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Enumeration	Reference	Cover	Find
1.	Andreasson, Joakim, 1973, et al. (author) A dihydroindolizine-porphyrin dyad as molecule-based all-photonic AND and NAND gates 2011 In: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 89:3, s. 284-289 Journal article (peer-reviewed)abstract A molecular dyad consisting of a photochromic dihydroindolizine unit covalently linked to a porphyrin performs, when illuminated through a third-harmonic-generating crystal, the functions of both an AND and a NAND Boolean logic gate with shared all-optical inputs. The NAND gate is of particular interest as it is a so-called universal gate, and hence all other digital systems can be implemented by combinations of NAND gates. The functions of the AND and the NAND gates rely on changes in absorption and emission of the dyad in the visible spectral region upon isomerization of the photochromic unit. The change in absorption which forms the basis for the AND gate function is ascribed to the colorization/decolorization of the photochrome itself in response to the optical inputs. The variation in emission intensity which constitutes the NAND gate function is a result of the changes in redox properties of the photochrome that follow upon isomerization, such that only one of the two isomers is competent to quench the porphyrin emission by electron transfer.
2.	Baryshnikov, Gleb V., et al. (author) Optical tuning of tetrabenzo[8]circulene derivatives through pseudorotational conformational isomerization 2018 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 151, s. 372-379 Journal article (peer-reviewed)abstract In order to further search efficient [8]circulene materials for OLED applications we have theoretically investigated the structure and electronic, absorption spectra of functionalized tetrabenzo[8]circulenes with different substituents in the outer perimeter. These hydrocarbon materials complement the wide family of [8]circulenes which earlier have been demonstrated to possess promising emissive and exciplex-forming properties suitable for organic light emitting diodes. The hydrocarbon tetrabenzo[8]circulenes show saddle shape of the molecular skeleton which can exist in two different conformations with different curvatures of the macrocycle. The aromaticity, electronic structure and orbital pattern are found to be principally different for these two isomers, where the global minimum isomer is weakly antiaromatic and electronically less stable comparing with the non-aromatic local minimum structure. The absorption spectra are also very different: the global minimum structure is more active in the long-wavelength region while the local minimum isomer shows absorption only at short wavelengths. Our computational findings suggest a new concept for optical tuning of curved [8]circulenes through conformational isomerization and aromaticity control, thus through structural variations without changing the molecular composition. Based on this principle we have designed novel functionalized [8]circulenes with promising fluorescence activity.
3.	Bu, L., et al. (author) An AIE and ICT based NIR florescent probe for cysteine and homocysteine 2017 In: Dyes and pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 136, s. 724-731 Journal article (peer-reviewed)abstract A combination of aggregation-induced emission and intramolecular charge transfer was achieved by using a triphenylamine analogue and a dicyanovinyl moiety as the electron donating and accepting units, respectively. Hence, we designed and synthesized a probe with a D-π-A framework as a near-infrared fluorescence turn-on probe for biothiols (cysteine and homocysteine). Owing to the remarkable intramolecular charge transfer effect as well as intramolecular rotations associated with the donor moiety, the probe exhibits extremely weak fluorescence, which becomes a good starting point for developing fluorescence “turn-on” probes. Upon reaction with cysteine or homocysteine utilizing the dicyanovinyl moiety, the intramolecular charge transfer character was weakened, and the reacting products were observed to aggregate in aqueous solutions, resulting in the aggregation-induced emission effect with red fluorescence at 651 and 656 nm, respectively. Hence, the probe could be used as a fluorescence “turn-on” sensor for cysteine and homocysteine, with the sensing time of less than 4 min and the detection limits of 8.4 μM and 5.7 μM towards cysteine and homocysteine, respectively. The probe could distinguish cysteine and homocysteine from glutathione. The sensing mechanism was systematically investigated by employing high resolution mass spectrometry, 1H NMR and density functional theory calculations as well as checking the solvent viscosity dependent fluorescence, and thus the nucleophilic addition products, the intramolecular charge transfer character, and the aggregation-induced emission behaviour were clearly elucidated. It is noteworthy that the low cytotoxicity, the intrinsic aggregation-induced emission nature and near-infrared emissions enable the application of the probe in living cell imaging.
