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Photopolymerization of the coumarin-containing reversible photo-responsive materials based on the wavelength selectivity
摘要： Photo-response of the coumarin derivative based on the reversible photodimerization and photocleavage has been studied for long time. This paper reports a novel approach of preparing photo-responsive polymer materials containing coumarin structure by photopolymerization based on the wavelength selectivity. A photo-polymerizable and photo-responsive monomer 7-(hydroxyethoxy)-4-methyl-coumarin (AECM) was synthesized and performed photo polymerization upon UV light irradiation (λ=405 nm). After polymerization the polymer with coumarin pendant groups can achieve reversible photoinduced [2+2] dimerization under UV light (λ>300 nm) and the photo-cleavage of crosslink to recovery back to the original structure through further irradiation with UV light (λ=254 nm). What’s more, this monomer could be used to produce high-resolution pattern and photo responsive pressure sensitive adhesive through photopolymerization. The demonstrated approach opens new perspectives for the design of photo-response materials.
关键词： coumarin,photopolymerization,photo-response,wavelength selectivity
更新于2025-09-19 17:15:36
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Intermolecular Interactions of Hybrid Organic Dyes Based on Coumarin 343 for Optoelectronic Applications
摘要： Understanding the intermolecular interactions in the organic dye mixtures could be critical for the design of high-performance optoelectronic devices. In the present study, we investigate the intermolecular interactions in dye systems combining two kinds of organic dyes, using the coumarin 343 (C343) as an example. The study employs the first principles calculations and the spectroscopic/electrochemical experiments to explore the intermolecular interactions (either synergistic or antagonistic) and their effects on the electronic and optical properties of the hybrid dye systems. The interactions between the coumarin dye and four other dyes, either as free dyes or as self-assembled monolayers that are adsorbed onto semiconductor substrate, are analyzed via the UV–Vis absorption, the emission and the photocurrent measurements. The four dyes include 4-(4-diethylaminophenylazo)pyridine, chlorophosphonazo III, methyl red, and catechol, which have been applied to optoelectronic devices. In particular, the interaction between C343 and 4-(4-diethylaminophenylazo)pyridine is found to be synergistic for the photocurrent generation using the aqueous electrolyte, which is not observed in other systems. The study suggests importance of the intermolecular interactions in the hybrid-dye systems, and might provide fundamental insights on the intermolecular interactions that could be leveraged to design optoelectronic devices.
关键词： synergistic,coumarin,optoelectronic,azo,TiO2 intermolecular
更新于2025-09-16 10:30:52
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Scale Effect of Fluorescent Waveguide in Organic Micro-Materials: A Case Study Based on Coumarin Microfibers
摘要： In the past decades, the rapid development of integrated optoelectronic devices has motivated the study of the miniaturized optoelectronic components, among which the micron or sub-micron waveguides have attracted a great deal of attention. In this regard, the waveguides made of organic materials show many advantages, such as intense fluorescence, tailor-made structure and facile crystallization. The waveguide ability was usually expressed in the form of the optical loss coefficient (denoted by <), which is mainly determined by the materials of the waveguide, and relatively low < usually corresponds to less optical loss and better propagation. The value of < was usually determined by the exponential fitting of the curves of the guided intensity (Itip/Ibody) versus the waveguiding distance (x). When the sectional size of the waveguide was down/close to the wavelength of the exerted light, the traditional evaluation is no longer valid, since < is also influenced by the diameter of the waveguide. For example, silica fibers with diameter more than one micron allow multimode waveguiding of visible and infrared light, while those with diameter of sub-micron allow single-mode operation. In case of organic waveguide, the situation becomes complicated, especially for those with size close to micron and sub-micron (range for majority organic waveguides). Except for the refraction index, the sectional size and the auto-absorption within the waveguide should also be considered. Models that accurately describes the waveguiding ability are highly demanded, but still dangling with no clues.
关键词： scale effect,organic micro-materials,fluorescent waveguide,coumarin microfibers,optical loss coefficient
更新于2025-09-12 10:27:22
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Reversibly Photoswitchable Dual-Color Fluorescence and Controlled Release Properties of Polymeric Nanoparticles
摘要： Here, we report a novel polymeric nanoparticle prepared by the self-assembly of amphiphilic copolymers containing a ?uorescent naphthalimide (NAPH) and a photochromic spiropyran (SP), which possesses reversibly photoswitchable dual-color ?uorescence and controlled release properties. The amphiphilic copolymers were synthesized by incorporating NAPH and SP into methyl ether poly(ethylene glycol)-poly(β-amino esters) (MPEG-PAE) via quaternization. The nanoparticles would change between yellow and purple reversibly upon UV and visible light irradiation because of the photoisomerization between SP and merocyanine (MC). The corresponding ?uorescence would be switched between green and orange-red reversibly upon blue light excitation through the ?uorescence resonance energy transfer from the excited NAPH to the photoisomerized MC. Meanwhile, the prepared spherical nanoparticles could be swollen under UV irradiation as the hydrophobic SP isomerized to hydrophilic MC; the nanoparticles could also be swollen under acidic conditions because of the protonation of the amino groups of PAE. Upon UV light irradiation and acidic stimulation, the cargoes, hydrophobic Coumarin 102, encapsulated in the nanoparticles would be released. The prepared nanoparticles, which exhibit not only excellent reversible dual-color ?uorescence properties but also prominent controlled release performance, will open up new possibilities for the combined application of ?uorescence imaging and controlled release.
