Fig. 3. Polymer 1 photodegrades upon irradiation with visible light in hydrophobic environments. (a) Spectral changes in the UV-Vis spectrum of polymer 1 irradiated in CH₂Cl₂ (0.04 mg mL^–1, 0.5 mL) with visible light (λ _ex = 400–500 nm, 0.18 W, 0.21 W cm^–2). The blue shaded area highlights visible light absorption. Inset: color change following complete photoconversion. (b) GPC chromatogram of polymer 1 before (blue trace, M _w = 31.7 kDa, PDI = 2.7, PMMA standard) and after irradiation in CH₂Cl₂ (0.04 mg mL^–1, 0.5 mL) with visible light (λ _ex = 400–500 nm, 0.18 W, 0.21 W cm^–2) for 2.5 min (black trace) and 10 min (red trace). Absorbance sampled at 300 nm; peak at 24 min is the toluene internal standard.