969 results on '"Phenoxazine"'
Search Results
102. Delayed Fluorescence, Room Temperature Phosphorescence, and Mechanofluorochromic Naphthalimides: Differential Imaging of Normoxia and Hypoxia Live Cancer Cells
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Pakkirisamy Thilagar, Satyam Jena, Gulista Bano, and Pandi Dhanalakshmi
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Luminescence ,Photoluminescence ,Quantum yield ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Fluorescence ,chemistry.chemical_compound ,Neoplasms ,0103 physical sciences ,Materials Chemistry ,Humans ,Physical and Theoretical Chemistry ,Hypoxia ,010304 chemical physics ,Chemistry ,Carbazole ,Temperature ,Diphenylamine ,Acceptor ,0104 chemical sciences ,Surfaces, Coatings and Films ,Naphthalimides ,Phosphorescence ,Phenoxazine - Abstract
We study the effect of molecular conformation on the electronic coupling between the donor amines and acceptor 1,8-naphthalimide (NPI) in a series of D-A systems 1-4 (A = NPI; D = phenothiazine, phenoxazine, carbazole, diphenylamine, respectively, for 1, 2, 3, and 4). Weakly coupled systems show dual emission in the solution state, while strongly coupled systems show single emission bands. The energy of transitions and photoluminescence (PL) quantum yield are sensitive to the molecular conformation and donor strength. These compounds show delayed emission in the solutions and aggregated state and phosphorescence in the solid state. Compounds 3 and 4 with weak donors exhibit intermolecular slipped π···π interactions in the solid state and consequently exhibit dual (intra- and inter-) phosphorescence at low temperature. Steady state and time-resolved PL studies at variable temperature together with computational and crystal structure analysis were used to rationalize the optical properties of these compounds. The delayed emission of these compounds is sensitive to molecular oxygen; accordingly, these molecules are utilized for differential imaging of normoxia and hypoxia cancer cells.
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- 2020
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103. Synthesis of novel organocatalysed phenoxazine for atom transfer radical polymerization of methyl methacrylate monomer
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Michal Michalak, Thu Vo Hoang, Ha Tran Nguyen, Huong Le, and Nhung Thanh Thi Truong
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chemistry.chemical_compound ,Monomer ,Chemistry ,Atom-transfer radical-polymerization ,Polymer chemistry ,Methyl methacrylate ,Phenoxazine - Published
- 2020
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104. Tetradentate Gold(III) Complexes as Thermally Activated Delayed Fluorescence (TADF) Emitters: Microwave‐Assisted Synthesis and High‐Performance OLEDs with Long Operational Lifetime
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Dongling Zhou, Wai-Pong To, Lili Du, Gang Cheng, Glenna So Ming Tong, David Lee Phillips, and Chi-Ming Che
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Materials science ,Substituent ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Microwave assisted ,Catalysis ,chemistry.chemical_compound ,Gold iii ,OLED ,Thermal stability ,Chelation ,010405 organic chemistry ,Ligand ,business.industry ,Diphenylamine ,General Chemistry ,General Medicine ,Fluorescence ,0104 chemical sciences ,chemistry ,Optoelectronics ,business ,Luminescence ,Phenoxazine ,Microwave - Abstract
Structurally robust tetradentate gold(III)-emitters have potent material applications but are rare and unprecedented for those displaying thermally activated delayed fluorescence (TADF). Herein, a novel synthetic route leading to the preparation of highly emissive, charge-neutral tetradentate [C^C^N^C] gold(III) complexes with 5-5-6-membered chelate rings has been developed through microwave-assisted C-H bond activation. These complexes show high thermal stability and with emission origin (3 IL, 3 ILCT, and TADF) tuned by varying the substituents of the C^C^N^C ligand. With phenoxazine/diphenylamine substituent, we prepared the first tetradentate gold(III) complexes that are TADF emitters with emission quantum yields of up to 94 % and emission lifetimes of down to 0.62 μs in deoxygenated toluene. These tetradentate AuIII TADF emitters showed good performance in vacuum-deposited OLEDs with maximum EQEs of up to 25 % and LT95 of up to 5280 h at 100 cd m-2 .
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- 2020
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105. Achieving Submicrosecond Thermally Activated Delayed Fluorescence Lifetime and Highly Efficient Electroluminescence by Fine-Tuning of the Phenoxazine–Pyrimidine Structure
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Rokas Skaisgiris, Jelena Dodonova, Sigitas Tumkevicius, Saulius Juršėnas, Karolis Kazlauskas, Tomas Serevičius, Dovydas Banevičius, and Laimis Jagintavičius
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TADF ,pyrimidine ,Materials science ,02 engineering and technology ,Electroluminescence ,010402 general chemistry ,01 natural sciences ,phenoxazine ,chemistry.chemical_compound ,OLED ,Molecule ,General Materials Science ,Diode ,business.industry ,OLEDs ,fluorescence ,TADF lifetime ,nonradiative decay ,EQE ,021001 nanoscience & nanotechnology ,Fluorescence ,0104 chemical sciences ,Intersystem crossing ,chemistry ,rISC ,Optoelectronics ,Quantum efficiency ,0210 nano-technology ,business ,Phenoxazine ,conformational disorder ,Research Article - Abstract
Thermally activated delayed fluorescence (TADF) materials, combining high fluorescence quantum efficiency and short delayed emission lifetime, are highly desirable for application in organic light-emitting diodes (OLEDs) with negligible external quantum efficiency (EQE) roll-off. Here, we present the pathway for shortening the TADF lifetime of highly emissive 4,6-bis[4-(10-phenoxazinyl)phenyl]pyrimidine derivatives. Tiny manipulation of the molecular structure with methyl groups was applied to tune the singlet–triplet energy-level scheme and the corresponding coupling strengths, enabling the boost of the reverse intersystem crossing (rISC) rate (from 0.7 to 6.5) × 106 s–1 and shorten the TADF lifetime down to only 800 ns in toluene solutions. An almost identical TADF lifetime of roughly 860 ns was attained also in solid films for the compound with the most rapid TADF decay in toluene despite the presence of inevitable conformational disorder. Concomitantly, the boost of fluorescence quantum efficiency to near unity was achieved in solid films due to the weakened nonradiative decay. Exceptional EQE peak values of 26.3–29.1% together with adjustable emission wavelength in the range of 502–536 nm were achieved in TADF OLEDs. Reduction of EQE roll-off was demonstrated by lowering the TADF lifetime.
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- 2020
106. Kinetics of N-substituted phenothiazines and N-substituted phenoxazines oxidation catalyzed by fungal laccases
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Tetianec Lidija and Kulys Juozas
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laccase ,kinetics ,phenoxazine ,phenothiazine ,oxygen ,bimolecular rate constant ,redox potential ,Biology (General) ,QH301-705.5 - Published
- 2009
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107. Highly efficient candlelight organic light-emitting diode with a very low color temperature
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Shahnawaz Shahnawaz, Iram Siddiqui, Mangey Ram Nagar, Abhijeet Choudhury, Jin-Tin Lin, Dovydas Blazevicius, Gintare Krucaite, Saulius Grigalevicius, Jwo-Huei Jou, and MDPI AG (Basel, Switzerland)
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amorphous layer ,Pharmaceutical Science ,Organic chemistry ,host derivative ,Article ,Analytical Chemistry ,light emitting diode ,phenoxazine ,QD241-441 ,Chemistry (miscellaneous) ,efficiency ,Drug Discovery ,Molecular Medicine ,Physical and Theoretical Chemistry - Abstract
Low color temperature candlelight organic light-emitting diodes (LEDs) are human and environmentally friendly because of the absence of blue emission that might suppress at night the secretion of melatonin and damage retina upon long exposure. Herein, we demonstrated a lighting device incorporating a phenoxazine-based host material, 3,3-bis(phenoxazin-10-ylmethyl)oxetane (BPMO), with the use of orange-red and yellow phosphorescent dyes to mimic candlelight. The resultant BPMO-based simple structured candlelight organic LED device permitted a maximum exposure limit of 57,700 s, much longer than did a candle (2750 s) or an incandescent bulb (1100 s) at 100 lx. The resulting device showed a color temperature of 1690 K, which is significantly much lower than that of oil lamps (1800 K), candles (1900 K), or incandescent bulbs (2500 K). The device showed a melatonin suppression sensitivity of 1.33%, upon exposure for 1.5 h at night, which is 66% and 88% less than the candle and incandescent bulb, respectively. Its maximum power efficacy is 23.1 lm/W, current efficacy 22.4 cd/A, and external quantum efficiency 10.2%, all much higher than the CBP-based devices. These results encourage a scalable synthesis of novel host materials to design and manufacture high-efficiency candlelight organic LEDs.
