BODIPY-Based Porous Organic Polymers: How the Monomeric Methyl Substituents and Isomerization Affect the Porosity and Singlet Oxygen Generation

Facile Friedel-Crafts coupling reaction prepared porous organic polymers BDP-POP-n (n = 1, 3, and 4) are reported. The influences of methyl substituents and single monomer isomerization on corresponding BDP-POPs' porosity and singlet oxygen generation properties have been investigated. The obtained BDP-POPs are thoroughly characterized by a combination of techniques such as Fourier transform infrared, solid C-13 NMR, scanning electron microscopy, and transmission electron microscopy. In addition, these porous polymers' singlet oxygen generation capacities under visible green light (480-510 nm) irradiation are compared. Results show that BDP-POP-1, whose pyrrolyl ring bears methyl substituents and the two 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BDP) units are at para-position of the phenyl ring, possesses the largest Brunauer-Emmett-Teller surface area and the best singlet oxygen generation ability. Control experiment reveals that the BDP-POP-1 shows superiority in generating singlet oxygen than that of model polymer CMPBDP. It is believed that this work may pave a road to design more effective porous materials for photocatalysis.