In intramolecular SF (iSF), the strong coupling nature and confinement of diffusional separation of 1(TT) limits the extraction and harnessing of triplet energy. A series of iSF-capable dibenzopentalene derivatives (DBPs) have been synthesized and their photoinduced dynamics are monitored. Intramolecular singlet fission occurs in DBPs with consecutive 1(TT) separation in polycrystalline film with ~100% yield, suggesting the strong intermolecular coupling from the closely packing configuration in the film facilitates the disentanglement of correlated 1(TT).
