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Regulation of fluorescence and self‐assembly of a salicylaldehyde azine‐containing amphiphile by a water‐soluble pillar[5]arene via host–guest recognition in water was realized. The fluorescence and the self‐assembled aggregates of the bola‐type amphiphile G can be tailored by adding different amounts of water‐soluble pillar[5]arene (WP5). In addition, the emission property and self‐assembly behavior of G and WP5 are responsive to pH conditions. Furthermore, the fluorescence emission property of G and the regulation by WP5 or pH conditions was applied as information encryption material, rewritable paper, and erasable ink. We believe that this fluorescence regulation strategy is promising for the construction of advanced fluorescent organic materials. [ABSTRACT FROM AUTHOR]

There is growing interest in developing printable paper sensors to enable rapid testing of analytes for environmental, food safety, and clinical applications. A major challenge is to find suitable bioinks that are amenable to high-speed printing and remain functional after printing. We report on a simple and effective approach wherein an aqueous ink composed of megadalton-sized tandem repeating structure-switching DNA aptamers (concatemeric aptamers) is used to rapidly create patterned paper sensors on filter paper by inkjet printing. These concatemeric aptamer reporters remain immobilized at the point of printing through strong adsorption but retain sufficient segmental mobility to undergo structure switching and fluorescence signaling to provide both qualitative and quantitative detection of small molecules and protein targets. The convenience of inkjet printing allows for the patterning of internally referenced sensors with multiplexed detection, and provides a generic platform for on-demand printing of sensors even in remote locations. [ABSTRACT FROM AUTHOR]

Distyrylbenzenes (DSBs) are well‐known for their strong multicolour fluorescence. Fluorescence tuning of DSB via further functionalization/arylation, on the other hand, is uncommon. This paper reports a Pd‐catalysed direct arylation approach for introducing different aryl groups onto fluorobenzene‐containing DSB moiety (7) in high yields (67–72 %). The versatile methodology allows the substitution of neutral [tolyl (1)], electron‐deficient [p‐formyl benzene (2), p‐acetyl benzene (3), p‐nitrobenzene (4)] and electron‐rich [carbazole (5), triphenylamine (6)] aryl groups. The electron‐deficient aryls render mono‐substitution, while the electron‐rich counterparts promote di‐substitution. The compounds (1–6) show blue, green, and yellow fluorescence in both the solution and solid states; the fluorescence quantum yields reach >98 % and the peak maxima span from 425 to 560 nm. The mono‐carbazole DSB (5) exhibit white light emission (WLM) in polar solvents (acetone, DMF, CH3CN, DMSO and NMP) with very high fluorescence quantum yields (φf) of 60–80 %. For WLM, such high efficiency (φf) is somewhat uncommon. Moreover, visible‐to‐NIR reversible electrochromism is demonstrated by the TPA‐integrated DSB (6). The colour of 6 changes from pristine light yellow to orange, and the absorption maxima shifts from 372 to 1500 nm when a positive potential of 1.0 V vs Ag/Ag+ is applied. Moreover, the system shows high colouration efficiency in the NIR region with fast switching speeds for colouration and decolouration as fast as 0.98 s and 1.05 s. [ABSTRACT FROM AUTHOR]

Stimulus‐responsive organic materials with luminescence switching properties have attracted considerable attention for their practical applications in sensing, security, and display devices. In this paper, bent‐type bisbenzofuropyrazine derivatives, Bent‐H and Bent‐sBu, with good solubilities were synthesized, and their physical and optical properties were investigated in detail. Bent‐H gave three crystalline polymorphs, and they showed different luminescence properties depending on their crystal packing structures. In addition, Bent‐H exhibited mechanochromic luminescence in spite of its rigid skeleton. Bent‐sBu exhibited unique concentration‐dependent vapochromic luminescence. Ground Bent‐sBu was converted to blue‐emissive, green‐emissive, and green‐emissive high‐viscosity solution states at low, moderate, and high concentrations of CHCl3 vapor, respectively. This finding represents a concentration‐dependent multi‐phase transition with an organic solvent, which is of potent interest for application in sensing systems. [ABSTRACT FROM AUTHOR]

A new fluorescent 1,3-diaminonaphthalimide conjugate of calix[4]arene receptor ( R) was synthesized and characterized. The receptor displays good selectivity towards trinitrophenol (TNP) over other explosive aromatic- and aliphatic-nitro compounds by exhibiting changes in its fluorescence emission. Receptor-coated cellulose paper strips are equally effective in terms of their selective detection of TNP over other aromatic- and aliphatic-nitro compounds. When used in solution or on cellulose paper strips, R can detect up to submicromolar concentration of TNP by exhibiting changes in its fluorescence emission and in its supramolecular structure upon interaction. Interestingly, the microscopy features of R, TNP, and { R+TNP} are quite distinct, indicating the interactions present between R and TNP, as studied by using AFM and TEM. Computationally modeled complexes of receptor with TNP and TNT show enormous difference in their interaction energies in the favor of TNP by showing the host-guest interaction of cation ⋅⋅⋅anion type in the presence of TNP but not TNT. This is because the receptor adopts an 'arms-open'-type structure in the case of the TNP complex, whereas it adopts an 'arms-closed'-type structure in the presence of TNT. Both the experimental and the computational studies reveal that the receptor selectively binds to TNP over TNT. Thus, R-coated Whatman No.1 filter paper strips provide easy, rapid, and economical detection of trace amounts of TNP both by visual and spectral measurement. [ABSTRACT FROM AUTHOR]

Easily synthesizable, fluorescent, organic nanoaggregates have been utilized, for the first time, in the selective recognition of d-(−)-ribose at pH 5.5 in water. In the self-assembled form, the reactive sites of the monomer units can be properly organized to form an effective 'recognition cleft' for ribose (limit of detection ≈23 μ m), in which binding mainly occurs through a combination of hydrogen-bonding and CH⋅⋅⋅π interactions. The degree of agglomeration shows a profound influence on the extent of ribose sensing. A reduction in the optical response (≈1.8-fold) is observed when ribose is allowed to interact with nanoaggregates of smaller dimensions (a decrease in the hydrodynamic diameter from (≈212.7±10.2) to (≈44.6±3.5) nm). The protocol is also utilized for the estimation of ribose in human urine samples and oral supplements. Low-cost paper strips have also been developed for rapid, on-site detection of ribose without involving any sophisticated instruments or skilled personnel. [ABSTRACT FROM AUTHOR]

