1-Mono- and 1,7-Disubstituted Perylene Bisimide Dyes with Voluminous Groups at Bay Positions: In Search for Highly Effective Solid-State Fluorescence Materials

Abstract

A series of 1-mono-and 1,7-disubstituted perylene bisimides (PBIs) with voluminous phenoxy groups at bay positions has been synthesized. These dyes show absorption and emission properties typical for PBIs in solution with high fluorescence quantum yields close to unity. In the solid state, the voluminous substituents at bay positions effectively wrap the dye core and prevent π−π interactions between twofold substituted chromophores. The comparison of UV−vis absorption and fluorescence properties for solutions as well as solid-state thin films, powders, and microcrystals in combination with the respective singlecrystal structures allows for establishing the packing structure−optical property relationships. According to this analysis, only with two bulky 2,4,6-tris(4-tertbutylphenyl)-phenoxy or 2,4,6-tris(3,5-di-tert-butylphenyl)-phenoxy substituents functionalized PBI chromophores are completely jacketed to afford efficient solid-state emitter materials with fluorescence quantum yields of over 60%. A comparative evaluation of PBIs bearing bulky substituents at imide positions reveals significantly higher solidstate fluorescence quantum yields of the 1,7-substituted PBIs.

Modular Synthesis of Organoboron Helically Chiral Compounds: Cutouts from Extended Helices

“…In contrast to other popular emitters, such as BODIPY [37] or perylene bisimide (PBI) dyes, [38] these organoboron helicenes do not undergo aggregation‐caused quenching of fluorescence. Whereas for PBIs, extensive molecular engineering via introduction of voluminous substituents is necessary in order to retain high emission properties in the solid state, [39] we could achieve this for H1‐Me 2 and H1‐Ph 2 without any special treatment, since their inherent non‐planar geometry effectively reduces intermolecular π–π interactions. In addition, the advantage of this molecular design manifests itself in the fact that the change in the emission color of H1 could be obtained by simply replacing Me with Ph substituents, hence without any modification of the π‐conjugated core.…”

Full-colour solvatochromic fluorescence emitted from a semi-aromatic imide compound based on ESIPT and anion formation

“…To achieve bright fluorescence, it is also important to suppress the aggregation caused quenching (ACQ) because the formation of aggregates induced by π−π stacking or charge transfer interactions in aromatic molecules frequently reduces the fluorescence quantum yields. The introduction of bulky functional groups [12,13] and helical structures [14] are known to be effective to suppress or reduce the ACQ. To achieve high UV absorption followed by full-colour emission with high efficiency, long-wavelength fluorescence with a very large Stokes shift (ν) is a prerequisite.…”

Zinc (II) and AIEgens: The “Clip Approach” for a Novel Fluorophore Family. A Review

“…In 2016, Hiroshi Nishihara [ 100 ] and coworkers studied the solid-state PL emission of seven encumbered tetradentate bis(dipyrrinato)zinc (II) complexes. The bulky effect [ 101 , 102 , 103 ] due to the meso-aryl group in the dipyrrin ligands proved to affect the emissive properties of the dipyrrin Zn(II) complexes. The conformation of the meso-aryl group in the excited state greatly affects the nonradiative decay pathways.…”