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- 2021
108. Novel Nile Blue Analogue Stains Yeast Vacuolar Membrane, Endoplasmic Reticulum and Lipid Droplets, Inducing Cell Death through Vacuole Membrane Permeabilization
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João C. C. Ferreira, Carla D. Lopes, Ana Preto, Maria João Sousa, Maria S. T. Gonçalves, and Universidade do Minho
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Microbiology (medical) ,Programmed cell death ,QH301-705.5 ,Plant Science ,Vacuole ,01 natural sciences ,vacuole/lysosome membrane permeabilization ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Lipid droplet ,Biology (General) ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,benzo[a]phenoxazine derivative ,0303 health sciences ,Ciências Naturais::Ciências Biológicas ,Science & Technology ,vacuole ,lysosome membrane permeabilization ,010405 organic chemistry ,Endoplasmic reticulum ,cell death mechanism ,yeast as a eukaryotic cell model ,Nile blue ,3. Good health ,0104 chemical sciences ,Cell biology ,Cytosol ,chemistry ,Nile Blue analogue ,Phenoxazine ,Intracellular - Abstract
Phenoxazine derivatives such as Nile Blue analogues are assumed to be increasingly relevant in cell biology due to their fluorescence staining capabilities and antifungal and anticancer activities. However, the mechanisms underlying their effects remain poorly elucidated. Using S. cerevisiae as a eukaryotic model, we found that BaP1, a novel 5- and 9-N-substituted benzo[a]phenoxazine synthesized in our laboratory, when used in low concentrations, accumulates and stains the vacuolar membrane and the endoplasmic reticulum. In contrast, at higher concentrations, BaP1 stains lipid droplets and induces a regulated cell death process mediated by vacuolar membrane permeabilization. BaP1 also induced mitochondrial fragmentation and depolarization but did not lead to ROS accumulation, changes in intracellular Ca2+, or loss of plasma membrane integrity. Additionally, our results show that the cell death process is dependent on the vacuolar protease Pep4p and that the vacuole permeabilization results in its translocation from the vacuole to the cytosol. In addition, although nucleic acids are commonly described as targets of benzo[a]phenoxazines, we did not find any alterations at the DNA level. Our observations highlight BaP1 as a promising molecule for pharmacological application, using vacuole membrane permeabilization as a targeted approach., Joao C. C. Ferreira (SFRH/BD/133207/2017) acknowledges a doctoral grant (from the Fundacao para a Ciencia e Tecnologia) FCT. This work was supported by the strategic programs UIDB/04050/2020, UID/QUI/0686/2016 and UID/QUI/0686/2019 funded by national funds through the FCT I.P. Thanks are due to FCT for financial support to the Portuguese NMR network (PTNMR), Bruker Avance III 400-Univ. Minho. This work was also funded by FCT within the scope of the project PTDC/QUIQIN/28662/2017.
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- 2021
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109. In Situ Synthesis of Phenoxazine Dyes in Water: A Cutting-Edge Strategy to 'Turn-On' Fluorogenic and Chromogenic Detection of Nitric Oxide
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Sylvain Debieu, Sébastien Jenni, Myriam Laly, Anthony Romieu, Garance Dejouy, and Kévin Renault
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chemistry.chemical_compound ,chemistry ,Cascade reaction ,Chromogenic ,Nitrosonium ,Ether ,Triphenylphosphine ,Combinatorial chemistry ,Fluorescence ,Phenoxazine ,Nitrosonium tetrafluoroborate - Abstract
The synthesis of phenoxazine dyes was revisited in order to access these fluorescent N,O-heterocycles under mild conditions. The combined sequential use of nitrosonium tetrafluoroborate (NOBF4) and triphenylphosphine enables the facile conversion of bis(3-dimethylaminophenyl) ether into the methyl analog of popular laser dye oxazine 1. The ability of nitrosonium cation (NO+) to initiate the domino reaction resulting in pi-conjugated phenoxazine molecules under neutral conditions, then led us to explore the feasibility of expanding it in aqueous media. Thus, we explored the use of reactive signaling molecule nitric oxide (NO) as a biological trigger of phenoxazine synthesis in water. The implementation of a robust analytical methodology based on fluorescence assays and HPLC-fluorescence/-MS analyses, have enabled us to demonstrate the viability of this novel fluorogenic reaction-based process to selectively yield an intense "OFF-ON" response in the near-infrared (NIR-I) spectral region. This study is an important step towards the popularization of the concept of "covalent-assembly" in the fields of optical sensing, bioimaging and molecular theranostics.
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- 2021
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110. Synthesis of novel phenothiazine, phenoxazine and carbazole derivatives via Suzuki-Miyaura reaction.
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Nhari, Laila M., Bifari, Elham N., Al-Marhabi, Aisha R., Al-Zahrani, Fatimah A.M., Al-Ghamdi, Huda A., Al-Ghamdi, Sameera N., Asiri, Abdullah M., and El-Shishtawy, Reda M.
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SUZUKI reaction , *CARBAZOLE derivatives , *PHENOTHIAZINE , *ELECTRON donors , *BORONIC acids , *CARBAZOLE - Abstract
• The Suzuki-Miyaura reaction furnished 15 new key electrons donors-based PTZ, POZ, CZ, and TPA in good to excellent yields. • The C C coupling reaction depended on the electronic nature of bother couplers, the donor moiety and the aryl boronic acid component. • Compared to heterocyclic-based donors, PTZ was the best to undergo efficient C C coupling. • The synthesized electron donors containing carbaldehyde groups would pave further success in constructing versatile π-conjugated systems. The Suzuki-Miyaura cross-coupling reaction was utilized for the synthesis of 15 new compounds containing phenothiazine (PTZ), phenoxazine (POZ), carbazole (Cz), and triphenylamine (TPA) as good electron donors. The synthesized compounds were furnished with active carbaldehyde groups and decorated with phenyl, thienyl, furyl, imidazolyl, or oxadiazolyl units linked to either one or two sides of the central cores (PTZ, POZ, and Cz). A simple catalytic systems based on Pd(PPh 3) 4 were tried and the results showed better C C coupling efficiencies of the electron-rich phenothiazine halides over phenoxazine and carbazole analogues when coupled with either electron-rich or electron-deficient boronic acid precursors. Besides, the coupling process of substituted phenothiazine halides with different boronic acids precursors, based on phenyl (Ph), furyl (Fu) and thienyl (Th) units, was found to be dependent on the electronic nature of both PTZ-halide and boronic acid precursors. Coupling efficiency of Ph, Fu, and Th rings with the skeleton of imidazolyl-PTZ-Br coupler to bring up compounds 6a-c showed the order: Ph>Fu>Th (with the yield of 86, 85, and 80%, respectively), while coupling efficiency of the brominated PTZ-oxadiazolyl-phenyl coupler with different arylboronic acids showed the order of Th>Ph>Fu to obtain compounds 8a-c. Additionally, the TPA derivative 11b was obtained with an excellent yield of 96% using Pd(PPh 3) 4. The successful activation of the synthesized derivatives with carbaldehyde groups and the integration of different spacers made them substantially suitable to be exploited as promising intermediates for the future synthesis of versatile π-conjugated systems. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2023
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111. Dibenzo [a, g] corannulene-phenoxazine dyads: Facile synthesis and optoelectronic properties.
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Yu, Yuming, Yang, Rongrong, Lan, Wei, Wang, Xin, Wang, Yaqiong, Gao, Ming, Xu, Xin, Shen, Lei, Wang, Dou, Wang, Duozhi, Abdukader, Ablimit, Cai, Xiaodong, Liang, Zhenjiang, and Tan, Hui
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INTRAMOLECULAR charge transfer , *LUMINESCENCE spectroscopy , *POLYCYCLIC aromatic hydrocarbons , *ELECTROCHROMIC devices , *DYADS , *REACTIVE oxygen species , *CORANNULENE - Abstract
Corannulene has a peculiar topology, while phenoxazine (PXZ) features extraordinary optoelectronic properties. In this study, two dibenzo [a, g] corannulene-phenoxazine dyads, BBC-C-PXZ and BBC-N-PXZ , connected via C–C and C–N bonds, respectively, were successfully prepared using PXZ as an electron donor and dibenzo [a, g] corannulene (BBC) as an electron acceptor. Photoelectrical properties of the compounds were studied using UV–vis absorption, luminescence spectroscopy, electrochemical tests and theoretical calculations. Both dyads showed Curve-Twist intramolecular charge transfer (C-TICT) in solution and aggregated state, which could be explained by the BBC-C-PXZ concave-convex crystal packing mode. They further exhibited moderate to good singlet oxygen quantum yields, the BBC-N-PXZ was 42.3% in toluene and BBC-C-PXZ was only 14.3% in n-hexane. The BBC-N-PXZ (connected by the C–N bond) exhibited contrasting reversible and anti-fatigue "turn-on" mechanochromic behavior, which displayed a blue shift under external stimulation, while the BBC-C-PXZ (linked by the C–C bond) did not exhibit this phenomenon. Analyses of the D-A (donor-acceptor) dyad systems revealed that the introduction of curved polycyclic aromatic hydrocarbons and diversified linkage positions result in unique optical and electrical properties of materials, and it provides new advances and breakthroughs in the design of organic electronic materials. • Novel multifunctional molecules based on the curved polycyclic aromatic hydrocarbon. • Curve-twisted intramolecular charge transfer C-TICT. • Good singlet oxygen quantum yields. • Stable and repeatable mechanical force response. [ABSTRACT FROM AUTHOR]
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- 2023
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112. D-D-π-A-π-A-based quinoxaline dyes incorporating phenothiazine, phenoxazine and carbazole as electron donors: Synthesis, photophysical, electrochemical, and computational investigation.
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Al-Marhabi, Aisha R., El-Shishtawy, Reda M., Bouzzine, Si Mohamed, Hamidi, Mohamed, Al-Ghamdi, Huda A., and Al-Footy, Khalid O.
