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By utilizing a pH-responsive ratiometric AIEgen, dihydro berberine (dhBBR), ion trapping phenomenon was successfully visualized., In clinical chemotherapy, some basic drugs cannot enter the hydrophobic cell membrane because of ionization in the acidic tumor microenvironment, a phenomenon known as ion trapping. In this study, we developed a method to visualize this ion trapping phenomenon by utilizing a pH-responsive ratiometric AIEgen, dihydro berberine (dhBBR). By observing the intracellular fluorescence of dhBBR, we found that non-ionized dhBBR can enter cells more easily than ionized forms, which is in accordance with the concept of ion trapping. In addition, dhBBR shows superior anti-photobleaching ability to Curcumin thanks to its AIE properties. These results suggest that dhBBR can serve as a bioprobe for ion trapping.

The microscopic control of macroscopic phenomena is one of the core subjects in materials science. In particular, the spatio-temporal control of material behaviors through a non-contact way is of fundamental importance but different to accomplish. Herein, a strategy to realize remote spatio-temporal control of luminescence behaviors is reported. A multi-arm salicylaldehyde benzoylhydrazone-based aggregation-induced emission luminogen (AIEgen)/metal ion system was developed of which the fluorescence can be gated by the UV irradiation with time dependency. By changing metal ion species, the fluorescence can also be tuned. The mechanism of the UV-mediated fluorescence change behaivors was investigated and it was revealed that a photo-triggered aggregation-induced emission (PTAIE) process dominates the behaviors. The AIEgen was further covalently integrated into a polymeric network and the formed gel/metal ion system can achieve laser-mediated mask-free writing enabled by the PTAIE process. Moreover, by further taking advantage of the time-dependent self-healing property of hydrazone-based dynamic covalent bond, transformable four- dimensional (4D) soft patterns were generated. The findings and the strategy increase the choice of ways to manipulate molecules on the supramolecule or aggregate level. They also show opportunities for the development of controllable smart materials and expand the scope of the materials in advanced optoelectronic applications.

This work provides a new strategy to design heterocycle-containing AIEgens from non-emissive heteroaromatics and promotes their applications for long-term lysosome imaging., The development of new aggregation-induced emission (AIE) systems is a hot research topic, from which functional materials with diversified structures and properties are derived. Here, based on rare, non-emissive and highly electron-withdrawing heteroaromatics of 1,4,5,8-tetraazaanthracene (TAA), experimental and theoretical studies reveal that attaching phenyl rotors to TAA is crucial to creating a new N-type AIE core structure. Furthermore, by covalent attachment of electron-donating aromatic amines to the peripheries of the AIE core, red AIEgens could be obtained readily, which exhibit excellent photostability for long-term lysosome tracking. This work not only provides a new strategy to design heterocycle-containing AIEgens from non-emissive heteroaromatics but also stimulates more their applications as bio-imaging materials.

A successful strategy for the design of ultrabright red luminogens with aggregation-induced emission (AIE) features is reported. The AIE dots can be utilized as efficient fluorescent probes for in vivo deep-tissue imaging with high penetration depth and high contrast., Reported here is a successful strategy for the design of ultrabright red luminogens with aggregation-induced emission (AIE) features, donor–acceptor structures, and intense charge transfer effects. These luminogens show no aggregation caused emission quenching in the solid state and have high quantum efficiency. They can be fabricated into AIE dots by a simple nanoprecipitation procedure. The AIE dots exhibit high brightness, a large Stokes shift, good biocompatibility, satisfactory photostability, and a high two-photon absorption cross section. The AIE dots can be utilized as highly efficient fluorescent probes for in vivo deep-tissue imaging by a two-photon technique, which outperforms the one-photon technique under the same experimental conditions, in terms of penetration depth and image contrast. This is the first report of using highly emissive AIE dots for the accurate measurement of capillary diameters in mouse ears. Such a strategy sheds light on the development of efficient solid state red/NIR emitters for biological applications.

PIP–TPE’s fluorescence turns on blue due to the large viscosity of lysosomes which restricts intramolecular motions but it red-shifts in the bulk., Lysosomes are involved in a multitude of cellular processes and their dysfunction is associated with various diseases. They are the most acidic organelles (pH 3.8–6.6, size 0.1–1.2 μm) with the highest viscosity (47–190 cP at 25 °C) in the cell. Because of their acidity, pH dependent non-AIE active fluorescent lysosomal probes have been developed that rely on protonation inhibited photoinduced electron transfer (PET). In this work, an acidic pH independent lysosome targetable piperazine–TPE (PIP–TPE) AIEgen has been designed with unique photophysical properties making it a suitable probe for quantifying viscosity. In a non-aggregated state PIP–TPE shows deep-blue emission as opposed to its yellowish-green emission in the bulk. It possesses high specificity for lysosomes with negligible cytotoxicity and good tracing ability due to its better photostability compared to LysoTracker Red. In contrast to most known lysosome probes that rely solely on PET, restriction of intramolecular motion (RIM) due to the larger viscosity inside the lysosomes is the mechanism responsible for PIP–TPE’s fluorescence. PIP–TPE’s high selectivity is attributed to its unique molecular design that features piperazine fragments providing a perfect balance between lipophilicity and polarity.

