scholarly journals Influence of chemical structure of branched and dendritic organosilicon luminophores on their optical and thermal properties

2017 ◽  
Vol 5 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Oleg V. Borshchev ◽  
Elena A. Kleymyuk ◽  
Nikolay M. Surin ◽  
Evgeniya A. Svidchenko ◽  
Yuriy V. Fedorov ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Thermal Properties ◽  
Quantum Yield ◽  
Decay Time ◽  
Extinction Coefficient ◽  
Chemical Structure ◽  
High Efficiency ◽  
Intramolecular Energy Transfer ◽  
Antenna Effect ◽  
Complex Molecules

AbstractSynthesis and investigation of optical and thermal properties of a homologous series of highly luminescent nanostructured organosilicon luminophores (NOLs) containing different donor to acceptor ratio (D:A) are reported. Each of the NOL consists of a 1,4-bis(5-phenylthienyl-2-yl)benzene (PTPTP) acceptor unit and four, six or twelve 2,2′-bithienyl donor fragments connected to each other through two or six silicon atoms. These complex molecules show a “molecular antenna” effect with high efficiency of intramolecular energy transfer about 97-98% combined with excellent photoluminescence (PL) quantum yield of 84-91% and fast PL decay time of 0.90-0.95 ns. A significant increase of the molar extinction coefficient from 94 000 to 257 000 M

Spectral-luminescent effects in heterometallic complexes of crown-porphyrins

2001 ◽  
Vol 05 (05) ◽  
pp. 481-485 ◽  
Author(s):  
YU. KOROVIN ◽  
Z. ZHILINA ◽  
N. RUSAKOVA ◽  
V. KUZ'MIN ◽  
S. VODZINSKY ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Alkali Metal ◽  
Heterometallic Complexes ◽  
Luminescence Spectra ◽  
Intramolecular Energy Transfer ◽  
Triplet Level ◽  
Molecular Luminescence ◽  
Sandwich Type

New complexes of ytterbium with porphyrins containing crown- and other oxygen-containing cyclic substituents were obtained. The absorption, excitation, ligand luminescence and 4f-luminescence spectra have been investigated. It has been shown that 4f-luminescence of ytterbium Yb ( III ) ions was a result of the intramolecular energy transfer from the triplet level of the ligands to the resonance 2F5/2 level of Yb ( III ). It has been also established that in presence of alkali metal Na , K and Cs the dimer complexes (sandwich-type) of ytterbium-crown-porphyrin were formed. Molecular luminescence of the porphyrin matrix was quenched completely in these dimers, but at the same time the quantum yield and lifetime of 4f-luminescence increase in the complexes.

scholarly journals Photophysical Challenges and Antenna Effect Between Click Reaction-based Bodipy Derivatives Manufactured From Knorr Pyrrole

2021 ◽  
Author(s):  
ahmed nuri kursunlu ◽  
Akif Kagan Yilmaz ◽  
Elif Bastug ◽  
Ersin Guler
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Absorption Coefficient ◽  
Organic Solvents ◽  
Click Reaction ◽  
Photophysical Properties ◽  
Molar Absorption Coefficient ◽  
Antenna Effect ◽  
Preliminary Study

Abstract In this paper, a series of click reaction-based Bodipy derivatives have been synthesized as part of a preliminary study. Following the characterization of the four challenger molecules, the photophysical properties (absorption, emission, excitation, molar absorption coefficient, quantum yield, etc.) were examined in various organic solvents. The results showed that the energy transfer from the Bodipy cores to other moieties was calculated between 71% and 93% depending on different π-electron configurations and chromophore groups.

Energieübertragung in Anthracen dotierten 2,3 Dimethyl- naphthalin-Einkristallen im Temperaturbereich 4K < T < 300 K / Energy Transfer in Anthracene Doped 2,3 Dimethylnaphthalene Single Crystals

1975 ◽  
Vol 30 (11) ◽  
pp. 1462-1469 ◽  
Author(s):  
P. Ganz
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Single Crystals ◽  
Decay Time ◽  
Fluorescence Spectra ◽  
Theoretical Interpretation ◽  
Impurity Molecule ◽  
Relative Quantum Yield ◽  
Light Pulses ◽  
Relative Quantum

The fluorescence spectra and the decay time of emission bands of pure and anthracene doped 2,3 Dimethylnaphthalin single crystals excited by short light pulses were examined for temperatures of 4 to 300 K.On raising the temperature from 40 to 120 K the decay time and the relative quantum yield of 2,3 DN decreases, the emission is shifted by about 150 cm-1 to higher energies and simultanously the energy transfer to the anthracene impurity molecule increases.A model calculation is presented which allows a theoretical interpretation of the experimental results

Synthesis, electrochemistry, spectroscopy and photophysical properties of a series of meso-phenylpyridylporphyrins with one to four pyridyl rings coordinated to [Ru(bipy)2Cl]+ groups

2002 ◽  
Vol 06 (01) ◽  
pp. 33-42 ◽  
Author(s):  
Fábio M. Engelmann ◽  
Pellegrino Losco ◽  
Herbert Winnischofer ◽  
Koiti Araki ◽  
Henrique E. Toma
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Electrochemical Behavior ◽  
Fluorescence Quantum Yield ◽  
Photophysical Properties ◽  
Intramolecular Energy Transfer ◽  
Porphyrin Ring ◽  
Transfer Processes ◽  
Redox Pair ◽  
Mlct State

A series of meso-phenylpyridylporphyrins and their respective supermolecular species obtained by the coordination of [ Ru ( bipy )2 Cl ]+ groups to the pyridyl substituents was synthesized and characterized. Their spectroscopic and electrochemical behavior were similar to that observed for the meso-tetra(4-pyridyl)porphyrin derivative, but the redox potential of the Ru (III/II) redox pair was about 70 mV more negative. The porphyrin centered fluorescence quantum yield exhibited a linear decrease as a function of the number of pyridyl substituents on the porphyrin ring. Efficient intramolecular energy transfer processes from the 3 MLCT state of the ruthenium complexes to the porphyrin center were observed at 77K in ethanol glass.

