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.

New soluble 4-(4-formyl-2,6-dimethoxyphenoxy) substituted phthalocyanines: Synthesis, characterization, photophysical and photochemical properties

2021 ◽  
pp. 1-10
Author(s):  
Ibrahim Erden ◽  
Betül Karadoğan ◽  
Fatma Aytan Kılıçarslan ◽  
Göknur Yaşa Atmaca ◽  
Ali Erdoğmuş
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Fluorescence Quantum Yield ◽  
Metal Ion ◽  
Mass Spectra ◽  
Quantum Yields ◽  
Therapeutic Outcomes ◽  
Ft Ir ◽  
Photochemical Properties ◽  
New Compounds

This work describes the synthesis, spectral and fluorescence properties of bis 4-(4-formyl-2,6-dimethoxyphenoxy) substituted zinc (ZnPc) and magnesium (MgPc) phthalocyanines. The new compounds have been characterized by elemental analysis, UV-Vis, FT-IR, 1H-NMR and mass spectra. Afterward, the effects of including metal ion on the photophysicochemical properties of the complexes were studied in biocompatible solvent DMSO to analyze their potential to use as a photosensitizer in photodynamic therapy (PDT). The fluorescence and singlet oxygen quantum yields were calculated as 0.04–0.15 and 0.70–0.52 for ZnPc and MgPc, respectively. According to the results, MgPc has higher fluorescence quantum yield than ZnPc, while ZnPc has higher singlet oxygen quantum yield than MgPc. The results show that the synthesized complexes can have therapeutic outcomes for cancer treatment.

The Photolysis in Acidic Aqueous Solutions of the Monooxalato-bisethylenediamine Chromium(III) Cation and the Bisoxalatomonoethylenediamine Chromate(III) Anion: Photolysis Modes and Quantum Yields

1971 ◽  
Vol 49 (3) ◽  
pp. 375-383 ◽  
Author(s):  
A. D. Kirk ◽  
K. C. Moss ◽  
J. G. Valentin
Keyword(s):  
Quantum Yield ◽  
Aqueous Solutions ◽  
Quantum Yields ◽  
Ligand Field ◽  
Intersystem Crossing ◽  
Empirical Correlations ◽  
Complex Ions ◽  
Ethylenediamine Complex ◽  
Ethylenediamine Ligand ◽  
Ph Range

The photolysis reactions of the complex ions [Cr(en)2ox]+ and [Cren(ox)2]− have been studied in the pH range 1 → 3 and at temperatures from 0 to 25 °C. It has been found that both ions photoaquate to a monodentate protonated ethylenediamine complex which then undergoes further aquation thermally with loss of the ethylenediamine ligand. Quantum yields for these aquations were measured for irradiation into the ligand field bands, the values obtained being 0.18 and 0.02, respectively. The results are discussed in terms of known empirical correlations for Cr(III) complexes. Assuming these reactions may occur from the 4T2g state as precursor, arguments are presented that the correlation between quantum yield and ΔE may depend on mixing of the 4T2g and 2Eg states, and its effect on the intersystem crossing rate constant.

Computational design of ratiometric two-photon fluorescent Zn2+ probes based on quinoline and di-2-picolylamine moieties

2021 ◽  
Author(s):  
Zhe Shao ◽  
Wen-Ying Zhang ◽  
Ke Zhao
Keyword(s):  
Quantum Yield ◽  
Cross Sections ◽  
Fluorescence Quantum Yield ◽  
Density Functional ◽  
Computational Design ◽  
Photon Absorption ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Two Photon ◽  
Before And After

Abstract To improve two-photon absorption (TPA) response of a newly synthesized probe, a series of ratiometric two-photon fluorescent Zn2+ sensors based on quinoline and DPA moieties have been designed. The one-photon absorption, TPA and emission properties of the experimental and designed probes before and after coordination with Zn2+ are investigated employing the density functional theory in combination with response functions. The design consists of two levels. In the first level of design, five probes are constructed through using several electron acceptors or donors to increase accepting or donating ability of the fluorophores. It shows that all the designed probes have stronger TPA intensities at longer wavelengths with respect to the experimental probe because of the increased intra-molecular charge transfer. Moreover, it is found that the probe 4 built by adding an acyl unit has the largest TPA cross section among the designed strictures due to the form of longer conjugated length and more linear backbone. One dimethylamino terminal attached along the skeleton can improve TPA intensity more efficiently than two side amino groups. Therefore, in the second level of design, a new probe 7 is formed by both an acyl unit and a dimethylamino terminal. It exhibits that the TPA cross sections of probe 7 and its zinc complex increase dramatically. Furthermore, the fluorescence quantum yields of the designed probes 4 and 7 are calculated in a new way, which makes use of the relation between the computed difference of dipole moment and the measured fluorescence quantum yield. The result shows that our design also improves the fluorescence quantum yield considerably. All in all, the designed probes 4 and 7 not only possess enhanced TPA intensities but also have large differences of emission wavelength upon Zn2+ coordination and strong fluorescence intensity, which demonstrates that they are potential ratiometric two-photon fluorescent probes.

