Dyes and Pigments最新文献

Aggregation-induced emission (AIE) materials are highly demanded for practical applications in optoelectronics, sensorics, material science and bio-imaging. However, highly torsionally-flexible and hybrid organic/inorganic AIE materials are limited. In this work we designed, synthesized and comprehensively studied AIE-active bis((9H-(4,5-diazafluoren)-9-ylidene)methyl)arylenes demonstrating high torsional freedom coupled with electron-accepting character and N,N′-chelating ability. One-rotor nonplanar structure of phenylene-linked derivative (BDFMP) allowed us to demonstrate its polymorphic diversity both in neat state and in coordination polymers. X-ray diffraction analysis indicated formation of crystals with extensive π-stacking interactions and slipped/side-by-side packing motifs, the former crystals demonstrating a photoluminescence quantum yield of 25 %. The reaction of both BDFMP/BDFMT with ZnCl₂ resulted in formation of unique coordination polymers and porous metal organic frameworks with photoluminescence sensitive to heating and (de/re)hydratation. The latter effect was exploited for security painting and anti-counterfeiting demonstration.

Research on fluorescent probes has come a long way in the last few years. Among a palette of small molecule fluorescent probes, coumarin-based probes have gained a lot of attention in the last few decades. Considerable advancements have been made in the development and application of coumarin fluorescent probes. These are becoming more widely used in biochemistry, environmental protection, and disease detection due to their substantial Stokes shift, high quantum yield, excellent biocompatibility, and cell-membrane permeability. Novel coumarin fluorescent probes can be designed by altering the current substituents on the coumarin scaffold and can be applied to detection and identification of several analytes by conjugating it with a variety of recognition units. To date, several reviews on coumarin-based small molecular probes have been reported. The current review focuses on the recent advances of these coumarin probes since 2018.

Hypochlorous acid (HClO) as a reactive oxygen species (ROS) plays an important role in many pathological and physiological processes. Abnormal concentrations of HClO in vivo have close contact with many diseases, including inflammatory diseases and cancer. Due to the measurement deviation caused by changes in external factors, a ratiometric fluorescent probe can effectively avoid this phenomenon. In this work, a ratiometric fluorescent probe PTB was synthesized based on phenothiazine for rapid and specific detection of HClO. PTB showed good selectivity, good biocompatibility, and a low detection limit (21.4 nM). Moreover, this ratiometric fluorescent nanoprobe was subsequently developed for visual on-site detection of HClO with the naked eyes under an ultraviolet lamp. In biology, PTB showed good mitochondrial targeting and was capable of rapidly detecting endogenous HClO within 10 s in living cells and in vivo, which makes it have broad application potential in the life sciences.

Novel polycrystalline phosphor-yttrium calcium borate doped with dysprosium ions (Dy³⁺: Y₂CaB₁₀O₁₉) was synthesized for the first time by solid-state reaction technique. The crystal structure was found to be monoclinic having C2 space group. SEM was performed to analyze the surface morphology of the phosphor materials and to assess the distribution of phosphor particles in the glass matrix. Fourier transform infrared (FTIR) spectroscopy of the samples was studied to know the molecules present. The emission spectra by 350 nm excitation possessed characteristic peaks at 480 nm (blue) and 577 nm (yellow). The CIE chromaticity co-ordinate and correlated color temperature (CCT) were deduced to be (x = 0.3384, y = 0.3823) and 5297 K respectively. Luminescence decay time for the optimized phosphor was determined to be 0.70 ms. The prepared phosphors were embedded in the glass matrix at an elevated temperature of 1000 °C. The transmittance spectra of the prepared glass materials were recorded to analyze its transparency in the visible region. The internal quantum yield was deduced to be 53.91 %.

Iron (Fe³⁺) is an essential trace element in biological organisms. Abnormal concentrations of Fe³⁺ in aquatic possess the potential to disrupt normal physiological and metabolic processes in living organisms. Consequently, the pursuit of developing fluorescent probes for detecting Fe³⁺ concentrations in water samples is highly significant. The lone electron pair on the nitrogen atom of quinoline demonstrates outstanding coordination capabilities, enabling the selective detection of metal ions through coordination. Nevertheless, the interaction between metal ions and quinoline-based fluorescent probes tends to lead to nanoparticle aggregation, causing aggregation-caused quenching (ACQ) phenomena. This severely restricts the practical application of these probes. To address this challenge, the study utilizes quinoline as the foundational framework and modulates the excited-state electronic structure of quinoline derivatives through substituent effects. This facilitates the transition from ACQ to aggregation-induced emission (AIE). By integrating theoretical calculations, the paper proposes a comprehensive strategy for designing AIE molecules based on quinoline. This contribution provides innovative perspectives on AIE molecule design. Ultimately, the AIE property of the 8-MQB molecule is harnessed to develop a fluorescent probe capable of detecting Fe³⁺ in water samples. The fluorescence intensity exhibits a robust linear correlation with Fe³⁺ concentrations within the range of 5.0 μM to 0.3 mM. Moreover, the probe demonstrates exceptional resistance to interference from other metal ions. In conclusion, this research presents a universal strategy for designing AIE molecules and introduces an AIE probe for the rapid detection of Fe³⁺ concentrations in water samples.