4.	Carmo, C., et al. (author) Exploring the impact of meso-position fluorination on BODIPYs : Synthesis, electrochemical Insights, and potential therapeutic applications in breast cancer 2024 In: Dyes and pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 229 Journal article (peer-reviewed)abstract Three boron dipyrromethane molecules (BODIPYs) were synthesized in this study with different quantities of fluorine in the meso position. The samples were characterized by NMR spectroscopy, absorption, mass spectrometry, and cyclic voltammetry, which was utilized to electrochemically measure the energy gaps between the HOMO (highest-energy occupied molecular orbital) and LUMO (lowest-energy unoccupied molecular orbital). The MTT and SRB assays were used to assess the viability of these dyes in breast cancer cells (MCF-7 and HCC-1806) and African green monkey kidney cells (Vero). The newly synthesized BODIPY tris(perfluorophenoxy)phenyl (1) compound has exhibited remarkable stability and lacks photocytotoxicity in this investigation, thus rendering it a promising candidate for application in bioimaging. At defined concentrations, the BODIPYs bearing perfluorophenyl (2) and hydroxyphenyl (3) moieties have been identified as prospective candidates for photosensitization in photodynamic therapy for breast cancer. Their notable phototoxic properties upon irradiation and the absence of significant metabolic activity reduction in normal VERO cells after 24 h of exposure suggest their potential efficacy in this therapeutic approach.
5.	Chen, W., et al. (author) Enhanced efficiency of polymer solar cells by improving molecular aggregation and broadening the absorption spectra 2019 In: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 166, s. 42-48 Journal article (peer-reviewed)abstract Alkylthio-substituted thiophene-based benzo[1,2-b:4,5-b’]dithiophene (BDT) was used to construct PBDTS-DTBT, a medium band gap donor-acceptor (D-A) polymer with 5,6-difluoro-4,7-bis[4-(2-octyldodecyl)thiophene-2-yl]benzo[c] [1,2,5]thiadiazole (DTBT). The incorporation of sulfur atoms into the side chains not only lowered the highest occupied molecular orbital (HOMO) energy level but also improved molecular aggregation and thus afforded lower band gap (1.68 eV) with full width at half maximum (FWHM) of 170 nm in comparison to that of the analogous polymer (PBDT-DTBT) without sulfur atoms in side chains. Therefore, the bulk heterojunction polymer solar cells based on PBDTS-DTBT with 2% diiodooctane (DIO) as processing additive showed a high power conversion efficiency (PCE) of 9.73% with high open-circuit voltage (V OC , 0.93 V), large short-circuit current density (J SC , 14.23 mA/cm 2 ) and high fill factor (FF, 0.735).
6.	Chen, X., et al. (author) A unimolecular platform based on diarylethene with multiple stimuli-gated photochromism 2019 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 164, s. 91-96 Journal article (peer-reviewed)abstract The gated photochromic systems have attracted great interest in scientific researches due to their merits in the opto-electronic fields, whereas the multi-stimuli gating function in a unimolecular platform has rarely been addressed. Herein, a new strategy to realize multi-stimuli gated photochromic function was devised relying on a simple Schiff-based diarylethene derivative. The compound shows no photoswitching properties in solution under irradiation with any wavelength of light. It is noteworthy that mecury(II) ions, water and protons can trigger its photo-reactivity independently with different absorption changes, respectively. Therefore, a molecular logic circuit with four inputs, including mecury(II) ions, water, protons and UV light, was fabricated on the basis of the unimolecular platform, suggesting promise for application in multi-controlled photoswitchings. These results could be valuable for the further development of photoswitchings with multiple stimuli responses.