For the first time, an AIEgen-conjugated monoclonal antibody is designed for “turn-on” and “wash-free” imaging of EGFR-overexpressed cancer cells., An antibody–AIEgen conjugate is designed and developed as a “turn-on” fluorescent probe for wash-free specific cancer cell imaging. The cetuximab-conjugated AIEgen shows red fluorescence only when it is internalized and accumulated in cancer cells with overexpressed epidermal growth factor receptor through endocytosis. The probe first lights up the lysosomes. After hydrolysis, its residue is accumulated in mitochondria, making them highly emissive with a long cell retention time. Compared with conventional “always-on” fluorescent probes, the antibody–AIEgen conjugate exhibits a very good image contrast during wash-free cancer cell imaging and less interference from normal cells. To the best of our knowledge, this is the first time “turn-on” antibody–AIEgen conjugates have been reported. This new strategy can be further extended to many proteins and water-soluble AIEgens, and many of their potential applications such as real-time tracking of cell dynamics and cancer theranostics will be explored. The present work is expected to inspire more marvellous research in the fields of AIE and cancer imaging.

采用示差扫描量热法（DSC）、一维（1D）、二维（2D）广角X-射线衍射（WAXD）和偏光显微镜（PLM）等研究手段对聚{11-[（4′-正庚氧基-4-联苯基）羰基]氧-1-十一炔}（PA-9,7）的本体相转变和相结构进行研究,并采用分子动力学方法对相结构进行模拟.结果表明,样品的相转变为近晶B相（SmB）近晶A相（SmA）各向同性态（Iso）.在近晶B相中,侧链在层状结构中排列成具有六次对称性的准长程有序结构。

Dynamic visualization of the morphology of membrane-bound organelles offers useful insights for studying various intracellular activities. Fluorescent probes with superior specificity and photostability are desirable for long-term tracking of these processes. In this work, we present the design and synthesis of an a-cyanostilbene derivative, abbreviated as ASCP, with the aggregation-induced emission (AIE) characteristic, and its application in cell imaging. ASCP can simultaneously label mitochondria and nucleolus in live cells with distinct fluorescence, which is demonstrative of a single molecule with dualcolour organelle imaging.

A tetraphenylethene derivative with a structure resembling Tamoxifen is designed and synthesized as a theranostic agent for cell imaging and anti-breast cancer therapy. Its high brightness, excellent photostability and long-term cell tracing properties enable elucidation of its working mechanism and hence provide new insights into drug development.

An atom-economical and straightforward polymerization method to generate functional isocoumarin-containing polymers was developed in this work. The oxidative polycoupling of 4,4'-(1,2-diphenyl-1,2-ethenylene)dibenzoic acid and 1,6-bis[4-(phenylethynyl)phenoxy]hexane proceeds efficiently in dimethylformamide under nitrogen or air in the presence of [Cp*RhCl2]2 and a catalytic amount of Cu(OAc)2·H2O at 120 °C for 24 h, generating a polymer with a high molecular weight of up to 42 900 in a high yield of up to 92.9%. An isocoumarin framework forms in situ during the polymerization from readily accessible and inexpensive monomers. The resulting polymer possesses good thermal stability, optical transparency and film-forming ability. Its thin film exhibits high and UV-tunable refractive indices (n =1.9697–1.6507) in a wide wavelength region of 390–890 nm. A two-dimensional fluorescent photopattern can be readily fabricated by irradiating its thin film under UV light through a copper mask. Due to the incorporation of tetraphenylethene units in the monomer, the polymer obtained is weakly emissive in solution but it emits intensely when aggregated, demonstrating a phenomenon of aggregation-induced emission.

The development of an efficient transition metal-free polymerization route has been an active research topic in polymer science owing to its low synthetic cost and decreased metal residue and hence elevated material performance in the products. In this work, we report a new such method for constructing conjugated polydiynes based on the organic reaction of 1-haloalkyne. In the presence of potassium iodide, the polymerizations of 1,2-bis[4-(iodoethynyl)phenyl]-1,2-diphenylethene (1), 1,4-bis(2-iodoethynyl)benzene (2) and 4,4'-bis(2-iodoethynyl)-1,1'-biphenyl (3) proceed smoothly in N,N-dimethylformamide at 120 °C under nitrogen, producing P1–3 consisting of alternate aromatic and 1,3-diyne moieties in moderate to satisfactory yields. While P1 possesses good solubility in common organic solvents, P2 and P3 are insoluble due to their rigid structures. All the polymers are thermally stable, losing 5% of their weight at a high temperature of up to 352 °C. A homogeneous film of P1 can be readily obtained by spin- coating its solution, which shows high and UV-tunable refractive index (n = 2.1125–1.7747) in a wide wavelength range (400–900 nm). A well-defined fluorescent photopattern can be generated by UV irradiation of the polymer film through a copper mask. This work thus opens a new avenue for constructing conjugated polymers with advanced functionalities.