关键词： naphthalimide,Coumarin 102,spiropyran,polymeric nanoparticles,photoswitchable,amphiphilic copolymers,acidic conditions,quaternization,self-assembly,FRET,UV/vis light irradiation,dual-color ?uorescence,MPEG-PAE,controlled release
更新于2025-09-11 14:15:04
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Whole-Eye Perfusion Model for Screening of the Ocular Formulations via Confocal Laser Scanning Microscopy
摘要： Various physiological, anatomical barriers make ocular drug delivery very challenging. Hence, better in vitro screening models are needed for rapid screening of the formulations. In this study, a simple whole-eye perfusion model was designed and its application was explored for screening targeted formulation across the full-thickness cornea laser scanning microscopy. PEG-cholecalciferol-based integrin targeted using confocal coumarin-6 micelles (TC6M) and non-targeted coumarin-6 micelles (NTC6M) were developed by solvent diffusion evaporation technique. The formulations NTC6M and TC6M had particles size 23.5 ± 5 nm and 28.5 ± 6 nm respectively and osmolality of 294–300 mOsml/Kg. The whole-eye perfusion model was developed using porcine eye. TC6M and NTC6M were instilled on the excised porcine eyes as well as in the eyes of NZW rabbits. Corneas were excised from the experimental eyes; coumarin-6 penetration across the corneas was analyzed using confocal microscope. Coumarin-6-loaded micelles had particle size below 50 nm. NTC6M formulations showed penetration to the deeper layers up to 500 μm porcine eyes and up to 50 μm in rabbit corneas. However, TC6M formulations exhibited superior retention, as higher ?uorescent intensities were observed in upper layers up to 50 μm depth in the porcine eye and 20 μm depth in rabbit eye. Hence, applicability of whole-eye perfusion model in preliminary screening of the formulations was successfully demonstrated. Whole-eye perfusion model when combined with confocal microscopy has potential to be used as an ef?cient tool for rapid screening and optimization of various ophthalmic formulations.
关键词： coumarin-6,confocal,micelles,perfusion model,ocular
更新于2025-09-11 14:15:04
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3D, covalent and noncovalent hybrid materials based on 3-phenylcoumarin derivatives and single walled carbon nanotubes as gas sensing layers
摘要： In this work, the effect of different types of functionalization of single walled carbon nanotubes (SWCNT) with 3-phenylcoumarin derivatives on the chemiresistive sensor response to ammonia (10–50 ppm) was studied. Covalent functionalization of SWCNT was performed according to the Huisgen reaction of azide-alkyne 1,3-dipolar cycloaddition between mono alkyne-substituted 3-phenylcoumarin and single walled nanotubes modified by azide groups. Covalent functionalization was shown by IR- and X-ray photoelectron spectroscopy. To obtain the 3D hybrid material, the dialkyne functionalized 3-phenylcoumarin molecules were used as linkers between nanotubes. Third hybrid material was prepared by noncovalent functionalization of SWCNT, namely by adsorption of 7-propinyloxy-3-(p-propinyloxyphenyl)coumarin on SWCNT surface. It was shown that the 3D hybrid and the hybrid obtained by covalent functionalization exhibit 2 and 4 times higher sensor responses to ammonia compared to noncovalently functionalized SWCNT. The value of sensor response is in good correlation with the degree of functionalization of SWCNTs with coumarin molecules.