Melanin‐like nanomaterials have found application in a large variety of high economic and social impact fields as medicine, energy conversion and storage, photothermal catalysis and environmental remediation. These materials have been used mostly for their optical and electronic properties, but also for their high biocompatibility and simplicity and versatility of preparation. Beside this, their chemistry is complex and it yields structures with different molecular weight and composition ranging from oligomers, to polymers as well as nanoparticles (NP). The comprehension of the correlation of the different compositions and morphologies to the optical properties of melanin is still incomplete and challenging, even if it is fundamental also from a technological point of view. In this minireview we focus on scientific papers, mostly recent ones, that indeed examine the link between composition and structural feature and photophysical and photochemical properties proposing this approach as a general one for future research. [ABSTRACT FROM AUTHOR]

Abstract: Detection of nitroaromatics at ultralow concentration is a major security concern in defense, forensics, and environmental science. To this end, a new triarylamine‐cored dendritic gelator (OGR) was synthesized, which produced thermoreversible, thixotropic, and fluorescent gels in n‐octanol. On gelation, both π–π* transitions and the emission peak of the gelator show redshifts with a 4.5‐fold increase of fluorescence intensity in the gel state indicating J‐aggregation. The nitrogen lone‐pair electrons of OGR make it a donor, and electron transfer occurs to acceptor nitroaromatics causing fluorescence quenching, which is further promoted due to its acidity. The Stern–Volmer rate constants measured for different nitroaromatics showed that it senses picric acid (PA) best. The contact‐mode technique with OGR‐treated paper strips can allow naked‐eye detection of PA under UV light down to 10−11  m concentration within 30 s. Reusability of the gel is achieved by treating OGR@PAx with NaOH solution. Impedance spectroscopic results indicated a decrease of both charge‐transport resistance and Warburg impedance on successive addition of PA. The limits of detection of PA determined from fluorescence and impedance measurements match well. Thus, the OGR gel is a reusable, low‐cost, specific sensor for PA by naked‐eye colorimetric, fluorescence, and impedance techniques. [ABSTRACT FROM AUTHOR]

The detection of food spoilage is a major concern in food safety as large amounts of food are transported globally. Direct analysis of food samples is often time-consuming and requires expensive analytical instrumentation. A much simpler and more cost-effective method for monitoring food fermentation is to detect biogenic amines generated as a by-product during food decomposition. In this work, a series of 1,2-dihydroquinoxaline derivatives (DQs) with aggregation-induced emission (AIE) characteristics were synthesised and their protonated forms, that is, H+DQs, can be utilised for the sensitive detection of biogenic amines. For example, upon exposure to amine vapours, deprotonation occurs that converts the red-coloured, non-emissive H+DQ2 back to its yellow-coloured, fluorescent parent form. The bimodal absorption and emission changes endow the system with high sensitivity, capable of detecting ammonia vapour at a concentration of as low as 690 ppb. Taking advantage of this, H+DQ2 was successfully applied for the detection of food spoilage and was established as a robust and cost effective technique to monitor food safety. [ABSTRACT FROM AUTHOR]

Specifically amplifying the emission signals of optical probes in tumors is an effective way to improve the tumor‐imaging sensitivity and contrast. In this paper, the first case of dendron‐based fluorescence turn‐on probes mediated by a Förster resonance energy transfer (FRET) mechanism is reported. Dendrons up to the fourth generation with a hydrophilic oligo(ethylene glycol) scaffold are synthesized by a solid‐phase synthesis strategy, and show precise and defect‐free chemical structures. To construct the fluorescence turn‐on probe, one Cy5.5 molecule is conjugated to the focal of a G3 dendron through a robust linkage and eight Black Hole Quencher 3 (BHQ‐3) molecules are conjugated to its periphery through a PEG chain bearing a reductively cleavable disulfide linkage. By in vitro and in vivo experiments, it is demonstrated that the fluorescence of the dendron‐based probe can be activated effectively and rapidly in the reductive environments of tumor cells and tissues, and the probe thus exhibits amplified tumor signals and weak normal tissue signals. Compared with the reported nanoscale turn‐on probes, the dendron‐based probe has several significant advantages, such as well‐defined chemical structure, precisely controllable fluorophore/quencher conjugation sites and ratio, desirable chemical stability, and reproducible pharmacokinetic and pharmacological profiles, and is very promising in tumor detection. [ABSTRACT FROM AUTHOR]

We report the synthesis and late‐stage diversification of a new class of hetero‐buckybowl, BN‐embedded dibenzocorannulenes (B2N2‐DBCs). The synthesis is achieved via one‐shot halogenative borylation, comprising the nitrogen‐directed haloboration of alkyne and an intramolecular bora‐Friedel‐Crafts reaction, which provides BN‐embedded dibenzocorannulene possessing two bromo substituents (B2N2‐DBC‐Br). B2N2‐DBC‐Br undergoes diversification via coupling reactions to provide a variety of arylated derivatives (B2N2‐DBC‐R), exhibiting strong blue fluorescence. An organic light‐emitting diode (OLED) employing one of the derivatives as an emitter exhibited a high external quantum efficiency of 6.6 % and long operational lifetime of 907 h at an initial luminance of 1000 cd m−2, indicating the significant potential for the development of efficient and stable hetero‐buckybowl‐based OLED materials. [ABSTRACT FROM AUTHOR]