7.	Danyliv, Yan, et al. (author) Carbazole-s-sulfobenzimide derivative exhibiting mechanochromic thermally activated delayed fluorescence as emitter for flexible OLEDs : Theoretical and experimental insights 2022 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 208 Journal article (peer-reviewed)abstract For the first time exploiting sulfobenzimide moiety as an acceptor unit, the new type of donor-sigma-acceptor emitter exhibiting thermally activated delayed fluorescence (TADF) is demonstrated. In different solutions, the synthesized compound emits light resulting from either locally excited carbazole moiety or trough-space charge transfer (exciplex-like) between carbazole and sulfobenzimide units. In the solid state, this emitter demonstrates aggregation-induced emission enhancement and different emission colours due to its different conformations. The mechanoluminescence of the donor-sigma-acceptor compound was observed and studied in detail by experimental and theoretical approaches including single-crystal and powder X-ray analyses. Electroluminescence of the different colours was observed when the compound was utilized as non-doped TADF emitter in rigid and flexible organic light-emitting diodes fabricated on glass or poly(ethylene terephthalate) substrates. The device fabricated on the rigid substrate exhibited the best performance with maximum current efficiency, power efficiency, and external quantum efficiency of 11.0 cd A(-1), 3.0 lm W-1, and 4.3%, respectively.
8.	Deligkiozi, Ioanna, et al. (author) Synthesis and characterization of new azobenzene-containing bis pentacyanoferrate(II) stoppered push-pull [2]rotaxanes, with alpha- and beta-cyclodextrin. Towards highly medium responsive dyes 2015 In: Dyes and pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 113, s. 709-722 Journal article (peer-reviewed)abstract The solvatochromic behavior of novel synthesized azo-containing viologen-based rotaxanes, combining push-pull linear and alpha or beta-cyclodextrin macrocyclic components is examined. These rotaxanes are stoppered by pentacyanoferrate(II) units. The latter stabilize these systems and furthermore act as strong electron donors. These units are linked to strong electron withdrawing viologen units thus giving rise to an exceptionally intense solvatochromic behavior. Suitable solvent polarity scales and Linear Solvation Energy Relationships (LSERs) were employed in order to rationalize the solvent polarity effects observed, both specific and non-specific ones. The results for the title compounds as well as their Cyclodextrin-Free-Dumbbell (CFD) like analogue, are compared to recent published solvatochromic data regarding similar smaller pentacyanoferrate(II) complexes as well as other highly solvatochromic compounds. Structural effects on the solvatochromic intensity as well as the contribution of different solvent-solute interactions are rationalized and quantified. (C) 2014 Elsevier Ltd. All rights reserved.
9.	Deska, Radoslaw, et al. (author) Two-photon excited luminescence and second-harmonic generation in quinacridone microstructures 2020 In: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 177 Journal article (peer-reviewed)abstract Nonlinear optical microscopy was employed to investigate the properties of microstructures of quinacridone, a hydrogen-bonded pigment, derivative of quinacridine. Recently, quinacridone hierarchical microstructures (mu-QNC) having different nature-inspired morphologies were reported, e.g. in the shape of hedgehogs formed by self-assembled nano-needles. We find that such microcrystals have structure-dependent linear optical properties and exhibit strong two-photon excited fluorescence when irradiated with a near-infrared femtosecond laser. mu-QNCs exhibit different nonlinear optical properties for different crystal structures, including the emergence of symmetry-forbidden second-harmonic generation.
10.	Du, Siying, et al. (author) Nonfullerene acceptors from thieno[3,2-b]thiophene-fused naphthalene donor core with six-member-ring connection for efficient organic solar cells 2021 In: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 185 Journal article (peer-reviewed)abstract Comprehensive design ideas on the fused-ring donor-core in state-of-the-art acceptor-donor-acceptor (A-D-A) nonfullerene acceptors (NFAs) are still of great importance for regulating the electron push-pull effect for the sake of optimal light-harvesting, frontier molecular orbital levels, and finally their photovoltaic properties. Herein, thieno[3,2-b]thiophenes were fused in bay-area of naphthalene via six-member-ring connection, resulting in the formation of dihydropyrenobisthieno[3,2-b]thiophene based octacyclic ladder-type donor core, which was flanked by two 1,1-dicyanomethylene-3-indanone (IC) acceptor motifs with and without 5,6-diflourination, namely PTT-IC and PTT-2FIC, respectively, as novel efficient A-D-A fused-ring electron acceptors (FREAs). Compared with PTT-IC, fluorinated PTT-2FIC possesses narrower optical bandgap of 1.48 eV, better π-π stacking, and its PBDB-T:PTT-2FIC blend film exhibited better morphology, and better hole and electron mobility. As a result, nonfullerene solar cells using PBDB-T:PTT-2FIC as the active layer achieved a decent PCE of 10.40%, with an open-circuit voltage (VOC) of 0.87 V, a fill factor (FF) of 0.65, and a much higher short-circuit current (JSC) of 18.26 mA/cm2. Meanwhile, the PBDB-T:PTT-IC cells delivered a lower JSC of 12.58 mA/cm2 but a higher VOC of 0.99 V, thus resulting in a PCE of 7.39% due to its wider optical bandgap of 1.58 eV and higher LUMO energy level. These results demonstrated that NFAs based on fused-ring donor core from fusing thieno[3,2-b]thiophenes with naphthalene via six-member-ring connection are promising for organic photovoltaic applications.
