Isostructural Perylene Diimide-Based Metal–Organic Frameworks for Efficient Photocatalytic Oxidation of Benzylamines

Incorporating a perylene diimide (PDI)-based ligand into metal–organic frameworks (MOFs) is an effective but scarcely studied strategy for fabricating high-performance photocatalysts. In this work, three isostructural PDI-based MOFs with a formula of [M 3 (HTCPDI) 2 (H 2 O) 4 ]·2DMF·H 2 O ( M-TCPDI, where M = Ni(II), Co(II), or Mg(II), H 4 TCPDI = N, N ′-bis(3,5-dicarboxyphenyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxylic diimide, and DMF = N, N -dimethylformamide) were successfully synthesized under solvothermal conditions. Crystal structure analysis demonstrated that these three MOFs are isostructural three-dimensional (3D) frameworks. In addition to retaining absorption features similar to those of H 4 TCPDI in the visible region, these materials exhibit additional pronounced and extended absorption spanning the range of 600–900 nm. To study their capability as photocatalysts, the oxidative coupling of benzylamine to imine was employed as a model reaction and the results revealed that the performance of Ni-TCPDI is slightly better than that of Co-TCPDI, but significantly better than that of Mg-TCPDI, under 50 W white light LED irradiation in air without any other additives. More impressively, Ni-TCPDI could deliver appreciable photocatalytic reactivity under simulated sunlight at a light intensity of 50 mW cm –2 . This study expands the scope of PDI-based MOFs in photocatalysis and offers an effective strategy for light-driven oxidative reactions through rational metal-node modulation.