Abstract: The nature of intramolecular charge transfer (CT) of N,N‐diaryl dihydrophenazine photocatalysts (PCs) in different solvents is explored in context of their performance in organocatalyzed atom transfer radical polymerization (O‐ATRP). PCs having a computationally predicted lowest energy excited state exhibiting CT character can operate a highly controlled O‐ATRP in a wide range of solvent polarities, from non‐polar hexanes to highly polar N,N‐dimethylacetamide. For PCs having a computationally predicted lowest energy excited state not possessing CT character, their ability to operate a controlled O‐ATRP is decreased. This study confirms the importance of CT character in the excited state for N,N‐diaryl dihydrophenazine PCs, and a deeper understanding of the activity of CT PCs has enabled the synthesis of polymers of low dispersity (<1.10) in a controlled fashion.
Reference: Ryan, M. D.; Theriot, J. C.; Lim, C.-H.; Yang, H.; G. Lockwood, A.; Garrison, N. G.; Lincoln, S. R.; Musgrave, C. B.; Miyake, G. M., Solvent effects on the intramolecular charge transfer character of N,N-diaryl dihydrophenazine catalysts for organocatalyzed atom transfer radical polymerization. J. Polym. Sci. A Polym. Chem. 2017, 55, 3017.