Aggregation-Induced Energy Transfer in a Decanuclear Os(II)/Ru(II) Polypyridine Light-Harvesting Antenna Dendrimer

Self-assembly of light-harvesting antenna (multichromophoric) systems is a typical feature of natural photosynthetic organisms, aimed at maximizing light absorption and solar energy conversion. Inspired by this concept, selfassembly strategies for integrating light-harvesting units are highly desirable objectives in supramolecular chemistry. Here, we demonstrate that self-assembly of light-harvesting dendrimers based on Ru(II) and Os(II) polypyridine complexes leads to aggregation-induced energy transfer. This phenomenon is proposed to be a result of inter-dendrimer electronic interactions involving electronic energy donors and acceptors of different dendrimers and suggests that the title dendrimer shows features reminiscent of the energy migration patterns occurring among LH1 and LH2 assemblies of natural systems. Even in consideration of the reported use of similar dendrimers for photochemical water oxidation, the aggregation-induced energy transfer reported here, as well as the self-assembly of the light-harvesting dendrimers itself, can be useful for designing new integrated systems for solar fuel production.