Herein, we propose a rational design strategy by introducing photoactive thienyl and pyridyl groups into an AIE‐active tetraarylethene skeleton to achieve highly efficient photochemistry‐activated fluorescence enhancement from dominantly photo‐physical aggregation‐induced emission behavior, and prove that such photoactivated fluorescence enhancement is perfectly suited for superstable photocontrollable dual‐mode patterning applications in both solution and solid matrix. It is found that the photoactivated fluorescence of designed AIEgen is attributed to the irreversible cyclized‐dehydrogenation reaction under UV irradiation, and the oxidation product has a brighter fluorescence in both solution and solid states owning to its rigid and planar structure. The overall transformation rate of the AIEgen from its opened form to dehydrogenated form is up to nearly 100 % in a short period of UV irradiation, and the fast transformation and the stable product of this photochemical reaction guarantees super stability of photocontrolled patterning, which can be applied in photoactivated dual‐mode patterning and advanced anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Complexes of the general formula [IrCl(cod)(bdp-NHC-bdp′)] and [IrCl(cod)(bdp-NHC)] (bdp=bodipy=4,4-difluoro-4-bora-3a,4a-diaza- s-indacene, cod=1,5-cyclooctadiene) were synthesized. The substitution reaction of cod with two molecules of CO converts weakly fluorescent into strongly fluorescent complexes [IrCl(CO)2(bdp-NHC-bdp′)] and [IrCl(CO)2(bdp-NHC)]. Bdp and bdp' form a fluorescence resonance energy transfer (FRET) pair and the excitation of bdp leads to a strong emission from bdp' with a virtual Stokes shift of 98 nm. The fluorescence gain ( IFl[Ir(CO)2]]/ IFl[Ir(cod)]=1.7) upon reaction with CO in this complex is modest. To increase the fluorescence gain, the quenching capacity of the transition metal was improved by increasing the electron density at iridium. This was achieved by substituting the metal-bound chloride with an electron-rich thiolate RC6H4S. Depending on the nature of the R substituent in [Ir(SC6H4R)(cod)(bdp-NHC-bdp′)], an improved fluorescence gain in the cod/CO substitution reaction of up to 4.3 was observed and up to 26 (from gain=5) in [Ir(SC6H4R)(cod)(bdp-NHC)]. DFT calculations on closely related [Ir(SC6H4R)(cod)(bdp-NHC)] complexes indicate that a photoinduced electron transfer mechanism is the dominant quenching pathway for the iridium thiolates with R=COMe, CF3, Cl, H, Me, tBu, OMe, NEt2. The CO-responsive FRET complex was immobilized on paper, displaying a red fluorescent color upon exposure to CO. [ABSTRACT FROM AUTHOR]

Bacterial bioluminescence with continuous glow has been applied to the fields of environmental toxin monitoring, drug screening, and in vivo imaging. Nonetheless, the chemical form of the bacterial bioluminophore is still a bone of contention. Flavin mononucleotide (FMN), one of the light-emitting products, and 4a-hydroxy-5-hydro flavin mononucleotide (HFOH), an intermediate of the chemical reactions, have both been assumed candidates for the light emitter because they have similar molecular structures and fluorescence wavelengths. The latter is preferred in experiments and was assigned in our previous density functional study. HFOH displays weak fluorescence in solutions, but exhibits strong bioluminescence in the bacterial luciferase. FMN shows the opposite behavior; its fluorescence is quenched when it is bound to the luciferase. This is the first example of flavin fluorescence quenching observed in bioluminescent systems and is merely an observation, both the quenching mechanism and quencher are still unclear. Based on theoretical analysis of high-level quantum mechanics (QM), combined QM and molecular mechanics (QM/MM), and molecular dynamics (MD), this paper confirms that HFOH in its first singlet excited state is the bioluminophore of bacterial bioluminescence. More importantly, the computational results indicate that Tyr110 in the luciferase quenches the FMN fluorescence via an electron-transfer mechanism. [ABSTRACT FROM AUTHOR]

Over the years, we developed highly selective fluorescent probes for K+ in water, which show K+‐induced fluorescence intensity enhancements, lifetime changes, or a ratiometric behavior at two emission wavelengths (cf. Scheme 1, K1–K4). In this paper, we introduce selective fluorescent probes for Na+ in water, which also show Na+ induced signal changes, which are analyzed by diverse fluorescence techniques. Initially, we synthesized the fluorescent probes 2, 4, 5, 6 and 10 for a fluorescence analysis by intensity enhancements at one wavelength by varying the Na+ responsive ionophore unit and the fluorophore moiety to adjust different Kd values for an intra‐ or extracellular Na+ analysis. Thus, we found that 2, 4 and 5 are Na+ selective fluorescent tools, which are able to measure physiologically important Na+ levels at wavelengths higher than 500 nm. Secondly, we developed the fluorescent probes 7 and 8 to analyze precise Na+ levels by fluorescence lifetime changes. Herein, only 8 (Kd=106 mm) is a capable fluorescent tool to measure Na+ levels in blood samples by lifetime changes. Finally, the fluorescent probe 9 was designed to show a Na+ induced ratiometric fluorescence behavior at two emission wavelengths. As desired, 9 (Kd=78 mm) showed a ratiometric fluorescence response towards Na+ ions and is a suitable tool to measure physiologically relevant Na+ levels by the intensity change of two emission wavelengths at 404 nm and 492 nm. [ABSTRACT FROM AUTHOR]

Photochemical oxidation of acenes can benefit or impede their function, depending on the application. Although acenes with alkoxy substituents on reactive sites are important for applications as diverse as drug delivery and organic optoelectronics, the influence of chemical structure on their photochemical oxidation remains unknown. This paper therefore describes the synthesis, spectroscopic properties, and reactivity with singlet oxygen (1O2) of a series of dialkoxyacenes that vary in the number and types of fused rings in the (hetero)acene cores. Reductive alkylation of quinone precursors yielded target dialkoxyacenes with fused backbones ranging from benzodithiophene to tetracenothiophene. Trends of their experimental spectroscopic characteristics were consistent with time‐dependent density functional theory (TD‐DFT) calculations. NMR studies show that photochemically generated 1O2 oxidizes all but one of these acenes to the corresponding endoperoxides in organic solvent. The rates of these oxidations correlate with the number and types of fused arenes, with longer dialkoxyacenes generally oxidizing faster than shorter derivatives. Finally, irradiation of these acenes in acidic, oxidizing environments cleaves the ether bonds. This work impacts those working in organic optoelectronics, as well as those interested in harnessing photogenerated reactive oxygen species in functional materials. [ABSTRACT FROM AUTHOR]

The exceptionally mild conditions of a titanium(III)‐catalyzed cyclization reaction paired with a convenient acid/base extraction have enabled the straightforward synthesis, isolation, and direct N‐functionalization of amino heterocycles such as 3‐aminoindoles and ‐pyrroles. The unprotected heterocycles are ideal building blocks for the installation of aminated indoles and pyrroles into target molecules, but their sensitivity has previously impeded their synthesis by modern catalytic methods. This full paper presents the development and extended scope of the new cyclization methodology. The transformation of the products into fused bis‐indoles is also demonstrated along with the discovery of an unusual palladium‐catalyzed reductive biphenyl coupling reaction. The titanium(III)‐catalyzed cyclization has also been applied to the synthesis of substituted 3‐iminoindolines, which are of potential interest for applications in natural product synthesis and exhibit tunable blue‐to‐green fluorescence properties. Success at last! A titanium(III)‐catalyzed imine–nitrile cyclization gives rise to free aminoindoles, aminopyrroles, and iminoindolines that are ideal but fragile building blocks for the installation of such motifs into target molecules. Herein, the development, extended scope, and application of this reaction are described. Moreover, the fluorescence properties of the iminoindoline products are briefly reported. [ABSTRACT FROM AUTHOR]

