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.

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.

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 Fluorescence properties of halogenated mono-hydroxyl corroles: the heavy-atom effects

2009 ◽  
Vol 13 (12) ◽  
pp. 1221-1226 ◽  
Author(s):  
Lei Shi ◽  
Hai-Yang Liu ◽  
Han Shen ◽  
Jun Hu ◽  
Guo-Liang Zhang ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Halogen Atom ◽  
Photophysical Properties ◽  
Heavy Atom ◽  
Phenyl Group ◽  
Atomic Weight ◽  
Quantum Yields ◽  
Intersystem Crossing ◽  
Fluorescence Quantum Yields ◽  
Atom Effect

A series of mono-hydroxyl corrole bearing a fluorine (1), chlorine (2), bromine (3) and iodine (4) atom on its 10-phenyl group have been synthesized. Fluorescence spectroscopy shows that the halogen atom at meso-phenyl group of corroles exhibit significant heavy-atom effect on their photophysical properties. Fluorescence quantum yields and the lifetime of these corroles decrease with the increasing of the atomic weight of halogen atoms. The quenching of the fluorescence could be interpreted in terms of a heavy atom-induced increase in intersystem crossing from S1 to T1. The intersystem crossing rate constant of these corroles were also determined by transient fluorescence spectra.

AEE-active cyclic tetraphenylsilole derivatives with ∼100% solid-state fluorescence quantum efficiency

2015 ◽  
Vol 44 (29) ◽  
pp. 12970-12975 ◽  
Author(s):  
Yuanjing Cai ◽  
Kerim Samedov ◽  
Brian S. Dolinar ◽  
Haley Albright ◽  
Zhegang Song ◽  
...  
Keyword(s):  
Solid State ◽  
Quantum Efficiency ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Solid State Fluorescence

Bright tetraphenylsilole-containing cyclosiloxanes with 500 nm emission and ∼100% solid-state fluorescence quantum yields.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽  
2021 ◽  
Author(s):  
Xianglong Chu ◽  
Yadi Niu ◽  
Chen Ma ◽  
Xiaodong Wang ◽  
Yunliang Lin ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Color Tunable ◽  
Palladium Catalyzed ◽  
Structure Relationship ◽  
High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

scholarly journals The Photostability of Novel Boron Hydride Blue Emitters in Solution and Polystyrene Matrix

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 589
Author(s):  
Jakub Ševčík ◽  
Pavel Urbánek ◽  
Barbora Hanulíková ◽  
Tereza Čapková ◽  
Michal Urbánek ◽  
...  
Keyword(s):  
Thin Films ◽  
Photophysical Properties ◽  
Inorganic Compounds ◽  
Solid Polymer ◽  
Organic Polymer ◽  
Quantum Yields ◽  
Boron Hydride ◽  
Polystyrene Matrix ◽  
Blue Emitters ◽  
Solvent Blends

In recent work, the boron hydride anti-B18H22 was announced in the literature as a new laser dye, and, along with several of its derivatives, its solutions are capable of delivering blue luminescence with quantum yields of unity. However, as a dopant in solid polymer films, its luminescent efficiencies reduce dramatically. Clarification of underlying detrimental effects is crucial for any application and, thus, this contribution makes the initial steps in the use of these inorganic compounds in electrooptical devices based on organic polymer thin films. The photoluminescence behavior of the highly luminescent boron hydrides, anti-B18H22 and 3,3′,4,4′-Et4-anti-B18H18, were therefore investigated. The quantum yields of luminescence and photostabilities of both compounds were studied in different solvents and as polymer-solvent blends. The photophysical properties of both boranes are evaluated and discussed in terms of their solvent-solute interactions using photoluminescence (PL) and NMR spectroscopies. The UV degradability of prepared thin films was studied by fluorimetric measurement. The effect of the surrounding atmosphere, dopant concentration and the molecular structure were assessed.

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.

Solid State Structure and Photoluminescence properties of poly(2,5-dialkoxy-p-phenyleneethynylene)s

1995 ◽  
Vol 413 ◽  
Author(s):  
Christoph Weder ◽  
Michael J. Wagner ◽  
Mark S. Wrighton
Keyword(s):  
Solid State ◽  
Long Range ◽  
Photophysical Properties ◽  
Significant Degree ◽  
Range Order ◽  
Quantum Yields ◽  
Side Chains ◽  
Long Range Order ◽  
Rigid Rod ◽  
Covalently Linked

ABSTRACTIn an effort to better understand the relationship between molecular structure and photophysical properties, we have prepared and investigated a series of novel poly(2,5-dialkoxy-p-phenyleneethynylene)s. Wide angle X-ray diffraction measurements show that the supramolecular structure can be easily and significantly influenced by the nature of substituents covalently linked to the rigid-rod polymer main chains. Polymers which have sterically hindered side chains are essentially amorphous, while those with only linear side chains can form lamellar structures with a significant degree of long-range order. High photoluminescence quantum yields, up to 0.86 in solution and 0.36 in the solid state, have been measured. While the solution quantum yields are independent of the functionalization, solid state quantum efficiencies were found to be related to the degree of long-range order in the samples. In samples with a high degree of long-range order, the close proximity of the coplanar oriented polymer backbones is assumed to lead to the formation of eximer complexes which provide non emissive decay channels and, hence, result in comparable low photoluminescence quantum yields. In samples that adopt only a small extent of long-range order, the rigid-rod conjugated polymer backbones behave as if they were ‘dissolved’ in a hydrocarbon solvent and consequently high quantum efficiencies are obtained. Preliminary results indicate the suitability of these polymers as the emitting layer in electroluminescent devices.

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