Synthesis and Applications of π‐Extended Naphthalene Diimides

Naphthalene diimides have received much attention due to their high electron affinities, high electron mobility, and good thermal and oxidative stability, therefore making them promising candidates for a variety of organic electronic applications. However, π‐extended naphthalene diimides with lower HOMO‐LUMO gaps and higher stability have only been developed recently because of the synthetic difficulties. This account describes recent developments in the structures, synthesis, properties, and applications of π‐extended naphthalene diimides, including pure‐carbon and heterocyclic acene diimides, from our research group.     

Synthesis of bis-2,7-substituted 1,2,3,6,7,8-hexahydroisoindolo[5,6-f]isoindole-1,3,6,8-tetraones

A series of bis-2,7-substituted 1,2,3,6,7,8-hexahydroisoindolo[5,6-f]isoindole-1,3,6,8-tetraones (naphthalene diimides) has been synthesized. The key intermediate required for synthesis of the naphthalene diimides, 2,3,6,7-naphthalnetetracarboxylic dianhydride ( 2 ) was prepared starting from allene and maleic anhydride. The bis-anhydride 2 was converted to the naphthalene diimides using conventional methodology by the reaction with amines in organic solvents.     

Direct synthesis of highly pure perylene tetracarboxylic monoimide

A series of perylene tetracarboxylic monoimides substituted with cycloalkanes were synthesized through a one-step reaction between cycloalkyl amines and the parent perylene dianhydride. The reaction demonstrates high selectivity for the production of monoimides with no formation of diimides. The high reaction selectivity is primarily due to the insolubility of the monoimides in the reaction medium, which in turn causes rapid precipitation of the products, shifting the reaction equilibrium to the right.     

Pyromellitic diimides: minimal cores for high mobility n-channel transistor semiconductors

Three pyromellitic diimides were synthesized in high yields by one conventional reaction between pyromellitic dianhydride and various amines. The films made from these pyromellitic diimides derivatives exhibit a mobility up to 0.079 cm2/(V.s). In addition, the on/off ratios of n-channel devices are as high as 1 000 000.     

Synthesis of Substituted 4‐Aroyl‐1‐indanone and 5‐Aroyl‐1‐tetralone

Several substituted 4‐aroyl‐1‐indanones 2 and 5‐aroyl‐1‐tetralones 3 were prepared in good yields from 1‐indanones 1 via a series of reasonable transformations.     

Synthesis and optical and redox properties of core-substituted naphthalene diimide dyes

2,6-Dichloronaphthalene dianhydride has been synthesized by a modified procedure. The imidization of this dichlorinated anhydride with amines and subsequent stepwise nucleophilic exchange of the chlorine atoms by alkyl- or arylamines afforded a series of hitherto unknown monoamino- and diamino-substituted naphthalene diimides. An alternative route for the synthesis of diamino-substituted naphthalene diimides is also reported. Optical and electrochemical properties of the newly synthesized amino-functionalized naphthalene diimides were studied in detail. The absorption maxima (530-620 nm) of these dyes are appreciably bathochromically shifted compared to those of the corresponding core-unsubstituted compounds. At the naphthalene core alkylamino-substituted diimides exhibit fluorescence quantum yields up to 60%.     

Columnar Liquid‐Crystalline Dibenzopentacenodithiophenes by Photocyclization

The twofold glyoxylic Perkin reaction of perylene‐3,9‐diglyoxylic acid with thiophene‐diacetic acid followed by oxidative photocylization and reaction with α‐branched primary alkylamines yields columnar liquid‐crystalline diimides with two sulfur atoms in the condensed arene system. A broad temperature range of the hexagonal columnar mesophase is induced by racemic doubly branched alkyl chains. The HOMO and LUMO energy levels of these thiophene‐derived diimides qualify them as electron donors with respect to perylene diimides.     

