Versatile Colorant Syntheses by Multiple Condensations of Acetyl Anilines with Perylene Anhydrides

Abstract

We report a key step forward in rylene chemistry: the transformation of rylenes into novel chromophore families. The imidization of rylene anhydrides with 2-acetyl anilines could be controlled by the choice of the solvent, thus causing a transformation into either a 4-hydroxyquinoline (4-HQ) or a 4-oxoquinoline (4-OQ) unit. The 4-OQ motif contains an aminoenone group formed by intramolecular aldol condensation and is the first vinylogous rylene imide. The concept of vinylogy was further developed by utilizing 2,6-diacetyl aniline leading to an 3a-aza-1,6-phenalenedione-extended rylene skeleton fully embracing the nitrogen atom. By functionalization of the aminoenone motifs, for example, malononitrile addition at the carbonyl groups, the optical and electronic properties could be further tuned.

Bandgap Engineering in π-Extended Pyrroles. A Modular Approach to Electron-Deficient Chromophores with Multi-Redox Activity

“…A simple and potentially productive design of such a hybrid structure, consisting of naphthalenemonoimide (NMI, red) and pyrrole (blue), is proposed in Figure . NMI is the key constituent of perylenediimide (PDI) − and naphthalenediimide (NDI) dyes, and is known to offer excellent chemical stability and diverse derivatization options, usually based in acyl chemistry, heterocyclic annulation reactions, and lateral ring fusion . Structural modifications can be used to change the electron-withdrawing character of the naphthalene fragment, which thus can serve as a tunable acceptor unit. , Consequently, the NMI-based and related chromophores can be tailored for use in various fields of application, e.g.…”

Porphyrin–Ryleneimide Hybrids: Tuning of Visible and Near-Infrared Absorption by Chromophore Desymmetrization

“…Ryleneimides, most notably perylenediimides (PDIs), are one of the most important classes of organic dyes, with an exceptional scope of industrial and research applications. − Their electronic and self-assembly properties can be tuned by homologation of the rylene backbone, modification of imide functionalities, peripheral substitution, and ring fusion. − Hybridization of ryleneimides with nonbenzenoid and heterocyclic moieties provides a versatile though still relatively unexplored route to structurally unique functional dyes. In one general strategy, , tandem Pd-catalyzed couplings have been used for synthesis of ryleneimide-fused indenes, azulenes, corannulenes, , and heteroaromatics .…”

Carbonyl-Functionalized Cyclazines as Colorants and Air-Stable n-Type Semiconductors

“…The title system (3) was synthesized using an optimized aldol condensation protocol that was recently developed in our group. 11 Using commercially accessible phthalic anhydride (a) or 2,3naphthalenedicarboxylic anhydride (b) as starting materials, cyclazine 3 was obtained via a three-step reaction. Considering that 2,6-diacetylaniline is not easily available and its reaction with anhydrides is accompanied by several byproducts, the initial imidization was performed between anhydrides a/b and 4-propyl-2,6-dibromoaniline in acetic acid under reflux conditions, leading to 1a and 1b in yields of 48% and 69%, respectively.…”

“…Considering that 2,6-diacetylaniline is not easily available and its reaction with anhydrides is accompanied by several byproducts, the initial imidization was performed between anhydrides a/b and 4-propyl-2,6-dibromoaniline in acetic acid under reflux conditions, leading to 1a and 1b in yields of 48% and 69%, respectively. 11 Subsequent Stille coupling was conducted in 1,2dioxane at 100 °C for 12 h, furnishing acetyl derivative 2a. The most critical step, the aldol condensation, was carried out using imidazole as a solvent at 120 °C for 2 h, giving 3a in 72% yield and 3b in 83% yield.…”

“…Furthermore, the strong electron acceptor 5 serves as n -type semiconductors in TFTs with high air stability. The title system ( 3 ) was synthesized using an optimized aldol condensation protocol that was recently developed in our group …”