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CARBAZOLE , *ELECTRON donors , *ORGANIC dyes , *PHENOTHIAZINE , *DYE-sensitized solar cells , *QUINOXALINES , *DENSITY functional theory - Abstract
[Display omitted] • Novel organic dyes bearing 2,3-diphenylquioxaline as an auxiliary acceptor and thiophene as π-spacers were efficiently synthesized. • PTZ, POZ, and CZ, the main electron donors linked with the tolyl unit as an auxiliary donor, constructed QX-D1 , QX-D2 , and QX-D3 , respectively. • The absorption spectra showed a redshift of the ICT band in the order QX-D2 > QX-D3 > QX-D1. • The overall data suggest that these dyes are suitable photosensitizers for DSSCs. Three novel D-D-π-A-π-A types of metal-free organic dyes, QX-D1 , QX-D2 , and QX-D3 , were designed and synthesized in excellent yields (94–99 %). An auxiliary acceptor of 2,3-diphenylquinoxaline was incorporated between two units of thiophene as π-spacers so that one ring is connected with cyanoacrylic acid as an anchoring electron acceptor, and the other one lies between the quinoxaline moiety and an electron donor to build the π-A-π-A part. The other D-D part of the dye skeleton was made using donors-based phenothiazine (PTZ), phenoxazine (POZ), and carbazole (CZ) containing a tolyl moiety as an auxiliary donor. For this purpose, an efficient multistep synthetic approach for the synthesis of the dyes was investigated. The chemical structures of all compounds were confirmed by spectral data (FTIR, 1H NMR, 13C NMR, and HRMS). The QX-D1 , QX-D2 , and QX-D3 dyes showed ICT bands in THF solution at 511, 542, and 526 nm, respectively and high molar absorptivity of 23434, 29825, and 23214 M−1 cm−1, respectively. Among the donor, QX-D2- based POZ revealed bathochromic and hyperchromic shifts in the absorption due to the influence of the oxygen atom in POZ compared with the sulfur atom and non in PTZ and CZ, respectively. The cyclic voltammetry data revealed that the HOMO and LUMO energy levels for QX-D1, QX-D2, and QX-D3 dyes were found to be (−5.07, −2.86 eV), (−4.90, −2.72 eV), and (−5.13, −3.04 eV), respectively. Furthermore, the density functional theory (DFT) and time-dependent TD-DFT at the B3LYP/6-31G(d) level were investigated to shed light on the bridged effect on geometric and TD-BH and H/6-31G(d) for optoelectronic properties. The binding energies of the complex dye@TiO2 cluster have also been explored. A good agreement between theoretical and experimental data was obtained. Thus, the dyes successfully achieved the desired outcomes, qualifying them for later use in photovoltaic applications such as sensitizers in dye-sensitized solar cells (DSSCs). [ABSTRACT FROM AUTHOR]
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- 2023
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113. The crystal structure of 10-(3,5-di(pyridin-4-yl)phenyl)-10H-phenoxazine dihydrate, C28H23N3O3
- Author
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Zhuqing Yang and Meng Hou
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Crystallography ,Chemistry ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,QD901-999 ,General Materials Science ,0210 nano-technology ,Phenoxazine - Abstract
C28H23N3O3, orthorhombic, Pna21 (no. 33), a = 29.0466(11) Å, b = 5.2448(3) Å, c = 14.4825(7) Å, V = 2206.32(19) Å3, Z = 4, R gt (F) = 0.0511, wR ref (F 2) = 0.1341, T = 100.00(10) K.
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- 2021
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114. Theoretical study of metal-free organic dyes based on different configurations for efficient dye-sensitized solar cells.
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Ferdowsi, Parnian and Mokhtari, Javad
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ORGANIC dyes , *SOLAR cells , *ELECTRON donors , *THIOPHENES , *DENSITY functional theory - Abstract
Considering different solar dyes configuration, four novel metal-free organic dyes based on phenoxazine as electron donor, thiophene and cyanovinylene linkers as the [ABSTRACT FROM AUTHOR]
- Published
- 2016
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115. Methylene versus carbonyl bridge in the structure of new tubulin polymerization inhibitors with tricyclic A-rings.
- Author
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Moise, Iuliana-Monica, Bîcu, Elena, Dubois, Joëlle, Farce, Amaury, Rigo, Benoît, and Ghinet, Alina
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TUBULINS , *METHYLENE group , *POLYMERIZATION , *CANCER cells , *CELL lines - Abstract
The phenothiazine group has been identified as a suitable A ring in the structure of tubulin polymerization inhibitors. In our search to identify more potent inhibitors, a study of different isosteric tricyclic groups as new potential A rings was first realized and permitted to identify 1-azaphenothiazine and iminodibenzyl as favorable modulations providing compounds with improved activity against tubulin. An investigation of the methylene group as the connector between the A and B rings revealed that the “CH 2 ” bridge was tolerated, improving the biological potency when the A unit was of phenothiazine, 1-azaphenothiazine or iminodibenzyl type. Molecules 6 – 8 and 12 showed increased biological activity in comparison to parent phenstatin 2 on COLO 205 colon cancer cell line. The most antineoplastic agent in the current study was phenothiazine 5 displaying a GI 50 of 25 nM against the melanoma MDA-MB-435 cell line. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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116. Insights into the effect of donor-acceptor strength modulation on physical properties of phenoxazine-based imine dyes.
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Damaceanu, Mariana-Dana, Constantin, Catalin-Paul, and Marin, Luminita
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OXAZINES , *IMINES , *DYES & dyeing , *ELECTRON donor-acceptor complexes , *PROPERTIES of matter , *ELECTROCHEMISTRY - Abstract
Novel phenoxazine-based imine dyes having a donor-acceptor-donor (D-A-D) topology were designed, synthesized and thoroughly investigated with regard to their thermotropic, photo-physical and electrochemical behaviour. The hexyl-substituted phenoxazine was selected as donor moiety and diphenyl-1,3,4-oxadiazole or fluorene-containing moieties were employed as electron-acceptor groups, being connected via the imine bond. The supramolecular architecture from solution and in molten state has been investigated by wide angle X-ray diffraction, differential scanning calorimetry and polarized light microscopy. The imines formed distinctive thermotropic mesophases in close relationship with their structure. The molecular rigid rods of the synthesized dyes formed supramolecular layered structures that further combine into worm-like anisotropic primary particles in the condensed phase with a strong impact on the physical properties of the dyes. UV–Vis absorption, photoluminescence, and electrochemical measurements proved the ability of the imine bond to facilitate the intramolecular charge-transfer transition from the donor to the acceptor units. The dyes showed an inverted solvatochromic behaviour, the fluorescence emission being highly sensitive to solvent polarity, yielding blue to green and even orange light in different organic solvents. A change in the relative intensity of the photoluminescence with the excitation wavelength of those phenoxazine-based imine dyes has been detected. The fluorescence quantum yield in solution reached up to 63%, whilst in film state it significantly dropped. By incorporating segments with different electron-accepting capability, the HOMO–LUMO energy gap was modulated from 1.88 to 1.92 eV. The electrochemical features demonstrate that p- and n- type doping to the conducting state of these phenoxazine-based imine materials is achievable. As a consequence of interesting physical properties encountered in these dyes, applications in optoelectronic devices are foreseen. [ABSTRACT FROM AUTHOR]
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- 2016
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117. Mechanistic insight into thermal 1,3- and 1,5-sulfonyl migrations of N-arenesulfonylphenothiazines and N-arenesulfonylphenoxazines.
- Author
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Wang, Jiandong, Son, Kwon-Il, and Xu, Jiaxi
- Abstract
The substrate scope and mechanistic insight of the thermal-induced 1,3- and 1,5-sulfonyl migration reactions of various sulfonamides have been investigated. The results indicate that both N-arenesulfonylphenothiazines and N-arenesulfonylphenoxazines can undergo 1,3- and 1,5-sulfonyl migrations to afford the corresponding aryl sulfone derivatives in modest regioselectivities and yields under thermal and neutral conditions. The homolytic cleavage of the sulfonamide bond and intermolecular radical-radical coupling reaction mechanism was proposed for the 1,3- and 1,5-sulfonyl migrations on the basis of intercrossing and competitive capture experiments. Graphical abstract: [ABSTRACT FROM AUTHOR]
- Published
- 2016
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118. Synthesis and structure of new alkynyl derivatives of phenothiazine and phenoxazine.
- Author
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Onoabedje, Efeturi A., Okoro, Uchechukwu C., Sarkar, Amitabha, and Knight, David W.
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PHENOTHIAZINE , *ACETONITRILE , *CARBONYL group , *ALKYNES , *CONDENSATION - Abstract
New alkynyl derivatives of phenothiazine and phenoxazine were obtained via Sonogashira cross-coupling reactions. This was achieved by first synthesizing the intermediates 6-chloro-5H-benzo[a] phenothiazin-5-one, 6-chloro-5H-benzo[a]phenoxazin-5-one and 6-chloro-5H-naphtho[2,1-b]pyrido[2,3-e][1,4]oxazin-5-one by anhydrous base-catalyzed condensations between 2,3-dichloro-1,4-naphthoqui none and 2-aminothiophenol, 2-aminophenol and 2-aminopyridinol, respectively. The cross-couplings of these electron-rich chlorophenothiazine and chlorophenoxazine intermediates with terminal alkynes, employing 4 mol% Pd and 7 mol% XPhos in the presence of base in acetonitrile at 80°C, afforded the highly colored alkynylated derivatives in good yields. These reaction conditions allowed the incorporation of both unprotected N-H and carbonyl groups. Structural assignments were established by spectroscopic (UV, IR, 1H and 13Cnmr), ms and elemental analytical data. [ABSTRACT FROM AUTHOR]
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- 2016
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119. Kesterite Inorganic-Organic Heterojunction for Solution Processable Solar Cells.
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Data, P., Bialoglowski, M., Lyzwa, K., Bacewicz, R., Dluzewski, P., Lapkowski, M., Gregorkiewicz, T., Podsiadlo, S., and Monkman, A.P.