11.	El-Zohry, Ahmed M., et al. (author) Ferrocene as a rapid charge regenerator in dye-sensitized solar cells 2016 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 132, s. 360-368 Journal article (peer-reviewed)abstract Using the reductive power of the ferrocene moiety (Fc), an ultrafast regeneration step via a covalent attachment of a Fc moiety to an organic triphenylamine-based dye (L1) when adsorbed on TiO2 is highlighted. Two modified dyes with one and two Fc moieties attached (L1Fc, and L1Fc2), respectively, were synthesized by addition to the L1 dye. These dyes have been studied spectroscopically using ultrafast transient absorption spectroscopy in the visible and the infrared (IR) regions. In acetonitrile, the results show an ultrafast excited state quenching of the modified dyes due to an expected electron transfer process from the Fc(s) to L1. Adsorbed onto TiO2, an electron transfer process is also detected from Fc to the oxidized dye (L1(+)). Despite the occurrence of an ultrafast regeneration step, the solar cell performance does not improve by the attachment of Fc(s) to the dye L1. Transient absorption measurements in the IR region revealed a fast electron recombination process to the Fc(+) moiety on an average time scale of ca. 300 ps, outcompeting the >12 ns process to L1(+). The reasons for the observed considerably faster recombination rate to Fc(+) than to L1(+) are discussed in detail. This study provides deep spectroscopic insights for such organic dyes utilized to afford ultrafast regeneration step without showing high performance in photovoltaic devices. In addition, this study will improve our understandings for the triangular relationship between the molecular design, electron kinetics, and the performance in photovoltaic devices. (C) 2016 Elsevier Ltd. All rights reserved.
12.	El-Zohry, Ahmed M. (author) The origin of slow electron injection rates for indoline dyes used in dye-sensitized solar cells 2019 In: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 160, s. 671-674 Journal article (peer-reviewed)abstract This work highlights the direct impact of selecting acceptor moiety for organic dyes on the electron dynamics at faster time scales, in which overlooked photo-physical properties are present on semiconductor surfaces with specific acceptor moieties. Four top-performing dyes of indoline family (D131, D102, D149, and D205) sharing the same donor moiety, but through different acceptor groups, were selected and compared with respect of electron injection process, using ultrafast transient-infrared probe. The presence of rhodanine moiety at the acceptor unit in D102, D149 and D205, shows an additional slow electron injection process, of picosecond time-scale, on the low band-gap semiconductor, TiO2. This slow process is expected to be present due to a twisted intramolecular charge transfer/isomerized state of the excited dye prior to electron injection. This isomerized state reduces as well the detrimental electron recombination process rates, and results of high performance in solar cells based on these rhodanine dyes. Replacing the rhodanine moiety by a cyano-acrylic group in D131 dye shows faster electron injection and recombination processes, due to the lower dipole moment present in the excited state, hindering the formation of an isomerized state. These findings will aid to enhance the organic dyes design used in dye sensitized solar cells, in which designed photo-physical processes on semiconductor surfaces can increase the efficiencies of the solar cells.