Novel tetraphenylethylene-substituted [1,2,5]oxadiazolo[3,4-b]pyrazines have been synthesized, and their ability to be transformed into other annulated pyrazines in good yields has been demonstrated. The photophysical properties of all new fluorophores have been investigated, by using both absorption and emission spectral analyses in MeCN solutions and solid-state. All fluorophores proved to possess very low absolute quantum yields in solutions and absolute quantum yields up to 0.06 in solid-state, depending on their azine parts. The incorporation of tetraphenylethylene unit in the backbone endows the fluorophore a significant aggregation induced emission behavior. It has been demonstrated that novel tetraphenylethylene-substituted pyrazino[2,3-b]pyrazines can be used as aggregation induced emission active probes for the effective detection of nitroaromatics in solutions with a high selectivity, a high sensitivity and a fast response. On the basis of the experimental data and DFT calculations, it has been shown that a static mechanism of fluorescence quenching with a significant contribution of dynamic components takes place in case of new fluorophores. This research provides new insights into the rational design of aggregation induced emission fluorophores based on azaheterocyclic push-pull systems exploited for sensing applications.

Fluoride ion plays crucial roles in many biological, chemical, medical and environmental processes. Constructing a highly sensitive florescent probe for naked-eye detection F⁻ is of particular importance but remains challenging. In this work, we developed a colorimetric and ratiometric fluorescent probe of pyrrolopyrrole aza-BODIPY (PPAB)-based polymer (P1) for recognizing F⁻. In presence of F⁻, P1 showed obvious color change from green to yellow with absorption maximum blueshift from 670 nm to 340 nm. The weak emission of 697 nm changed to strong orange fluorescence with appearance of new broad emission with maximum bands at 520 and 642 nm. P1 was capable of sensitively and selectively detecting F⁻ with a low detection limit of 0.07 μM. The sensing mechanism revealed that B–N bond cleavage and following hydrolysis of P1 induced by F⁻ was responsible for the distinct colorimetric and ratiometric fluorescent signals. The results indicated that PPAB core was an efficient recognition unit for F⁻ detection for the first time. Finally, P1-loaded silicone or test paper could detect F⁻ by naked-eye signals. The probe can be successfully applied in real water samples to detect F⁻ concentration.

γ-Glutamyltranspeptidase (GGT) is a cell surface-associated enzyme, which has been proven to be closely related to many diseases. Thus, development of simple and effective GGT-activatable fluorescent probes for early diagnosis of diseases is of great significance. Herein, a series of simple isomeric pyridine-based GGT-activatable fluorescent probes has been successfully designed and synthesized. The preliminary experimental results indicate that Py-GGT-1 has a significant fluorescence response to GGT via a rare fluorescence-off approach. Further fluorescence response experiments, such as the time-/dose-dependent fluorescence change and the selectivity/specificity estimation, reveal that Py-GGT-1 has an excellent ability to monitor endogenous GGT activity. Mechanism studies through HRMS analysis, DFT calculations and molecular docking have theoretically verified the catalytic process between Py-GGT-1 and GGT. To develop its practical application, live-cell imaging and serum-sample analysis were carried out, demonstrating that Py-GGT-1 coud effectively track GGT within cells and organisms. Based its high selectivity and reasonable sensitivity, we expect that the probe will be applied in clinical diagnosis of GGT-related diseases in the future.

This manuscript investigates the catalytic potential of terpyridine-based metal complexes (C1–C6) in the efficient degradation of methylene blue dye. The synthesized terpyridine complexes were characterized using various spectroscopic techniques, and their catalytic activity was evaluated in the degradation of methylene blue dye under different experimental conditions. The study reveals that the target complex compounds exhibit notable catalytic efficiency, leading to the effective degradation of the envisioned dye. The reaction kinetics, mechanism, and the influence of various parameters on the catalytic performance were systematically explored. Among different synthesized complexes, Zn-complexes showed better performance than Fe-complexes. Remarkably, the complex C5 showed the best photocatalytic efficiency with a degradation of 79.84 % at optimized conditions of initial dye concentration = 15 mg/L, catalyst dosage = 10 mg, pH = 4, and temperature = 323 K. The recyclability test indicated good stability of the photocatalyst over five cycles with a very small loss of photocatalytic efficiency (∼11.64 %) and the photocatalytic reaction followed pseudo-first order kinetics with a high-rate constant of 0.009 min⁻¹. The trapping experiment revealed the active role of hydroxyl radicals (OH•) and superoxide anions ${(•O}_2^{-})$ as reactive species on the basis of which a plausible degradation mechanism is proposed. This research contributes valuable insights into the development of terpyridine-based catalysts for the degradation of organic dyes, paving the way for further advancements in the field of catalysis and environmental remediation.

Small molecule (SM) organic semiconductor materials have attracted further attention for their significant advancement in light-harvesting devices and optoelectronic applications. Their ease of preparation, well-defined structures, cost-effectiveness, and highly tunable properties promote them for organic solar cells (OSCs), organic field-effect transistors (OFETs), and dye-sensitized solar cells (DSSCs) devices. Conjugated heterostructure donor-π-acceptor SMs have possessed an efficient system for stimulating faster charge transfer and achieving high photon-to-electron conversion. Their structure can be readily modified to incorporate additional π-extension, further elevating their performance in OSCs, DSSCs, and OFETs. Benzothiadiazole, a well-known electron-deficient heterostructure moiety, when flanked by thiophene, has been strongly involved in numerous photoelectronic molecular designs. In this comprehensive review, we will explore the interaction between design strategies, side-chain engineering, molecular structure characteristics, and device engineering, as well as the molecular morphology of 4,7-di-(2-thienyl)-2,1,3-benzothiadiazole (DTBT) based organic SMs on the power conversion efficiency and the charge mobilities in three particular optoelectronic devices: OSCs, DSSCs, and OFETs. The challenges should be resolved with recommendations for DTBT-based molecular architectures for better device performance.