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Herein, we realized the quick generation of stable photoinduced radicals in donor–acceptor triarylphosphines with associated color changes of emission and absorption, which was deciphered by the electron paramagnetic resonance (EPR) spectra.

Room temperature phosphorescence (RTP) and mechanoluminescence (ML) materials are in high demand because of their promising applications in optoelectronic devices. However, most materials bear only one of these properties and molecules bearing both of them are rarely reported. Here, we report a carbazole derivative 1, which displays both RTP activity and near-ultraviolet ML properties. These properties are highly related to the packing modes and molecular configuration as revealed by the analysis of their crystal structures and theoretical calculations. The near-ultraviolet ML of 1 can further serve as the exciting light source to transfer its energy to luminescent dyes to realize colorful ML. The thermal-responsive RTP of 1 can be utilized to prepare anti-counterfeiting tags for simple security protection. This work has put forward a simple but efficient strategy to prepare multifunctional molecular systems bearing both RTP and ML properties.

Triplet excitons in organic molecules underscore a variety of processes and technologies as a result of their long lifetime and spin multiplicity. Organic phosphorescence, which originates from triplet excitons, has potential for the development of a new generation of organic optoelectronic materials and biomedical agents. However, organic phosphorescence is typically only observed at cryogenic temperatures and under inert conditions in solution, which severely restricts its practical applications. In the past few years, room-temperature-phosphorescent systems have been obtained based on organic aggregates. Rapid advances in molecular-structure design and aggregation-behaviour modulation have enabled substantial progress, but the mechanistic picture is still not fully understood because of the high sensitivity and complexity of triplet-exciton behaviour. This Review analyses key photophysical processes related to triplet excitons, including intersystem crossing, radiative and non-radiative decay, and quenching processes, to illustrate the intrinsic structure–property relationships and draw clear and integrated design principles. The resulting strategies for the development of efficient and persistent room-temperature-phosphorescent systems are discussed, and newly emerged applications based on these materials are highlighted. Advances in molecular-structure design and modulation of the aggregation behaviour have enabled much progress in the observation of room-temperature phosphorescence from organic aggregates. This Review analyses key photophysical processes related to triplet excitons, illustrating the intrinsic structure–property relationships and identifying strategies to design efficient and persistent room-temperature-phosphorescent systems.

Polymorphism of organic semiconductor films is of key importance for the performance of organic thin film transistors (OTFTs). Herein, we demonstrate that the polymorphism of solution-processed organic semiconductors in thin film transistors can be controlled by finely tuning the surface nanostructures of substrates with self-assembled monolayers (SAMs). It is found that the SAMs of 12-cyclohexyldodecylphosphonic acid (CDPA) and 12-phenyldodecylphosphonic acid (PhDPA) induce different polymorphs in the dip-coated films of 2-dodecyl[1]benzothieno[3,2-b][1]benzothiophene (BTBT-C12). The film of BTBT-C12 on CDPA exhibits field effect mobility as high as 28.1 cm2 V−1 s−1 for holes, which is higher than that of BTBT-C12 on PhDPA by three times. The high mobility of BTBT C12 on CDPA is attributable to the highly oriented films of BTBT C12 with a reduced in-plane lattice and high molecular alignment.

Novel accessible scaffold featuring circularly-polarized room-temperature phosphorescence (RTP) is attractive but challenging. Herein, we report a new feasibly separable bidibenzo[b,d]furan compound with strong circularly-polarized RTP when doping into the rigid polymer matrix. The simple silica-gel column can separate the absolute chiral R-isomer with excellent chiroptical properties. The experimental data reveal that the treated films exhibit an RTP efficiency of 14.8 %, a largest dissymmetric factor of 0.12, and a longest lifetime of 0.56 s under ambient conditions. It is found that reducing the nonradiative decays boosts the intrinsic circularly-polarized RTP emission. The impressive results indicate that the locked axial chirality skeleton endows the potential of achieving superior circularly-polarized emission for the small organic optoelectronic molecules.