13.	Emam, Hossam E., et al. (author) Self-cleaned photoluminescent viscose fabric incorporated lanthanide-organic framework (Ln-MOF) 2018 In: Dyes and pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 159, s. 491-498 Journal article (peer-reviewed)abstract Photoluminescent textiles emitted light in ultraviolet (UV)-radiation region has advanced a variety of applications including military and police clothes. The current study reports the preparation of photoluminescent viscose fabrics incorporated lanthanide metal-organic framework (Ln-MOF) and their applications for self-cleaning. In situ growth of Ln (Eu3+, Tb3+) MOF into viscose fabrics were achieved using Ln (NO3)(3) and 1,2,4,5-benzenetetracarboxylic dianhydride as organic ligand. The in-growth Ln-MOF within fabrics were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, energy dispersive X-ray, and fluorescence spectroscopy. Under the UV lamb (345 nm), Eu-MOF@viscose fabric and Tb-MOF@viscose fabric visually emitted red and green color, respectively. The excitation-emission spectra showed the spectra for the D-5(0)-> F-7(0.4) transitions and D-5(4)-> F-7(5) transitions in case of Eu-MOF and Tb-MOF@viscose fabrics, respectively. The photoluminescent properties of Ln-MOF@viscose fabrics were enhanced after reactive dying process. The self-cleaning functions of Ln-MOF@viscose fabrics were estimated through studying the photo-degradation of Rhodamine B (RhB) dye over the fabrics. After 120 min irradiation time, the photo-degradation of RhB dye was 85-97%, indicating high performance of Ln-MOF@viscose fabric. The materials are promising for advanced applications including protective clothing, textile-based sensors, smart tagging and tickets.
14.	Fleming, Cassandra, 1987, et al. (author) On the use of diarylmaleimide derivatives in biological contexts: An investigation of the photochromic properties in aqueous solution 2017 In: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 137, s. 410-420 Journal article (peer-reviewed)abstract A series of photochromic diarylmaleimide derivatives has been synthesized and studied with respect to the photochromic properties in aqueous solution. The main rationale is to investigate if these compounds could be used as photoswitchable units in biological contexts, motivated by the fact that the diarylmaleimide structural motif is identified in many pharmacophores. Thus, photoswitchable variants of this class of compounds could be very useful in the quest for photoactivatable drugs. The photoinduced cyclization reaction (colorization) is suppressed in solvents of high polarity, whereas the ring-opening reaction (decolorization) still occurs with high efficiency. The photochromically active anti-parallel conformer of the open form is more abundant in the asymmetrically substituted derivatives, which in turn favors the formation of the closed isomeric form. The rates of the thermal isomerization reactions have also been assessed, together with the resistance toward thermal degradation. Here it was observed that the maleimide derived compounds were not susceptible to the thermally driven reactions (hydrolysis and isomerization). (C) 2016 Elsevier Ltd. All rights reserved.
15.	Gao, Shimin, et al. (author) Stable thiophene-embedded N-confused homoporphyrins : Partial conjugation, fusion and fluoride binding 2021 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 194 Journal article (peer-reviewed)abstract In the past decades, porphyrin analogues have attracted increasing attention in light of their unique properties and potential applications in various areas. In this work, novel nonconjugated thiophene-embedded N-confused homoporphyrins 1 and 2 as well as a fully-conjugated N-fused homoporphyrin 3 have been prepared through acid-catalyzed condensation reactions followed by oxidation. Both 1 and 2 comprise two meso-sp3-carbon atoms. However, they are insensitive to the air or common oxidants. Single crystal X-ray diffraction analysis reveals that 2 adopts a highly distorted boat-like conformation, with the NH moieties of two pyrrolic units pointing outwards and an O atom attached to the alpha position of the N-confused pyrrole unit. As a result, hydrogen-bonded dimers are formed through the intermolecular hydrogen bonds between the lactam-like moieties. In contrast to the highly distorted structure of 2, N-fused homoporphyrin 3 contains a unique 5,5,5-tricyclic fused ring, and thus demonstrates a relatively coplanar conformation except one inverted pyrrole unit. Because of the different structural characters, 3 exhibits F- binding behavior distinct from that of 1 and 2.