Engineering the properties of conjugated materials in the solid state is an unsolved, ongoing challenge important to fundamental understanding of how non‐covalent interactions dictate packing and key properties, as well as the development of technologies based in organic optoelectronics. The most common design paradigm of such materials divide them into a "main chain" with extended conjugation, the chemical structure of which determines optoelectronic properties, and "side chains" not conjugated to the backbone, which provide solubility when they are long alkyl chains. This paper describes comparisons between phenylene‐ethynylene molecules in which slight changes to the structure of "side chains"—swapping hydrogen and fluorine atomic position on an aromatic ring—results in unexpectedly large changes in the solid‐state optical properties. In a pair of anisyl‐terminated three‐ring phenylene‐ethynylenes, switching the side chain arenes of benzyl esters from 2,4,6‐trifluoro to 2,3,6‐trifluoro results in a shift in fluorescence emission spectra of over 100 nm, as well as the opposite direction of force‐induced shifting of emission. Through a combination X‐ray crystal structures, electronic structure calculations, and comparisons with other derivatives, we describe how the 2,4,6‐trifluorinated side chains yield cofacial fluoroarene‐arene stacking interactions that twist the PE backbone out of conjugation, while the 2,3,6‐trifluoro side chains do not stack, instead yielding more coplanar PE backbones that form intermolecular aggregates. Overall, this work demonstrates how slight modifications to parts of conjugated materials normally considered ancillary to optoelectronic properties can determine their solid‐state properties, epitomizing the challenge of rational design but at the same time offering opportunities for materials discovery and improved understanding of non‐covalent interactions. The optical properties of solid phenylene‐ethynylenes depend heavily upon the regiochemistry of fluorinated aromatic side chains not conjugated to the chromophore. In addition to a >100 nm difference of fluorescence, force‐induced shifting of emission switches direction between the two isomers. X‐ray crystal structures rationalize these effects. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we designed a kind of aggregation‐induced emission (AIE) chiral fluorescence emitters (R/S‐BINOL‐CN enantiomers) in the aggregate state. Chiral emissive nematic liquid crystals (N*‐LCs) prepared by doping this kind of AIE‐active R/S‐BINOL‐CN enantiomers into a common achiral nematic liquid crystal (N‐LC, E7) can self‐assemble as the regularly planar Grandjean texture leading to high luminescence dissymmetry factor (glum) of aggregation‐induced circularly polarized luminescence (AI‐CPL) signal up to 0.41, which can be attributed to dipolar interactions from polar cyano groups and π–π interactions between binaphthyl moiety of the dopant R/S‐BINOL‐CN and biphenyl group of the host molecules (E7). [ABSTRACT FROM AUTHOR]

Abstract: The luciferin/luciferase system of the firefly has been used in bioluminescent imaging to monitor biological processes. In order to enhance the efficiency and expand the application range, some efforts have been made to tune the light emission, especially the effort to obtain NIR light. However, those case‐by‐case studies have not together revealed the nature and mechanism of the color tuning. In this paper, we theoretically investigated the fluorescence of all kinds of typical oxyluciferin analogues. The present systematical modifications of both oxyluciferin and luciferase indicate that the essential factor affecting the emission color is the charge distribution (or the electric dipole moment) on the oxyluciferin, which impacts on the charge transfer to form the light emitter and, subsequently, influence the strength and wavelength of the emission light. More negative charge distributed on the “thiazolone moiety” of the oxyluciferin or its analogues leads to a redshift. Based on this conclusion, we theoretically designed optimal pairs of luciferin analogue and luciferase for emitting NIR light, which could inspire new synthetic procedures and practical applications. [ABSTRACT FROM AUTHOR]

The reversible modulation of fluorescence signals by light is of high interest for applications in super‐resolution microscopy, especially on the DNA level. In this article we describe the systematic variation of the core structure in nucleoside‐based diarylethenes (DAEs), in order to generate intrinsically fluorescent photochromes. The introduction of aromatic bridging units resulted in a bathochromic shift of the visible absorption maximum of the closed‐ring form, but caused reduced thermal stability and switching efficiency. The replacement of the thiophene aryl unit by thiazol improved the thermal stability, whereas the introduction of a benzothiophene unit led to inherent and modulatable turn‐off fluorescence. This feature was further optimized by introducing a fluorescent indole nucleobase into the DAE core, resulting in an effective photoswitch with a fluorescence quantum yield of 0.0166 and a fluorescence turn‐off factor of 3.2. The site‐specific incorporation into an oligonucleotide resulted in fluorescence‐switchable DNA with high cyclization quantum yields and switching efficiency, which may facilitate future applications. [ABSTRACT FROM AUTHOR]

We report the synthesis, gelation abilities and aggregation‐induced, blue‐shifted emission (AIBSE) properties of two minimalistic diketopiperazine‐based gelators. Despite containing a highly insoluble luminophore that makes up more than half of their respective molecular masses, efficient hydrogelation by multiple stimuli for one and efficient organogelation for the other compound are reported. Insights into the aggregation and gelation properties were gained through examination of the photophysical and material properties of selected gels, which are representative of the different modes of gelation. The synthesis of the gelators is highly modular and based on readily available amino acid building blocks, allowing the efficient and rapid diversification of these core structures and fine‐tuning of gel properties. [ABSTRACT FROM AUTHOR]

The assembly of two tripyridinium‐tricarboxylate ligands and different metal ions leads to seven isostructural MOFs, which show novel 2D→2D supramolecular entanglement featuring catenane‐like interlocking of tricyclic cages. The MOFs show tripyridinium‐afforded and metal‐modulated photoresponsive properties. The MOFs with d10 metal centers (1‐Cd, 1‐Zn, 2‐Cd, 2‐Zn) show fast and reversible photochromism and concomitant fluorescence quenching, 1‐Ni displays slower photochromism but does not fluoresce, and 1‐Co and 2‐Co are neither photochromic nor fluorescent. It is shown here that the network entanglement dictates donor‐acceptor close contacts, which enable fluorescence originated from interligand charge transfer. The contacts also allow photoinduced electron transfer, which underlies photochromism and concomitant fluorescence response. The metal dependence in fluorescence and photochromism can be related to energy transfer through metal‐centered d‐d transitions. In addition, 1‐Cd is demonstrated to be a potential fluorescence sensor for sensitive and selective detection of UO22+ in water. [ABSTRACT FROM AUTHOR]

