Solution-shear-processed quaterrylene diimide thin-film transistors prepared by pressure-assisted thermal cleavage of swallow tails

A scalable synthesis of swallow-tailed quaterrylene diimides (STQDIs) and a method for the solution processing of sparingly soluble quaterrylene diimide (QDI) thin films are described. The pressure-assisted thermal cleavage of swallow tails yields crystalline QDI layers with electron mobility up to 0.088 cm(2) V(-1) s(-1). The developed method opens up a new route toward the solution processing of higher rylene diimides with poor solubility.     

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.     

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.     

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.     

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%.     

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.     

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.     

TAS+(Z)-Me3CNSN- and TAS+(E)-Me3SiNSN-: does the anion-cation interaction influence the configuration?

TAS+ salts (TAS = (Me2N)3S) of the sulfur diimide anions Me3XNSN- (X = C (1a), Si (1b)) were prepared by Si-N bond cleavage from the corresponding sulfur diimides Me3XNSNSiMe3 and TAS-fluoride ((Me2N)3S+Me3SiF2-) and characterized by X-ray crystallography and multinuclear NMR spectroscopy. According to the experimentally determined bond lengths and theoretical calculations, the Me3XNSN- anions are best described as thiazylamides Me3X-N-S identical to N rather than sulfur diimides Me3X-N=S=N. In agreement with the calculated and experimentally determined structures of the isoelectronic thionylimides RNSO, 1a adopts the Z-configuration, which is electronically favored due to anomeric effects. The electronically disfavored E-configuration of 1b in the solid state can be explained by weak anion-cation interaction.     

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.     

Crystal Growth and Characterization of Fluorinated Perylene Diimides

One-dimensional crystals of fluorinated perylene diimides were achieved by the self-assembly of them via solvent-nonsolvent exchanging.The π-conjugated fluorinated perylene diimides were assembled into highly-ordered nanostructures of well-defined morphologies in organic solvents due to the π-π interaction between the aromatic cores.It was found that with more introduced F atoms,perylene diimides showed remarkably improved solubility and thus were much easier to grow into crystals,due to the increased polarity induced by the strong electron-withdrawing F group.More importantly,single crystal of N,N＇-diperfluorophenyl-3,4,9,10-perylenetetracarboxylic diimide（DPFPP）was obtained,and the unit cell-dimensions of triclinic structure were determined by the selected area electron diffraction（SAED） pattems to be a=0.712 nm,b=1.072 nm,c=2.914 nm,a=97.0°,β=89.6°,γ=93.4°.Owing to most of the longest c-axis orienting nearly vertically to the long axis of the needle crystal,the molecular planes are expected to be vertical to the needle axis.     

Conformations and energetics of sulfur and selenium diimides

The geometries and energetics of different conformations of sulfur and selenium diimides E(NR)(2) (E = S, Se; R = H, Me, (t)Bu, C(6)H(3)Me(2)-2,6, SiMe(3)) have been studied by using various ab initio and DFT molecular orbital techniques. The syn,syn conformation is found to be most stable for parent E(NH)(2), but in general, the preferred molecular conformation for substituted chalcogen diimides is syn,anti. In the case of E(NH)(2) the present calculations further confirm that syn,syn and syn,anti conformations lie energetically close to each other. From the three different theoretical methods used, B3PW91/6-31G proved to be the most suitable method for predicting the geometries of chalcogen diimides. The optimized geometrical parameters are in a good agreement with all available experimental data. While qualitative energy ordering of the different conformations is independent of the level of theory, the quantitative energy differences are dependent on the method used. The performance and reliability of higher level ab initio calculations and DFT methods using large basis sets were tested and compared with experimental information where available. All of the higher level ab inito methods give very similar results, but the use of large basis sets with the B3PW91 method does not increase the reliability of the results. The combination of CCSD(T)/cc-pVDZ with the B3PW91/6-31G-optimized geometries is found to be the method of choice to study energetic properties of chalcogen diimides.     

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.     

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.     