16.	Grabarz, Anna M., et al. (author) The impact of the heteroatom in a five-membered ring on the photophysical properties of difluoroborates 2019 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 170 Journal article (peer-reviewed)abstract A series of novel BF2 complexes, bearing a five-membered heterocyclic ring (with X = NMe, O, and S), were synthesized and characterized with a focus on the influence of atom exchange on the photophysical properties of both unsubstituted and dimethylamino derivatives. The experimental results show that the optical spectra substantially differ in both sets of dyes. In particular, the dimethylamino series are more strongly affected by heteroatom substitution, i.e., the insertion of X = O or X = S in lieu of X = NMe causes substantial bathochromic shifts of the absorption and emission bands, as well as marked changes in their topologies. In contrast, the optical spectra of the unsubstituted compounds undergo only relatively small red-shifts, and no variation of band shapes is observed. Moreover, the measured absorption spectra of the unsubstituted compounds bearing X = NMe and X = O are almost identical. Interestingly, the fluorescence yields of the dimethylamino derivatives are much larger (up to one order of magnitude) than those of the corresponding unsubstituted compounds. The experimental analyses are supported by state-of-the-art quantum chemistry calculations, which satisfactorily reproduced the experimental trends and provided further insights into the observed optical signatures.
17.	Huang, Yanping, et al. (author) Syntheses and coordination of linear and macrocyclic pentapyrroles possessing a fused moiety : Confusion modulated structural diversity 2024 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 223 Journal article (peer-reviewed)abstract Porphyrinoids have attracted wide interest because of their vital roles in biological processes and fascinating structural and functional characters. In this work, a doubly N-confused pentapyrrane precursor N2C–P5 has been synthesized with terminal pyrrole ring A and middle pyrrole C incorporated in the N-confused mode. On this basis, pentapyrrin 1 and sapphyrin 2 have been synthesized by oxidizing N2C–P5 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). Both 1 and 2 possess a [5.5.5]-tricyclic fused ring involving pyrrole B and the neighboring confused pyrrole C. Meanwhile, the formation of 2 involves ring closure between the terminal rings A and E. Notably, 2 exists as a diradical showing a half-field signal in the electron paramagnetic resonance (EPR) spectrum and a singlet ground state with a negative singlet-triplet energy gap of −0.50 kcal/mol. Excellent thermal stability has been observed for 2, which may be related to its large π-conjugated framework involving the fused structure. On this basis, 1 and 2 were treated with Cu(acac)2 to afford Cu(II) complexes 3 and 4, respectively. As a result, an acetylacetonyl moiety is attached at the terminal pyrrole ring E to afford an NNNO coordination environment for complex 3, and the sapphyrin macrocycle of 2 has been cleaved between rings A and B to afford a fused pentapyrrin ligand, furnishing an NNNN coordination environment for complex 4, in which a pentafluorophenyl-ketal group generated during the ring cleavage reaction is attached to ring A, and it can be hydrolyzed to the corresponding pentafluorobenzoyl substituent to afford complex 5. Compared with free bases 1 and 2, complexes 3−5 show more intense low-energy near-infrared (NIR) absorption bands at ca. 791, 926 and 907 nm, respectively. This work provides an effective approach for the syntheses of linear and macrocyclic oligopyrroles with intriguing structures and properties by oxidizing oligopyrranes with precisely designed numbers and positions of N-confused pyrroles.
18.	Ivaniuk, K., et al. (author) BaZrO3 perovskite nanoparticles as emissive material for organic/inorganic hybrid light-emitting diodes 2017 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 145, s. 399-403 Journal article (peer-reviewed)abstract In the present work we have demonstrated double-channel emission from organic exciplexes coupled to inorganic nanoparticles. The process is demonstrated by yellow-green emission in light-emitting diodes based on organic exciplexes hybridized with perovskite-type dispersed BaZrO3 nanoparticles. Such double-channel emission provides a broadening of the electroluminescence spectrum and a resultant yellow-green emission color of the device. We have realized an energy transfer from the exciplexes arranged by the interface between two organic layers and the spherical-shaped BaZrO3 nanoparticles randomly deposited on the organic interface constructed of the tris(4-carbazoyl-9-ylphenyl)amine and 4,7-diphenyl-1,10-phenanthroline molecules. The fabricated device exhibits a current efficiency value of 3.88 C d/A, maximum brightness of 3465 cd/m2 (at 15 V), and external quantum efficiency of about 1.26%. In order to estimate the efficiency of the energy transfer from the exciplex to the BaZrO3 nanoparticles we have applied the Förster model for the dipole-dipole energy transfer accounting for the mutual overlap of the exciplex emission spectrum and the absorption spectrum of the BaZrO3 nanoparticles.
