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 of carbon nitride oligomer as a precursor of melon with improved fluorescence quantum yield

2021 ◽  
Vol 2 (18) ◽  
pp. 6083-6093
Author(s):  
Yuto Miyake ◽  
Goichiro Seo ◽  
Kotaro Matsuhashi ◽  
Noriyuki Takada ◽  
Kaname Kanai
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Carbon Nitride

Melem tetramer, the newly synthesized carbon nitride compound is composed of oligomers with four melem units, is stable in air, and has improved optical properties compared to melon.

Electronic Structure and Optical Response of Electroluminescent Conjugated Polymers

1997 ◽  
Vol 488 ◽  
Author(s):  
J. L. Bredas ◽  
J. Cornil ◽  
D. Beljonne ◽  
D. A. Dos Santos ◽  
Z. Shuaiv ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Electronic Structure ◽  
Quantum Yield ◽  
Conjugated Polymers ◽  
Quantum Chemical Calculations ◽  
Theoretical Approach ◽  
Quantum Chemical ◽  
Fluorescence Quantum Yield ◽  
Remarkable Agreement

AbstractIn this contribution, we investigate by means of correlated quantum-chemical calculations the influence of intermolecular interactions on the absorption and emission properties of conjugated chains. Various strategies are suggested to avoid a substantial decrease in fluorescence quantum yield in condensed media. Finally, the reliability of our theoretical approach is validated by showing the remarkable agreement obtained between the experimental data and the calculated optical properties of clusters formed by sexithienyl molecules.

The Synthesis and Electro-Optical Properties of Perylene Dicarboximide Dimer with Electron Withdrawing Groups

2014 ◽  
Vol 936 ◽  
pp. 950-954
Author(s):  
Hui Min Wei ◽  
Nan Zhao ◽  
Nan Jiang ◽  
Wen Feng Duan ◽  
Bao Xiang Gao
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Electron Affinity ◽  
Fluorescence Quantum Yield ◽  
Nmr Spectra ◽  
Band Gaps ◽  
Reduction Wave ◽  
Positive Potential ◽  
H Nmr ◽  
C Nmr

Perylene dicarboximide dimer with electron withdrawing groups were synthesized and fully characterized by 1H-NMR and 13C-NMR spectra. The effects of the substituted groups on the optical and electrochemical properties of the two compounds were investigated. The ∏-∏* absorption peak of the perylene dicarboximide dimer compounds were red shifted from 525nm to 535nm. The band gaps of the dimer could be tuned from 2.28 eV to 2.13 eV. The first reduction wave of the dimer with electron withdrawing groups is shifted by 60 mV to more positive potential compared to that of perylene dicarboximide, suggesting the enhanced electron affinity. Furthemore, the dimer exhibited intermolecular aggregation, and decrease fluorescence quantum yield.

scholarly journals CNDO/S-CI Calculations of some Carbonyl-containing Organic Luminophores with a Stilbene Subchromophore

1985 ◽  
Vol 40 (8) ◽  
pp. 859-863
Author(s):  
G. Olbrich ◽  
P. Nikolov ◽  
F. Fratev ◽  
O. E. Polansky
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Electronic States ◽  
Solvent Polarity ◽  
Energy Separation ◽  
Triplet States ◽  
Organic Luminophores ◽  
Calculated Energy ◽  
Singlet And Triplet States ◽  
Ci Calculations

For a series of carbonyl-containing compounds with a stilbene subchromophore the lowest ten singlet and triplet states have been calculated with the aid of the CNDO/S-CI method. The results were used to rationalize the relative ordering of the lowest-lying S(ππ*), S(ππ*), T(ππ*), and T(ππ*) electronic states. Using the calculated energy separation between the singlet ππ*and nπ* states and between the singlet ππ* and triplet nπ* states the fluorescence ability of the compounds studied is interpreted. The connection between the structure of the compounds and their fluorescence is discussed. It is shown that an increase of the solvent polarity in some cases may lead to an inversion of the singlet nπ* and ππ* levels and to an enhancement of the fluorescence quantum yield.

Tuning the optical properties of BODIPY dyes by N-rich heterocycle conjugation using a combined synthesis and computational approach

2021 ◽  
Author(s):  
Jean Michel Merkes ◽  
Tobias Ostlender ◽  
Fufang Wang ◽  
Haitao Sun ◽  
Fabian Kiessling ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Computational Approach

The increased number of N-atoms induced a blueshift in absorption and a gain in fluorescence quantum yield, from 750 nm and ~0 % for pyrrole to 635 nm and ~40...

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.

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.

scholarly journals Preparation of Graphene Quantum Dots and Their Application in Cell Imaging

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jie Zhang ◽  
Yong-qiang Ma ◽  
Na Li ◽  
Jing-li Zhu ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Reaction Time ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Laser Scanning ◽  
Cell Imaging ◽  
Graphene Quantum Dots ◽  
Dimethyl Formamide ◽  
Experimental Conditions ◽  
Solvothermal Route

Objective. This study aims to increase the fluorescence quantum yield by improving the conditions of preparing graphene quantum dots (GQDs) through the solvothermal route and observe the GQDs performance in imaging oral squamous cells.Methodology. The following experimental conditions of GQDs preparation through the solvothermal route were improved: graphene oxide (GO)/N-N dimethyl formamide (DMF) ratio, filling percentage, and reaction time. A fluorescence spectrophotometer was used to measure photoluminescence, and the peak values were compared. Methylthiazolyldiphenyl-tetrazolium (MTT) bromide was used to detect the cytotoxicity of GQDs, which was compared with that of cadmium telluride quantum dots (CdTe QDs). GQDs were cultured with tongue cancer cells. After the coculture, a laser scanning confocal microscope (LSCM) was used to observe cell imaging.Results. The optimal conditions of GQD preparation through the solvothermal route included the following: 10 mg/mL GO/DMF ratio, 80% filling percentage, 12 h reaction time, and 17.4% fluorescence quantum yield. As the cell concentration increased, the GQD and CdTe QD groups exhibited a decreasing cell survival rate, with the decrease in the CdTe QD group being more significant. The LSCM observations showed bright green fluorescence images.Conclusion. The improved experimental conditions increased the fluorescence quantum yield of GQDs. In this study, the prepared GQDs exhibited low cytotoxicity level and satisfactory cell imaging performance.

Synthesis and Photoproperties of Fluorescent Brighteners Modified by Polyaminamide

2011 ◽  
Vol 233-235 ◽  
pp. 3064-3067
Author(s):  
Jing Liu ◽  
Guang Hua Zhang
Keyword(s):  
Condensation Reaction ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Solvent Polarity ◽  
Molecular Structures ◽  
Paper Coating ◽  
Fluorescence Emission Spectra ◽  
Coating Application ◽  
Light Stability ◽  
Photochemical Properties

One of amino compounds of traditional fluorescent brighteners with polyaminamide was replaced and new triazinyl aminostilbene fluorescent brightener was modified by polyaminamide which synthesized through three-step condensation reaction. The molecular structures were characterized by IR spectrum and photoproperties in aqueous and ethanol were studied by ultraviolet absorption spectra, fluorescence emission spectra, photochemical stability and paper coating application test. The results show that the light stability and fluorescence quantum yield of polyaminamide fluorescent brighteners (PFBs) were improved obviously, which compared with the traditional FBs, such as VBL, and the whitening performance of paper coating enhanced and used widely. Meanwhile, the photophysics and photochemical properties of triazene-stilbene fluorescence brighteners are markedly determined by solvent polarity.

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