Ethylene-Bridged Oligo-BODIPYs: Access to Intramolecular J-Aggregates and Superfluorophores

Abstract

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), outstandingly high attenuation coefficients (up to 1 042 000 M cm), and quantum yields of up to unity.

Improved photon absorption in dye-functionalized silicon nanocrystals synthesizedviamicrowave-assisted hydrosilylation

“…Thus, the less pronounced BET with η BET = 7% (calculated with eqn (5)) is observed in the (C6)-(3)-SiNc system due to the lower dye surface concentration and the higher energy of the BODIPY triplet (∼750 nm). 47,48 Secondly, the ns-decay measured for the range 550-600 nm indicates strong quenching of BODIPY luminescence with η DET = 94%. In contrast to the unreacted dye (3) with lifetime of 7.2 ns (Fig.…”

On the Aggregation Behaviour and Spectroscopic Properties of Alkylated and Annelated Boron‐Dipyrromethene (BODIPY) Dyes in Aqueous Solution

“…[63,64] As has been recently shown by Werz's group, chemical fixation of BODIPY units to oligomers can strongly drive J aggregate formation. [65] These authors have also observed that subtle structural modifications can have a pronounced impact on the nature of the aggregates formed.…”

Optoelectronic Properties of Carbon‐Bound Boron Difluoride Hydrazone Dimers

“…Owing to the ease of tuning their redox, absorption, and emission properties by modifying the ligands, these complexes have found numerous applications as cell imaging agents, active components of optoelectronic devices, and stimuli‐responsive materials . The best‐known class of fluorescent BF 2 complexes is the boron‐dipyrromethenes (BODIPYs, 1 ), which have desirable photophysical properties including intense and narrow absorption and emission bands and, in some cases, near‐unity emission quantum yields ( Φ em ) in dilute solutions …”