Acquiring desirable device performance with deep‐blue color purity that fulfills practical application requirements is still a challenge. Bipolar fluorescent emitters with hybrid local and charge transfer (HLCT) state may serve to address this issue. Herein, by inserting anthracene core in the deep‐blue building blocks, the authors successfully developed two highly twisted D‐π‐A fluorescent emitters, ICz‐An‐PPI and IP‐An‐PPI, featuring different acceptor groups. Both exhibited superb thermal stabilities, high photo luminescent quantum yields and excellent bipolar transport capabilities. The non‐doped OLEDs using ICz‐An‐PPI and IP‐An‐PPI as the emitting layers showed efficient blue emission with an external quantum efficiency (EQEmax) of 4.32 % and 5.41 %, and the CIE coordinates of (0.147, 0.180) and (0.149, 0.150), respectively. In addition, the deep blue doped device based on ICz‐An‐PPI was achieved with an excellent CEmax of 5.83 cd A−1, EQEmax of 4.6 % and the CIE coordinate of (0.148, 0.078), which is extremely close to the National Television Standards Committee (NTSC) standard. Particularly, IP‐An‐PPI‐based doped device had better performance, with an EQEmax of 7.51 % and the CIE coordinate of (0.150, 0.118), which was very impressive among the recently reported deep‐blue OLEDs with the CIEy <0.12. Such high performance may be attributed to the hot exciton HLCT mechanism via T7 to S2. Our work may provide a new approach for designing high‐efficiency deep‐blue materials. [ABSTRACT FROM AUTHOR]

Three new zinc(II) coordination units [Zn(1–3)] based on planar‐directing tetradentate Schiff base‐like ligands H2(1–3) were synthesized. Their solid‐state structures were investigated by single crystal X‐ray diffraction, showing the tendency to overcome the square‐planar coordination sphere by axial ligation. Affinity in solution towards axial ligation has been tested by extended spectroscopic studies, both in the absorption and emission mode. The electronic spectrum of the pyridine complex [Zn(1)(py)] has been characterized by MC‐PDFT to validate the results of extended TD‐DFT studies. Green emission of non‐emissive solutions of [Zn(1–3)] in chloroform could be switched on in the presence of potent Lewis‐bases. While interpretation in terms of an equilibrium of stacked/non‐fluorescent and destacked/fluorescent species is in line with precedents from literature, the sensitivity of [Zn(1–3)] was greatly reduced. Results of a computation‐based structure search allow to trace the hidden Lewis acidity of [Zn(1–3)] to a new stacking motif, resulting in a strongly enhanced stability of the dimers. [ABSTRACT FROM AUTHOR]

We report a generalizable strategy for biosensing that takes advantage of the resistance of DNA aptamers against nuclease digestion when bound with their targets, coupled with toehold mediated strand displacement (TMSD) and rolling circle amplification (RCA). A DNA aptamer containing a toehold extension at its 5′‐end protects it from 3′‐exonuclease digestion by phi29 DNA polymerase (phi29 DP) in a concentration‐dependent manner. The protected aptamer can participate in RCA in the presence of a circular template that is designed to free the aptamer from its target via TMSD. The absence of the target leads to aptamer digestion, and thus no RCA product is produced, resulting in a turn‐on sensor. Using two different DNA aptamers, we demonstrate rapid and quantitative real‐time fluorescence detection of two human proteins: platelet‐derived growth factor (PDGF) and thrombin. Sensitive detection of PDGF was also achieved in human serum and human plasma, demonstrating the selectivity of the assay. [ABSTRACT FROM AUTHOR]

Peptides and nucleic acids can self‐assemble to give supramolecular structures that find application in different fields, ranging from the delivery of drugs to the obtainment of materials endowed with optical properties. Forces that stabilize the "suprastructures" typically are hydrogen bonds or aromatic interactions; in case of nucleic acids, Watson‐Crick pairing drives self‐assembly while, in case of peptides, backbone hydrogen bonds and interactions between aromatic side chains trigger the formation of structures, such as nanotubes or ribbons. Molecules containing both aromatic peptides and nucleic acids could in principle exploit different forces to self‐assemble. In this work we meant to investigate the self‐assembly of mixed systems, with the aim to understand which forces play a major role and determine formation/structure of aggregates. We therefore synthesized conjugates of the peptide FF to the peptide nucleic acid dimer "gc" and characterized their aggregates by different spectroscopic techniques, including NMR, CD and fluorescence. [ABSTRACT FROM AUTHOR]

Organic small‐molecule fluorophores with near‐infrared IIa (NIR‐IIa) emission have great potential in pre‐clinical detection and inoperative imaging due to the high‐spatial resolution and deep penetration. However, developments of the NIR‐IIa fluorophores are still facing considerable challenges. In this work, a series of diketopyrrolopyrrole (DPP)‐based fluorophores were designed and synthesized. Subsequently, nanomaterial T25@F127 with significant NIR‐IIa emission properties was rationally prepared by encapsulating DPP‐based fluorophore T25, and was selected for fluorescence angiography and cerebral vascular microscopic imaging with nearly 800 μm penetrating depth and excellent signal‐background ratio of 4.07 and 2.26 (at 250 and 400 μm), respectively. Furthermore, the nanomaterial T25@cRGD with tumor targeting ability can image tiny metastatic tumor on intestine with a small size of 0.3 mm×1.0 mm and high‐spatial resolution (SBR=3.84). This study demonstrates that the nanomaterials which encapsulated T25 behave as excellent NIR‐IIa fluorescence imaging agents and have a great potential for in vivo biological application. [ABSTRACT FROM AUTHOR]

Aroyl‐S,N‐ketene acetal‐based bichromophores can be readily synthesized in a consecutive three‐component synthesis in good to excellent yields by condensation of aroyl chlorides and an N‐(p‐bromobenzyl) 2‐methyl benzothiazolium salt followed by a Suzuki coupling, yielding a library of 31 bichromophoric fluorophores with substitution pattern‐tunable emission properties. Varying both chromophores enables different communication pathways between the chromophores, exploiting aggregation‐induced emission (AIE) and energy transfer (ET) properties, and thus, furnishing aggregation‐based fluorescence switches. Possible applications range from fluorometric analysis of alcoholic beverages to pH sensors. [ABSTRACT FROM AUTHOR]

