Table ). in MeCN after 24 h with λexc = 455 nm. In general, the reaction is sluggish in THF, with the highest yield of 26% being obtained using tDABNA ( Table , Entry 4). A small solvent screen showed that in MeCN the yields drop drastically using each of the four PCs ( to reduce TsCl (Ered = -0.94 V vs SCE). The photostability of tDABNA was investigated under the reaction conditions (Figure ). As we had shown that this compound in solution is photostable in THF but not in DCM (Figure ) we wanted to determine whether there is a connection between the low yield in THF compared to DCM and the photostability of the PC. After irradiation in each of DCM and THF, the absorption profile of tDABNA changed significantly, with the complete disappearance of the low energy SRCT absorption band. This clearly shows that tDABNA is not stable under the reaction conditions regardless of the solvent used. Bryden et al. have shown that the of photostability of a wide range of photocatalysts engaged in photoredox reactions is generally poor. Figure . Degradation study of the ATRA reaction with tDABNA as the PC. TsCl (0.25 mmol), styrene (0.50 mmol) and PC (3 mol%) in 1 mL solvent under inert conditions. Absorption before and after 24 h irradiation at 440 nm in THF and DCM.