Figure 2.

Production of ¹O₂ by the AQ series upon photoactivation. (a) Amount of ¹O₂ generated by the AQ series with light exposure analyzed by the ABDA assay and their quantum yields (Φ). Error bars represent the standard error of the mean from three independent experiments. (b) DFT-calculated energy transfer barriers (ΔG^‡) and their components (ΔG, singlet–triplet free energy gap; λ, reorganization energy) for each compound. (c) Structural comparison between HQ (Group A) and Dan (Group B) and key intramolecular hydrogen transfer that determines the different reorganization energy. Conditions: [compound] = 25 μM; [ABDA] = 100 μM; room temperature; Kessil lamp (467 nm) for 0, 1, 2, 3, 4, and 5 min. ^an.d., not determined due to the limited production of ¹O₂.