Strategies for the synthesis of functional naphthalene diimides

Construction of a highly efficient near-IR solid emitter based on naphthalene diimide with AIE-active tetraphenylethene periphery

AIE-active TTPEcNDI shows distinct near-IR optical properties and self-assembles into hollow spheres, fibrils and leaf-like nanostructures via solvophobic control.

Synthesis and characterization of novel dibenz[a,c]anthracenedicarboxythioimides: the effect of thionation on self-assembly

The effect of thionation on the formation of columnar liquid crystalline phases of dibenzanthracenedicarboximides as well as their self-association in solution is described.

Synthesis of a disulfide-bridged bispillar[5]arene and its application in supramolecular polymers

A disulfide-bridged bispillar[5]arene was synthesized efficiently and applied to fabricate supramolecular polymers, which were redox-responsive and could be used to prepare fluorescent water-dispersible nanospheres.

Polycyclic aromatic hydrocarbons with orthogonal tetraimides as n-type semiconductors

We report two novel n-type polycyclic aromatic hydrocarbons bearing orthogonal tetraimides with high electron mobilities.

A cross-coupling-annulation cascade from peri-dibromonaphthalimide to pseudo-rylene bisimides

A novel synthetic strategy based on cascade C–C cross-coupling and C–H arylation afforded structurally unique polycyclic aromatics with desirable optical and redox properties.

Design of three-component randomly incorporated copolymers as non-fullerene acceptors for all-polymer solar cells

A series of randomly arranged donor–acceptor-type copolymers, used as replacements for fullerene-based acceptors in organic solar cells, were synthesized by the Stille coupling copolymerization.

Arylmercapto Substituted Tetraazaperopyrene Derivatives and Their Oxidation to Tetrasulfones: Photophysics and Electrochemistry

Fourfold arylmercapto substituted tetraazaperopyrene (TAPP) derivatives were obtained by direct nucleophilic substitution of the tetrabrominated TAPP or via Cu-catalyzed S-C coupling. These new materials display a characteristic bathochromic shift of their visible absorption and emission bands by ca. 200 nm compared to the unsubstituted parent compound. Two of the sulfide derivatives were oxidized with periodate to give their corresponding sulfones.

Selective acceleration of disfavored enolate addition reactions by anion-π interactions

In chemistry and biology, cation-π interactions contribute significantly to many important transformations. In sharp contrast, reactions accomplished with support from the complementary anion-π interactions are essentially unknown. In this report, we show that anion-π interactions can determine the selectivity of the enolate chemistry of malonate half thioesters. Their addition to enolate acceptors is central in natural product biosynthesis but fails without enzymes because non-productive decarboxylation dominates. The newly designed and synthesized anion-π tweezers invert this selectivity by accelerating the disfavored and decelerating the favored process. The discrimination of anionic tautomers of different planarization and charge delocalization on π-acidic surfaces is expected to account for this intriguing "tortoise-and-hare catalysis." Almost exponentially increasing selectivity with increasing π acidity of the catalyst supports that contributions from anion-π interactions are decisive.

Radical-mediated dehydrative preparation of cyclic imides using (NH4)2S2O8-DMSO: application to the synthesis of vernakalant

Ammonium persulfate–dimethyl sulfoxide (APS–DMSO) has been developed as an efficient and new dehydrating reagent for a convenient one-pot process for the synthesis of miscellaneous cyclic imides in high yields starting from readily available primary amines and cyclic anhydrides. A plausible radical mechanism involving DMSO has been proposed. The application of this facile one-pot imide forming process has been demonstrated for a practical synthesis of vernakalant.

Fluoro-Substituted n-Type Conjugated Polymers for Additive-Free All-Polymer Bulk Heterojunction Solar Cells with High Power Conversion Efficiency of 6.71

Fluorinated n-type conjugated polymers are used as efficient electron acceptor to demonstrate high-performance all-polymer solar cells. The exciton generation, dissociation, and charge-transporting properties of blend films are improved by using these fluorinated n-type polymers to result in enhanced photocurrent and suppressed charge recombination.

