A porous and photoactive perylene diimide-based metal-organic framework for the selective oxidation of sulfides to sulfoxides

Making chemical transformations more sustainable is an important goal in modern chemistry, driving the development of more efficient and environmentally friendly methodologies. The selective oxidation of sulfides to sulfoxides is an utilized transformation in pharmaceuticals and fine chemicals, yet conventional methods often require stoichiometric oxidants and generate unwanted waste. Herein, a porous PDI-based metal–organic framework, [Cd(tpda)(DMA)(H 2 O)] (Cdtpda), constructed from 1,6,7,12-tetrachloroperylenediimide-N,N′-diacetic acid and Cd 2+ nodes, is reported as a visible-light-responsive photosensitizer for sustainable sulfide oxidation. Cdtpda features three-dimensional nanosheets connected via π–π interactions, creating continuous pores, and exhibits broad UV/Vis absorption and complete fluorescence quenching, indicative of strong H-type aggregation and efficient photoinduced electron transfer. Under visible-light irradiation and molecular oxygen, Cdtpda selectively converts aryl sulfides to sulfoxides with high yield and minimal overoxidation, while remaining recyclable and structurally intact. Mechanistic investigations, including reactive oxygen species scavenging and EPR spectroscopy, reveal that this high selectivity is governed by singlet oxygen generated via photosensitization as the dominant reactive species. These findings encourage further exploration of structural diversity in PDI-based MOFs and the development of additional applications.