Base‐Assisted Imidization: A Synthetic Method for the Introduction of Bulky Imide Substituents to Control Packing and Optical Properties of Naphthalene and Perylene Imides

Abstract

We report the direct imidization of naphthalene and perylene dicarboxylic anhydrides/esters with bulky ortho , ortho ‐diaryl‐ and ortho , ortho ‐dialkynylaniline derivatives. This imidization method uses n ‐butyllithium as a strong base to increase the reactivity of bulky amine derivatives, proceeds under mild reaction conditions, requires only stoichiometric amounts of reactants and gives straightforward access to new sterically crowded rylene dicarboximides. Mechanistic investigations suggest an isoimide as intermediary product, which was converted to the corresponding imide upon addition of an aqueous base. Single‐crystal X‐ray diffraction analyses reveal dimeric packing motifs for monoimides, while two‐side shielded bisimides crystallize in isolated molecules without close π–π‐interactions. Spectroscopic investigations disclose the influence of the bulky substituents on the optical properties in the solid state.

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

“…Finally, if we compare the discussed findings on molecular packing in the crystal structures and their impact on the solid-state fluorescence quantum yield (Φ fl ) of bay-substituted PBIs 2 and 3 with data reported for imide-functionalized PBIs 4 , we can draw interesting conclusions concerning the affectivity of these two shielding approaches (Figures and S13). Crystal structures and partially solid-state fluorescence quantum yield of imide-substituted PBIs (Figure b) including BASF’s Lumogen Orange 4a as well as on more heavily shielded chromophores were reported by Wong and co-workers ( 4d′ – f′ , R = n Bu) and by our group ( 4c – e , R = H), where the latter just differ in the kind of residue R in the para-position of the imide substituents. Their respective solid-state fluorescence quantum yield is plotted against the chromophore concentration ( M PBI / M W ) in Figure .…”

Water‐Soluble Doubly‐Strapped Isolated Perylene Diimide Chromophore

“…The macrocyclization reaction between PDI-4Py and 4,4'bis(bromomethyl)biphenyl proceeded smoothly in CH 3 CN/ CHCl 3 (v/v 1 : 1) at 60 °C for 48 h, to afford GBox-1•4 PF 6 after anion exchange and purification in an overall cyclization yield of 31 %. Due to the high preorganization of PDI-4Py with rigid convergent conformation, [15,37] the cyclization procedure was straightforward without the use of template, catalyst and highly diluted concentration method. The water-soluble GBox-1•4 Cl was obtained by mixing the acetonitrile solution of GBox-1•4 PF 6 and tetrabutylammonium chloride.…”

Base‐Assisted Imidization: A Synthetic Method for the Introduction of Bulky Imide Substituents to Control Packing and Optical Properties of Naphthalene and Perylene Imides

“…Crystal structures of a,b) 8d and c,d) 9d.ORTEP drawing at 50 %p robability for thermal ellipsoids. [40] Angewandte Chemie Forschungsartikel times up to 30.5 ns (6a)i nt he solid state (Table S17) compared to monomeric naphthalene monodicarboximides in solution reported in the literature (typically < 0.5 ns). [29,33] In contrast, the structured luminescence of 6d at shorter wavelengths and with short lifetimes can be attributed to an emission from amonomeric species,which is attributed to the rather small overlap of the naphthalimide moieties in the solid state (Figure 1d).…”

“…Crystal structures of a,e) 6a,b,f) 6b,c ,g) 6c,d ,h) 6d as obtained by single-crystalX -ray diffraction analysis. [40] Figure 2. Crystal structures of a,b) 8d and c,d) 9d.ORTEP drawing at 50 %p robability for thermal ellipsoids.…”