Research on molecularly imprinted polymers (MIPs) has long been receiving much attention, but issues concerning the recognition mechanism and how the impact factors work are still far from clear. In this work, we studied the imprinting and recognition procedures from a new perspective. Two factors that have a major impact on the imprinting performance were studied separately: one is the functional groups (FGs) of the template and the other is the size of the template. A series of aggregation-induced emission molecules (AIEgens) was employed as the templates, and they were selected elaborately, one group of which having different functional groups with a similar size, while the other being different in molecular size. It was found that the MIP was inclined to combine with molecules with more effective functional groups or with smaller sizes. Meanwhile, the more ordered sites and the larger cavities in the polymers afforded the MIP with better adsorption performance. The binding energy (ΔE) and the mechanism at the molecular level between templates and polymers were analyzed by using density functional theory (DFT) calculations, and the results were consistent with experimental results in the aspect of the FG effect. In addition, the unique luminescence properties of AIEgens allow for visible observation of the change of the template within the polymer during preparation and rebinding processes. More importantly, quantification of template molecules during the adsorption process was fulfilled based on their solid-state fluorescence intensities, which opens a new door for AIEgen application. A comparison with the common method of UV-vis spectrometry revealed that solid-state fluorescence measurement has the advantages of direct detection, easy operation, a wide linear range and so on.

A pentagonal macrocycle (MC5-PER) with radialene topology was facilely synthesized through a selective one-pot Suzuki-Miyaura cross-coupling reaction. The resulting product is endowed with a pentagonal architecture as revealed by its single crystal structure, which affords the smallest ring strain and the best conjugation. As tetraphenylethene subunits are embedded, MC5-PER is highly emissive in the solid state due to the aggregation-induced emission effect. Because of the flexible structure and preferable fibre-like self-assembly, the aggregate of MC5-PER displays interesting polymorphism-dependent emission and acts as a sensitive fluorescence sensor for explosives detection.

Many aggregation-induced emission (AIE) materials are featured by the diphenylethene (DPE) moiety which exhibits rich photophysical and photochemical activities. The understanding of these activities behind AIE is essential to guide the design of fluorescent materials with improved performance. Herein by fusing a flexible DPE with a rigid spiro scaffold, we report a class of novel deep-blue material with solid-state fluorescent quantum yield (ΦF) up to 99.8%. Along with the AIE phenomenon, we identified a reversible photocyclization (PC) on DPE with visible chromism, which is, on the contrary, popularized in solutions but blocked by aggregation. We studied the steric and electronic effects of structural perturbation and concluded that the PC is a key process behind the RIMs (restriction of intramolecular motions) mechanism for these materials. Mitigation of the PC leads to enhanced fluorescence in solutions and loss of the AIE characteristics.

Controlling molecular assembled structures of a single luminogen through external manipulation is a general and powerful concept for designing emission-tunable materials. However, these reported powder-like compounds generally show limited emission color, high serendipitous-discovery dependence and poor mechanical properties. To overcome these limitations, we describe a simple yet powerful strategy that is adapted from methods used to control bulk commodity polymers, to modulate the molecular assembled architecture of dopant. We use luminogens with aggregation-induced emission characteristics and intrinsic blue and yellow emissions at their crystalline and amorphous states as demonstrations. When incorporating such luminogens (AIEgens) in the desired polymer matrix with tailored microstructure, white light and white circularly polarized light are generated, which are inaccessible from single and achiral AIEgen alone. The introduced strategy for realizing diverse light emission is an innovative way of developing luminogens and provides useful continuous emissive materials in the forms of macroscopic films and fibers for developing flexible devices and wearable systems.

