Fig. 2. ¹H NMR spectra (in the range of 0.5–4.0 ppm) of (salen)Co–CO₂CH₃ I (5.0 mM) and TEMPO (50 mM) in benzene-d ₆ under visible light irradiation (I = 3 mW cm^–2 at 420–780 nm wavelength) at room temperature for 1 h (*salen ligand in I, see ESI, Fig. 2S†).