Chiral nematic liquid crystals (N*LCs) are a kind of smart material that can be obtained directly from cholesteric LCs or from nematic LCs by adding a chiral dopant. As a 1D photonic crystal, [ 1 ] the helical and periodic structure of a N*LC leads to unique optical properties, including selective reflection, circular dichroism (CD), optical rotation, and so on. [ 2–5 ] The most important property of N*LCs is the selective reflection of circularly polarized (CP) light. When N*LCs are sandwiched between two substrates with planar anchoring surfaces, CP light with the same handedness as the helix will be selectively reflected whereas light with opposite handedness will be transmitted.

Multicomponent sequential reactions have recently received much attention owing to their outstanding advantages, such as simple operation, atom economy, and environmental benefit. In this work, we report a new multicomponent sequential reaction and the corresponding multicomponent sequential polymerization approach to construct conjugated structures with advanced functionalities. By employing 1,8-diazabicyclo[5.4.0]undec-7-ene as an additive, alkynes, carbonyl chloride and amino ester salts undergo a one-pot three-component sequential reaction successfully. Similarly, the derived multicomponent sequential polymerizations of diyne, terephthaloyl chloride and amino ester proceed smoothly in a regioand stereoregular manner and generate conjugated nitrogen-substituted poly(enaminone)s with high molecular weights in satisfactory yields. All the resulting polymers are soluble in common solvents, and possess high thermal stability and good film-forming ability. Interestingly, the incorporation of optically active chiral amino esters as pendants leads to polymeric products with helical rotating backbones, as revealed by their circular dichroism spectra in the solutions and as cast films. With fluorescent tetraphenylethene moieties embedded in the polymer chains, the polymers display a phenomenon of aggregation enhanced emission. They emit weakly in the solution state, but fluoresce intensely as aggregates. Moreover, the thin films of the polymers exhibit high light refractivity (n = 1.9305–1.5992) in a wide wavelength region (400–1000 nm), which can be readily modulated by UV irradiation. Additionally, the polymeric products with photosensitivity can generate highly resolved two-dimensional luminescent patterns by UV treatment.

A new near-infrared AIE luminogen (TPE-AC) with high specificity, good biocompatibility and excellent photostability is designed and synthesized for lipid droplet (LD) imaging in cells. TPE-AC can monitor the process of LD accumulation in cells, thus making it potential for the diagnosis of early-stage fat-related diseases.

In this work, a morpholine-functionalized aggregation-induced emission luminogen (AIEgen), AIE-LysoY, is reported for lysosomal imaging and autophagy visualization. To attain outstanding imaging contrast, AIE-LysoY is equipped with excited state intramolecular proton transfer (ESIPT) characteristic. AIE-LysoY provides a new platform for lysosome visualization with good biocompatibility, large Stokes shift, superior signal-to-noise ratio, and high photostability.

Chromophores containing olefinic double bonds are the core components of many important luminogen systems that show the novel photophysical effect of aggregation-induced emission (AIE). The role and extent of E–Z isomerization (EZI) of the double bond in affecting the solution emissions of the AIE luminogens (AIEgens), however, have not been fully understood. In this work, we verified the occurrence of EZI in the dilute solutions of TPE-cored AIEgens by NMR spectroscopy using elaborate experimental procedures. We further designed a TPE-fluorescein adduct to quantify that EZI plays a minor role whereas intramolecular rotation plays a major role in the emission quenching processes of the AIEgen solutions. This study fills the gap in the research on the restriction of the intramolecular rotation (RIR) mechanism for the AIE effect and provides a useful tool for the mechanistic investigation of photoluminescence processes.

In this work, several new compounds containing tetraphenylene (TPE) units and dimesitylboron groups were synthesized through Sonogashira coupling reaction. The compounds showed the aggregation induced emission (AIE), emitted the different color and gave the relatively high quantum yield of fluorescence in solid state. Two of the compounds demonstrated the prospective application in data storage, and one molecule also displayed the potential value in biological fluorescent cell imaging.

Multilayer self-assembled films, consisting of partially doped polyaniline (PAN) as a polycation and water-soluble poly(4-carboxyphenyl)acetylene (PCPA) as a polyanion, were fabricated through electrostatic attraction. These ultrathin PCPA/PAN films were relatively stable toward aqueous electrolyte solutions and polar organic solvents, and the photoelectric conversion properties of the self-assembled PCPA/PAN films could be measured with traditional three-electrode cells in 0.5 M KCl aqueous solutions. With an increase in the bilayer number, the photocurrent rose, and it reached its maximum at eight bilayers. A further increase led to a current drop due to an increase in the recombination probability and weak visible-light transmission. When neutral PAN films were used, the photocurrent increased consecutively within 15 bilayers, and this indicated that the PAN molecules in the neutral state were stronger electron donors than those in the partially doped state. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3224–3229, 2004