Synthesis and Characterization of ROSA Dye - A Rhodamine B-type Fluorophore, Suitable for Bioconjugation and Fluorescence Studies in Live Cells

2019 ◽  
Vol 26 (10) ◽  
pp. 758-767
Author(s):  
Vicente Rubio ◽  
Vijaya Iragavarapu ◽  
Maciej J. Stawikowski
Keyword(s):  
Quantum Yield ◽  
Cancer Cells ◽  
Fluorescent Probe ◽  
Extinction Coefficient ◽  
Rhodamine B ◽  
Solid Phase ◽  
Total Yield ◽  
Molar Extinction Coefficient ◽  
Αvβ3 Integrin ◽  
Αvβ3 Integrins

Background: Herein we report the multigram-scale synthesis, characterization and application of a rhodamine B-based fluorophore (ROSA) suitable for fluorescent studies in biological applications. This fluorophore is devoid of rhodamine spirolactone formation and furthermore characterized by a high molar extinction coefficient (ϵ=87250 ± 1630 M-1cm-1) and quantum yield (φ) of 0.589 ± 0.070 in water. Reported here is also the application of ROSA towards synthesis of a ROSA-PEG-GRGDS-NH2 fluorescent probe suitable for live cell imaging of αvβ3 integrins for in vitro assays. Objective: The main objective of this study is to efficiently prepare rhodamine B derivative, devoid of spirolactone formation that would be suitable for bioconjugation and subsequent bioimaging. Methods: Rhodamine B was transformed into rhodamine B succinimide ester (RhoB-OSu) using N-hydroxysuccinimide. RhoB-OSu was further coupled to sarcosine to obtain rhodamine Bsarcosine dye (ROSA) in good yield. The ROSA dye was then coupled to a αvβ3 integrin binding sequence using standard solid-phase conditions. Resulting ROSA-PEG-GRGDS-NH2 probe was used to image integrins on cancer cells. Results: The rhodamine B-sarcosine dye (ROSA) was obtained in multigram scale in good total yield of 47%. Unlike rhodamine B, the ROSA dye does not undergo pH-dependent spirolactone/spirolactam formation as compared with rhodamine B-glycine. It is also characterized by excellent quantum yield (φ) of 0.589 ± 0.070 in water and high molar extinction coefficient of 87250 ± 1630 M-1cm-1. ROSA coupling to the RGD-like peptide was proved to be efficient and straightforward. Imaging using standard filters on multimode plate reader and confocal microscope was performed. The αvβ3 integrins present on the surface of live WM-266-4 (melanoma) and MCF- 7 (breast cancer) cells were successfully imaged. Conclusion: We successfully derivatized rhodamine B to create an inexpensive, stable and convenient to use fluorescent probe. The obtained derivative has excellent photochemical properties and it is suitable for bioconjugation and many imaging applications.

Delocalized Excitation or Intramolecular Energy Transfer in Pyrene Core Dendrimers

2021 ◽  
pp. 7717-7725
Author(s):  
Dayujia Huo ◽  
Minjie Li ◽  
Zujin Zhao ◽  
Xian Wang ◽  
Andong Xia ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Intramolecular Energy Transfer

scholarly journals Monte Carlo Modeling and Design of Photon Energy Attenuation Layers for >10× Quantum Yield Enhancement in Si-Based Hard X-ray Detectors

Instruments ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 17
Author(s):  
Eldred Lee ◽  
Kaitlin M. Anagnost ◽  
Zhehui Wang ◽  
Michael R. James ◽  
Eric R. Fossum ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Quantum Yield ◽  
Photon Energy ◽  
High Efficiency ◽  
High Energy ◽  
Yield Enhancement ◽  
X Ray ◽  
Simulation Results ◽  
Conversion Efficiencies

High-energy (>20 keV) X-ray photon detection at high quantum yield, high spatial resolution, and short response time has long been an important area of study in physics. Scintillation is a prevalent method but limited in various ways. Directly detecting high-energy X-ray photons has been a challenge to this day, mainly due to low photon-to-photoelectron conversion efficiencies. Commercially available state-of-the-art Si direct detection products such as the Si charge-coupled device (CCD) are inefficient for >10 keV photons. Here, we present Monte Carlo simulation results and analyses to introduce a highly effective yet simple high-energy X-ray detection concept with significantly enhanced photon-to-electron conversion efficiencies composed of two layers: a top high-Z photon energy attenuation layer (PAL) and a bottom Si detector. We use the principle of photon energy down conversion, where high-energy X-ray photon energies are attenuated down to ≤10 keV via inelastic scattering suitable for efficient photoelectric absorption by Si. Our Monte Carlo simulation results demonstrate that a 10–30× increase in quantum yield can be achieved using PbTe PAL on Si, potentially advancing high-resolution, high-efficiency X-ray detection using PAL-enhanced Si CMOS image sensors.

Identification of intramolecular energy transfer pathways in a reactive triatomic system

1988 ◽  
Vol 89 (5) ◽  
pp. 2948-2957 ◽  
Author(s):  
R. Scott Smith ◽  
Randall B. Shirts
Keyword(s):  
Energy Transfer ◽  
Intramolecular Energy Transfer
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