A Facile Method for the Synthesis of Aroyl Pyrazoles from Functionalized Ketene Dithioacetals

On treating with ammonium acetate in DMSO aroyl formyl ketene dithioacetals were transformed into valuable intermediates 3‐amino‐2‐aroyl‐3‐(methylsulfanyl)‐2‐propenals, which could be explored for the synthesis of aroyl aminopyrazoles.     

Interaction of pyromellitic diimide derivatives with beta-cyclodextrin and anthracene-appended beta-cyclodextrin: rim binding vs inclusion complexation

Complex formation of pyromellitic diimide derivatives with beta-cyclodextrin and anthracene-appended beta-cyclodextrin was studied with use of induced circular dichroism and 1H NMR spectroscopies. It is revealed that pyromellitic diimides form rim-binding type complexes with beta-CD and in these complexes the pyromellitic diimides lie just outside of the narrow rim of the CD. With anthracene-appended beta-CD the pyromellitic diimides form true inclusion complexes. Implications of the formation of rim-binding type complexes are also discussed.     

The impact of vertical π-extension on redox mechanisms of aromatic diimide dyes

The impact of vertical π-extension on redox mechanisms of aromatic diimides in the organic lithium-ion batteries have been carefully studied by a combined experiment and theoretical analyses.     

Synthesis and properties of poly(imide-sulfonate)s

Polycondensations of N,N′-bis(hydroxyalkyl)pyromellitic diimides, N,N′-bis(hydroxyphenyl)-pyromellitic diimides, N,N′-bis(hydroxyalkyl)-3,3′,4,4′-benzophenonetetracarboxylic diimides and N,N′-bis(hydroxyphenyl)-3,3′-4,4′-benzophenonetetracarboxylic diimides with aromatic disulfonyl chlorides were carried out in pyridine to produce poly(imide-sulfonate)s. The resulting polymers had inherent viscosities in the range of 0.25–0.38 dL/g. These poly(imide-sulfonate)s were insoluble in common organic solvents and had relatively good thermal stability. The TGA data showed 10% weight losses at 253–365°C and residual weights at 500°C were 22–72% in nitrogen.     

Stereochemistry and mechanism of acylation of acetylenes

The addition of acid chloride-AlCl₃ complexes and of acyl triflates to several acetylenes has been performed. Evidence is given that these additions occur at least partly through a vinyl cation intermediate. In the case of aroyl chlorides or aroyl triflates the intermediate vinyl cation can be attacked by the aromatic nucleus of the aroyl group, leading to the formation of indenones. The difference in behaviour between aroyl chloride-AlCl₃ complexes and aroyl triflates is explained by the hardness of the triflate anion as a nucleophile, compared to the tetrachloraluminate anion. Further evidence for the intermediate vinyl cation is found in the formation of rearranged products in the addition of 3,5 dimethoxybenzoyl chloride-AlCl₃ complex and benzoyl triflate to 4,4-dimethyl-2-pentyne.     

Synthesis of ketones from aroyl chlorides and nickel(0) complexes

Summary Facile syntheses of ketones have been achieved starting from bis(1,5-cyclooctadiene)nickel(0) and aroyl halides containingortho-substituents. Electrophilic or nucleophilic attack of aroyl groups upon organic substrates also give rise to other classes of ketones.     

Perylene-3,4,9,10-tetracarboxylic acid diimides: synthesis, physical properties, and use in organic electronics

Perylene-3,4,9,10-tetracarboxylic acid diimides (perylene diimides, PDIs) have been used as industrial pigments for many years. More recently, new applications for PDI derivatives have emerged in areas including organic photovoltaic devices and field-effect transistors. This Perspective discusses the synthesis and physical properties of PDI derivatives and their applications in organic electronics.     

