A Photocatalytically Active Rotaxane Mimicking Photosystem I

Highly efficient and environmentally friendly catalysis as observed in nature remains a pivotal yet unresolved challenge with broad scientific and societal relevance. In synthetic settings, the prevention of catalyst deactivation from chemical changes to its molecular structure during active operation is the primary concern and remains elusive. Inspired by membrane and protein integration of the natural photosynthetic apparatus of green plants ensuring structural integrity of key components, we report a photocatalytically active rotaxane mimicking photosystem I. Strategically burying sensitive alkyne-units of the metal-connecting bridging ligand in a macrocycle cavity, i.e. in cucurbit[7]uril, the heterodinuclear rotaxane photocatalyst preserves both, structural integrity and activity of its components yielding superior, long-term photocatalytic activity under enzyme-like H-bond-driven substrate preorganization at the catalytic center. These results underscore the pivotal function of rationally engineered interplay between supramolecular assemblies in catalysis, thereby inaugurating novel catalytic paradigms for more sophisticated and sustainable supramolecular methodologies with direct applications in artificial photosynthesis and light-driven water splitting.