THE EFFECT OF DIMETHYLSULFOXIDE ON THE FLUORESCENCE PROPERTIES OF SOME 4-HYDROXYQUINOLINES

2021 ◽  
Vol 55 (2 (255)) ◽  
pp. 112-117
Author(s):  
Karine R. Grigoryan ◽  
Hasmik A. Shilajyan ◽  
Iskuhi L. Aleksanyan ◽  
Zara L. Grigoryan ◽  
Lilit P. Hambardzumyan
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Aqueous Solutions ◽  
Electron Density ◽  
Aromatic Ring ◽  
Fluorescence Quantum Yield ◽  
Tautomeric Equilibrium ◽  
Fluorescence Properties ◽  
Fluorescence Efficiency ◽  
Dmso Concentration

Fluorescence properties of 4-hydroxy-2-methylquinoline (1) and 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinoline-4-ol (2) were studied in dimethylsulfoxide (DMSO) aqueous solutions. The fluorescence properties of 1 and 2 exhibit substantial dependence on the DMSO concentration. The fluorescence quantum yield $(\Phi_f)$ of 1 decreases upon adding DMSO due to the shift in the keto-enol (E) tautomeric equilibrium toward E form․ On the contrary 2 demonstrates a tendency of increase of $\Phi_f$ upon adding DMSO due to intermolecular charge transfer from DMSO to the aromatic ring of quinoline, which increases the electron density on the ring and hence the fluorescence efficiency.

scholarly journals Fluorescence quantum yield rationalized by the magnitude of the charge transfer in π-conjugated terpyridine derivatives

2016 ◽  
Vol 18 (42) ◽  
pp. 29387-29394 ◽  
Author(s):  
Marie Humbert-Droz ◽  
Claude Piguet ◽  
Tomasz A. Wesolowski
Keyword(s):  
Dipole Moment ◽  
Charge Transfer ◽  
Quantum Yield ◽  
Excited States ◽  
Charge Separation ◽  
Fluorescence Quantum Yield ◽  
Molecular Design ◽  
Electron Hole ◽  
Two Measures

Two measures of charge separation in ground and excited states (length of the change in dipole moment and the electron–hole distance) provide a remarkable tool for the molecular design of a fluorescent polyaromatic antenna.

An exemplary relationship between the extent of cofacial aggregation and fluorescence quantum yield as exhibited by quaternized amphiphilic phthalocyanines

2014 ◽  
Vol 43 (15) ◽  
pp. 5886-5892 ◽  
Author(s):  
Thiago Teixeira Tasso ◽  
Yasuhiro Yamasaki ◽  
Taniyuki Furuyama ◽  
Nagao Kobayashi
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Properties

A good correlation between aggregation and fluorescence properties of amphiphilic phthalocyanines can be observed.

scholarly journals Estimation of quantum yields of weak fluorescence from eosin Y dimers formed in aqueous solutions

2018 ◽  
Vol 17 (6) ◽  
pp. 793-799 ◽  
Author(s):  
Masami Enoki ◽  
Ryuzi Katoh
Keyword(s):  
Quantum Yield ◽  
Aqueous Solutions ◽  
Fluorescence Quantum Yield ◽  
Quantum Yields ◽  
Eosin Y

A weak fluorescence from eosin Y dimers can be observed. The fluorescence quantum yield was estimated to be 0.005.

A Study of the Optical Properties of Triazene-Cinnamic Acid Polymeric Fluorescent Brighteners

2012 ◽  
Vol 184-185 ◽  
pp. 868-871
Author(s):  
Jing Liu
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Aqueous Solutions ◽  
Cinnamic Acid ◽  
Fluorescence Quantum Yield ◽  
Solvent Polarity ◽  
Polymerization Reaction ◽  
Dimethyl Formamide ◽  
Coating Application ◽  
Light Stability

Series of the triazene-cinnamic acid polymeric fluorescent brighteners were synthesized through three-step condensation reactions and polymerization reaction with styrene under replacing one of amino compounds of traditional fluorescent brighteners by cinnamic acid. The optical properties in aqueous solutions and N,N’- dimethyl formamide as well as paper coating application test were evaluated. The results showed that the light stability and fluorescence quantum yield of polymeric fluorescent brighteners was improved obviously and photoinduced isomerization was lower. Meanwhile the optical properties of polymeric fluorescent brightener were affected by concentration and solvent polarity, fluorescence quantum yield increasing and hypochromatic shift of fluorescence emmission wavelength with the decrease of solvent polarity. When the concentration was over 1 10-4 g/mL, the fluorescence was quenched.

