查看更多>>摘要：Near-infrared (NIR) photochromic materials, especially with aggregation-induced emission (A1E) features, have lately aroused great research interest for their wide application potential in the fields of functional biomaterials and optical electronics. In this contribution, a new donor-acceptor-type (D-A-type) dithienyletiiene (TDC) appended by triphenylethene and dicyanovinyl fragments at both ends of dithienylethene was rationally constructed and prepared. The chemical structure of TDC has been well analyzed by HRMS (ESI), ~1H NMR, ~(13)C NMR, and XRD. TDC displayed NIR-like photochromic properties with strong fatigue resistance in toluene, THF and 1,4-dioxane when exposed to UV/NIR light. The ring-open isomer TDC (o) showed typical luminescent and AIE-like behaviors in the solid state before illumination with UV light. Furthermore, effective photochromic properties and fluorescent switching behavior was observed in the solid and aggregated states. Interestingly, TDC displayed unexpected aggregation-controlled photochromism in the mixtures of H20/DMSO. Accordingly, TDC represents a new multi-state NIR photochromic dithienylethene and can be further applied in smart optoelectronics and functional biomaterials.
查看更多>>摘要：Five arylene diimides containing N-phenylphenothiazine or N-phenyl-3,7-di-tert-butylphenothiazine units as N-substituents, coded as PTZ-PMDI, PTZ-NTDI, tBuPTZ-PMDI, tBuPTZ-NTDI and tBuPTZ-PTDI, were synthesized from condensation of N-(4-aminophenyl)phenothiazine and N-(4-aminophenyl)-3,7-di-tert-butylphenothiazine with pyromellitic dianhydride (PMDA), naphthalene-l,4,5,8-tetracarboxylic dianhydride (NTDA) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTDA), respectively. Incorporation of rert-butyl substituents on the PTZ active sites reduces the oxidation potential and increases the redox stability and solubility of the PTZ-diimides. PTZ-PMDI and PTZ-NTDI without tert-butyl substituents on the PTZ units are insoluble in suitable organic solvents, therefore the characterization of their electrochemical and electrochromic properties is unavailable. All the tBuPTZ-diimide compounds were electrochemically active and underwent reversible oxidation and quasi-reversible reduction as evidenced by cyclic voltammetry studies. These diimide compounds changed colors when they were reduced and oxidized, demonstrating their multi-electrochromic properties. The tBuPTZ-diimides gave a colored state of pink and red upon electro-oxidation, together with a low onset bias of 0.6 V and good switching stabilities. The electrochromic devices using these diimides as electroactive compounds were constructed and their electrochromic performance was studied.
查看更多>>摘要：Biothiols are a class of amino acids containing mercaptan (thiol, SH) groups that have similar structures but play different roles in physiological activities, making it important to effectively distinguish them. Here, a simple water-soluble probe, PMCI, was developed for the first time to rapidly discriminate Cys/Hcy and GSH by dual excitation and emission wavelengths. The introduction of an N-Me pyridinium salt thioether group into the fluorophore structure not only makes the probe highly water-soluble, but also serves as a potential reactive site for biothiols, which together with an aldehyde group allows the simultaneous differential detection of Cys/Hcy and GSH. The probe itself has no background fluorescence due to the intramolecular photoinduced electron transfer (PET) effect. After reaction with biothiols, the probe solution showed different strong fluorescent signals (green: Cys and Hey, red: GSH). It can respond quickly to biothiols (Cys: 190 s; Hey: 155 s; GSH: 80 s) with high selectivity and low detection limit. Moreover, the probe has been successfully used for die rapid discrimination imaging of endogenous and exogenous biothiols in cells and zebrafish through dual fluorescent channels.
查看更多>>摘要：In this work, a series of blue chromophores containing PAH core with different conjugation lengths and end-capped with diphenylamine were developed and introduced into PPF derivatives. Since the blue chromophores can enhance the thermal stability and suppress the interchain interactions efficiently, all copolymers present outstanding thermal decomposition temperatures up to 425 °C, high photoluminescence quantum yields (PLQYs) up to 48% and smooth surface morphology. Furthermore, the corresponding single-layer blue polymer light-emitting devices (PLEDs) based on these blue copolymers show good blue light emission peaking at 456-468 nm, and excellent stability of electroluminescence (EL) spectra. In particular, the best PLED with a maximum luminance of 8938 cd m~2, a maximum luminous efficiency (LEmax) of 3.73 cd A-1, Commission International de L'Eclairage (CIE) coordinates of (0.14, 0.16) is achieved based on PPF-F. These results demonstrate that tuning the conjugation length of the bulky chromophores in blue light-emitting polymers is a novel and effective molecular design strategy toward highly stable and efficient blue polymer light-emitting diodes.