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SOLAR cells , *KESTERITE , *HETEROJUNCTIONS , *SOLUTION (Chemistry) , *SEMICONDUCTORS , *AZINES - Abstract
New synthesis of solution processable kesterite and kesterite-phenoxazine nanopowders were presented. The direct band-gap semiconductor Cu 2 ZnSnS 4 has attracted the attention of many due to its large absorption coefficient (α > 10 4 cm −1 ) and (optical) band-gap energy close to the optimal value for solar light conversion (1.4–1.6 eV). The presence of a kesterite nanocrystal structure has been investigated and confirmed by (HR)TEM, X-ray powder diffraction, EDX and EXAFS measurements. Low-temperature photoluminescence (PL) measurements indicate the absence of PL in the Cu 2 ZnSnS 4 nanocrystals. Electrochemical studies helped to prove that an inorganic-organic heterojunction of nanokesterite-phenoxazine was obtained. Device studies showed a two fold improvement in efficiency upon addition of a kesterite or phenoxazines-kesterite layer. [ABSTRACT FROM AUTHOR]
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- 2016
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120. One-Pot Transformation of Hypervalent Iodines into Diversified Phenoxazine Analogues as Promising Photocatalysts
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Liangsen Huang, Shulin Jiang, Jiajia Cheng, and Hongxiang Xiao
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Chemistry ,Aryl ,Organic Chemistry ,Radical polymerization ,Heteroatom ,Hypervalent molecule ,Substrate (chemistry) ,Iodides ,Combinatorial chemistry ,Redox ,Catalysis ,Polymerization ,chemistry.chemical_compound ,Oxazines ,Phenoxazine - Abstract
A facile and efficient quinoline-fused 4H-benzo[b][1,4]oxazine has been successfully fabricated through an oxidative O-arylation, Pd-catalyzed double N-arylation of 4-hydroxyquinoline derivatives and trivalent aryl iodides. Diversified fused heterocycles could be easily constructed in overall high isolated yields with great substrate scope. The afforded heteroatom-"doped" phenoxazine 3 demonstrated high molar absorptivities and excellent stability and redox reversibility. These phenoxazine analogues therefore could be utilized as promising catalysts in the photoredox catalyzed perfluoroalkylation of heteroarenes and photopromoted radical polymerization (OATRP).
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- 2021
121. Double Heterohelicenes Composed of Benzo[b]- and Dibenzo[b,i]phenoxazine: A Comprehensive Comparison of Their Electronic and Chiroptical Properties
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Hideki Fujiwara, Mayu Takino, Daisuke Sakamaki, Kazuo Tanaka, Katsuki Tanaka, Hiroshi Yamamoto, Shunya Tanaka, Daichi Hirobe, Takashi Hirose, and Masayuki Gon
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Materials science ,Optical properties ,Crystal structure ,Heteroatom ,Molecular electronics ,Ring (chemistry) ,Inherent chirality ,Helicity ,Deformation ,Dipole ,Crystallography ,chemistry.chemical_compound ,chemistry ,Helicene ,General Materials Science ,Physical and Theoretical Chemistry ,Chirality ,Luminescence ,Magnetic dipole ,Molecular structure ,Phenoxazine - Abstract
application/pdf, The Journal of Physical Chemistry. 2021, 12 (38), P.9283-9292
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- 2021
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122. Phenoxazine nucleoside derivatives with a multiple activity against RNA and DNA viruses
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Andrey V. Aralov, Anna A. Shtro, Elena S. Matyugina, Graciela Andrei, Viktor P. Volok, Yulia V. Nikolaeva, Dmitry I. Osolodkin, Aydar Ishmukhametov, Vladimir A. Korshun, Liubov I. Kozlovskaya, Robert Snoeck, Artjom V. Jegorov, Evgeny S. Belyaev, and Alexey A. Chistov
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RNA viruses ,Microbial Sensitivity Tests ,medicine.disease_cause ,Virus Replication ,01 natural sciences ,Antiviral Agents ,Article ,Madin Darby Canine Kidney Cells ,03 medical and health sciences ,chemistry.chemical_compound ,Structure-Activity Relationship ,Dogs ,Cell Line, Tumor ,Drug Discovery ,Chlorocebus aethiops ,Oxazines ,medicine ,Structure–activity relationship ,Animals ,Humans ,Phenoxazine ,Vero Cells ,030304 developmental biology ,Coronavirus ,Pharmacology ,0303 health sciences ,Nucleoside analogue ,Molecular Structure ,010405 organic chemistry ,Chemistry ,SARS-CoV-2 ,Organic Chemistry ,DNA Viruses ,RNA ,Nucleosides ,General Medicine ,Antivirals ,Virology ,0104 chemical sciences ,Viral replication ,Nucleoside analogs ,DNA viruses ,Nucleoside ,DNA ,medicine.drug - Abstract
Emerging and re-emerging viruses periodically cause outbreaks and epidemics all over the world, eventually leading to global events such as the current pandemic of the novel SARS-CoV-2 coronavirus infection COVID-19. Therefore, an urgent need for novel antivirals is crystal clear. Here we present the synthesis and evaluation of an antiviral activity of phenoxazine-based nucleoside analogs divided into three groups: (1) 8-alkoxy-substituted, (2) acyclic, and (3) carbocyclic. The antiviral activity was assessed against a structurally and phylogenetically diverse panel of RNA and DNA viruses from 25 species. Four compounds (11a-c, 12c) inhibited 4 DNA/RNA viruses with EC50 ≤ 20 μM. Toxicity of the compounds for the cell lines used for virus cultivation was negligible in most cases. In addition, previously reported and newly synthesized phenoxazine derivatives were evaluated against SARS-CoV-2, and some of them showed promising inhibition of reproduction with EC50 values in low micromolar range, although accompanied by commensurate cytotoxicity., Graphical abstract Image 1
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- 2021
123. Phenoxazine as a high-voltage p-type redox center for organic battery cathode materials: small structural reorganization for faster charging and narrow operating voltage
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Soo Young Park, Illia E. Serdiuk, Dong Joo Min, Kyunam Lee, Ji Eon Kwon, Giyun Kwon, and Kisuk Kang
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Materials science ,Renewable Energy, Sustainability and the Environment ,Composite number ,Organic radical battery ,Electrochemistry ,Pollution ,Redox ,Cathode ,law.invention ,chemistry.chemical_compound ,Nuclear Energy and Engineering ,Transition metal ,Chemical engineering ,chemistry ,law ,Environmental Chemistry ,Phenoxazine ,Voltage - Abstract
Although organic p-type cathode materials with high redox potential (>3.5 V vs. Li/Li+) are sustainable alternatives to transition metal oxide cathodes for lithium-ion batteries, only a limited number of these materials have been investigated to date. Therefore, the discovery of new p-type redox centers is essential for further development of successful organic cathodes. Herein, we report phenoxazine (PXZ) as a new p-type redox center for high-voltage cathode materials. Negligible structural reorganization of this PXZ center facilitates a kinetically faster electrochemical pathway, leading to a narrow voltage plateau, full utilization of the capacity, and superior rate capability in a new PXZ-based cathode material, PXZ trimer (3PXZ). The 3PXZ cathode delivered a specific capacity of 112 mA h g−1 at 1C with a high average discharge voltage of 3.7 V vs. Li/Li+ in a Li-organic cell; moreover, even at a high rate of 20C, 73% capacity retention (76 mA h g−1) was achieved. In addition, a 3PXZ composite with mesoporous carbon CMK-3 exhibited a capacity of 100 mA h g−1 with high stability, losing only 0.044% capacity per cycle over 500 cycles at 5C. As 3PXZ outperforms most reported p-type cathodes in terms of both rate capability and stability, we suggest the adoption of the PXZ unit as a novel and promising redox center for high-performance and sustainable energy storage systems.
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- 2020
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124. Molecular engineering of dendritic luminogens with thermally activated delayed fluorescence and aggregation-induced emission characteristics for efficient solution-processed non-doped OLEDs
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Hefang Ji, Kamran Hasrat, Fulong Ma, Dongdong Zhang, Zhengjian Qi, and Xinxin Zhao
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Materials science ,business.industry ,General Chemistry ,Molecular configuration ,Fluorescence ,Acceptor ,Molecular engineering ,chemistry.chemical_compound ,Intersystem crossing ,chemistry ,Materials Chemistry ,OLED ,Optoelectronics ,business ,Luminescence ,Phenoxazine - Abstract
Endowing thermally activated delayed fluorescence (TADF) emitters with aggregation-induced emission (AIE) characteristics and a fine film-forming ability is significant for realizing efficient solution-processed non-doped organic light-emitting diodes (OLEDs). Herein, a class of AIE-active TADF emitters adopting phenyl ketone as an acceptor and 9,9-diphenyl-9,10-dihydroacridine (or 9,9-dimethyl-9,10-dihydroacridine and phenoxazine) as a donor are exploited. The suppressed intermolecular packing derived from the highly twisted molecular configuration and multiple transition channels induce improved luminescence efficiency and more efficient reverse intersystem crossing (RISC) simultaneously in the solid state. Solution-processed non-doped and doped devices with the maximum external quantum efficiencies (EQEs) of 12.1% and 17.6%, respectively, are obtained when employing the dendritic luminogens of 3PXZ-BPCTPA as the emitter, which are better than the reference non-dendritic luminogens of PXZ-BPCTPA. This work thus provides an approach for designing dendritic luminogens with TADF and AIE features as promising candidates for high-performance solution-processed OLEDs.
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- 2020
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125. Methoxy substituents activated carbazole-based boron dimesityl TADF emitters
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Deng-Gao Chen, Meng-Chi Chen, Chun Ying Huang, Chun-Sing Lee, Yun Chi, Jia-An Lin, Paramaguru Ganesan, Pi-Tai Chou, Wen-Cheng Chen, and Premkumar Gnanasekaran
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Materials science ,Carbazole ,General Chemistry ,Photochemistry ,Acceptor ,chemistry.chemical_compound ,Intersystem crossing ,chemistry ,Acridine ,Materials Chemistry ,OLED ,Molecule ,Quantum efficiency ,Phenoxazine - Abstract
N-Borylated emitters bearing both boron dimesityl acceptor (Mes)2B and phenoxazine or acridine donors are a class of efficient TADF emitters; however, switching to a carbazole donor nullifies the TADF characteristics. This work is targeted at improving the TADF characteristics of the carbazole based (Mes)2B emitters by introducing up to two methoxy substituents at the carbazoles. We hereby report the design and synthesis of three methoxy substituted carbazoles (Cz-1, Cz-2 and Cz-3) and the corresponding directly N-borylated emitters, CzBM-1, CzBM-2 and CzBM-3. Moreover, a p-phenylene spacer was also introduced between the (Mes)2B unit and carbazole, giving CzPBM-2 and CzPBM-3. As confirmed by the bi-exponential transient decay analyses, all title compounds exhibit prominent TADF character, while the parent molecules CzBM-0 and CzPBM-0 without methoxy groups show no TADF characteristics. The results manifest the importance of the donor strength of substituents and degrees of spatial orthogonality in harnessing the charge transfer properties, minimalizing the S1–T1 energy gap and facilitating the reverse intersystem crossing process. OLED devices with doped CzBM-2 and CzPBM-3 emitters exhibited a maximum external quantum efficiency of 12.5% and 13.3%, respectively, confirming the potential of methoxy substituents in improving their TADF characteristics.
