Ethylene-Bridged Oligo-BODIPYs: Access to Intramolecular J-Aggregates and Superfluorophores.
Lukas J PatalagLuong Phong HoPeter G JonesDaniel B WerzPublished in: Journal of the American Chemical Society (2017)
A versatile and rapid access to various chain lengths of ethylene-bridged BODIPY motifs was discovered. Corresponding oligomers comprising up to eight monomeric units were studied with respect to their microstructures by photophysical, X-ray crystallographic, and computational means. The investigation of three different dipyrrin cores revealed a crucial dependence on the substitution pattern of the core, whereas the nature of the meso-periphery is less critical. The impact of substituent effects on the conformational space was investigated by Monte Carlo simulations and a set of DFT methods (B3LYP, PBEh-3c, TPSS/PWPB95), including dispersion effects. Cryptopyrrole-derived oligo-BODIPYs are characterized by a tight intramolecular arrangement triggering a dominant J-type excitonic coupling with red-shifts up to 45 nm, exceptionally small line widths of the absorption and emission event (up to 286 cm-1), outstandingly high attenuation coefficients (up to 1 042 000 M-1 cm-1), and quantum yields of up to unity.
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