Wavelength Selective Single Molecule Photobase/Photoacid Generator Enabling Dynamic Control of Soft Matter Materials Functions

Abstract Photoremovable protecting groups (PRPGs) enable precise spatiotemporal control over molecular release and functional activation. Recent advances have introduced wavelength‐selective systems for sequential deprotection, broadening applications in drug delivery, material synthesis, and photopolymerization. In parallel, PRPGs play a crucial role in photobase generators (PBGs) and photoacid generators (PAGs), enabling oxygen‐tolerant, spatially controlled polymerization and depolymerization through light‐induced base and acid release. Herein, we present a novel benzophenazine‐based photocleavable system capable of the sequential, wavelength‐selective release of both a base and an acid. This design integrates 1,1,3,3‐tetramethylguanidine (TMG) and p ‐toluene sulfonic acid functionalities, which are independently uncaged upon irradiation with blue (≥ 410 nm) and UV (≥ 310 nm) light, respectively. We demonstrated the versatility of this dual‐responsive system in modulating soft matter properties, including wavelength‐selective polymer crosslinking, degradation, and debonding‐on‐demand adhesives. This work establishes a new platform for advanced photochemical control over polymeric transformations, with broader implications in responsive soft matter engineering.