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- 2020
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126. Application of small molecules based on a dithienogermole core in bulk heterojunction organic solar cells and perovskite solar cells
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Surya Prakash Singh, Towhid H. Chowdhury, Ashraful Islam, Vinay Gupta, K. Narayanaswamy, and B. Yadagiri
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Materials science ,Organic solar cell ,Energy conversion efficiency ,Small molecule ,Acceptor ,Polymer solar cell ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Materials Chemistry ,Molecule ,General Materials Science ,Phenoxazine ,Perovskite (structure) - Abstract
We report the synthesis and characterization of a dithienogermole (DTGe) based small molecule, named Ge-PO-2CN, as a donor material for bulk heterojunction (BHJ) organic solar cells (OSCs) and as a hole transport material (HTM) for dopant-free perovskite solar cells (PSCs). This molecule consists with a high planar and electron rich DTGe core as a central core unit and covalently linked with an electron rich phenoxazine group. Finally, it is end-capped with electron-deficient malononitrile group. This molecule was synthesized by a facile synthetic protocol, without using costly and complicated purification techniques. The Ge-PO-2CN compound has a suitable HOMO level with respect to the valence band of the perovskite absorber and the BHJ OSCs. The BHJ OSC device made with Ge-PO-2CN as the donor and PC71BM as an acceptor results in a power conversion efficiency (PCE) of 5.4%. Subsequently, the PSC with an active area of 1.02 cm2 constructed with dopant-free Ge-PO-2CN as an HTM achieved a PCE of up to 11.63%.
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- 2020
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127. High-efficiency thermally activated delayed fluorescence emitters via a high horizontal dipole ratio and controlled dual emission
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Jong-In Hong and Youngnam Lee
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chemistry.chemical_classification ,Materials science ,Photoluminescence ,Analytical chemistry ,General Chemistry ,Electron acceptor ,Fluorescence ,Dipole ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,OLED ,Phenoxazine ,Current density ,Diode - Abstract
Thermally activated delayed fluorescence (TADF) emitters containing 1,5-naphthyridine as an electron acceptor and phenoxazine and phenothiazine as electron donors, namely, 2,6-bis(4-(10H-phenoxazin-10-yl)phenyl)-1,5-naphthyridine (NyDPO) and 2,6-bis(4-(10H-phenothiazin-10-yl)phenyl)-1,5-naphthyridine (NyDPt), were developed. Because of the linear molecular structures, NyDPO and NyDPt showed high horizontal emitting dipole ratios of 81% and 84%, respectively. Furthermore, NyDPO and NyDPt exhibited TADF characteristics with photoluminescence quantum yields (PLQYs) of 79% and 45%, respectively. In particular, NyDPt showed dual photoluminescence (PL) emission from quasi-axial and quasi-equatorial conformers. However, only quasi-equatorial emission was observed in the organic light-emitting diode (OLED) at low current density, resulting in a high device efficiency despite a low PLQY. OLED devices based on NyDPO and NyDPt exhibited high external quantum efficiencies of 29.9% and 25.8%, and maximum luminance values of 33 540 cd m−2 and 14 480 cd m−2, respectively.
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- 2020
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128. AIE-active multicolor tunable luminogens: simultaneous mechanochromism and acidochromism with high contrast beyond 100 nm
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Yuntao Qiu, Zhongyan Huang, Shaolong Gong, Chuluo Yang, Yiyu Yang, Wei Yang, and Xiaosong Cao
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chemistry.chemical_compound ,High contrast ,Materials science ,chemistry ,Materials Chemistry ,General Materials Science ,Photochemistry ,Luminescence ,Phenoxazine ,Organic molecules - Abstract
The development of intelligent luminescent materials, particularly those exhibiting high-contrast (Δλem,max > 100 nm) and multicolor mechanochromic luminescent (MCL) characteristics, is highly desirable but a formidable challenge. In this work, we designed three luminogens with aggregation-induced emission (AIE) features, namely 7PTP-BPXZ, 5PTP-BPXZ and 5,7PTP-BPXZ. The synergistic effect between the folded conformation of the benzo[a]phenoxazine fragment and various intermolecular non-covalent interactions is beneficial for multicolor tunable emission upon external stimuli. Impressively, 7PTP-BPXZ and 5PTP-BPXZ displayed reversible tricolor MCL behavior with high contrast (Δλem,max, 114 nm and 137 nm, respectively). Furthermore, 7PTP-BPXZ possessed acidochromic function with Δλem,max of 132 nm. This is the first report of single-component small organic molecules featuring both multicolor and high-contrast beyond 100 nm mechanochromism and acidochromism.
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- 2020
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129. N-Rich electron acceptors: triplet harvesting in multichromophoric pyridoquinoxaline and pyridopyrazine-based organic emitters
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Samarth Sharma, Anto James, Bahadur Sk, Abhijit Patra, and Subhankar Kundu
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chemistry.chemical_classification ,Materials science ,Carbazole ,Band gap ,General Chemistry ,Electron acceptor ,Photochemistry ,Acceptor ,chemistry.chemical_compound ,Quinoxaline ,chemistry ,Materials Chemistry ,Molecule ,Phosphorescence ,Phenoxazine - Abstract
Controlling the nonradiative deactivation of triplet states and tuning the singlet–triplet energy gap are the major challenges in developing materials that exhibit thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP). Additionally, the conformational flexibility/rigidity around the donor–acceptor bond and the π-spacer unit significantly alters the charge transfer efficiency, subsequently impacting the relative propensity of TADF and RTP. Herein, we propose a new class of multichromophoric tridonor–acceptor (D3–A) compounds with rigid and flexible π-spacers having N-rich pyridoquinoxaline and pyridopyrazine acceptor cores, respectively. The molecule with carbazole donors meta to the quinoxaline nitrogen of the rigid pyridoquinoxaline core exhibits TADF, whereas the variation of the linkage position of carbazole to the pyridoquinoxaline as well as the twisted and flexible pyridopyrazine core shows predominantly RTP due to a relatively higher singlet–triplet energy gap. Increasing the donor strength with phenoxazine in the pyridopyrazine system leads to TADF and RTP simultaneously. Furthermore, we demonstrate the promising scope of the all-organic triplet harvesting materials in solid-state security encryption.
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- 2020
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130. Bright mechanoluminescent luminogens even in daylight through close intermolecular interaction with the characteristic of hybridized local and charge transfer (HLCT)
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Manman Fang, Xiaoning Li, Yunsheng Wang, Zhen Li, Dongxia Zhu, Dan Li, and Jie Yang
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chemistry.chemical_classification ,Materials science ,Solvatochromism ,Intermolecular force ,General Chemistry ,Electron acceptor ,Triphenylamine ,chemistry.chemical_compound ,chemistry ,Chemical physics ,Excited state ,Materials Chemistry ,Molecule ,Phenoxazine ,Mechanoluminescence - Abstract
The study of mechanoluminescence (ML) has attracted much attention for its widespread applications. Until now, organic ML luminogens are still very scarce, especially those with bright emissions. Herein, three donor–acceptor (D–A) molecules with triphenylamine, phenothiazine and phenoxazine as electron donors and p-fluorophenylcarbonyl as an electron acceptor are designed and synthesized via a facile approach with the Friedel–Crafts reaction in one step, named FCO-TPA, FCO-CzS and FCO-CzO, which exhibit high emission quantum yields both in solution and solid states. The fluorescence solvatochromic experiments and theoretical calculations prove their unique HLCT state characteristics, which can largely enhance the excited state energy utilization. Accordingly, very bright mechanoluminescence (ML) even in daylight is achieved in FCO-TPA with non-centrosymmetric molecular arrangement and close intermolecular interactions.
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- 2020
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131. Impact of A–D–A‐Structured Dithienosilole‐ and Phenoxazine‐Based Small Molecular Material for Bulk Heterojunction and Dopant‐Free Perovskite Solar Cells
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Towhid H. Chowdhury, B. Yadagiri, K. Narayanaswamy, Vinay Gupta, Ashraful Islam, Surya Prakash Singh, and Thokala Swetha
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Organic solar cell ,Dopant ,Chemistry ,Organic Chemistry ,Energy conversion efficiency ,Electron donor ,General Chemistry ,Acceptor ,Catalysis ,Polymer solar cell ,chemistry.chemical_compound ,Chemical engineering ,Phenoxazine ,Perovskite (structure) - Abstract
Herein, the synthesis of the novel acceptor-donor-acceptor (A-D-A)-structured small molecule Si-PO-2CN based on dithienosilole (DTS) as building block flanked by electron-rich phenoxazine (POZ) units, which are terminated with dicyanovinylene, is presented. Si-PO-2CN showed unique electrochemical and photophysical properties and has been successfully employed in perovskite solar cells (PSCs) as well as in bulk heterojunction organic solar cells (OSCs). The PSCs fabricated with dopant-free Si-PO-2CN as hole-transport material (HTM) exhibited a power conversion efficiency (PCE) of 14.1 % (active area=1.02 cm2 ). Additionally, a PCE of 5.6 % has been achieved for OSCs, which employed Si-PO-2CN as p-type donor material when blended with a [6,6]-phenyl C71 butyric acid methyl ester (PC71 BM) acceptor. The versatile application of Si-PO-2CN provides a pathway for further implementation of DTS-based building blocks in solar cells for designing new molecules.
