scholarly journals Towards Blue AIE/AIEE: Synthesis and Applications in OLEDs of Tetra-/Triphenylethenyl Substituted 9,9-Dimethylacridine Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 445 ◽  
Author(s):  
Monika Cekaviciute ◽  
Aina Petrauskaite ◽  
Sohrab Nasiri ◽  
Jurate Simokaitiene ◽  
Dmytro Volyniuk ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Yields ◽  
Yellow Emission ◽  
Blue Color ◽  
Television System ◽  
Fluorescence Quantum Yields ◽  
Deep Blue ◽  
Wide Range ◽  
Cyano Groups ◽  
High Yields

Aiming to design blue fluorescent emitters with high photoluminescence quantum yields in solid-state, nitrogen-containing heteroaromatic 9,9-dimethylacridine was refined by tetraphenylethene and triphenylethene. Six tetra-/triphenylethene-substituted 9,9-dimethylacridines were synthesized by the Buchwald-Hartwig method with relatively high yields. Showing effects of substitution patterns, all emitters demonstrated high fluorescence quantum yields of 26–53% in non-doped films and 52–88% in doped films due to the aggregation induced/enhanced emission (AIE/AIEE) phenomena. In solid-state, the emitters emitted blue (451–481 nm) without doping and deep-blue (438–445 nm) with doping while greenish-yellow emission was detected for two compounds with additionally attached cyano-groups. The ionization potentials of the derivatives were found to be in the relatively wide range of 5.43–5.81 eV since cyano-groups were used in their design. Possible applications of the emitters were demonstrated in non-doped and doped organic light-emitting diodes with up to 2.3 % external quantum efficiencies for simple fluorescent devices. In the best case, deep-blue electroluminescence with chromaticity coordinates of (0.16, 0.10) was close to blue color standard (0.14, 0.08) of the National Television System Committee.

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

Highly fluorescent triazolopyridine–thiophene D–A–D oligomers for efficient pH sensing both in solution and in the solid state

2019 ◽  
Vol 21 (13) ◽  
pp. 7174-7182 ◽  
Author(s):  
Nannan Jian ◽  
Kai Qu ◽  
Hua Gu ◽  
Lie Zou ◽  
Ximei Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Fluorescence Quenching ◽  
Quantum Yields ◽  
Ph Sensing ◽  
Fluorescence Quantum Yields ◽  
High Fluorescence ◽  
Printed Patterns

Triazolopyridine–thiophene fluorophores exhibit high fluorescence quantum yields both in solution (80–89%) and in the solid state (13–26%). Because of an excellent and reversible pH induced fluorescence quenching/recovery, sensing devices such as fluorescent papers and complex inkjet-printed patterns are successfully fabricated for the detection of volatile acids both in solution and in a vapor atmosphere.

scholarly journals Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

2019 ◽  
Vol 15 ◽  
pp. 2684-2703 ◽  
Author(s):  
Natascha Breuer ◽  
Irina Gruber ◽  
Christoph Janiak ◽  
Thomas J J Müller
Keyword(s):  
Solid State ◽  
Michael Addition ◽  
Photophysical Properties ◽  
Ethyl Cyanoacetate ◽  
Product Formation ◽  
Quantum Yields ◽  
Substitution Pattern ◽  
Fluorescence Quantum Yields ◽  
Emission Enhancement ◽  
Donor Acceptor

Starting from substituted alkynones, α-pyrones and/or 1H-pyridines were generated in a Michael addition–cyclocondensation with ethyl cyanoacetate. The peculiar product formation depends on the reaction conditions as well as on the electronic substitution pattern of the alkynone. While electron-donating groups furnish α-pyrones as main products, electron-withdrawing groups predominantly give the corresponding 1H-pyridines. Both heterocycle classes fluoresce in solution and in the solid state. In particular, dimethylamino-substituted α-pyrones, as donor–acceptor systems, display remarkable photophysical properties, such as strongly red-shifted absorption and emission maxima with daylight fluorescence and fluorescence quantum yields up to 99% in solution and around 11% in the solid state, as well as pronounced emission solvatochromism. Also a donor-substituted α-pyrone shows pronounced aggregation-induced emission enhancement.