scholarly journals Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

2016 ◽  
Vol 12 ◽  
pp. 1812-1825 ◽  
Author(s):  
Adrian E Ion ◽  
Liliana Cristian ◽  
Mariana Voicescu ◽  
Masroor Bangesh ◽  
Augustin M Madalan ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Aqueous Solutions ◽  
Crystal Structures ◽  
Fluorescence Quantum Yield ◽  
Membered Ring ◽  
Methyl Groups ◽  
Redox Behavior ◽  
Fluorescent Emission ◽  
Tddft Calculations ◽  
Oxidation Reduction

4′-Azulenyl-substituted terpyridines were efficiently synthesized following the Kröhnke methodology via azulenylchalcone intermediates. These azulenyl-containing terpyridines showed fluorescent emission with a fluorescence quantum yield varying from 0.14, in the case of parent terpyridine, to 0.64 when methyl groups are grafted on the azulenyl seven-membered ring. According to the crystal structures and TDDFT calculations, different twisting of the aromatic constituents is responsible for the observed fluorescent behavior. The electrochemical profile contains one-electron oxidation/reduction steps, which can only be explained on the basis of the redox behavior of the azulene unit. The ability of the 4′-azulenyl 2,2′:6′,2″-terpyridine to bind poisoning metal cations was studied by UV–vis titrations using aqueous solutions of Hg(II) and Cd(II) chlorides as illustrative examples.

Spin-Bahn-Kopplungseffekte in nicht-ebenen Biarylen / Spin-orbit Coupling Effects in Non-planar Biaryls

1977 ◽  
Vol 32 (3-4) ◽  
pp. 339-340 ◽  
Author(s):  
M. Zander
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Transition Probability ◽  
Heavy Atom ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Effects ◽  
Triplet Formation

Abstract The non-planar biaryls 2,2′-dimethyl-biphenyl, 1,1′-bi-naphthyl and 9,9′-biphenanthryl have higher phosphorescence/fluorescence quantum yield ratios than biphenyl, naphthalene and phenanthrene respectively. The increase of spin-orbit coupling in 1,1′-binaphthyl in comparison to naphthalene results in an increase of the phosphorescence transition probability while the triplet formation quantum yield is not enhanced. The much weaker effect of an external heavy atom pertuber on the spin-forbidden electronic tran­ sition rate probabilities in the case of 1,1′-binaphthyl in comparison to naphthalene is explained on the basis of a weaker charge-transfer interaction between luminescer and pertuber in the case of binaphthyl.

Synthesis and fluorescence properties of novel squarylium–boron complexes

2017 ◽  
Vol 4 (8) ◽  
pp. 1522-1527 ◽  
Author(s):  
Yasuhiro Kubota ◽  
Masahiro Tsukamoto ◽  
Katsuhiro Ohnishi ◽  
Jiye Jin ◽  
Kazumasa Funabiki ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescence Properties ◽  
Enhanced Fluorescence ◽  
Boron Complexes ◽  
Squarylium Dyes

Novel squarylium–boron complexes showed a significantly enhanced fluorescence quantum yield compared to the corresponding uncomplexed squarylium dyes.

scholarly journals Novel turn-on fluorescent sensor for cyanide ion based on the charge transfer transition of phenothiazine/indolium compounds

2021 ◽  
Author(s):  
Yasuhiro Morikawa ◽  
Miku Hirabara ◽  
Keiji Nishiwaki ◽  
Shigeo Suzuki ◽  
Isao Nakanishi
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Fluorescent Sensor ◽  
Stokes Shift ◽  
Charge Transfer Transition ◽  
Cyanide Ion ◽  
Large Stokes Shift ◽  
Turn On

A new fluorescent sensor combining phenothiazine and indolium, which reacts specifically with the cyanide ion with a large Stokes shift and a good fluorescence quantum yield, was prepared. When CN-.

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