Synergistic Degradation of Durable Polymer Networks by Light and Acid Enabled by Pyrenylsilicon Crosslinks.

Material photocontrol has gained importance in process engineering and biomedical applications. However, highly photoreactive materials are intrinsically unstable to light, which limits their continuous use in lit environments owing to their gradual deterioration. Herein, synergistically photocontrollable materials in the presence of acid are developed to overcome the conventional trade-off between their photoreactivity and photostability. Pyrenylsilicon derivatives are designed as synergistically cleavable moieties on C-Si bonds under simultaneous treatment with light and acid through photoinduced dearomatization and protonation to generate the Wheland intermediate, whereas the derivatives are highly stable to light or acid alone. The unique reactivity of pyrenylsilicon derivatives is applied to various polymer network crosslinkers, enabling synergistic control and degradation of materials with light and acids. Because of their high photostability in the absence of acids, these materials can be utilized as optical materials, robust elastomers, and 3D photoprinted gels.