Visible light-mediated ring-opening polymerization of lactones based on the excited state acidity of ESPT molecules

The excited state acidity of ESPT molecules is first demonstrated as a suitable means of catalysis for the light-regulated ring-opening polymerization of lactones, in combination with a photosensitizer as the energy-transfer cocatalyst to harness light. Under blue light irradiation, this method could afford metal-free polyesters with well-controlled molecular weights and narrow dispersities.