19.	Ivaniuk, K., et al. (author) BODIPY-core 1,7-diphenyl-substituted derivatives for photovoltaics and OLED applications 2020 In: Dyes and pigments. - : Elsevier Ltd. - 0143-7208 .- 1873-3743. ; 175 Journal article (peer-reviewed)abstract In the current study we demonstrate an application of four previously synthesized 1,7-diphenyl-substituted BODIPY species for inverted photovoltaic cells and for organic light-emitting devices (OLEDs). Depending on the type of substituents or annulation of the pyridone rings these dyes exhibit spectral properties in the full visible region up to the near-infrared wavelengths. All the studied compounds show very strong visible absorption that can be ascribed to the low lying LUMO levels making them electronically suitable as acceptors for many donor materials. The best fabricated inverted photovoltaic device based on the BODYPI-core derivatives demonstrates a power conversion efficiency equal to 1.36% which is close to previously published reports for related species. Two kinds of deep red OLEDs (doped and undoped) with narrow electroluminescence spectra (full width at half maximum up to 45 nm) have been fabricated. Maximum brightness of 3900 cd m−2 and an external quantum efficiency by 2.3% were achieved for the best OLED structure.
20.	Jiang, Tao, et al. (author) Tetraphenylethene end-capped diketopyrrolopyrrole fluorogens with AIE and large two-photon absorption cross-sections features and application in bioimaging 2016 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 133, s. 201-213 Journal article (peer-reviewed)abstract In this work, a series of new diketopyrrolopyrrole-based dyes have been synthesized by connecting tetraphenylethene to the diketopyrrolopyrrole core. All the four compounds exhibit good aggregation induced emission property with nonemissive in the solution but strong red fluorescence in the aggregate or solid state. Also, these new dyes exhibit large two-photon absorption cross sections (a), in which the a data measured by the open aperture Z-scan technique are determined to be 150, 300, 1140 and 1016 GM for four dyes, respectively. In addition, compound with stilbene and four tetraphenylethene units (DPP-TPE-3) was used as the luminogen and encapsulated into nanoparticles for cell imaging and two-photon excited fluorescence blood vessels imaging. The result indicates that it can be used as the effective fluorescence probe for bioimaging and has great potential for bioapplications. (C) 2016 Elsevier Ltd. All rights reserved.
21.	Karlsson, Mikael, 1978, et al. (author) Characterisation of silicon, zirconium and aluminium coated titanium dioxide pigments recovered from paint waste 2019 In: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 162, s. 145-152 Journal article (peer-reviewed)abstract © 2018 Elsevier Ltd Titanium dioxide (TiO2) is the major white pigment used by the paint industry. However, the production of TiO2is associated with a high carbon footprint. An alternative source of pigment could be created by developing a method to recover it from waste paint. In this paper two rutile pigments with different surface treatments were recovered from paint by a thermal recycling process. The pigments were analysed using powder x-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface area measurements (BET), laser diffraction for particle size analysis and zeta potential measurements before and after the recycling process. It was concluded that the rutile cores of both pigments were intact and there were no major changes in particle size distribution or surface charge for either pigment induced by the recycling process. However, XPS and zeta potential measurements showed that the surface coating of the pigments can be more or less degraded depending on the chemical nature, which might imply the need for further re-coating after-treatment. Another option would be to find another application for the pigment where the quality and function of the coating is of less importance.