Novel electron donor–acceptor–donor (D‐A‐D) compounds comprising dibenzo[a,j]phenazine as the central acceptor core and two 7‐membered diarylamines (iminodibenzyl and iminostilbene) as the donors have been designed and synthesized. Investigation of their physicochemical properties revealed the impact of C2 insertion into well‐known carbazole electron donors on the properties of previously reported twisted dibenzo[a,j]phenazine‐core D‐A‐D triads. Slight structural modification caused a drastic change in conformational preference, allowing unique photophysical behavior of dual emission derived from room‐temperature phosphorescence and triplet–triplet annihilation. Furthermore, electrochemical analysis suggested sigma‐dimer formation and electrochemical polymerization on the electrode. Quantum chemical calculations also rationalized the experimental results. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue is the group of Yoshiaki Nishibayashi at The University of Tokyo. Read the full text of the article at 10.1002/chem.201805129. "The biggest surprise was the observation of fluorescence behavior for ferrocenium(III) cation in acetonitrile solution." Read more about the story behind the cover in the Cover Profile and about the research itself on page 18618 ff. (DOI: 10.1002/chem.201805129). [ABSTRACT FROM AUTHOR]

The effects of defect states on the fluorescence (FL) and electrochemiluminescence (ECL) properties of graphite phase carbon nitride (g‐CN) are systematically investigated for the first time. The g‐CN nanosheets (CNNSs) obtained at different condensation temperatures are used as the study models. It can be found that all the CNNSs have two kinds of defect states, one is originated from the edge of CNNSs (labeled as CN‐defect) and the other is attributed to the partially carbonization regions (labeled as C‐defect). Both two kinds of defect states substantially affect the luminescent properties of CNNSs. Both the FL and ECL signals of CNNSs contain a band gap emission and two defect emissions. For the FL of CNNSs, decreasing the density of defect states can increase efficiently the FL quantum yield, while increasing the density of defect states can make the FL spectra red shift. For the ECL of CNNSs, increasing the density of CN‐defect states and decreasing the density of C‐defect states are greatly important to improve the ECL activity. This work provides a deep insight into the FL and ECL mechanisms of g‐CN, and is of significance in tuning the FL and ECL properties of g‐CN. Also, it will greatly promote the applications of CNNSs based on the FL and ECL properties. [ABSTRACT FROM AUTHOR]

Fluorescent chemodosimeters based on small organic molecules are widely used in the detection of various analytes. However, chemodosimeters for metal ion detection are still limited to a few transition metals, such as HgII, CuII, FeIII, AuIII, etc. In this work, a fluorescent chemodosimeter of 5-chloro-7-phenyliminomethyl-8-hydroxyquinoline ( 2) for the detection of AlIII is reported. Chemodosimeter 2 exhibits a turn-on fluorescence response to AlIII owing to an AlIII-promoted hydrolysis of carbon-nitrogen double bonds. This reaction yielded a 1- Al complex, which exhibited high fluorescence emission at 487 nm based on inhibition of excited-state intramolecular proton transfer (ESIPT). Because of the specific catalytic ability of AlIII, the selectivity of 2 to AlIII is excellent both in aqueous solutions and in solid matrix. The fluorescence enhancement was as high as 582-fold and the turn-on fluorescence can be observed even by the naked eye upon an irradiation with a UV lamp. The detection limit of 2 for AlIII sensing is 54 nmol L−1 and the linear range is 0-50 μmol L−1. This work provides a new strategy for designing main-group-metal chemodosimeters based on small organic molecules. [ABSTRACT FROM AUTHOR]

The design, synthesis and aggregation-induced emission properties of a new series of triarylborane-oligothiophene-dicyanovinyl (DCV) conjugates 4- 6 (A-D-A' type molecular configuration) are reported. The optical properties of 4- 6 can be modulated by judiciously varying the number of thiophene units between electron deficient boryl and dicyanovinyl units. Compound 6 with terthiophene spacer showed highly red-shifted absorption and emission compared to 5 and 4 with bithiophene and monothiophene spacers, respectively. Compounds 5 and 6 show aggregation-induced emission enhancement in water/THF mixtures. Compounds 5 and 6 also showed solvent viscosity dependent emission characteristics. All the three compounds show distinct optical responses for small anions such as fluoride and cyanide. Filter paper strips coated with compounds 5 and 6 can detect F− and CN− in aqueous media with different colorimetric responses. [ABSTRACT FROM AUTHOR]

Mono‐ and di‐boranil‐substituted helicenes were prepared by BF2‐borylation of the corresponding anils, readily synthesized by condensation of 2‐amino‐ and 2,15‐diamino‐helicenes with 4‐(diethylamino)salicylaldehyde. After enantiomeric resolution using HPLC, their chiroptical properties including circularly polarized fluorescence in solution and in PMMA films were investigated and rationalized with the help of NMR, X‐ray and quantum‐chemical calculations. [ABSTRACT FROM AUTHOR]

High‐performance deep‐blue emitters with external quantum efficiencies (EQEs) exceeding 5 % are still scarce in organic light‐emitting diodes (OLEDs). In this work, by introducing a [1,2,4]triazolo[1,5‐a] pyridine (TP) unit at the N1 position of phenanthroimidazole (PI), two luminescent materials, PTPTPA and PTPTPA, were obtained. Systematic photophysical analysis showed that the TP block is suitable for constructing hybridized local and charge‐transfer (HLCT) emitters. Its moderate electron‐withdrawing ability and rigid planar structure can enhance the CT component while ensuring color purity. In addition, compared with PTPTPA, the additional phenyl ring of PTPBPTA not only increased the oscillator strength, but also decreased the Stokes shift. TDDFT calculations pointed out facile reverse intersystem crossing processes in PTPTPA from high‐lying triplet states to the singlet excited state. A nondoped device based on PTPTPA as emitter showed impressive performance with EQEmax of 7.11 % and CIE coordinates of (0.15, 0.09). At the same time, it was also an efficient host for yellow and red phosphorescent OLEDs. By doping yellow (PPYBA) and red (BTPG) phosphorescent dyes into PTPTPA, a white OLED with a high EQE of 23.85 % was achieved. The successful design of PTPTPA not only provided an optimization choice for OLED emitters, but also demonstrated the empirical rules for the design of multifunctional deep‐blue emitters. [ABSTRACT FROM AUTHOR]

There is increasing interest in the development and applications of synthetic receptors that recognize target biomolecules in aqueous media. We have developed a new tweezer‐type synthetic receptor that gives a significant fluorescence response upon complexation with heme in aqueous solution at pH 7.4. The synthetic receptor consists of a tweezer‐type heme recognition site and sulfo‐Cy5 as a hydrophilic fluorophore. The receptor–heme complex exhibits a supramolecular amphiphilic character that facilitates the formation of self‐assembled aggregates, and both the tweezer moiety and the sulfo‐Cy5 moiety are important for this property. The synthetic receptor also exhibits significant fluorescence responses to biliverdin and bilirubin, but shows very weak fluorescence responses to flavin mononucleotide, folic acid, and nicotinamide adenine dinucleotide, which contain smaller π‐scaffolds. [ABSTRACT FROM AUTHOR]