Herein we reported a new facile one-pot multicomponent sequential polymerization approach for the construction of conjugated nitrogen-substituted polymers. Catalyzed by Pd(PPh3)2Cl2/CuI at room temperature, the coupling-hydroamination polymerizations of 1,2-bis(4-ethynylphenyl)-1,2-diphenylethene, terephthaloyl chloride and secondary aliphatic amines proceeded smoothly in a regioregular and stereoselective manner, furnishing poly(arylene enaminone)s (PAEs) with high molecular weights (Mw up to 34 600) in satisfactory yields (up to 91%). A model compound was elaborately designed and synthesized to verify the chemical structures of the corresponding polymeric products. All the PAEs exhibited good solubility in common organic solvents and were thermally stable with degradation temperatures of up to 313 °C under nitrogen. They possessed good film-forming ability and their thin solid films showed high refractive indices (RI = 1.9318–1.6320) in a wide wavelength region of 400–1000 nm, whose value could be further modulated by UV irradiation. Although the model compound and the PAEs possessed a typical aggregation-induced emission luminogen of tetraphenylethene, they were weakly emissive either in solution or in the aggregated state, due to the photoinduced electron transfer (PET) effect. Their strong emission in the aggregated state could be readily recovered by the blockage of the PET effect through protonation of the amino groups. Thus, this work demonstrated a powerful polymerization tool to access conjugated polymeric materials with pH-responsive properties.

Two bifunctional red AIE luminogens with efficient solid-state emission and good hole-transporting characteristics are reported. Efficient non-doped OLEDs are fabricated with high external quantum efficiencies of up to 3.9%. Bilayer EL devices using them as both EMLs and HTLs are fabricated with good performances.

Self-assembling of luminescent molecules into one-dimensional nanostructures is of particular interest in fabricating nanoscale electronic and photonic devices. Herein, we report the rational design and synthesis of a chiral fluorescent tetraphenylethylene derivative containing L-leucine methyl ester moiety (TPE-Leu). In solution, TPE-Leu is non-emissive and CD silent, but becomes highly emissive and CD active upon aggregation, exhibiting aggregation-induced emission (AIE) and chirality (AIC). Upon evaporation of its solution, TPE-Leu readily self-assembles into helical fluorescent micro/nanofibers, which show circularly polarized luminescence (CPL) and have the CPL dissymmetry factors in the range of 0.02–0.07. This molecular design combines the AIE effect, chirality, and self-assembling capability together, and is highly efficient in constructing novel functional micro/nanomaterials with well-defined structures and enhanced emission.

Polyhydroaminations for the synthesis of stable nitrogen-substituted conjugated polymers with welldefined structures remain a great challenge and the control of the regio- and stereochemistry of the enamine product of the hydroamination is non-trivial. Herein we report an efficient tandem polymerization of alkynes, carbonyl chlorides and primary amines to afford regio- and stereoregular conjugated poly(enaminone)s. The atom-economical one-pot sequential polycoupling–hydroamination polymerization catalyzed by Pd(PPh3)2Cl2/CuI proceeded smoothly under mild conditions, furnishing nitrogensubstituted conjugated polymers with high molecular weights (up to 46 100) and high regio-/stereoregularities (100%) in nearly quantitative yields (up to 99%). The single crystal structure of the model compound, together with the NMR spectra comparison of the model compound and polymers provided direct insight into the stereoselectivity of the polymerization, verifying the sole Z-vinylene isomer of the polymers. Through the exquisite structural design strategy of the intramolecular hydrogen bond of the resulting hydroamination product, the tautomerization between enamine and imine as well as E/Z isomerization was successfully avoided, providing products with high chemical stability and sole Z-vinylene isomers. The conjugated polymers display excellent solubility in common organic solvents, good filmforming ability, and high thermal stability. The hydrogen bond formation of the polymer helps to block the potential photo-induced electron transfer process and the polymer shows a unique aggregation-enhanced emission phenomenon: their solutions are weakly emissive, while their nanoaggregates or thin films are brightly emissive. Furthermore, thin films of the polymers enjoy high refractive indices (1.9103–1.6582) in a wide wavelength region of 400–1000 nm, which can be further modulated by UV irradiation. Meanwhile, well-resolved fluorescent photopatterns of the polymers can be fabricated through the UV irradiation of thin films via a copper photomask.

Two azide-functionalized tetraphenylethene derivatives with AIE features are synthesized and used as fluorescent agents for detecting S-phase DNA synthesis and cell proliferation based on EdU assay. Compared to the Alexa-azide dye, a commercial DNA bioprobe, the AIE fluorogens show better photostability and sensitivity, making them promising alternatives.

Non-charged, water soluble poly(ethylene glycol) (PEG)-decorated teraphenylethenes (TPEs) with different polymer chain numbers are synthesized in high yields by azide–alkyne cycloaddition. Their aggregation and thermosensitive behaviours are investigated by means of fluorescence spectroscopy, transmission electron microscopy (TEM), zeta potential and dynamic mechanical analyses. All the luminogens are non-emissive in solutions, but emit intensely when aggregated in aqueous solutions, or forming micelles, demonstrating a phenomenon of aggregation-induced emission. The TPE derivative (1) carrying one PEG chain forms hydrogels in the THF–water mixture depending on the concentration, water fraction and temperature. All the luminogens are thermosensitive, with their cloud point being tunable by varying the solvent composition and their hydrophilicity. Luminogen 1 is biocompatible and can function as a fluorescent visualizer for intracellular imaging.