22.	Kong, Jiahui, et al. (author) Modulation of the structures and properties of bidipyrrin zinc complexes by introducing terminal alpha-methoxy groups 2017 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 137, s. 430-436 Journal article (peer-reviewed)abstract A bidipyrrin nickel complex was synthesized in a high yield by oxidatively coupling between the ligands in the corresponding 2:1 (L:M) type of dipyrrin nickel complex, and further demetallation afforded the free bidipyrrin ligand. Interestingly, when treating the bidipyrrin nickel complex or the free bidipyrrin with FeCl3 in CH2Cl2/MeOH, the symmetric di-alpha-methoxy bidipyrrin could be synthesized in a high yield, with two methoxy groups attached to the terminal pyrrolic alpha-positions. Moreover, the coordination of the unsubstituted and disubstituted bidipyrrins with Zn(OAc)(2),2H(2)O afforded two similar M2L2 type of bidipyrrin helical complexes with different ligand conformations and different Zn center dot center dot center dot Zn distances of 5.353 and 3.357 angstrom, respectively. The difference in the conformations may be related to the electrostatic repulsions between the methoxy substituents. These results indicate that the dyes based on helical bidipyrrin zinc complexes with tunable structures and photophysical properties may be developed simply by modulating the terminal alpha-substituents.
23.	Landström, Anton, et al. (author) Fluorescent silica MCM-41 nanoparticles based on flavonoids: Direct post-doping encapsulation and spectral characterization 2021 In: Dyes and pigments. - : Elsevier. - 0143-7208 .- 1873-3743. ; 185, Part A Journal article (peer-reviewed)abstract Flavones and flavonols are naturally-occurring organic molecules with interesting biological, chemical and photophysical properties. In recent years their interaction with silica surfaces has received increasing attention. In this work, the flavonol 3-hydroxyflavone (3HF) and the flavone 7-hydroxyflavone (7HF) have been encapsulated in MCM-41 mesoporous silica nanoparticles (NP) via a post-doping procedure, and their photophysics characterized by both steady state and time-resolved spectroscopic techniques. Both flavonoid-doped NPs resulted to be highly fluorescent, even after two months of exposure to air at room temperature. UV light irradiation results in a moderate decrease of the fluorescence quantum yield. Complementary UV-Vis and fluorescence experiments of 3HF and 7HF in solutions and TD-DFT calculations to simulate absorption and emission spectra have been carried out in order to better rationalize the exact nature of the emitting species. Whereas for 3HF-doped NPs the tautomer emission in the green predominates, the fluorescence of 7HF-doped NPs is likely to arise from the cationic or the phototautomeric form of the flavonoid. The results show that organic fluorophore-based fluorescent silica NPs can be easily obtained by a post-doping procedure and represent a first step towards the development of a simple strategy for the encapsulation in MCM-41 NPs of flavonoids and other organic molecules.
24.	Ledwon, Przemyslaw, et al. (author) The effect of molecular structure on the properties of quinoxaline-based molecules for OLED applications 2020 In: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 173 Journal article (peer-reviewed)abstract Different donor-acceptor-donor (D-A-D) and donor-pi-bridge-acceptor-pi-bridge-donor (D-pi-A-pi-D) systems based on a quinoxaline acceptor are compared. A significant difference in electrochemical and photophysical properties was found depending on molecular structure. A luminescence shift from 539 rim up to 671 nm was observed upon extension of conjugation length. The studied compounds were tested in fluorescent organic light emitting diodes (OLEDs) demonstrating an external quantum efficiency up to 4.5% for a deep red non-doped device and 7% when doped into an exciplex host device. A quantum-chemical interpretation of the electroluminescence spectra for the fabricated OLEDs was carried out including modelling of excimers and exciplexes.
25.	Li, Jiajia, et al. (author) Phenoxazine-based panchromatic organic sensitizers for dye-sensitized solar cells 2015 In: Dyes and pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 116, s. 58-64 Journal article (peer-reviewed)abstract A series of metal-free organic dyes LJJ101-LJJ103 composed of phenoxazine unit and indolinum carboxyl acid derivative have been synthesized for dye-sensitized solar cells. A systematic investigation has been conducted for the photology and electrochemistry properties of dyes LJJ101-LJJ103. Panchromatic spectra responses for all the three dyes have been obtained and extended to about 800 nm in near-infrared region. Compared to LJJ101, the introduction of thiophene and squaraine unit causes a red-shift absorption response for LJJ102 and LJJ103, respectively. When applied in dye-sensitized solar cells under AM 1.5 illumination, the device sensitized by LJJ103 yields the best conversion efficiency of 5.1% with a short-circuit photocurrent density of 13.7 mA/cm(2), an open-circuit photovoltage of 502 mV and a fill factor of 74.0%.

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