Facile synthesis of a pyrrole-fused dibenzo[a,e]pentalene and its application as a new extended, ladder-type fused aromatic system

A novel ladder-type pyrrole-fused dibenzo[a,e]pentalene, in which two benzo[a,e]pentalene units are held coplanar by a nitrogen bridge, is synthesized via double intermolecular Pd-catalyzed cascade crossover annulations. The introduction of a nitrogen bridge not only has a substantial influence on the optoelectronic properties but also improves the processability and stability.

Tetralithiated tetraazaperopyrene as a key intermediate for the synthesis of functionalized derivatives

A new synthetic approach to core-functionalized tetraazaperopyrenes (TAPP) is reported. In-situ reaction of 4-fold lithiated TAPP with electrophiles results in the formation of various unprecedented TAPP derivatives, which are highly emissive fluorophores, show promising photophysical and electrochemical properties and act as valuable starting materials. Thus, lithiation of the TAPP core opens up a facile way for developing new organic materials.

J-aggregation, its impact on excited state dynamics and unique solvent effects on macroscopic assembly of a core-substituted naphthalenediimide

Herein we reveal a straightforward supramolecular design for the H-bonding driven J-aggregation of an amine-substituted cNDI in aliphatic hydrocarbons. Transient absorption spectroscopy reveals sub-ps intramolecular electron transfer in isolated NDI molecules in a THF solution followed by a fast recombination process, while a remarkable extension of the excited state lifetime by more than one order of magnitude occurred in methylcyclohexane likely owing to an increased charge-separation as a result of better delocalization of the charge-separated states in J-aggregates. We also describe unique solvent-effects on the macroscopic structure and morphology. While J-aggregation with similar photophysical characteristics was noticed in all the tested aliphatic hydrocarbons, the morphology strongly depends on the "structure" of the solvents. In linear hydrocarbons (n-hexane, n-octane, n-decane or n-dodecane), formation of an entangled fibrillar network leads to macroscopic gelation while in cyclic hydrocarbons (methylcyclohexane or cyclohexane) although having a similar polarity, the cNDI exhibits nanoscale spherical particles. These unprecedented solvent effects were rationalized by establishing structure-dependent specific interactions of the solvent molecules with the cNDI which may serve as a general guideline for solvent-induced morphology-control of structurally related self-assembled materials.

Effect of dye end groups in non-fullerene fluorene- and carbazole-based small molecule acceptors on photovoltaic performance

Fluorene- and carbazole-based small molecules with dye end groups were synthesized for use as non-fullerene acceptors in organic photovoltaic cells.

A highly selective colorimetric Cys sensor based on core-substituted naphthalene diimides

This study presents the core-substituted naphthalenediimide based probe 1 for the selective detection of cysteine via photoinduced electron transfer (PET) effect.

Assorted morphosynthesis: access to multi-faceted nano-architectures from a super-responsive dual π-functional amphiphilic construct

An electronically segmented amphiphile was created by conjugating two π-functional units (HQ/NDI) for the first time.

Synthesis of monolateral and bilateral sulfur-heterocycle fused naphthalene diimides (NDIs) from monobromo and dibromo NDIs

Monolateral and bilateral sulfur-heterocycle fused naphthalene diimides (NDIs) are successfully synthesized from monobromo and dibromo NDIs via nucleophilic aromatic substitution reactions and the subsequent oxidative aromatization processes.

A panchromatic hybrid crystal of iodoplumbate nanowires and J-aggregated naphthalene diimides with long-lived charge-separated states

A panchromatic hybrid crystal of anionic iodoplumbate nanowires and J-aggregated protonated naphthalene diimides has been formed through charge-assisted anion–π and lone pair–π interactions.