N,N′-Di-(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) possesses high thermal and morphological stability and is one of the well-known hole-transporting materials for the fabrication of organic light-emitting diodes (OLEDs). Modification of NPB by the covalent integration of tetraphenylethene (TPE) into its structure dramatically changes its emission behavior: the resulting adduct (TPE–NPB) is highly emissive in the aggregated state, showing a novel phenomenon of aggregation-induced emission (AIE). The adduct is thermally and morphologically stable. Non-doped multilayer electroluminescence (EL) devices using TPE–NPB as an emitting layer were fabricated, which emitted green light with a maximum luminance and current efficiency of 11[thin space (1/6-em)]981 cd m−2 and 11.9 cd A−1, respectively. Even better device performances are observed in the bilayer device without NPB. Our strategy takes the full advantage of the AIE property in the solid state and retains the inherent properties of conventional luminophores. It opens a new avenue in the development of stable and efficient solid-state fluorescent materials for OLED application.

Elevated levels of homocysteine (Hcy) in blood are indicative of many high risk cardiovascular and neurodegenerative diseases. Thus, development of highly efficient and selective dyes for monitoring Hcy levels has attracted much attention. This paper reports the utilization of TPE-Cy, an aggregation-induced-emission active hemicyanine dye, as a probe for the detection of Hcy. More interestingly, this dye shows high selectivity to Hcy over cysteine, glutathione and other amino acids in weakly basic buffer solution.

A tetraphenylethene-containing A4-type tetrayne, named 1,1,2,2-tetrakis(4-ethynylphenyl)ethene is synthesized and its TaCl5-Ph4Sn catalyzed homopolycyclotrimerization affords hyperbranched poly(tetraphenylethene) with high molecular weight (Mw = 280,000) in high yield (97%). The polymer shows good solubility and high thermal stability. It is aggregation-enhanced emission (AEE)-active and functions as a fluorescent chemosensor for explosive detection with a superamplification effect and large quenching constants up to 758,000 M−1. The polymer shows high and tunable refractive indices (RI = 1.9288−1.6746) in a wide wavelength region. Porous fluorescent polymer thin film is prepared by breath figure (BF) methods and real-time monitoring of the elusive BF formation process is realized. Photolithography of the thin films readily generates well-resolved fluorescent photopattern without and with porous secondary structure. The polymer is metallified and pyrolysed to give magnetic ceramics with high magnetic susceptibilities (Ms = 83 emu/g) and near-zero coercivity (Hc = 0.08 kOe).

The luminescent liquid crystals (LLCs) are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs. Herein, we developed a new strategy of applying aggregation-induced emission (AIE) phenomenon to the molecular design of LCs towards LLCs. In this report, a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by 1H, 13C NMR, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) high-resolution mass spectra. The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM). The crystal structure was obtained by X-ray diffraction crystallography with P1 space group. Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic, smectic C and smectic B phase.

Biotin-decorated fluorescent silica nanoparticles (FSNPs) were successfully fabricated by a sol–gel reaction of silole-functionalized siloxane followed by a sequential reaction with tetraethoxysilane, (3-aminopropyl)triethoxysilane and biotin. The FSNPs were uniformly sized, spherical in shape and monodispersed. While their silole precursor was non-emissive in solution, the suspension of the FSNPs emitted strong green light upon photoexcitation due to the aggregation-induced emission characteristics of the silole aggregates in the hybrid nanoparticles. Morphology study and cell viability, trypan blue exclusion, Annexin V-FITC/PI apoptosis and ROS generation assays showed that the FSNPs showed low toxicity to living cells. The FSNPs worked as fluorescent visualizers for selective imaging of the cytoplasm of tumor cells with over-expressed biotin receptors. The fluorescent nanoparticles were lastingly retained inside the living cells, thus enabling long-term tumor cell tracking over multiple passages and quantitative analysis of tumor cell migration.

Enlarged tetrasubstituted alkenes with high fluorescent efficiency and good thermal stability are constructed. They exhibit luminance up to 35[thin space (1/6-em)]160 cd m−2 and efficiency of 16 cd A−1 in OLEDs.

A high molecular weight poly(arylene ynonylene) with an aggregation-enhanced emission characteristic was synthesized in high yield by a newly developed polymerization route. Its emission can be turned 'on' by hydrazine, as well as 'off' by picric acid, demonstrating the first fluorescent sensor that works for both hydrazine and explosives detection.

The emission of pyrrole-substituted benzoic acid can be repeatedly switched between the dark and bright states in the solid state by chemical fuming and heating processes, enabling it to work as a rapid sensitive fluorescent sensor for primary amine detection.

Ferrocene-based poly(aroxycarbonyltriazole)s with high molecular weights and regioregularities were prepared in high yields by the efficient metal-free click polymerization of dipropiolates and the ferrocene-containing diazide under mild reaction conditions. The resulting polytriazoles are redox active, and could be used as precursors to generate soft magnetic ceramics with high magnetizability and low coercivity when pyrolyzed at elevated temperatures.

