Singlet fission mediates carotenoid-to-bacteriochlorophyll energy transfer in purple photosynthetic bacteria

Article excerpt

Nature Chemistry, Published online: 23 June 2026; doi:10.1038/s41557-026-02186-7 The biological role of singlet fission, where two excitons are generated by one photon, is poorly understood. Now it has been shown that heterofission occurs in bacterial light-harvesting complexes, creating a triplet-pair reservoir that enhances carotenoid-to-bacteriochlorophyll energy transfer efficiency and temporarily staggers energy delivery to the reaction centre.