Porphycene, a porphyrin isomer, is an efficient fluorophore. However, four‐fold meso substitution with alkyl groups decreases the fluorescence quantum yield by orders of magnitude. For aryl substituents, this effect is small. To explain this difference, we have synthesized and studied a mixed aryl‐alkyl‐substituted compound, 9,20‐diphenyl‐10,19‐dimethylporphycene, as well as the 9,20‐diphenyl and 9,20‐dimethyl derivatives. Analysis of the structural, spectroscopic, and photophysical data of the six porphycenes, combined with quantum chemical calculations, shows a clear correlation between the strength of the intramolecular NH⋅⋅⋅N hydrogen bonds and the efficiency of the radiationless depopulation of the lowest‐excited singlet state. This result led us to propose a model in which the delocalization of the inner protons in the cavity of the macrocycle is responsible for the nonradiative deactivation channel. The applicability of the model is confirmed by the literature data for other alkyl‐ or aryl‐substituted porphycenes. The finding of a correlation between structural and emissive characteristics enables a rational design of porphycenes with desired photophysical properties. [ABSTRACT FROM AUTHOR]

Wrinkles and photo‐oxidation reactions are widely found in soft materials, which are intimately associated with the failure of materials and structures. It is expected that the photo‐oxidation process could also have a positive effect on the material and its surface. Here, we report the photo‐oxidation of 2‐(4‐dietheylaminophenyl)‐4,5‐bis(4‐methoxyphenyl) imidazole (DEA‐TAI) into a wrinkled bilayer system to control surface wrinkle and fluorescent patterns, in which a supramolecular polymer network composed of carboxylic acid‐containing copolymer (PS‐BA‐AA; PS=poly(styrene), BA=butyl acrylate; AA=acrylic acid) and DEA‐TAI were used as the skin layer. Ultraviolet (UV) irradiation can induce photo‐oxidation of the imidazole ring of DEA‐TAI to weaken the intermolecular hydrogen bonding between PS‐BA‐AA and DEA‐TAI, resulting in the release of stress in the bilayer system. The wrinkled morphology and fluorescence of the surface can be simultaneously regulated by photo‐oxidation of DEA‐TAI under UV light, and the resulting wrinkles are extremely sensitive to the pH value, which can be quickly and reversibly erased by NH3 gas. Smart surfaces with specific hierarchical wrinkles and fluorescence can be achieved by selective irradiation with photomasks, which may find potential applications in smart displays and multi‐code information storage. [ABSTRACT FROM AUTHOR]

A bright near‐infrared (NIR) fluorescent molecule was developed based on the donor–acceptor–donor (D–A–D) approach using an aza‐BODIPY analog called pyrrolopyrrole aza‐BODIPY (PPAB) as an electron‐accepting chromophore. Directly introducing electron‐donating triphenylamine (TPA) to develop a D–A–D structure caused redshifts of absorption and emission of PPAB into the NIR region with an enhanced fluorescence brightness of up to 5.2×104 m−1 cm−1, whereas inserting a phenylene linker between the TPA donor and the PPAB acceptor induced solvatochromic behavior in emission. Transient absorption spectra and theoretical calculations revealed the presence of a highly emissive hybridized locally excited and charge‐transfer state in the former case and the contribution of the dark charge‐separated state to the excited state in the latter case. The bright D–A–D PPAB as a novel emitter resulted in a NIR electroluminescence with a high external quantum efficiency of 3.7 % and a low amplified spontaneous emission threshold of ca. 80 μJ cm−2, indicating the high potential for NIR optoelectronic applications. [ABSTRACT FROM AUTHOR]

In this study, photoswitchable fluorescent supramolecular metallacycles with high fatigue‐resistance have been constructed by coordination‐driven self‐assembly by using bithienylethene with dipyridyl units (BTE) as a coordination donor and a fluorescent di‐platinum(II) (Pt‐F) as a coordination acceptor. The photo‐triggered reversible transformation between the ring‐open and ring‐closed form of the metallacycles was confirmed by 1H NMR, 31P NMR, and UV/Vis spectroscopy. This unique property enabled a reversible noninvasive "off–on" switching of fluorescence through efficient Förster resonance energy transfer (FRET). Importantly, the metallacycles remained structurally intact after up to 10 photoswitching cycles. The photoresponsive property and exceptional photostability of the metallacycles posit their potential promising application in optical switching, image storage, and super‐resolution microscopy. [ABSTRACT FROM AUTHOR]

Bulges are essential structural elements in nucleic acids. The detection and targeting of bulged DNA sequences are highly important. Small molecules capable of targeting DNA bulges have attracted considerable attention because they cannot only be used as reagents for bulge recognition, but also as potential therapeutic drugs. Herein, the interactions of DNA duplexes, containing bulges of various sizes and base compositions, with a series of FeII triplex‐forming metallohelices are reported. The results obtained, with the aid of molecular biophysics methods, show that the investigated metallohelices prefer to bind to bulged DNA, rather than double‐stranded DNA, and that their binding affinities towards bulges differ among individual metallohelices. Moreover, their binding affinities towards bulges strongly depend on the bulge size and the base composition of the bulge loop. The investigated metallohelices can enter eukaryotic cells and accumulate in the cell nucleus, allowing them to interact with nucleic acids. Hence, it is reasonable to suggest that the interaction of metallohelices with nucleic acid bulges might contribute to the mechanism of their biological activity. [ABSTRACT FROM AUTHOR]

Cover Feature: Symmetry Reduction of Porphycenes with Finely Tuned Optical and Electronic Properties through Oxidative Cyclization of E/Z-Mixed Dipyrroethenes (Chem. Eur. J. 50/2019) The type and position of substituents in the unsymmetric porphycenes enabled fine-tuning of the optical and electronic properties. More information can be found in the Full Paper by N. Xu, T. Ono, and Y. Hisaeda on page 11680. [Extracted from the article]

