posted on 2017-09-26, 00:00authored byLukas
J. Patalag, Luong Phong Ho, Peter G. Jones, Daniel B. Werz
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.