Fluorescent self-assembled organogels are interesting supramolecular soft materials with polymer-like structures and have received particular attention due to their fascinating properties and promising practical applications. However, most planar π-conjugated gelators are highly emissive in the solution state but become weak emitters when self-assembled. Recently, a novel phenomenon of aggregation-induced emission (AIE) has drawn increasing research interest and has been the subject of numerous investigations. This intriguing finding paves a new way for creating fluorescent organogels by utilizing gelators with AIE characteristics. This review focuses on the recent advances in fluorescent organogels with gelation-enhanced emission features. Various kinds of low molecular weight gelators consisting of typical AIE luminogens, conventional planar chromophores, and photoactive molecules are introduced and the mechanisms for the emission enhancement are discussed.

In this work, a heteroatom-containing luminogen (TPE-Py) with multi-functionalities was synthesized in a reasonable yield by melding a pyridinium unit with tetraphenylethene through vinyl functionality. TPE-Py is weakly emissive in solution but becomes a strong emitter when aggregated as nanoparticle suspensions in poor solvents or in the solid state, displaying a phenomenon of aggregation-induced emission. Crystallization generally weakens and red-shifts the light emission. The crystalline aggregates of TPE-Py, however, emit stronger and bluer light than their amorphous counterparts. The solid-state emission of TPE-Py can be reversibly switched between green and yellow color by grinding–fuming and grinding–heating processes with a high contrast due to the transformation from the crystalline to the amorphous state and vice versa. The large Stokes shift and well-ordered molecular arrangement of the crystalline microrods of TPE-Py make it promising as an optical waveguide material with a low optical loss coefficient of ∼0.032 dB μm−1. TPE-Py works as a good fluorescent visualizer for specific staining of mitochondria in living cells with a high photostability, thanks to its hydrophobic and cationic features.

A heteroatom-containing organic fluorophore 1-(4-pyridinyl)-1-phenyl-2-(9-carbazolyl)ethene (CP3E) was designed and synthesized. CP3E exhibits the effect of intramolecular charge transfer (ICT) caused by the donor–acceptor interaction between its carbazole and pyridine units. Whereas it emits faintly in solution, it becomes a strong emitter in the aggregated state, demonstrating the phenomenon of aggregation-induced emission (AIE). Its emission can be reversibly switched between blue and dark states by repeated protonation and deprotonation. Such behaviour enables it to work as a fluorescent pH sensor in both solution and the solid state and as a chemosensor for detecting acidic and basic organic vapors. Analyses by NMR spectroscopy, single-crystal X-ray diffraction and computational calculations suggest that the change in electron affinity of the pyridinyl unit and molecular conformation of CP3E upon protonation and deprotonation is responsible for such sensing processes.

A new route for the synthesis of functional polymers was developed. Oxidative polycoupling of 4,4′-(α,ω-alkylenedioxy) bis(diphenylacetylene)s with phenylboronic acid and (1,1,2-triphenylvinyl)phenylboronic acid, respectively, was catalyzed by [Cp*RhCl2]2 and oxidants in dimethylformamide, affording soluble polymers with highly substituted naphthalene rings in satisfactory yields with moderate molecular weights. All the polymers were thermally and morphologically stable, showing high thermal-degradation and glass-transition temperatures of 317–404 °C and 95–168 °C, respectively. They were film-forming and their thin solid films showed high refractive indices (RI = 1.7414–1.6038) in a wide wavelength region of 400–1600 nm. The polymer carrying tetraphenylethene unit was weakly emissive in solution but emitted intensely in the condensed phase, displaying a phenomenon of aggregation-induced emission. The emission of its nanoaggregates could be quenched by picric acid with large quenching constants, making it promising as a sensitive chemosensor for efficient detection of explosives.

A new route for atom-economical synthesis of functional polymers was developed. Oxidative polycoupling of 3,5-dimethyl-1-phenylpyrazole with 4,4′-(α,ω-alkylenedioxy) bis(diphenylacetylene)s and 1,2-diphenyl-1,2-bis[4-(phenylethynyl)phenyl]ethene, respectively, were catalyzed by [Cp*RhCl2]2, 1,2,3,4-tetraphenylcyclopenta-1,3-diene and copper(II) acetate in dimethylformamide under stoichiometric imbalance conditions, affording soluble poly(pyrazolylnaphthalene)s in satisfactory yields (isolation yield up to 82%) with high molecular weights (Mw up to 35[thin space (1/6-em)]700). All the polymers were thermally stable, losing little of their weight at high temperatures of 323–422 °C. They possessed good film-forming property and their thin solid films showed high refractive indices (RI = 1.747 − 1.593) in a wide wavelength region of 400–1000 nm. The polymer carrying tetraphenylethene units displayed a phenomenon of aggregation-induced emission and showed enhanced light emission in the aggregated state. The emission of its nanoaggregates could be quenched efficiently by picric acid in both solution and solid states, suggesting that it is a promising sensitive chemosensor for detecting explosives for real-world applications.

The study of hyperbranched polymers is a ''young'' but ''hot'' area of research. Hyperbranched polymers are expected to show size-, shape-, branch-, and surface-related properties,1 which may enable them to find an array of technological applications as nanoscale catalysts, chemical sensors, molecular antennae, supramolecular assemblies, micelle mimics, drug-delivery carriers...