关键词： Non covalent functionalization,3D carbon nanostructures,Covalent functionalization,Carbon nanomaterials,Ammonia sensor,Coumarin
更新于2025-09-11 14:15:04
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White-Light Emitting Di-Ureasil Hybrids
摘要： White-light emitting materials have emerged as important components for solid state lighting devices with high potential for the replacement of conventional light sources. Herein, amine-functionalized organic-inorganic di-ureasil hybrids consisting of a siliceous skeleton and oligopolyether chains codoped with lanthanide-based complexes, with Eu3+ and Tb3+ ions and 4,4'-oxybis(benzoic acid) and 1,10-phenanthroline ligands, and the coumarin 1 dye were synthesized by in situ sol–gel method. The resulting luminescent di-ureasils show red, green, and blue colors originated from the Eu3+, Tb3+, and C1 emissions, respectively. The emission colors can be modulated either by variation of the relative concentration between the emitting centers or by changing the excitation wavelength. White light emission is achieved under UV excitation with absolute quantum yields of 0.148 ± 0.015, 0.167 ± 0.017, and 0.202 ± 0.020 at 350, 332, and 305 nm excitation, respectively. The emission mechanism was investigated by photoluminescence and UV–visible absorption spectroscopy, revealing an efficient energy transfer from the organic ligands to the Ln3+ ions and the organic dye, whereas negligible interaction between the dopants is discerned. The obtained luminescent di-ureasils have potential for optoelectronic applications, such as in white-light emitting diodes.
关键词： lanthanide complexes,di-ureasil organic–inorganic hybrids,in situ sol–gel synthesis,white light emission,coumarin 1
更新于2025-09-10 09:29:36
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Metal ion sensing ability and photo-physical properties of 4-hydroxy-3-nitroso-2H-chromen-2-one: Interaction studies with calf thymus-DNA
摘要： 4-Hydroxy-3-nitroso-2H-chromen-2-one (HNC), a coumarin derivative has been synthesized through a very simple method, and its photo-physical properties were studied. HNC is used as a simple colorimetric as well as spectrophotometric chemosensor for the detection of Fe2+, Co2+, Ni2+ and Cu2+ ions, some even by naked-eyes. This process gives a sensitive readout of chemosensor HNC within a wide range of (4.5–1219.5) × 10?7 (M) at λmax 258 nm. HNC has greater binding and detection ability toward Fe2+ than that of 1,10-phenanthrolin, and it has greater binding ability for Fe2+ than that with Fe3+ also. We have also established a method for solid state sensing of iron salts by HNC. Moreover, the binding interaction of HNC with calf-thymus DNA (CT-DNA) established a groove binding mode.
关键词： CT-DNA,Coumarin,Solid state Fe2+ ion sensing,Naked-eye metal sensing,Chemosensor
更新于2025-09-10 09:29:36
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New fluorescent sensor based on a calix[4]arene bearing two triazole–coumarin units for copper ions: application for Cu2+ detection in human blood serum
摘要： A novel fluorescent chemosensor calix[4]arene L, containing two fluorogenic coumarin units at the lower rim has been synthesized via click reaction. The structure of this chemosensor, was characterized by IR, NMR spectra and elemental analysis. Ion-binding properties of L were investigated in acetonitrile with different metal ions and the recognition process was monitored by fluorescence, UV-Vis and 1H NMR spectral changes. In comparison with other metal ions, chemosensor L showed a specific selectivity toward copper ions. The Job plot analysis revealed that the binding between L with Cu2+ is in 1:1 stoichiometry. The association constant (Ka) for the complex L.Cu2+ was found to be 1.6 × 105 M?1. The limit of detection of the sensor L was determined to be 5.4 × 10?7 M. This sensitive and selective chemosensor was successfully applied for the detection of Cu2+ ions in human blood serum with 90–100% recovery.
关键词： Coumarin units,Blood serum,Calix[4]arene,Fluorescent sensor,Copper ion
更新于2025-09-10 09:29:36
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Red emitting coumarin based 4, 6-disubstituted-3-cyano-2-pyridones dyes – Synthesis, solvatochromism, linear and non-linear optical properties
摘要： New coumarin fluorescent based D-π-A-π-D dyes are synthesized and studied for their optical properties. Their show absorption and emission respectively are in the range of 471-504 nm and 506-550 nm. Viscosity induced emission intensity increase is examined with 0-100% PEG-400 in ethanol MLK 4 is good FMR as compared to the MLK 1-3 due to the presence of extra-π-conjugation. FMO analysis and Generalised Mulliken Hush analysis show a strong interaction of molecular charge transfer characteristics. The first (α), second (β) and third (γ) order polarizability of MLK 1-4 are calculated by the solvatochromic technique and corroborated by DFT calculations using CAM-B3LYP/6-31G(d) method. The outcomes found by solvatochromic technique are compared theoretically with DFT using B3LYP/6-31G(d) and CAM-B3LYP/6-31G(d) methods. These methods reveal that, CAM-B3LYP/6-31G(d) carry out for calculating α, β, γ. Photophysical data was also applied to establish the ground and excited state dipole moment ratio using Bakhshiev, Bilot-Kawski, and Liptay functions. Liptay function shows better correlations than the other two functions for all dyes.
关键词： Viscosity sensor,TD-DFT,Coumarin,NLO properties,Carbazole,Intramolecular charge transfer
更新于2025-09-10 09:29:36