Fig. 3. Experiments for mechanistic investigation. (a) Control experiments for mechanistic studies. (b) Quenching experiments for investigating the key ROS. (c) High-resolution mass spectrometry of the adduct between TEMPO and ·CH₂CN. (d) High-resolution mass spectrometry of the adduct between BHT and ·CH₂CN. ^aDetermined by GC-MS using 1,3,5-trimethoxybenzene as the internal standard. ^bStandard conditions: 1a (0.3 mmol) in CH₃CN (15 mL) with γ-ray radiation (dose rate: 110 Gy min⁻¹, measured using a Fricke dosimeter) at room temperature and under an air atmosphere for 15 h. n.d. = no detected.