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- 2019
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132. Low efficiency roll-off phosphorescent organic light-emitting devices using thermally activated delayed fluorescence hosts materials based 1, 2, 4-triazole acceptor
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Joseph Shinar, Jing Zhang, Bingshe Xu, Yanqin Miao, Ruth Shinar, Hua Wang, Yaping Zhao, Huixia Xu, and Di Zhang
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Materials science ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Fluorescence ,Acceptor ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Phenothiazine ,Materials Chemistry ,Molecule ,Molecular orbital ,Electrical and Electronic Engineering ,0210 nano-technology ,Phosphorescence ,Phenoxazine ,HOMO/LUMO - Abstract
The host in phosphrescent organic light emitting devices (PhOLEDs), showing the thermally activated delayed fluorescence (TADF) charateristic, can effectively overcome the efficiency roll-off. Herein, six bipolar compounds with donor-π-acceptor (D-π-A) and D-π-A-π-D structures have been synthesized using 1,2,4-triazole derivative (TAZ) as an acceptor and phenothiazine (PTZ), phenoxazine (PXZ), and 9, 9-dimethylacridane (DMAC) as donors. The molecular structures were confirmed by 1H NMR, 13C NMR and X-ray single-crystal diffractions. The large steric hindrance endows these molecules with typical TADF features, including the small singlet-triplet energy splitting ( Δ E S T ) of 0.08–0.30 eV and completely spatially separate highest occupied molecular orbitals (HOMO) and the lowest unoccupied molecular orbitals (LUMO) electron densities. The PhOLEDs hosted by these novel TADF materials display excellent performances with low efficiency roll-off.
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- 2019
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133. New antimalarial agents derived from nonlinear phenoxazine ring system
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Efeturi A. Onoabedje, Onyinyechi N. Ogbonna, Fidelia N. Ibeanu, Evelyn U. Godwin-Nwakwasi, Sunday N. Okafor, Mercy A. Ezeokonkwo, and B. E. Ezema
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Drug ,Quinine ,biology ,010405 organic chemistry ,Chemistry ,media_common.quotation_subject ,Organic Chemistry ,Pharmacology ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,In vivo ,medicine ,Plasmodium berghei ,Antimalarial Agent ,Hemoglobin ,General Pharmacology, Toxicology and Pharmaceutics ,Receptor ,Phenoxazine ,medicine.drug ,media_common - Abstract
In vivo antimalarial screening of nine nonlinear phenoxazine compounds was carried out on the blood stages of Plasmodium berghei using standard methods. The activities of the compounds were compared with that of quinine as a standard antimalarial drug. LD50 and histopathological studies were also done. Molecular docking studies were carried out on four different protein targets of Plasmodium spp. The effects of these compounds on the hematological parameters (Hemoglobin, Hb; packed cell volume, PCV; white blood cells, WBC; and red blood cells, RBC) were also evaluated. The in vivo antimalarial studies showed that all the synthesized compounds had significant parasitaemia load reduction (89.00–94.05%) at 200 mg/ml when compared with the control, with (2-aminophenoxyl)benzo[a]phenoxazin-5-one 3b showing the highest activity. There was no significant difference in the activities of these compounds compared with the standard drug used (96%). The LD50 was found to be ≥5000 mg/kg. Histopathological studies showed a significant restoration of the liver intoxicated with malaria parasite after 5 days. The hematological analysis showed normal values for Hb, PCV, WBC, and RBC in the course of the treatment. The compounds showed more binding affinities for the P. falciparum receptors than the standard drug. The nine synthesized nonliner phenoxazine compounds had significant antimalarial activities and did not significantly affect the hematological parameters. They showed strong binding affinity to the parasite receptors. Hence, they are good candidates for antimalarial drugs. More preclinical investigations are needed.
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- 2019
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134. Crystal Packing of a Series of 1,2,3,4-Substituted Phenoxazine and Dibenzodioxin Heterocycles
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Lana K. Hiscock, Kenneth E. Maly, and Louise N. Dawe
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Materials science ,Series (mathematics) ,010405 organic chemistry ,Intermolecular force ,Supramolecular chemistry ,General Chemistry ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,3. Good health ,Crystal ,chemistry.chemical_compound ,Crystallography ,chemistry ,General Materials Science ,Phenoxazine - Abstract
Understanding and control of weak intermolecular interactions, including π-interactions, is an element toward the strategic design of supramolecular materials. In this work, we describe an approach...
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- 2019
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135. Oxidative Polymerization of 3,6-Phenylenediamino-2,5-dichlorobenzoquinone
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G. P. Karpacheva, A. V. Orlov, S. G. Kiseleva, and Galina N. Bondarenko
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chemistry.chemical_classification ,Polymers and Plastics ,Induction period ,Phenazine ,technology, industry, and agriculture ,macromolecular substances ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Aniline ,Monomer ,Polymerization ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Reactivity (chemistry) ,0210 nano-technology ,Phenoxazine - Abstract
The oxidative polymerization of 3,6-phenylenediamino-2,5-dichlorobenzoquinone is studied for the first time, and the monomer is shown to exhibit a high reactivity in this process. The rate of its polymerization is much higher than that of aniline and 3,6-dianiline-2,5-dichlorobenzoquinone, and the induction period of oxidation is absent. The kinetic features of the oxidative polymerization of 3,6-phenylenediamino-2,5-dichlorobenzoquinone are investigated by measuring variation in the redox potential of the reaction mixture in the course of time. It is found that the kinetic curves of 3,6-phenylenediamino-2,5-dichlorobenzoquinone polymerization do not follow the S-shaped pattern typical of aniline polymerization. The mechanism of polymerization proceeding through a number of successive tautomeric rearrangements is advanced. The structure of the polymers is studied by FTIR and X-ray photoelectron spectroscopy. During the reaction of oxidative polymerization, cyclization processes occur to form phenazine and phenoxazine rings which give rise to a ladder polyconjugated polymer. The effect of reaction conditions, such as the concentration of reagents, their ratio, and the pH of the reaction medium, on the process is investigated.
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- 2019
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136. Spin–Orbit Charge-Transfer Intersystem Crossing (SOCT-ISC) in Bodipy-Phenoxazine Dyads: Effect of Chromophore Orientation and Conformation Restriction on the Photophysical Properties
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Yu Dong, Ahmet Karatay, Xiaolian Li, Jianzhang Zhao, Ayhan Elmali, Bernhard Dick, A. A. Sukhanov, and Violeta K. Voronkova
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Materials science ,Electron donor ,Charge (physics) ,02 engineering and technology ,Chromophore ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,General Energy ,Intersystem crossing ,chemistry ,Physical and Theoretical Chemistry ,Orbit (control theory) ,BODIPY ,0210 nano-technology ,Spin (physics) ,Phenoxazine - Abstract
The spin–orbit charge-transfer-induced intersystem crossing (SOCT-ISC) in Bodipy-phenoxazine (BDP-PXZ) compact electron-donor/-acceptor dyads was studied. PXZ is the electron donor, and BDP is the ...
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- 2019
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137. Synthesis and Antimicrobial Activity of New Derivatives of Angular Polycyclic Phenoxazine Ring System
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Mercy Amarachukwu Ezeokonkwo, Kingsley Chizoba Iloka, Uchechukwu Chris Okoro, Efeturi Abreham Onoabedje, Benjamin Ebere Ezema, Fidelia Ngozi Ibeanu, David Izuchukwu Ugwu, Florence Uchenna Eze, and Chiamaka Peace Uzoewulu
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Green chemistry ,010405 organic chemistry ,Chemistry ,Ornamental horticulture ,Industrial chemistry ,General Chemistry ,010402 general chemistry ,Antimicrobial ,Ring (chemistry) ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,Elsevier Biobase ,chemistry.chemical_compound ,Drug Discovery ,Environmental Chemistry ,Phenoxazine ,Material chemistry - Abstract
Synthesis of angular polycyclic phenoxazine derivatives incorporating different phenols is reported in 30-99% yields. O-arylation of 6-chlorodibenzo[a,j] phenoxazin-5-one with a variety of electron-deficient, electron-neutral and electron-rich phenols under the catalytic palladium (II) acetate/t-BuXphos system furnished the compounds of interest. The highest yields were obtained when the intermediate was coupled with electron-rich phenols. IR, 1H-NMR, 13C-NMR and Mass spectra data, confirmed the structures of all the synthesized compounds. Study on the in vitro biological evaluation of the compounds against microorganisms revealed that they are potent antibacterial and antifungal agents, as they showed significant biological activity against Staphylococcus aureus, Streptococcus pneumonia, Escherichia coli, Salmonella typhi, klebsiella pneumonia, Pseudomonas aeruginasa, Basillus substilis, Candida albicans and Aspergillus niger.
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- 2019
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138. Visible light-mediated metal-free atom transfer radical polymerization with N-trifluoromethylphenyl phenoxazines
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Eung Man Choi, Gyeong Su Park, Kyung-sun Son, Jisu Back, and Eunsung Lee
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Atom-transfer radical-polymerization ,Organic Chemistry ,Dispersity ,General Physics and Astronomy ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Micelle ,0104 chemical sciences ,chemistry.chemical_compound ,Monomer ,chemistry ,Materials Chemistry ,Copolymer ,0210 nano-technology ,Phenoxazine ,Visible spectrum - Abstract
The metal-free atom transfer radical polymerization (ATRP) process mediated by visible light and catalyzed by new organic photocatalysts (PCs) is investigated. The new PCs, designed by diversifying N-trifluoromethylphenyl phenoxazine, are analyzed and evaluated for organocatalyzed ATRP (O-ATRP) experimentally and theoretically. Especially, 3,7-di(4-biphenyl) 4-trifluoromethylphenyl-10-phenoxazine (4) enables successful O-ATRP with good catalytic performance, to produce well-defined polymers with low dispersity (Đ) under irradiation with a CFL bulb, white LEDs, or sunlight. The structure–property–performance relationships of PCs are investigated to determine the key parameters required for a good PC for use in O-ATRP. The scope of this process is explored in terms of monomer substrates and initiators using our new PC 4. Finally, a well-defined amphiphilic block copolymer is prepared using this method to form micelles, providing a basis for future biomedical applications.