Structure Property Analysis of the Solution and Solid-State Properties of Bistable Photochromic Hydrazones

2019 ◽  
Author(s):  
Baihao Shao ◽  
Hai Qian ◽  
Quan Li ◽  
ivan aprahamian
Keyword(s):  
Solid State ◽  
Phenyl Group ◽  
Quantum Yields ◽  
Structure Property ◽  
Pull System ◽  
X Ray Crystallography ◽  
Fluorescence Quantum Yields ◽  
Property Analysis ◽  
Fluorescence Characteristics ◽  
Almost All

The development of new photochromic compounds, and the optimization of their photophysical and switching properties are prerequisites for accessing new functions and opportunities that are not possible with currently available systems. To this end we recently developed a new bistable hydrazone switch that undergoes efficient photoswitching and emission ON/OFF toggling in both solution and solid-state. Here, we present a systematic structure-property analysis using a family of hydrazones, and show how their properties, including activation wavelengths, photostationary states (PSSs), photoisomerization quantum yields, thermal half-lives (<i>t</i><sub>1/2</sub>), and solution/solid-state fluorescence characteristics vary as a function of electron donating (EDG) and/or withdrawing (EWG) substituents. These studies resulted in the red-shifting of the absorption profiles of the <i>Z</i> and <i>E</i> isomers of the switches, while maintaining excellent PSSs in almost all of the compounds. The introduction of <i>para</i>-NMe<sub>2</sub>, and/or <i>para</i>-NO<sub>2</sub> groups improved the photoisomerization quantum yields, and the extremely long thermal half-lives (tens to thousands of years) were maintained in most cases, even in a push-pull system, which can be activated solely with visible light. Hydrazones bearing EDGs at the stator phenyl group are an exception and show up to 6 orders of magnitude acceleration in<i>t</i><sub>1/2 </sub>(<i>i.e.</i>, days)<sub> </sub>because of a change in the isomerization mechanism. Moreover, we discovered that a <i>para</i>-NMe<sub>2</sub> group is required to have reasonable fluorescence quantum yields in solution, and that rigidification enhances the emission in the solid-state. Finally, X-ray crystallography analysis showed that the switching process is more efficient in the solid-state when the hydrazone is loosely packed.<br>

Lithium superoxide encapsulated in a benzoquinone anion matrix

2021 ◽  
Vol 118 (51) ◽  
pp. e2019392118
Author(s):  
Matthew Nava ◽  
Shiyu Zhang ◽  
Katharine S. Pastore ◽  
Xiaowen Feng ◽  
Kyle M. Lancaster ◽  
...  
Keyword(s):  
Solid State ◽  
Lithium Ion ◽  
Spectroscopic Characterization ◽  
Blue Color ◽  
Paramagnetic Resonance ◽  
Deep Blue ◽  
Lithium Peroxide ◽  
X Ray Absorption ◽  
Electron Paramagnetic ◽  
Lithium Air Batteries

Lithium peroxide is the crucial storage material in lithium–air batteries. Understanding the redox properties of this salt is paramount toward improving the performance of this class of batteries. Lithium peroxide, upon exposure to p–benzoquinone (p–C6H4O2) vapor, develops a deep blue color. This blue powder can be formally described as [Li2O2]0.3 · [LiO2]0.7 · {Li[p–C6H4O2]}0.7, though spectroscopic characterization indicates a more nuanced structural speciation. Infrared, Raman, electron paramagnetic resonance, diffuse-reflectance ultraviolet-visible and X-ray absorption spectroscopy reveal that the lithium salt of the benzoquinone radical anion forms on the surface of the lithium peroxide, indicating the occurrence of electron and lithium ion transfer in the solid state. As a result, obligate lithium superoxide is formed and encapsulated in a shell of Li[p–C6H4O2] with a core of Li2O2. Lithium superoxide has been proposed as a critical intermediate in the charge/discharge cycle of Li–air batteries, but has yet to be isolated, owing to instability. The results reported herein provide a snapshot of lithium peroxide/superoxide chemistry in the solid state with redox mediation.

1,4,7,10-Tetraisoalkyltetracenes: Tuning of Solid-State Optical Properties and Fluorescence Quantum Yields by Peripheral Modulation (Eur. J. Org. Chem. 16/2010)

2010 ◽  
Vol 2010 (16) ◽  
pp. 2987-2987
Author(s):  
Chitoshi Kitamura ◽  
Hideki Tsukuda ◽  
Akio Yoneda ◽  
Takeshi Kawase ◽  
Takashi Kobayashi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields

Synthesis and properties ofB-cyano-BODIPYs

2016 ◽  
Vol 20 (12) ◽  
pp. 1409-1419 ◽  
Author(s):  
Alex L. Nguyen ◽  
Maodie Wang ◽  
Petia Bobadova-Parvanova ◽  
Quynh Do ◽  
Zehua Zhou ◽  
...  
Keyword(s):  
Room Temperature ◽  
Chemical Shifts ◽  
Quantum Yields ◽  
Enhanced Fluorescence ◽  
Nmr Chemical Shifts ◽  
Bond Lengths ◽  
Fluorescence Quantum Yields ◽  
Acidic Conditions ◽  
Cyano Groups ◽  
Enhanced Stability