Background The current debate over the optimal Enoxaparin prophylactic dosing strategies in obese patients centre around whether it should be based on the actual weight of the patient (i.e. weight-based), or at an artificially fixed amount, as it is the case in Australia (40 mg daily). The vast majority of the evidence available today is laboratory-based, measuring serum Antifactor-X a activities as a marker for physiological response. Aim The aim of the parent study is to compare the clinical outcomes for obese patients who received fixed doses of enoxaparin compared to those who received weight-based doses within the licensed dosage recommendations. This review was conducted to examine whether a gap in knowledge exists in relation to dosing obese patients with enoxaparin as VTE prophylaxis after hospital admission to aid in development of the parent study concept. Method Databases such as Medline, EBSCOhost, ProQuest were interrogated using combinations of words such as “enoxaparin”, AND “dosing strategy”, AND “obese/obesity” AND “prophylaxis”. Only eleven out of 14 primary studies which were considered to be sufficiently similar in methodology and anticipated outcomes were reviewed and analysed. Results Pooled data from the eleven studies suggested that weight-based or higher-than-fixed dosing had a 36.2% higher success rate than fixed dosing, and was more likely to achieve the desired serum Anti-X a activity levels (52.2% and 16% respectively). The rate of failure to achieve this is significantly lower in the weight-based groups (13.3%) than in fixed-dose groups (18.5%). These eleven studies reviewed included 601 patients in total. Conclusion There is insufficient evidence to support or negate the current enoxaparin health outcomes in obese and very obese patients due to the lack of post-discharge follow-up from hospitals. Further research is required to compare long-term outcomes after fixed and weight-based dosing of enoxaparin. The optimal dose of enoxaparin per kilogram of body weight for prophylaxis remains to be determined.

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.

The development of solid-state intelligent materials, in particular those showing photoresponsive luminescence (PRL), is highly desirable for their cutting-edge applications in sensors, displays, data-storage, and anti-counterfeiting, but is challenging. Few PRL materials are constructed by tethering the classic photochromic systems with newly-emerged solid-state emitters. Selective solid-state photoreactions are demanded to precisely manipulate the luminescent behavior of these emitters, which require dramatic structural change and enough free space, thus limiting the scope of the PRL family. Here, a new PRL material, TPE-4N, that features sensitive and reversible fluorescence switching is reported. The interesting on-off luminescent property of TPE-4N can be facilely tuned through fast phototriggering and thermal annealing. Experimental and theoretical investigations reveal that subtle molecular conformation variation induces the corresponding PRL behavior. The crystalline and amorphous state endows an efficient and weak ISC process, respectively, to turn on and off the emission. The readily fabricated thin-film of TPE-4N exhibits non-destructive PRL behavior with high contrast (>102 ), good light transmittance (>72.3%), and great durability and reversibility under room light for months. Remarkably, a uniform thin-film with such fascinating PRL properties allows high-tech applications in invisible anti-counterfeiting and dynamic optical data storage with micro-resolution.

Poly(1,5-diaminonaphthalene) microparticles with abundant reactive amino and imino groups on their surface were synthesized by one-step oxidative polymerization of 1,5-diaminonaphthalene using ammonium persulfate as the oxidant. The molecular, supramolecular, and morphological structures of the microparticles were systematically characterized by IR and UV-vis spectroscopies, elementary analysis, wide-angle X-ray diffractometry, and transmission electron microscopy. The microparticles demonstrate electrical semiconductivity and high resistance to strong acid and alkali, and strong adsorption capability for lead(II), mercury(II), and silver(I) ions. The experimental conditions for adsorption of Pb(II) were optimized by varying the persulfate/monomer ratio, adsorption time, sorbent concentration, and pH value of the Pb(II) solution. The maximum adsorption capacity is 241 mg·g−1 for particles after a 24 h-exposure to a solution at an initial Pb(II) concentration of 29 mM. The adsorption data fit a Langmuir isotherm and follow a pseudo-second-order reaction kinetics. This indicates a chemical adsorption that is typical for a chelation interaction between Pb(II) and amino/imino groups on the sorbent.

