Porphyrin-acene Dyads for Controlled Singlet Oxygen Generation and Depletion

The controlled generation, capture, and release of singlet oxygen (1O2) holds significant promise for applications in catalysis and biomedicine. In this study, we designed and synthesized a novel series of bichromophoric compounds integrating a central porphyrin core, which efficiently generates singlet oxygen, with acene units that serve as reservoirs for its reversible storage via endoperoxides. A comprehensive investigation, including detailed photophysical characterization, singlet oxygen generation, capture, and release efficiency measurements, and quantum-chemical calculations, was conducted to elucidate structure-property relationships critical for 1O2 control. Our findings indicate that the optimal performance depends on a delicate interplay between singlet oxygen generation efficiency, its capture kinetics, and the thermal reversibility of oxygen release. Among the studied porphyrin-acene dyads, the tetracene derivative emerged as the best-performing compound, combining high singlet oxygen generation, efficient formation of endoperoxides, and sufficient thermal singlet oxygen release. In contrast, pentacene and anthracene derivatives exhibited limitations due to either lower singlet oxygen yields or poor reversibility, respectively. These insights open new pathways for the rational design of advanced materials and systems capable of precise and controlled singlet oxygen delivery.