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- 2019
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139. Effects of phenothiazine and phenoxazine on photophysical properties of coumarin derivatives
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Yanmei Li, Yuling Zhao, Youjia Wang, Tianzhi Yu, Xinyu Li, and Yanyan Wang
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Chemistry ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,Coumarin ,01 natural sciences ,Biochemistry ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,chemistry.chemical_compound ,Elemental analysis ,Phenothiazine ,Materials Chemistry ,Ultraviolet light ,Moiety ,Thermal stability ,0210 nano-technology ,Phenoxazine - Abstract
Two new coumarin derivatives containing phenothiazine or phenoxazine moiety, 3-(benzo[d]oxazol-2-yl)-7-(10H-phenoxazin-10-yl)coumarin (PXZ-C) and 3-(benzo[d]oxazol-2-yl)-7-(10H-phenothiazin-10-yl)coumarin (PTZ-C), were synthesized and characterized by elemental analysis, NMR spectroscopy, and MS. Their photophysical and electrochemical properties and thermal stabilities were investigated systematically. The results showed that these compounds have good thermal stability. The compound PTZ-C exhibits weak blue–green emission upon ultraviolet light excitation, whereas the compound PXZ-C displays weak blue emission.
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- 2019
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140. The Synthesis and Theoretical Anti-Tumor Studies of Some New Monoaza-10H-Phenothiazine and 10H-Phenoxazine Heterocycles
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Uchechukwu C. Okoro, Kovo G. Akpomie, Efeturi A. Onoabedje, Sunday N. Okafor, and University of Nigeria
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Antitumor activity ,synthesis ,carboxyamide ,General Chemical Engineering ,phenothiazine ,General Chemistry ,anticancer ,Combinatorial chemistry ,протипухлинні засоби ,phenoxazine ,chemistry.chemical_compound ,синтез ,chemistry ,Phenothiazine ,феноксазин ,docking ,карбоксиамід ,фенотіазин ,Phenoxazine ,докінг - Abstract
Синтезовано ряд нових 3-амінопохідних 3-хлор-10Н-піридо[3,2-b][1,4]бензоксазину та 3-хлор-10H- піридо[3,2-b][1,4]бензотіазину та визначено їх протипухлинну активність. Синтезовані сполуки проаналізовані УФ-, 1H ЯМР-спектроскопією, спектроскопією Фур’є та елемент- ним аналізом. На основі фізико-хімічних властивостей за методом in silico виявлено, що проміжні продукти 3-хлор-10Н- піридо[3,2-b][1,4]бензоксазину і 3-хлор-10H-піридо[3,2-b] [1,4]бензотіазину, та їх карбоксиамідні похідні не порушують правила Ліпінського. За допомогою молекулярного докінгу показано, що синтезовані сполуки непогано взаємодіють з ре- цепторами раку. Визначено, що найвищу протипухлинну активність має 1,3-ді-10H-піридо[3,2-b][1,4]бензотіазин-3-ілсечовина. The synthesis and anticancer activity of a series of new 3-amido derivatives of 3-chloro-10Hpyrido[ 3,2-b][1,4]benzoxazine and 3-chloro-10H-pyrido [3,2-b][1,4]benzothiazine is presented. The synthesized structures were characterized by UV-visible, FT-IR, 1H NMR spectroscopy and elemental analytical data. The in silico physicochemical properties disclosed that neither 3-chloro-10H-pyrido[3,2-b][1,4]benzoxazine and 3-chloro- 10H-pyrido[3,2-b][1,4]benzothiazine intermediates nor their carboxyamido derivatives violate Lipinski’s rule of five. In addition, molecular docking studies showed that they exhibited good interaction with cancer receptors. 1,3-di-10H-Pyrido[3,2-b][1,4]benzothiazin-3-ylurea which showed a significant interaction with all the employed receptors possessed the highest anticancer activity.
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- 2019
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141. Simple Fluorescence Turn-On Chemosensor for Selective Detection of Ba2+ Ion and Its Live Cell Imaging
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Kwan Seob Shim, Sivakumar Allur Subramaniyan, Palanisamy Ravichandiran, Dong Jin Yoo, Antony Paulraj Bella, Ae Rhan Kim, and Princy Merlin Johnson
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Detection limit ,Sulfonyl ,chemistry.chemical_classification ,HEPES ,010401 analytical chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Fluorescence ,Binding constant ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Live cell imaging ,Benzamide ,Phenoxazine - Abstract
A phenoxazine-based fluorescence chemosensor 4PB [(4-(tert-butyl)-N-(4-((4-((5-oxo-5H-benzo[a]phenoxazin-6-yl)amino)phenyl)sulfonyl)phenyl)benzamide)] was designed and synthesized by a simple synthetic methods. The 4PB fluorescence chemosensor selectively detects Ba2+ in the existence of other alkaline metal ions. In addition, 4PB showed high selectivity and sensitivity for Ba2+ detection. The detection limit of 4PB was 0.282 μM and the binding constant was 1.0 × 106 M-1 in CH3CN/H2O (97.5:2.5 v/v, HEPES = 1.25 mM, pH 7.3) medium. This chemosensor functioned through the intramolecular charge transfer (ICT) mechanism, which was further confirmed by DFT studies. Live cell imaging in MCF-7 cells confirmed the cell permeability of 4PB and its capability for specific detection of Ba2+ in living cells.
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- 2019
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142. A solution-processable small-organic molecules containing carbazole or phenoxazine structure as hole-transport materials for perovskite solar cells
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Saulius Grigalevicius, Gintare Krucaite, Ewa Schab-Balcerzak, Z. Starowicz, D. Tavgeniene, M. Lipiński, and K. Gawlińska-Nęcek
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Radiation ,Materials science ,Carbazole ,Thermal decomposition ,Energy conversion efficiency ,02 engineering and technology ,Electroluminescence ,021001 nanoscience & nanotechnology ,01 natural sciences ,Amorphous solid ,010309 optics ,Hexane ,chemistry.chemical_compound ,chemistry ,0103 physical sciences ,Physical chemistry ,General Materials Science ,Electrical and Electronic Engineering ,0210 nano-technology ,Phenoxazine ,Perovskite (structure) - Abstract
Three low molecular weight compounds bearing carbazole units (1,6-di{3-[2-(4-methylphenyl)vinyl]carbazol-9-yl}hexane and 9,9'-di{6-[3-(2-(4-methylphenyl)vinyl)-9-carbazol-9-yl]hexyl}-[3,3']bicarbazole) and phenoxazine structure (10-butyl-3,7-diphenylphenoxazine) were tested as hole-transporting materials in perovskite solar cells. Two of them were successfully applied as hole transporting layers in electroluminescent light emitted diodes. The examined compounds were high-thermally stable with decomposition temperature found at the range of 280–419 °C. Additionally, DSC measurement revealed that they can be converted into amorphous materials. The compounds possess adequate ionization potentials, to perovskite energy levels, being in the range of 5.15–5.36 eV. The significant increase in power conversion efficiency from 1.60% in the case of a device without hole-transporting layer, to 5.31% for device with 1,6-di{3-[2-(4-methylphenyl)vinyl]carbazol-9- yl}hexane was observed.
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- 2019
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143. Using phenothiazine as electron donor for new second-order nonlinear optical chromophore
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Jialei Liu, Yuhui Yang, Jiacheng Zhao, and Wangcong Xu
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Materials science ,Mechanical Engineering ,Hyperpolarizability ,Electron donor ,02 engineering and technology ,Chromophore ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Thiophene ,General Materials Science ,Density functional theory ,Thermal stability ,0210 nano-technology ,Phenoxazine - Abstract
A novel chromophore based on the phenoxazine and tricyanofuran acceptor linked together via thiophene as the bridges have been synthesized by the conventional technique and systematically investigated. Structure analysis and photophysical properties were carried out to investigate the new structure chromophore. Density functional theory was used to calculate the hyperpolarizability (β) and the result shows that chromophore A showed a lower energy gap. In addition, chromophore A displayed good thermal stability with the onset decomposition temperature over 240 °C. These results showed that chromophore A, which had good thermal stability and nonlinear optical properties was a promising candidate for practical use.
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- 2019
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144. Biomimetic catalytic activity and structural diversity of cobalt complexes with N3O-donor Schiff base ligand
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Narayan Ch. Jana, Moumita Patra, Anangamohan Panja, and Paula Brandão
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Schiff base ,010405 organic chemistry ,Ligand ,Substrate (chemistry) ,chemistry.chemical_element ,Chromophore ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Catalytic oxidation ,chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Phenoxazine ,Cobalt - Abstract
This report describes the syntheses and structural characterizations of four new cobalt(III) compounds (1–4) derived from a tetradentate Schiff base ligand and their catalytic oxidation of different o-aminophenols in aerobic condition. X-ray crystal structural studies reveal that both pseudohalide ions and solvents used for the syntheses have significant influence on the structural diversity in these systems. All these compounds show the diverse catalytic activity towards the aerial oxidation of different o-aminophenols. As expected, the substitutionally labile coordination sites available for substrate binding is responsible for significantly higher catalytic activity of 1 and 2 then others. Literature reports reveal that although significant attention has been made to the catalytic oxidation of some substituted o-aminophenols in terms of the isolations and characterizations of their oxidised products with the native enzyme and its models, but the detailed kinetic studies were not available in the literature. Herein, we have examined the detailed kinetic studies of the aerobic oxidation of two substituted o-aminophenols, namely 2-amino-5-methylphenol and 2-amino-4-methylphenol, using 1 and 2 as catalysts. ESI mass spectrometry provides significant information to get insight into the mechanistic details and further disclose that the methyl substation in aromatic ring does not inhibit formation of the complex-substrate aggregate but it resulted the phenoxazine chromophore instead of phenoxazinone chormophore.