Photochemistry of naphthalene diimides: EPR study of free radical formation via photoredox process

Earlier studies have shown that on exposure to UVA, hydroperoxynaphthalene diimide (IA) generates hydroxyl radicals, induces DNA strand scission, and kills cells.Here we employed electron paramagnetic resonance (EPR) and spin trapping to investigate the free radical photochemistry of IA and that of related naphthalene diimides, which are devoid of the hydroperoxyl moiety (N,N'-bis[2-methyl]-1,4,5,8-naphthaldiimide [IB], N,N'-bis[2-thiomethyl-2-methoxyethyl]-1,4,5,8-naphthaldiimide [IC]) and therefore are unable to generate hydroxyl radicals. It is shown that on UV irradiation (>300 nm) in air-free methanol or ethanol solutions all these naphthalene diimides undergo one-electron reduction to corresponding anion radicals, positively identified by EPR. With EPR and a spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO), we found that the photogeneration of the naphthalene diimide radicals is concomitant with the formation of radicals from the solvents, presumably through electron/hydrogen atom abstraction by photoactivated diimides. Irradiation of IA, IB or IC in the presence of oxygen generates superoxide, which was detected as a DMPO adduct. The high photoreactivity of IB and IC supports the notion that hydroperoxide IA can induce oxidative damage via photoprocesses that are independent of *OH generation. These observations could be pertinent to the application of naphthalene diimides as selective photonucleases, PDT anticancer agents or both.     

Linear fused dithieno[2,3-b:3'2'-d]thiophene diimides

Linear fused dithieno[2,3-b:3'2'-d]thiophene diimides (DTTDIs, 1-4) were synthesized. Physicochemical investigations suggested that these diimides might be used as potential n-channel organic semiconductors. Single-crystal analysis of N-propyl DTTDI (1) revealed that molecules adopt a layered herringbone packing motif.     

Novel polycyclic heterocyeles. XIII. Derivatives of the oxime and carbinol derived from 1,2-dihydro-11-(trifluoromethyl)-3H,7H-quino[8,1-cd] [1,5]benzoxazepin-3-one

The anions derived from the oxime, 2 , and the carbinol, 3 , generated by reaction with sodium hydride, were reacted with aminoalkyl chlorides and an aroyl chloride to give a number of amino-alkyl ethers and an aroyl ester. In addition, 2 and 3 were reacted with phenylisocyanate to yield O-phenylcarbamoyl derivatives. The pmr spectra of several of these compounds are discussed.     

One-pot synthesis of stable NIR tetracene diimides via double cross-coupling

Tetracene tetracarboxylic diimides have been synthesized based on direct double ring extension of electron-deficient naphthalene diimides involving metallacyclopentadienes. Atomic structure and electronic transitions responsible for their NIR absorption spectra are investigated with quantum-chemical calculations. In light of their unique structure and admirable photophysical and electronic properties, this new molecular skeleton is promising candidate for n-type semiconductors.     

The impact of vertical π-extension on redox mechanisms of aromatic diimide dyes

Aromatic diimide dyes are an attractive class of redox-active organic molecules for lithium-ion batteries, whose battery performances (stabilities, conductivities and cyclicities) are strongly dependent on the sizes of their π-systems. However, due to the different Clar’s structures possessed, three vertically π-extended aromatic diimides, namely, naphthalene diimide (two one-electron reductions), perylene diimide and terrylene diimide (two one-electron reductions), exhibit different electronic redox mechanisms when served as cathode materials in organic lithium-ion batteries. Herein, we have studied carefully the different electrochemical characteristics of the three aromatic diimides through experimental and theoretical calculations. Their battery present different shape of charge/discharge curves resulting from stability of their reduction state during charge/discharge process. Terrylene diimide shows better cycle and rate capacities than those of naphthalene diimide and perylene diimide, which could be attributed to the more energies released during terrylene diimide combining with lithium ions than those of other two diimides.     

Recherches sur le benzofuranne. LIX. Orientation de l'aroylation de l'éthyl-2 benzofuranne selon la nature du chlorure d'aroyle utilise

While both hindered and unhindered alkanoyl chlorides and some aroyl chlorides react with 2-ethylbenzofuran at the 3 position, most aroyl chlorides also react with 2-ethylbenzofuran at the 6 position and to a lesser extent at the 4 position.