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.

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.

Red-emitting boron difluoride complexes with a mega-large Stokes shift and unexpectedly high fluorescence quantum yield

2020 ◽  
Vol 56 (14) ◽  
pp. 2159-2162 ◽  
Author(s):  
Xiaojie Ren ◽  
Fan Zhang ◽  
Hongchen Luo ◽  
Lide Liao ◽  
Xiangzhi Song ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Stokes Shift ◽  
Quantum Yields ◽  
Large Stokes Shift ◽  
Fluorescence Quantum Yields ◽  
Boron Difluoride ◽  
High Fluorescence ◽  
Stokes Shifts ◽  
High Fluorescence Quantum Yield

Introduction of a tetrahydroquinoxaline donor into boron difluoride complexes largely extended their emissions (617–684 nm), highly improved their fluorescence quantum yields (up to 0.68) and greatly increased their Stokes shifts (up to 209 nm).

Enhanced fluorescence quantum yield of syndiotactic side-chain TPE polymers via Rh-catalyzed carbene polymerization: influence of the substitution density and spacer length

2019 ◽  
Vol 10 (13) ◽  
pp. 1575-1584 ◽  
Author(s):  
Xiao Li ◽  
Yuhao Sun ◽  
Jian Chen ◽  
Zhongying Wu ◽  
Pin Cheng ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Fluorescence Quantum Yield ◽  
Quantum Yields ◽  
Side Chain ◽  
Enhanced Fluorescence ◽  
Spacer Length ◽  
Fluorescence Quantum Yields

The fluorescence quantum yields of the TPE-based C1 polymers also increase with the shortened spacer lengths and further improve by about 20% as compared with the corresponding C2 polyacrylate counterparts.

Limitations Arising from Optical Saturation in Fluorescence and Thermal Lens Spectrometries Using Pulsed Laser Excitation: Application to the Determination of the Fluorescence Quantum Yield of Rhodamine 6G

1996 ◽  
Vol 50 (12) ◽  
pp. 1505-1511 ◽  
Author(s):  
J. Georges ◽  
N. Arnaud ◽  
L. Parise
Keyword(s):  
Quantum Yield ◽  
Thermal Lens ◽  
Fluorescence Quantum Yield ◽  
Rhodamine 6G ◽  
Optical Absorption Coefficient ◽  
Quantum Yields ◽  
Wide Energy Range ◽  
Relaxation Processes ◽  
Fluorescence Quantum Yields ◽  
Fluorescence Measurements

The high incident irradiances available with pulsed lasers can lead to a significant depletion of the ground-state population of the chromophore and to optical saturation effects. As a result, the optical absorption coefficient decreases as a function of the excitation energy and, because the amount of energy released by radiative and nonradiative relaxation processes depends on the amount of energy absorbed, nonlinear energy-dependent signals are obtained. Therefore, large errors can be introduced when fluorescence and photothermal data are used to determine fluorescence quantum yields. This work provides experimental results describing the effects of optical saturation on fluorescence and thermal lens measurements for rhodamine 6G in various media and over a wide energy range. It is shown that, when optical saturation is avoided, the photothermal method gives accurate absolute values of Φf ranging from 0.93 to 0.95, depending on the solvent. On the contrary, fluorescence measurements seem to be sensitive to additional experimental artifacts that are more difficult to characterize and to eliminate. Index Headings: Optical saturation; Thermal lens spectrometry; Fluorescence; Rhodamine 6G; Fluorescence quantum yield.

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.

Comparison of Fluorescence-to-Phosphorescence Quantum Yield Ratios in Solid-Matrix Luminescence as a Function of Temperature

1993 ◽  
Vol 47 (3) ◽  
pp. 283-286 ◽  
Author(s):  
R. J. Hurtubise ◽  
S. M. Ramasamy
Keyword(s):  
Quantum Yield ◽  
Singlet State ◽  
Yield Ratio ◽  
Solid Matrix ◽  
Quantum Yields ◽  
Phosphorescence Lifetime ◽  
Fundamental Parameters ◽  
Fluorescence Quantum Yields ◽  
Photophysical Parameters ◽  
Phosphorescence Quantum Yield

An equation that relates the ratio of fluorescence to phosphorescence quantum yields as function of temperature to basic photophysical parameters is considered. The quantum yields were obtained from three compounds on three different solid matrices. Fluorescence quantum yields did not change much with temperature, while phosphorescence quantum yields changed more substantially with temperature. For some of the systems considered, it was possible to show that, as the temperature was lowered, the quantum yield ratio was only a function of the phosphorescence lifetime of the phosphor. However, with other systems, the quantum yield ratio was dependent on both the rate constant of intersystem crossing from the singlet state to the triplet state and the phosphorescence lifetime. The equation discussed is important in defining the fundamental parameters that cause the luminescence quantum yield ratio to change as temperature is lowered.

Determination of Polycyclic Aromatic Hydrocarbons in the Presence of Humic Acid in water

2016 ◽  
Vol 70 (9) ◽  
pp. 1520-1528 ◽  
Author(s):  
Ruifang Yang ◽  
Nanjing Zhao ◽  
Xue Xiao ◽  
Shaohui Yu ◽  
Jianguo Liu ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Humic Acid ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Quantum Yield ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Polycyclic Aromatic ◽  
Pahs Concentration ◽  
Test Sets

The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the  concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L−1 in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L−1, relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.

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.

meso-(2-Benzimidazolyl)-substituted BODIPYs: Synthesis, structures and spectroscopic properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 230-237
Author(s):  
Hu Gao ◽  
Chenhong Li ◽  
Zhen Shen
Keyword(s):  
Quantum Yield ◽  
Spectroscopic Properties ◽  
Crystallographic Analysis ◽  
Membered Ring ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Nir Dyes ◽  
Nir Fluorescence ◽  
Yield Formula ◽  
Post Modification

A series of meso-(2-benzimidazolyl)-substituted boron dipyrromethene (BODIPY) derivatives 3a–3c and 4 have been synthesized and characterized. The absorption and fluorescence bands of 3a are bathochromically shifted by 36 nm and 61 nm, respectively, compared with those of the meso-phenyl BODIPY in toluene. More importantly, the fluorescence quantum yields of these meso-(2-benzimidazolyl)-substituted BODIPYs (up to 0.45 in toluene) are much higher than those of the previously reported meso-heterocyclic BODIPYs. X-ray crystallographic analysis of the single crystal structure of 3a revealed that the dihedral angle of meso-benzimidazolyl ring and indacene plane (40.47[Formula: see text] ) is smaller compared with that of the meso-tolyl substituted BODIPY (61.4[Formula: see text] ). Replacement of the six-membered ring with a five-membered ring, as well as the absence of hydrogen at the imino-nitrogen, generated the reduced repulsion and the hydrogen bonding interaction. The increased planarity not only provided the substantial delocalization of [Formula: see text] electrons and red shifted the absorption and emission bands but also enhanced the fluorescence quantum yield by reducing free rotation induced nonradiative deactivation pathway. Furthermore, 3,5-distyryl coupled BODIPY 4 exhibits a NIR fluorescence band at 712 nm with moderate quantum yield ([Formula: see text] [Formula: see text] 0.3) in nonpolar and polar solvents, which indicate that meso-(2-benzimidazolyl) BODIPY acts as a good candidate for post modification toward NIR dyes for biological applications.

Sign in / Sign up

Export Citation Format

Share Document