We present a nitrogen-containing polycyclic aromatic hydrocarbon (N-PAH), namely 12-methoxy-9-(4-methoxyphenyl)-5,8-diphenyl-4-(pyridin-4-yl) pyreno[1,10,9-h,i,j]-isoquinoline (c-TPE-ON), which exhibits high quantum-yield emission both in solution (blue) and in the solid state (yellow). This molecule was unexpectedly obtained by a three-fold, highly regioselective photocyclodehydrogenation of a tetraphenylethylene-derived AIEgen. Based on manifold approaches involving UV/Vis, photoluminescence, and NMR spectroscopy as well as HRMS, we propose a reasonable mechanism for the formation of the disk-like N-PAH that is supported by density functional theory calculations. In contrast to most PAHs that are commonly used, our system does not suffer from entire fluorescence quenching in the solid state due to the peripheral aromatic rings preventing p-p stacking interactions, as evidenced by single-crystal X-ray analysis. Moreover, its rod-like microcrystals exhibit excellent optical waveguide properties. Hence, c-TPE-ON comprises a N-PAH with unprecedented luminescent properties and as such is a promising candidate for fabricating organic optoelectronic devices. Our design and synthetic strategy might lead to a more general approach to the preparation of solution-and solid-state luminescent PAHs.

Organic fluorophores with reversible emission switching behavior are promising materials for applications in sensors, optical recording, security inks, and optoelectronics. A variety of aggregation-induced emission (AIE) luminogens with mechanochromic luminescence has been prepared, and the transformation of efficient bluer-emitting crystals to amorphous powders with redder and weaker emission is proposed to be the cause for such behavior. However, detailed mechanistic understanding from experimental to theoretical is lacking. In this work, we present the design and synthesis of a group of bis(diarylmethylene)dihydroanthracenes with butterfly-like shapes. These molecules exhibit aggregation-induced emission characteristics due to the restriction of intramolecular motion in the aggregated state. They show mechanochromism, because of the transformation between crystal and amorphous states with different colors and efficiencies aided by grinding/heating or solvent fuming processes. By investigation of their ...

The facile synthesis of a tetraphenylethene-based macrocycle having aggregation-induced emission characteristics and that expresses illusory topology of the Penrose stairs is presented. As a result of the twisted chirality (P or M) of the tetraphenylethene unit and the axial chirality of the macrocyclic linkage (R or S), the macrocycle exhibits two absolute configurations whose interconversion is energetically favorable as revealed by theoretical calculations.

Solid-state photochromism was found in bis(diphenylmethylene)dihydrotetracene, caused by photocyclization of the embedded cis-stilbene motifs., Reported herein is a new class of pure polycyclic hydrocarbon molecules, designed through a novel aggregation-induced emission (AIE) strategy, with unexpected photochromic properties. The restriction of intramolecular motion was found as a comprehensive mechanism for the AIE effect. The photochromism mechanism study revealed that the photocyclization reaction of cis-stilbene, the molecular conformation in the single crystal and the tetracene backbone should contribute to the unique photo behavior. In particular, the fast responsive, photo-reversible and thermo-irreversible photochromic effect facilitated in the solid state opens a new field of aggregation-promoted photochromism.

Conjugated macrocycles can be equipped with interesting functions by having polycyclic aromatic hydrocarbon (PAH) building blocks that are larger than benzene. The building block explored herein is phenanthrene, which is connected with varied linkers leading to new trimeric conjugated macrocycles (1–4). The coronal macrocycle 1, whose π-backbone is a new segment of [6,6]-carbon nanotube, is synthesized from the flat macrocycle 2 by Lewis acid-catalyzed [4 + 2] benzannulation. This suggests a new strategy to synthesize π-extended nanorings from conjugated macrocycles that are more easily accessed. As found from a comparative study with focus on self-assembly and organic semiconductor behavior, flat or nearly flat conjugated macrocycles 2–4 function as p-type organic semiconductors in solution-processed thin film transistors. Their field effect mobility as measured from as-cast films is dependent on their ability of self-aggregation in solution.