Hydrosilylation polymerizations of 1,1-dimethyl-2,5-bis(4-ethynylphenyl)-3,4-diphenylsilole with aromatic silylhydrides including 1,4-bis(dimethylsilyl)benzene, 4,4′-bis(dimethylsilyl)biphenyl, 2,5-bis(dimethylsilyl)thiophene, and 2,7-bis(dimethylsilyl)-9,9-dihexylfluorene in the presence of Rh(PPh3)3Cl catalyst in refluxed tetrahydrofuran afford a series of silole-containing poly(silylenevinylene)s. Under optimum condition, the alkyne polyhydrosilylation reactions progress efficiently and regioselectively, yielding polymers with high molecular weights (Mw up to 95,300) and good stereoregularity (E content close to 99%) in high yields (up to 92%). The polymers are processable and thermally stable, with high decomposition temperatures in the range of 420−449 °C corresponding to 5% weight loss. They are weakly fluorescent in the solution state but become emissive in the aggregate and film states, demonstrating their aggregation-enhanced emission characteristics. The explosive sensing capabilities of the polymers are examined in both solution and aggregate states. The emissions of the polymers aggregates in aqueous mixture are quenched more efficiently by picric acid in an exponential pattern with high quenching constants (up to 27,949 L/ mol), suggesting that the polymers aggregates are sensitive chemosensors for explosive detection.

Carbazole-containing 1-phenyl-1-alkynes with different spacer lengths [C6H5C C(CH2)(m)Car 1(m) (m = 3, 4, 9), Car = 9-carbazolyl] were synthesised in high yields by consecutive substitution and coupling reactions of n-chloro-1-alkynes. Polymerisation of the monomers was effected by NbCl5- and WCl6-Ph4Sn catalysts, furnishing soluble polymers P1(m) with high molecular weights in high yields. All the polymers were thermally stable, commencing to lose their weights at high temperatures (>= 400 degrees C). Photoexcitation of their THF solutions induced strong blue light emissions with high quantum efficiencies up to 92 %. Multilayer electroluminescence devices with configurations of ITO/P1(m)(:PVK)/BCP/Alq(3)/LiF/Al were constructed, which gave blue light with maximum luminance and external quantum efficiency of 438 cdm(-2) and 0.63 %. UV irradiation of a thin film of P1(4) through a mask oxidized and quenched the light emission of the exposed parts, generating a two-dimensional luminescent photopattern.

Self-assembly of fluorescent functional materials has attracted increasing interest in the fabrication of optoelectronic and biological nanodevices. Tetraphenylethene (TPE) is a typical dye molecule with aggregation-induced-emission (AIE) characteristics. Melding TPE carrying triple-bond functionality with diazide-containing biphenyl through ''click'' chemistry generates AIE-active luminogens [1,1'-biphenyl]-4,4'-diyl bis(6-(4-(4-(1,2,2-triphenylvinyl)phenyl)-1H-1,2,3-triazol-1-yl) hexanoate) [1(5)] and[1,1'-biphenyl]-4,4'-diyl bis(11-(4-(4-(1,2,2-triphenylvinyl)phenyl)-1H-1,2,3-triazol-1-yl) undecanoate)[1(10)] with solid state efficiencies up to unity. Slow addition of dilute THF solutions of 1(m) (m ¼ 5, 10) into nonsolvents such as n-hexane and water yields self-assembled white wooly solids. TEM and SEM observations reveal the (helical) nanofibrous structure of the aggregates. Upon cooling from their concentrated hot solutions, 1(m) readily precipitate. Meanwhile, they can also form gels at high concentrations. Both precipitates and gels of 1(m) exhibit structures similar to those of the aggregates formed in nonsolvents. These results indicate that 1(m) can facilely self-assemble into high emission efficiency (helical) nanofibers, thus paving the way for their optoelectronic and biological applications.

Tetraphenylethene-containing diyne (1), named 1,2-bis(4-ethynylphenyl)-1,2-diphenylethene, was synthesized and polymerized by TaBr5 catalyst, affording the hyperbranched polymer hb-P1 with a high molecular weight (Mw up to 157[thin space (1/6-em)]800) in a nearly quantitative yield. The cyclotrimerization of 1-(4-ethynylphenyl)-1,2,2-triphenylethene was also carried out to give 1,3,5- and 1,2,4-tris[4-(1,2,2-triphenylvinyl)phenyl]benzene (1,3,5-2 and 1,2,4-2) that served as model compounds for structural characterization and properties investigation. The structures of hb-P1 and 2 are characterized by MS, IR, and NMR spectroscopies with satisfactory results. All the molecules and polymer are completely soluble in common organic solvents such as chloroform, toluene and THF. They show high thermal stability with degradation temperatures up to 443 and 446 °C, respectively, in nitrogen and air. Whereas their solutions are almost non-emissive or weakly fluorescent, their aggregates in poor solvents and solid powders emit intensely with fluorescence quantum yields up to 81%, demonstrating a novel phenomenon of aggregation-induced or enhanced emission. The unreacted triple bonds on the periphery of hb-P1 allow its thin film to cross-link under UV irradiation, generating well-resolved photopatterns. The hyperbranched polymer can limit harsh laser pulses. Its emission can be quenched efficiently by picric acid in solution and aggregated states with large quenching constants, suggesting that it is a promising fluorescent chemosensor for explosives detection.

