A ring-controlled fluorescent platform for visualizing polymer degradation

The creation of a new photoluminescent platform to study their photo physics and further applications is important in the fields of chemistry, material, physics, etc. In this work, we developed benzene-based fluorophores generated by chemical reactions on conjugate acceptor precursors. Their optical properties have been studied, and the large Stokes shifts, high molar extinction coefficients and quantum yields have been revealed. The starting precursors containing bis-intercalated vinyl thioester shows no luminescence, which is turned on by the chemically triggered cyclization. From spectroscopic, crystallographic, and computational studies, cyclization-induced emission enhancement is proposed as a mean to explain the photoluminescent performances, a principle extended in the substituent incorporated fluorophores. Furthermore, they were applied to the chemically triggered degradation of a polymer and achieved visual tracking, quantifying, and downcycling of the processes. The method for designing and developing series fluorophores and visually tracking polymer degradation represents a new photoluminescent platform, allowing its further applications.