Juraj FiloLucie Muzikova CechovaEliska Prochazkova
9页
查看更多>>摘要：Solid-state photoswitching enables the development of smart materials. However, the close packing of molecules and the lack of free volume in this state prevent sterically demanding structural changes induced by irradiation, thereby precluding the use of azobenzene photoswitches. Nevertheless, we report here the solid-state photo-switching of their derivatives, 5-phenylazopyrimidines, in crystalline powders and in amorphous thin layers. After identifying trans-cis photoisomerization by NMR spectroscopy, we demonstrated the applicability of 5-phenylazopyrimidines for future all-optical switching applications. For this purpose, we prepared thin films by spin-coating and confirmed their solid-state optical switching by optical transmission spectroscopy and their favorable surface topography by atomic force microscopy. Therefore, thin films of 5-phenylazopyrimidines are suitable for on-chip integration for emerging all-optical technologies.
查看更多>>摘要：Hypochlorous acid (HOC1), one of the physiologically important reactive oxygen species (ROS), is engaged in a diverse variety of biological and pathophysiological functions. Excessive HOC1 buildup can cause a variety of illnesses, therefore, the identification of events in real-time of abnormal levels of exogenous and endogenous HOC1 in biological settings is extremely important. In the present paper, we reported a new near-infrared emissive fluorescent probe D-HBT-HOC1 for die detection and bioimaging of HOC1 in live cells. With regard to the construction of D-HBT-HOC1, we combined the dicyanoisophorone motif with a 2-aminobenzenethiol unit, resulting in the near-infrared emission wavelength of 700 nm and an ultra-large Stokes shift of 180 nm, which potentially endowed D-HBT-HOC1 with superiority in biological imaging. In addition, the N, N-dimethylth-iocarbamate served as an efficient recognition group for HOC1 as well as a fluorescence quenching group in the probe. The results of the experiments showed that the newly designed probe exhibited excellent sensing capacity, including outstanding selectivity, a high signal-to-noise ratio, and a rapid response time for the detection of HOC1. What's more, this probe was further effectively leveraged for the imaging of both extrinsic and intrinsic HOCl in live cells, demonstrating its versatility, and possessed the potential to be used to further investigate the physiological and pathological activity of HOCl in biological systems.
查看更多>>摘要：Herein we designed three novel fluorescent brightening agents based on a benzodifuran skeleton. The compounds are colorless fluorophores emitting in the blue region with an improved water solubility and ability to interact with living cells. A complete understanding of the emission mechanisms was achieved by Density Functional Theory study based on X-ray crystallographic analysis. The fluorescence quantum yields were measured in different solvents and at different pH values. The ability of the different fluorophores to stain cell compartments of plant root samples was tested in water-and glycerol-based solutions. Through fluorescence microscopy technique two probes with a different functionalized branching chain proved to be efficient stains for plant root cell wall. The cationic probe has no harmful effect on plant tissues and is suitable for in vivo fluorescent visualization of plant root cell boundaries. This study sheds light on the potential use of brighteners containing a central benzodifuran core as tools for imaging of fixed and alive plant tissues.
查看更多>>摘要：A polyamide containing bis(diphenylamine-spirodifluorene) moieties was designed and synthesized. Owing to the stable electroactive amine center of conjugated system and loose interchain packing of twisted double triphenylamine-fluorophore moieties, the resulting polyamide revealed good overall properties, especially ultrahigh cycle stability (less than 11.0% of fluorescence contrast loss after 800 cycles), as well as rapid switching speed (2.9/1.8 s) and high fluorescence/color contrast (111/69.2%). The study will promote then practical applications in the near future.
查看更多>>摘要：Drug-induced liver injury (DILI) as an acute liver disease has caused serious concern in public health problems. As a kind of reactive oxygen species, HCIO has come into scientists' vision as a marker of DILI. Herein, we construct a BODIPY-based near-infrared (NIR) fluorescent probe (BDP-R-CIO) for the selective and sensitive response of hypochlorous acid. The probe could realize the rapid detection of HCIO, with a 20-fold fluorescence enhancement at 661 nm and the detection value of which was only 1.8 nM. Moreover, BDP-R-CIO could diagnose and visualize DILI by monitoring the fluctuation of HCIO concentration in vitro and in vivo, and evaluate the detoxification of hepatoprotective drugs. Through the visualization of HCIO in the mice liver injury models, BDP-R-CIO not only proved its applicability but also indicated that it had great potential in the diagnosis and monitoring of HClO-related diseases.
查看更多>>摘要：Benzothiazole-based fluorescent probes are formed by decorating benzothiazole fluorophore with a small chemical fragment capable of detecting a particular biological species or physiological condition. Due to a variety of their photophysical mechanism, like, intramolecular charge transfer (ICT), excited-state intramolecular proton transfer (ESIPT), photoinduced electron transfer (PET), and aggregation-induced emission (AIE), these fluorescent probes selectively interact with various analytes and lead to change in their luminescence features that afford the detection of the analyte. These probes showed advantages of large Stokes shift, high quantum yields, and excellent color transitions. Benzothiazole fluorescent probes can be applied to diagnose various diseases or disorders by monitoring essential biomolecules by imaging cells or intracellular organelles. To date, several benzothiazole-based small molecular probes have been reported. The current review is mainly centered on the recent advances made by these fluorescent probes in the last five years.
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