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- 2019
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145. Alcohol soluble Cu(I) complexes with aggregation-induced phosphorescent emission in ethanol/water solvents
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Xia Zhang, Xiuling Li, Jie Xu, Yuyu Shan, Xia Liu, and Sitong Shang
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Ethanol ,010405 organic chemistry ,Chemistry ,Xantphos ,Alcohol ,Ether ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Materials Chemistry ,Chelation ,Physical and Theoretical Chemistry ,Luminescence ,Phenoxazine ,BINAP - Abstract
A series of ionic and neutral alcohol soluble Cu(I) complexes were obtained by reaction of 2-(pentafluorophenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline (ppipH), [Cu(MeCN)4]ClO4 and the chelating diphosphine ligands bis[(2-diphenylphosphino)phenyl]ether (POP), 4,6-bis(diphenylphosphino)phenoxazine (nixantphos), 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos) and (±)-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) in neutral and strong alkaline media, respectively. Most complexes display moderate to intense luminescence in the solid state and weak, negligible luminescence in EtOH solutions. The aggregation-induced emission for the Cu(I) complexes of flexible POP ligands in ethanol/water system was studied.
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- 2019
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146. A naked-eye colorimetric sensor for chloroform
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Kai Sheng, Di Sun, Yuantao Liu, Yanmin Wang, Anbang Sun, Wenchao Bian, Haifeng Lu, Yang Li, Rui Kuang, and Feng Chen
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Chloroform ,Chemistry ,Solvatochromism ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Chromism ,Bathochromic shift ,Naked eye ,0210 nano-technology ,Phenoxazine - Abstract
A phenoxazine based molecule termed SP has been synthesized and used as selective sensor for halogenated solvents. This molecule shows selective fast response towards halogenated solvent via naked-eye detectable chromism. SP shows colorless solution when dissolved in most solvents initially but changes to blue color in chloroform under UV irradiation (λ = 365 nm) within 5 s. The luminescence spectra of SP in halogenated solvent show a large bathochromic shift (> 100 nm) with 60-fold enhanced emission intensity compared to that in halogen-free solvents. It is also worth mentioning that the photoinduced reaction between SP molecule and the halogenated solvents occurred. Based on the detailed NMR, fluorescence and mass spectra, the possible radical reaction mechanism was proposed. Different from the majority of solvatochromic sensors that based on the polarity of solvents for detection of halogenated solvents, our sensor system worked in a special fashion
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- 2019
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147. New coumarin- and phenoxazine-based fluorescent probes for live-cell STED nanoscopy
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Hana Majaron, Janez Štrancar, Stane Pajk, Boštjan Kokot, and Matej Novak
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0301 basic medicine ,030103 biophysics ,Cell Survival ,Biophysics ,Cell Line ,03 medical and health sciences ,symbols.namesake ,chemistry.chemical_compound ,Coumarins ,Stokes shift ,Oxazines ,Humans ,Nanotechnology ,Fluorescent Dyes ,Photobleaching ,Chemistry ,STED microscopy ,Epithelial Cells ,General Medicine ,Fluorescence ,Superresolution ,Light intensity ,030104 developmental biology ,Membrane ,Microscopy, Fluorescence ,symbols ,Phenoxazine - Abstract
The potential of live-cell stimulated emission depletion (STED) nanoscopy has not yet been fully exploited. Currently, the main limitation is the small number of fluorophores and probes that can sustain high light intensity/high dose employed in STED. Namely, fluorophores suitable for STED nanoscopy must be bright and highly photostable and exhibit a large Stokes shift. To expand the list of available probes, we synthesized and evaluated several new membrane probes for live-cell STED nanoscopy. Of the tested probes, probes MePyr500, ThiaCN545 and NB640 not only allow high-resolution STED images, but also partition into the intracellular membranes relatively quickly, thus lacking the selectivity of labelling solely the plasma membrane. During experiments, cytotoxicity was observed merely with the probe ThiaCN545, which blebs the plasma membrane. In comparison with commercially available CellMask Orange and STAR RED (KK114) DPPE, all our tested probes exhibited better photostability with the exception of NB640, which had the fastest bleaching rate of all tested probes. The best overall results can be assigned to the probe MePyr500, providing high-resolution STED images as well as high photostability with no noticeable cytotoxicity, making it an excellent candidate for further development.
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- 2019
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148. Modulation of p-type units in tripodal bipolar hosts towards highly efficient red phosphorescent OLEDs
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Man-Keung Fung, Jian Fan, Quan Ran, Xiao-Chen Hua, Liang-Sheng Liao, and Yuan-Lan Zhang
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Materials science ,Dopant ,Carbazole ,Process Chemistry and Technology ,General Chemical Engineering ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Benzonitrile ,chemistry.chemical_compound ,chemistry ,Phenothiazine ,OLED ,Quantum efficiency ,0210 nano-technology ,Benzene ,Phenoxazine - Abstract
Three novel tripodal bipolar compounds (CNTPA-CZ, CNTPA-PXZ and CNTPA-PTZ) were designed and synthesized, where three functional groups were attached to 1,3,5-positions of the central benzene ring, respectively. In these three compounds, carbazole/phenoxazine/phenothiazine (CZ/PXZ/PTZ) and benzonitrile were applied as electron-donating and electron-withdrawing groups, respectively, to achieve bipolar transport functionality, which was confirmed by the hole-only and electron-only device results. Due to the efficient energy transfer from these compounds to the dopant (Ir(MDQ)2(acac)), the red phosphorescent OLEDs demonstrated high device performance with maximum external quantum efficiency (EQE) over 20%. Particularly, the red OLED hosted by CNTPA-PTZ achieved a maximum efficiency of 42.5 cd/A, 44.3 lm/w and 23.4% with the EQE roll-off ratio of 3.4% from the peak value to that at a brightness of 500 cd/m2.
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- 2019
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149. Molecular engineering of triphenylamine functionalized phenoxazine sensitizers for highly efficient solid-state dye sensitized solar cells
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Ming Cheng, Li Xu, Huaming Li, Henan Li, Xingdong Ding, Hongping Li, Cheng Chen, and Fen Qiao
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Photocurrent ,Materials science ,Process Chemistry and Technology ,General Chemical Engineering ,Energy conversion efficiency ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,Triphenylamine ,01 natural sciences ,Acceptor ,0104 chemical sciences ,Molecular engineering ,Dye-sensitized solar cell ,chemistry.chemical_compound ,chemistry ,Thiophene ,0210 nano-technology ,Phenoxazine - Abstract
Two novel organic dyes POZ7 and POZ8, with D35 donor functionalized phenoxazine (POZ) derivative as donor and cyanoacrylic acid as acceptor, have been developed and applied in the solid-state dye-sensitized solar cells (s-DSCs). Compared with the dye POZ7 without π-bridge (6.24%), an impressive overall conversion efficiency of 7.37% for s-DSCs device based on POZ8 containing one thiophene unit as π-bridge, was obtained under standard AM 1.5 illumination (100 mW cm−2) by using 2, 2‘, 7, 7‘-tetrakis-(N, N-di-pmethoxyphenyl-amine)9, 9‘-spiro-bifluorene (Spiro-OMeTAD) as hole-transport materials (HTMs). This can be attributed to the impressive panchromatic photocurrent response over the whole visible range (380 nm–720 nm), which is much broader than that of POZ7, resulting in a much higher Jsc for POZ8 based device. The results clearly show that POZ derivative could be a promising donor unit to construct efficient dyes for s-DSCs.
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- 2019
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150. Effect of donor substituents on thermally activated delayed fluorescence of diphenylsulfone derivatives
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Viktorija Mimaite, Dalius Gudeika, Oleksandr Bezvikonnyi, Bernard Ronit Sebastine, Dmytro Volyniuk, and Juozas V. Grazulevicius
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TADF ,Materials science ,Photoluminescence ,Biophysics ,Quantum yield ,02 engineering and technology ,Diphenylsulphone ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Bathochromic shift ,NATURAL SCIENCES:Physics [Research Subject Categories] ,Carbazole ,Solvatochromism ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,OLED ,chemistry ,Excited state ,Density functional theory ,Emitter ,0210 nano-technology ,Phenoxazine - Abstract
This research was funded by the European Social Fund according to the activity ‘Improvement of researchers’ qualification by implementing world-class R&D projects’ of Measure No. 09.3.3-LMT-K-712. DG acknowledges to the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/177, Diphenylsulfones substituted by acridan, carbazole, phenothiazine and phenoxazine moieties were synthesized and characterized by thermal analysis, UV-, steady-state and time-resolved luminescent spectrometries, cyclic voltametry. Quantum chemical calculations on the molecular level were performed to interpret photophysical properties of the derivatives. Structural parameters, electronic properties, HOMO-LUMO gaps, molecular orbital densities, ionization potentials, reorganization energies were determined. The lowest excitation energies and the wavelengths of absorption maxima were also estimated using the time-dependent density functional theory. All the compounds were found to be capabale to form glasses with glass transition temperatures ranging from 82° to 91°C. They exhibited high thermal stabilities, with 5% weight loss temperatures exceeding 385 °C. Strong solvatochromism arising from the intramolecular charge transfer in the excited state was evidenced by bathochromic shifts of emission maxima with increasing solvent polarity. The compounds containing acridan and phenoxazine moieties showed relatively high photoluminescence quantum yield (up to 35%) in the non-doped solid state, long delayed fluorescence lifetime (in µs range) and small singlet-triplet energy splitting (ΔEST) that is attributed to thermally activated delayed fluorescence. These compounds were tested as emissive species for the fabrication of OLEDs. The sky-blue and green devices showed maximum brightness of 3200 and 12300 cd/m2 and maximum external quantum efficiency of 6.3% and 6.9%, respectively., European Social Fund 09.3.3-LMT-K-712; European Regional Development Fund 1.1.1.2/VIAA/1/16/177; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²
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- 2019
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