and NUT-18-Me demonstrated photocatalytic efficiency, with conversion and selectivity exceeding 98 % in the various organic sulfides’ photocatalytic oxidation. Notably, the photocatalytic performance is well-maintained even after 5 cycles, indicating good recyclability. Investigation of the catalytic mechanisms revealed that the selective catalytic oxidation of sulfides is based on the synergistic promotion of dual pathways for electron and energy transfer. This research highlights the potential of PDI molecules in designing and synthesizing porous materials as promising photocatalysts.