A biomimetic supramolecular platform enables sequential four-step energy transfer and reactive oxygen species...

Natural photosynthesis, a quintessential energy conversion process sustaining life on Earth through its sophisticated multi-step energy transfer cascades, has inspired the development of artificial light-harvesting systems aimed at mimicking its efficiency and complexity. Here, we report a supramolecular energy transfer platform constructed via electrostatic interactions between sodium polystyrene sulfonate (RSS) and a quaternary ammonium salt modified cyano-substituted phenylenevinylene derivative (PPTA) in H₂O medium, achieving a sequential four-step energy relay. Energy is sequentially transferred from the PPTA-RSS complex to eosin Y (EY), rhodamine B (RhB), sulforhodamine 101 (SR101), and cyanine 5 (Cy5), with stepwise enhancement in superoxide anion radical (O₂˙^-) generation efficiency. Notably, the unique energy transfer pathway effectively suppresses the generation of singlet oxygen (¹O₂), mechanistically circumventing the oxidative damage to small molecules and the formation of by-products commonly encountered in organic synthesis. Moreover, the selective oxidative activity of O₂˙^- not only enables the visible-light-induced amidation of aromatic aldehydes with amines in an aqueous solution and a transition-metal-free system, providing an economical, green, and mild approach for amide bond formation, but also simultaneously achieves the oxidative dehydroaromatization of nitrogen-containing heterocycles (e.g., tetrahydroquinolines and dihydroindoles), offering a universal strategy for the efficient synthesis of unsaturated nitrogen heterocyclic skeletons. This study has constructed an ordered multi-step energy transfer system with precise reactive oxygen species (ROS) regulation through supramolecular assembly, providing a reliable research paradigm for efficient light-to-chemical energy conversion and green organic synthesis.