Fluorescent surfactants from common dyes – Rhodamine B and Eosin Y

2020 ◽  
Vol 92 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Ashleigh D. Smith McWilliams ◽  
Selin Ergülen ◽  
Meredith M. Ogle ◽  
Carlos A. de los Reyes ◽  
Matteo Pasquali ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Chain Length ◽  
Rhodamine B ◽  
Fluorescence Quantum Yield ◽  
Fluorescent Dyes ◽  
Boron Nitride Nanotubes ◽  
Aliphatic Chain ◽  
Eosin Y ◽  
Imaging Tool ◽  
Potential Applications

AbstractEight fluorescent surfactants were synthesized by attaching aliphatic chains of 6, 10, 12, or 16 carbons to the fluorescent dyes Rhodamine B and Eosin Y. The obtained critical micelle concentrations (CMC) demonstrate an increasing CMC with decreasing aliphatic chain length, which is a typical behavior for surfactants. Additionally, fluorescence quantum yield experiments show a decrease in quantum yield with increasing aliphatic chain length, suggesting that the tails can interact with the dye, influencing its excited state. Finally, applications for the fluorescent surfactants were demonstrated; as a cellular stain in Panc-1 cells and as a dispersion and imaging tool for carbon and boron nitride nanotubes. These surfactants could provide a useful tool for a wide array of potential applications, from textile dyes to fluorescence imaging.

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.

Einfluß von Chlorsubstitution auf die El ektronenspektren von Biphenyl

1972 ◽  
Vol 27 (5) ◽  
pp. 756-759 ◽  
Author(s):  
H. Dreeskamp ◽  
O. Hutzinger ◽  
M. Zander
Keyword(s):  
Excited State ◽  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Emission Spectra ◽  
Liquid Solution ◽  
Quantum Yields ◽  
Decay Times ◽  
Fluorescence And Phosphorescence Spectra ◽  
Fluorescence And Phosphorescence ◽  
Phosphorescence Spectra

Abstract Absorption spectra in liquid solution, fluorescence and phosphorescence spectra, phosphores-cence quantum yields, phosphorescence to fluorescence quantum yield ratios, and phosphorescence decay times of 9 chloro substituted biphenyls dissolved in low temperature EPA glass were in-vestigated. The emission spectra of sterically unhindered systems are structured and significantly Stokes-shifted. Ortho substitution shifts the conjugation band in absorption as well as the un-structured fluorescence and phosphorescence bands to shorter wave lengths presumably by pre-venting the system from attaining a planar excited state. Chloro substitution which increases the rate constant of phosphorescence in the order meta < para < ortho, is nearly additive for multiple substituted systems and is correlated to the MO coefficients at the chloro substituted position in the absence of steric hindrance

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 Сравнительные исследования фотофизических свойств димегина, фотодитазина и радахлорина

2019 ◽  
Vol 126 (2) ◽  
pp. 162
Author(s):  
И.В. Багров ◽  
А.В. Дадеко ◽  
В.М. Киселев ◽  
Т.Д. Муравьева ◽  
А.М. Стародубцев
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation

AbstractThe photophysical properties of three photosensitizers—dimegine, photoditazine, and radachlorin—have been comparatively examined. For dimegine and photoditazine, two techniques have been used to measure the singlet oxygen generation quantum yields and the quenching constants of singlet oxygen by dimegine and photoditazine, as well as the dimegine fluorescence quantum yield.

scholarly journals The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

2012 ◽  
Vol 8 ◽  
pp. 1018-1026 ◽  
Author(s):  
Renjie Wang ◽  
Shouzhi Pu ◽  
Gang Liu ◽  
Shiqiang Cui
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Quantum Yields ◽  
Cyclic Voltammograms ◽  
Ortho Position ◽  
Formyl Group ◽  
Absorption Coefficients ◽  
Electrochemical Behaviors ◽  
Group Position ◽  
The One

Three new isomeric asymmetric diarylethenes with a naphthyl moiety and a formyl group at the para, meta or ortho position of the terminal benzene ring were synthesized. Their photochromism, fluorescent-switch, and electrochemical properties were investigated. Among these diarylethenes, the one with a formyl group at the ortho position of benzene displayed the largest molar absorption coefficients and fluorescence quantum yield. The cyclization quantum yields of these compounds increased in the order of para < ortho < meta, whereas their cycloreversion quantum yields decreased in the order of meta > para > ortho. Additionally, all of these diarylethenes functioned as effective fluorescent switches in both solution and PMMA films. Cyclic voltammograms proved that the formyl group and its position could effectively modulate the electrochemical behaviors of these diarylethene derivatives.

scholarly journals The morphologies and fluorescence quantum yields of perylene diimide dye-doped PS and PHVB microspheres

RSC Advances ◽  
2018 ◽  
Vol 8 (62) ◽  
pp. 35534-35538 ◽  
Author(s):  
Jia Chen ◽  
Shuoxun Jia ◽  
Xiaohuan Ji ◽  
Mohamed Nourrein ◽  
Hengxue Xiang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Perylene Diimide ◽  
Quantum Yields ◽  
Polymer Microspheres ◽  
Polystyrene Microspheres ◽  
Fluorescence Quantum Yields

A POSS functionalized perylene diimide (PDI) derivative, PPP, is applied to polymer microspheres as a red fluorophore. Hollow PPP/polystyrene microspheres show a fluorescence quantum yield (ΦF) of nearly unity.

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