Surface architectures built around perylenediimide stacks

Simple stacks of perylenediimides (PDIs) grown directly on solid surfaces are an intriguing starting point for the construction of multicomponent architectures because their intrinsic activity is already very high. The ability of PDI stacks to efficiently generate photocurrent originates from the strong absorption of visible light and the efficient transport of both electrons and holes after generation with light. The objective of this study was to explore whether or not the excellent performance of these remarkably simple single-channel photosystems could be further improved in more sophisticated multicomponent architectures. We report that the directional construction of strings of anions or cations along the PDI stacks does not significantly improve their activity; that is, the intrinsic activity of PDI stacks is too high to yield ion-gated photosystems. The directional construction of electron- and hole-transporting stacks of naphthalenediimides (NDIs) and oligothiophenes along the central PDI stack did not improve photocurrent generation under standard conditions either. However, the activity of double-channel photosystems increased with increasing thickness, whereas increasing charge recombination with single-channel PDI stacks resulted in decreasing activity with increasing length. Most efficient long-distance charge transport was found with double-channel photosystems composed of PDIs and NDIs. This finding suggests that over long distances, PDI stacks transport holes better than electrons, at least under the present conditions. Triple-channel photosystems built around PDI stacks with oligothiophenes and triphenylamines were less active, presumably because hole mobility in the added channels was inferior to that in the original PDI stacks, thus promoting charge recombination.

Tailor-made rylene arrays for high performance n-channel semiconductors

Rylene dyes, made up of naphthalene units linked in peri-positions, are emerging as promising key building blocks to create π-functional materials. Chemists have found uses for these ribbonlike structures in a wide range of applications of optoelectronic devices. Because their structure combines two sets of six-membered electron-withdrawing dicarboxylic imide rings, rylene diimides exhibit enhanced solubility, excellent chemical and thermal stabilities, high electron affinities, and remarkable electron-transporting properties. Among them, perylene diimide (PDI) and naphthalene diimide (NDI) derivatives are important representatives improving the performance of electron-transporting technologies, relative to their p-channel counterparts. Pioneering works by Müllen and Langhals have inspired chemists to extend the π-conjugation along the peri-positions of rylene diimides, which generally results in impressive bathochromic shifts and a nearly linear increase in the extinction coefficient. In addition, in the past years, researchers have focused on π-expansion of NDI or PDI systems through bay-functionalization with carbocyclic and heterocyclic rings annulated onto the skeleton. However, chemists have rarely investigated lateral expansion via both bay- and nonbay-functionalization to construct homologous series of rylene arrays with different electronic delocalization and fine-tuned flexible linkage. This is probably due to the lack of effective procedures for the (multi) carbon-carbon formation and annulation of electron-deficient rylene imide units. In this Account, we discuss our recent progress in the design and synthesis of laterally expanded rylene dyes based on homocoupling and cross-coupling reactions of core-functionalized PDIs and NDIs to achieve novel high performance n-channel organic semiconducting materials. These new achievements offer us opportunities to learn fundamental issues about how chemical and physical properties alter with incremental changes in structure. We highlight synthetic methodology of transition-metal mediated coupling reactions (and/or C-H transformation) for singly linked, doubly linked, and fully conjugated triply linked oligoPDIs, and further for the construction of hybrid rylene arrays via bay- and/or nonbay-functionalization. In addition, we summarize the informative correlations between the molecular structures and their optoelectronic properties, especially the modulation of progressively red-shifted absorption maxima and positive shifts in the redox potentials. This decreases the energy gaps and increases the electron-accepting abilities through expansion of π-system, which has direct impacts on the compounds' potential applications in optoelectronic devices. Finally, we introduce the promising applications of these laterally expanded rylene dyes as exceptional high performance n-channel semiconductors in organic field-effect transistors (OFETs) and competitive candidates for non-fullerene acceptors in high efficient organic photovoltaic devices (OPVs).

Direct core functionalisation of naphthalenediimides by iridium catalysed C–H borylation

We report the first boron-substituted naphthalenediimides (NDIs), prepared by iridium catalysed C–H activation. Both mono- and diborylated products are available, which have been further elaborated by Suzuki–Miyaura coupling.