A series of boron-functionalized BODIPY dyes with cyano groups were prepared from their corresponding BF2derivatives using SnCl4/TMSCN at room temperature for 10 min. Replacement of the fluorines by cyano groups reduces the B–N bond lengths, decreases the charge on boron, and causes characteristic [Formula: see text]B NMR chemical shifts. The 4,4[Formula: see text]-dicyano-BODIPYs show significantly enhanced stability to acidic conditions (excess TFA) and, with one exception, enhanced fluorescence quantum yields. Furthermore, the B(CN)2-BODIPYs were non-cytotoxic to HEp2 cells, both in the dark and upon exposure to light (1.5 J/cm[Formula: see text], and rapidly accumulated within cells, localizing mainly in the lysosomes, ER and Golgi.

Multicomponent reaction-based discovery of pyrimido[2,1-b][1,3]benzothiazole (PBT) as a novel core for full-color-tunable AIEgens

2021 ◽  
Author(s):  
Shan-Shan Gong ◽  
Rui Kong ◽  
Chunhong Zheng ◽  
Congbin Fan ◽  
Chengjun Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Multicomponent Reaction ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Full Color ◽  
Color Tunable ◽  
Solid State Fluorescence ◽  
Color Tunability

The Hf(OTf)4-catalyzed three-component (3CR) was employed as a powerful tool for facile access to a library of 23 pyrimido[2,1-b][1,3]benzothiazole (PBT)-based AIEgens with full-color tunability, solid-state fluorescence quantum yields up to...

scholarly journals Emission Quenching in Tetraphenylfuran Crystal: Why This Propeller-Shaped Molecule Does Not Emit in the Condensed Phase?

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 522
Author(s):  
Ljiljana Stojanović ◽  
Rachel Crespo-Otero
Keyword(s):  
Solid State ◽  
Ground State ◽  
Light Emission ◽  
Quantum Yields ◽  
Triplet States ◽  
Fluorescence Quantum Yields ◽  
The Family ◽  
Emission Quenching ◽  
Significant Attention

Due to their substantial fluorescence quantum yields in the crystalline phase, propeller-shaped molecules have recently gained significant attention as potential emissive materials for optoelectronic applications. For the family of cyclopentadiene derivatives, light-emission is highly dependent on the nature of heteroatomic substitutions. In this paper, we investigate excited state relaxation pathways in the tetraphenyl-furan molecule (TPF), which in contrast with other molecules in the family, shows emission quenching in the solid-state. For the singlet manifold, our calculations show nonradiative pathways associated with C-O elongation are blocked in both vacuum and the solid state. A fraction of the population can be transferred to the triplet manifold and, subsequently, to the ground state in both phases. This process is expected to be relatively slow due to the small spin-orbit couplings between the relevant singlet-triplet states. Emission quenching in crystalline TPF seems to be in line with more efficient exciton hopping rates. Our simulations help clarify the role of conical intersections, population of the triplet states and crystalline structure in the emissive response of propeller-shaped molecules.

Synthetic Routes to Core-fluorinated Perylene Bisimide Dyes and their Properties

2009 ◽  
Vol 64 (6) ◽  
pp. 735-746 ◽  
Author(s):  
Rüdiger Schmidt ◽  
Peter Osswald ◽  
Martin Könemann ◽  
Frank Würthner
Keyword(s):  
Potassium Fluoride ◽  
Quantum Yields ◽  
Primary Amines ◽  
Yellow Emission ◽  
Exchange Reactions ◽  
Hydrogen Atoms ◽  
Perylene Bisimide ◽  
Fluorescence Quantum Yields ◽  
Halogen Exchange ◽  
Perylene Bisimides

Numerous core-fluorinated perylene bisimide (PBI) dyes with various substituents at the imide positions have been synthesized by different methods. Core-difluorinated PBIs 4a-f are obtained by imidization of difluoro-substituted perylene bisanhydride 1 with appropriate primary amines or, alternatively, by nucleophilic halogen exchange reactions (Halex process) of the corresponding dibromosubstituted PBIs 2a-d,f with potassium fluoride. Core-tetrafluorinated PBIs 5a-c could also be synthesized by halogen exchange reactions of the respective tetrachlorinated PBIs 3a-c. In particular, core-fluorinated perylene bisimide pigments 4h, 5h containing hydrogen atoms in the imide positions could be obtained for the first time by deprotection of α-methylbenzyl-substituted precursors. Compared with core-unsubstituted perylene bisimides, these fluorinated dyes display hypsochromically shifted absorption and fluorescence spectra, and they exhibit fluorescence quantum yields up to unity, enabling bright yellow emission. The electrochemical properties of these electron-poor perylene bisimides have been studied. Furthermore, the packing features of a tetrafluorinated PBI derivative in the solid state have been discussed.

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