A 2,1,3 benzothiadiazole (BTZ)–based vinyl crosslinker was synthesized and copolymerized with large excesses of styrene using free radical polymerization to deliver heterogeneous triplet photosensitizers in three distinct physical formats: gels, beads and monoliths. These photosensitizers were employed for the production of singlet oxygen (1O2) and for the aerobic hydroxylation of aryl boronic acids via superoxide radical anion (O2) whereby the materials demonstrated good chemical and photo stability. BTZ containing beads and monoliths were exploited as photosensitizers in a commercial flow reactor, and 1O2 production was also demonstrated using direct sunlight irradiation, with a conversion rate comparable to the rates achieved when using a 420 nm LED module as the source of photons.
- flow chemisty
- free-radical polymerisation
- heterogeneous photosensitizer
- reactive oxygen species
- singlet oxygen
- visible light
Tobin, J. M., McCabe, T. J. D., Prentice, A. W., Holzer, S., Lloyd, G. O., Paterson, M. J., Arrighi, V., Cormack, P. A. G., & Vilela, F. (2017). Polymer-supported photosensitizers for oxidative organic transformations in flow and under visible light irradiation. ACS Catalysis, 7(7), 4602-4612. https://doi.org/10.1021/acscatal.7b00888