Rational combination of aggregation-induced emission active luminogens and mesogens generates high solid-state efficiency luminescent liquid crystals, thus resolving the problem of aggregation-caused quenching normally occurs in the fabrication of luminescent mesomorphic films.

Aggregation-induced emission (AIE) is a newly developed phenomenon that is exactly opposite to the aggregation-caused emission quenching effect observed with some conventional luminophores. The AIE phenomenon was first realized in propeller-like small molecules and now has extended to polymeric systems. In this review, we summarize the recent progress on the preparation of luminogenic polymers with AIE or aggregation-enhanced emission (AEE) characteristics, which are generally prepared by attaching AIE-active luminogens, such as tetraphenylethene and silole, as pendants to the polymer backbones or utilizing them as skeletons for main chain polymers. An AIE phenomenon was observed in succinic anhydride-containing nonconjugated polymers bearing no luminogens, presumably due to the agglomeration of carbonyl groups. The AIE/AEE-active polymers show unique properties, such as emission superquenching, high and tunable light refractivity, and aggregation-enhanced two-photon excited fluorescence, and have found potential applications as fluorescent sensors, biological probes, and active layers for the fabrication of light-emitting diodes.

In organic light-emitting devices, materials with efficient electron-transporting properties, are essential. In this report, oxadiazole-containing tetraphenylethene TPE-Oxa is synthesized and its optical physics and electronic properties are investigated. The dye is almost nonluminescent when molecularly dissolved in solutions, but becomes highly emissive when aggregated in poor solvents or fabricated as thin films in the solid state. A quantum yield of unity has been achieved in its solid thin film. Inherited from the oxadiazole component, the dye molecule enjoys low-lying electronic band energies. Benefiting from the good electron-transporting and hole-blocking properties of the dye, the two-layer OLED devices using TPE-Oxa as both light-emitting and electron-transporting materials show superior performance, i.e., lower turn-on voltage, higher brightness and efficiencies, to the devices of typical configuration with a dedicated electron-transporting layer.

Photoconduction under visible light illumination is investigated using xerographic discharge technique in the photoreceptors of the following substituted polyacetylenes: [BOND][HC[DOUBLE BOND]C(C6H5-p-R)]n[BOND], [BOND][HC[DOUBLE BOND]C(3-C4H2S-β-R′)]n[BOND], and [BOND]{HC[DOUBLE BOND]C[(CH2)m-R″]}n[BOND], where R = CH3 (2), CO2(CH2)6OCO-Biph-OC7H15 (Biph = 4,4′-biphenylyl; 3); R′ = Si(CH3)3 (4), Br (5); and R″ [DOUBLE BOND]CO2(CH2)6OCO-Biph-OC9H19 (m = 2; 6), 9-carbazolyl (m = 3; 7), OCO-Biph-OC7H15 (m = 9; 8). In the undoped state, 2–4 and 6–8 show much higher photosensitivity than poly(phenylacetylene)(R = H; 1). The polyacetylenes with electron-donating and/or hole-transporting substituents perform better than do those with electron-accepting ones. The liquid crystalline polyacetylene 6 exhibits very high photosensitivity, probably because of the crystalline aggregates of its mesogenic pendants. C60 acts as a photoconductivity enhancer when doped to amorphous 3 but functions as a quencher when mixed with liquid crystalline 6. While 3 shows low photosensitivity in the undoped state, doping with I2 and sensitization with crystal violet dramatically increase its photosensitivity up to 41.2 × 10−3 lx−1 sec−1.

Luminogenic molecules [(TPE)3 (1), TPE-C = C-TPE-C = C-TPE (2), and TPE-C≡C-TPE-C≡C-TPE (3)] and their polymersP1–P3 are constructed from tetraphenylethene (TPE) building blocks in high yields by Suzuki, Witting, and Sonogashira coupling reactions. All the compounds are soluble and enjoy high thermal stability, losing little of their weights when they are heated to 290–528 °C under nitrogen or 288–436 °C in air. Analyses by UV spectroscopy and cyclic voltammetry as well as theoretical calculations show that the conjugation of the luminophores is in the order of 2 > 3 > 1, P2 > P3 > P1, and P1–P3 > 1–3. All the molecules and polymers are weakly emissive in solutions. They, however, become strong emitters in the aggregate state with fluorescence quantum yields up to 90%. Both 1–3 and P1–P3 exhibit the feature of aggregation-enhanced two-photon excited fluorescence. Large two-photon absorption cross sections (up to 900 GM) are observed in the nanoaggregates of the polymers. Thin solid films of the polymers show high refractive indices (RI = 1.7649 − 1.6873) in a wide wavelength region of 400–1700 nm, high modified Abbé numbers (vD′ up to 3436), and low optical dispersions (D′ down to 2.9 × 10−4). The light emissions of the polymers can be quenched exponentially by picric acid with large quenching constants, suggesting that they can be utilized as efficient chemosensors for explosive detection.