Fluorescent probes that light‐up upon reaction with complementary bioorthogonal reagents are superior tools for no‐wash fluorogenic bioimaging applications. In this work, a thorough study is presented on a set of seventeen structurally diverse coumarin–tetrazine probes that produce fluorescent dyes with exceptional turn‐on ratios when reacted with trans‐cyclooctene (TCO) and bicyclononyne (BCN) dienophiles. In general, formation of the fully aromatic pyridazine‐containing dyes resulting from the reaction with BCN was found superior in terms of fluorogenicity. However, evaluation of the probes in cellular imaging experiments revealed that other factors, such as reaction kinetics and good cell permeability, prevail over the fluorescence turn‐on properties. The best compound identified in this study showed excellent performance in live cell‐labeling experiments and enabled no‐wash fluorogenic imaging on a timescale of seconds. [ABSTRACT FROM AUTHOR]

The weak fluorescence (quantum yield <1 % in cyclohexane) of phenothiazine (PTZ) impedes its further application. In addition, the nitro group (NO2) is a well‐known fluorescence quencher. Interestingly, we obtained a highly fluorescent chromophore by combining these two moieties, forming 3‐nitrophenothiazine (PTZ‐NO2). For comparison, a series of PTZ derivatives bearing electron‐withdrawing groups (EWGs; CN and CHO) or electron‐donating groups (EDGs; OMe) at the 3‐position have been designed and synthesized. The phenothiazines bearing EWGs exhibited enhanced emission compared with the parent PTZ or EDG derivatives. Computational approaches unveiled that for PTZ and PTZ‐OMe, the transitions are from HOMOs dominated by π orbitals to LUMOs of mixed sulfur nonbonding–π* orbitals, and hence are partially forbidden. In contrast, the EWGs lower the energy level of the lone‐pair electrons on the sulfur atom, thereby suppressing the mixing of the nonbonding orbital with the π* orbital in the LUMO, such that the allowed ππ* transition becomes dominant. This work thus demonstrates a judicious chemical design to fine‐tune the transition character in PTZ analogues, with PTZ‐NO2 attaining 100 % emission quantum yields in nonpolar solvent. [ABSTRACT FROM AUTHOR]

Nitrogen Heterocycles A new opportunity in the design and synthesis of organic emitters is demonstrated in the preparation of new fused N‐heterocycle tethered fluorenes including a chiral fluorene architecture. Intramolecular oxidative arylations of 7‐azaindoles and pyrroles provided access to 7‐azaindole or pyrrole fused isoindolines and its chiral congeners. For more details, see the Full Paper by J. K. Laha et al. on page 2044 ff. [ABSTRACT FROM AUTHOR]

Two switches are shown to control the fluorescence in an efficient red ‐ emitting fluorescent indicator with a steep sensing profile. Intramolecular charge transfer from the peripheral tertiary amine and protonation of azomethine nitrogen atoms in azaphthalocyanine are involved in the sensing mechanism. The particular pH range is driven by the basicity of these two centers and can be simply tuned by structural changes in the molecule. More information can be found in the Full Paper by V. Nemykin, P. Zimcik, V. Novakova et al. on page 1795 ff. [ABSTRACT FROM AUTHOR]

Soft Materials A new blue‐fluorescent soft material with high quantum yield (89.6 %) and eutectic feature was facilely prepared by simple heat treatment of citric acid and l‐cysteine aqueous mixtures below 100 °C in air. The as‐prepared fluorescent material has the features of facile preparation, low cost, scalable production and easy to process, making it suitable for applications like fluorescent labeling and light‐emitting devices. For more details, please see the Full Paper by H.‐X. Wang, H.‐L. Zhang et al. on page 8096 ff. [ABSTRACT FROM AUTHOR]

Tuning fluorescence colour of solid‐state materials has become a topic of increasing interest for both fundamental mechanism study and practical applications such as sensors, optical recording and security printing. In this work, a fluorescent colour tuneable molecule BA‐C16 is rationally designed and facilely synthesized by attaching flexible long alkyl chains to 2‐hydroxybenzophenone azine (BA), which shows both aggregation‐induced emission (AIE) and excited‐state intramolecular proton transfer (ESIPT) characteristics. Compared to BA, the simple introduction of long alkyl chains in BA‐C16 leads to an emission wavelength redshift from 542 to 558 nm. This strategy of extending emission wavelength is rarely reported, and is ascribed to the enlarged through‐space π‐conjugation between interplanar molecules in the aggregate of BA‐C16. Three crystals of BA‐C16 are obtained with green, yellowish green and yellow emission. According to characterization by X‐ray crystallography, X‐ray powder diffraction and differential scanning calorimetry, alkyl chains play an important role in inducing different stacking modes of the three crystals, which further leads to polymorph‐dependent fluorescence colour. BA‐C16 exhibits tuneable solid‐state fluorescence upon vapor fumigation, or annealing based on a transition between a "near‐monomer" crystalline state and a "dimer" crystalline state. BA‐C16 is further applied for rewritable fluorescence printing tuned by vapor‐ and thermal‐treatment. [ABSTRACT FROM AUTHOR]

With the rapid progress in the development of supramolecular soft materials, examples of low-molecularweight gelators (LMWGs) with the ability to immobilise both water and organic solvents by the same structural scaffold are very limited. In this paper, we report the development of pyrene-containing peptide-based ambidextrous gelators (AGs) with the ability to efficiently gelate both organic and aqueous solvents. The organo- and hydrogelation efficiencies of these gelators are in the range 0.7–1.1% w/v in various organic solvents and 0.5–5% w/v in water at certain acidic pH values (pH 2.0–4.0). Moreover, for the first time, AGs have been utilised to prepare single-walled carbonnanotube (SWNT)-included soft nanocomposites in both hydro- and organogel matrices. The influence of different non-covalent interactions such as hydrogen bonding, hydrophobic, π–π and van der Waals interactions in self-assembled gelation has been studied in detail by circular dichroism, FTIR, variable-temperature NMR, 2D NOESY and luminescence spectroscopy. Interestingly, the presence of the pyrene moiety in the structure rendered these AGs intrinsically fluorescent, which was quenched upon successful integration of the SWNTs within the gel. The prepared hydroand organogels along with their SWNT-integrated nanocomposites are thermoreversible in nature. The supramolecular morphologies of the dried gels and SWNT–gel nanocomposites have been studied by transmission electron microscopy, fluorescence microscopy and polarising optical microscopy, which confirmed the presence of three-dimensional self-assembled fibrillar networks (SAFINs) as well as the integrated SWNTs. Importantly, rheological studies revealed that the inclusion of SWNTs within the ambidextrous gels improved the mechanical rigidity of the resulting soft nanocomposites up to 3.8-fold relative to the native gels. [ABSTRACT FROM AUTHOR]