Sila-annulated terrylene diimides for balanced ambipolar transporting

The key building blocks, tetrachlorinated terrylene diimides and the targeted sila-annulated terrylene diimides (Si-TDIs and 2Si-TDIs) were synthesized for the first time. Single-crystal analysis verified the almost planar molecular configurations of both Si-TDIs and 2Si-TDIs. They exhibited intriguing optical properties including red-shifted absorption and near-infrared emission properties with excellent fluorescence quantum yields, as well as precisely controlled HOMO/LUMO energy levels by Si-heteroannulation. The single-crystal organic field-effect transistors based on 2Si-TDI 5a featuring long and branched alkyl chains demonstrated well-balanced ambipolar transporting properties with electron/hole mobilities of 0.10/0.18 cm² V⁻¹ s⁻¹.     

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.     

First synthesis of 2,3,6,7-tetrabromonaphthalene diimide

N,N'-Bis(n-octyl)-2,3,6,7-tetrabromonaphthalene diimide (TBNDI) was synthesized by a new imidization reaction and characterized by HRMS, (1)H NMR, (13)C NMR, elemental analyses, FT-IR, UV-vis, and single-crystal X-ray analysis. The TBNDIs are the key precursors for the synthesis of core-tetrasubstituted-naphthalene diimides.     

An In-Situ Cyanidation Strategy To Access Tetracyanodiacenaphthoanthracene Diimides with High Electron Mobilities Exceeding 10 cm2 V−1 s−1

A family of novel highly π-extended tetracyano-substituted acene diimides, named as tetracyanodiacenaphthoanthracene diimides (TCDADIs), have been synthesized using a facile four-fold Knoevenagel condensation strategy. Unlike conventional cyano substitution reactions, our approach enables access to a large π-conjugated backbone with the in-situ formation of four cyano substitutents at room temperature while avoiding extra cyano-functionalization reactions. TCDADIs decorated with different N-alkyl substituents present good solubility, near-coplanar backbones, good crystallinity, and low-lying lowest unoccupied molecular orbital energies of −4.33 eV, all of which contribute to desirable electron-transport performance when applied in organic field-effect transistors (OFET). The highest electron mobility of an OFET based on a 2-hexyldecyl-substituted TCDADI single crystal reaches 12.6 cm² V⁻¹ s⁻¹, which is not only among the highest values for the reported n-type organic semiconductor materials (OSMs) but also exceeds that of most n-type OSMs decorated with imide units.     

1,1'-Binaphthol annulated perylene diimides: Aggregation-induced emission enhancement and chirality inversion

Aggregation-induced emission enhancement and aggregation-induced chirality inversion are two individual phenomena for the enantiomerically pure organic dyes in the aggregates. Herein we reported for the first time that these two interesting phenomena could be observed simultaneously in the aggregated states of enantiomerically pure S/R-1,1’-binaphthol annulated perylene diimides, in which two perylene diimides moieties were bridged by S/R-1,1’-binaphthol(BINOL) at the bay positions. Owing to the...     

Anodic oxidation of hydrazine and its methylderivatives on bare Pt and Pt electrode surfaces modified by underpotential metal adsorbates in acetonitrile

The electrooxidation of hydrazine and its methylderivatives (methylhydrazine and 1,1-dimethylhydrazine) on bare Pt and Pt electrode surfaces modified by underpotential metal adsorbates was studied in acetonitrile. On bare Pt, one-third of the molecules of the substances under examination undergo a two-electron oxidation to the corresponding diimides, while the remaining number of molecules act as the required proton acceptors in neutral acetonitrile. In alkaline solutions, hydrazine undergoes a quantitative four-electron oxidation process, while its methyl derivatives are oxidized quantitatively to the corresponding diimides in the same media. The pronounced inhibition effects on hydrazine oxidation caused by underpotential T1 and Pb adsorbates were interpreted in terms of a change in the chemical interaction of hydrazine molecules and the electrode surface modified by the underpotential metal adsorbates.     

One-pot synthesis of core-expanded naphthalene diimides: enabling N-substituent modulation for diverse n-type organic materials

A mild and versatile one-pot synthesis of core-expanded naphthalene diimides has been developed, which undergoes a nucleophilic aromatic substitution reaction and then an imidization reaction, allowing an easy and low-cost access to diverse n-type organic materials. Some newly synthesized compounds by this one-pot operation exhibited high electron mobility of up to 0.70 cm(2) V(-1) s(-1) in ambient conditions.