Fluorescence quantum yields, lifetimes, and critical distances for energy transfer for chlorophyll ? and its pheophytin in solutions

1986 ◽  
Vol 45 (2) ◽  
pp. 798-803 ◽  
Author(s):  
A. P. Losev ◽  
E. I. Sagun ◽  
G. A. Kochubeev ◽  
I. N. Nichiporovich
Keyword(s):  
Energy Transfer ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields

H2O2-activated triplet–triplet annihilation upconversion via modulation of the fluorescence quantum yields of the triplet acceptor and the triplet–triplet-energy-transfer efficiency

2015 ◽  
Vol 51 (62) ◽  
pp. 12403-12406 ◽  
Author(s):  
Renjie Tao ◽  
Jianzhang Zhao ◽  
Fangfang Zhong ◽  
Caishun Zhang ◽  
Wenbo Yang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Energy Transfer Efficiency ◽  
Transfer Efficiency ◽  
Quantum Yields ◽  
Fluorescent Product ◽  
Triplet Energy ◽  
Fluorescence Quantum Yields ◽  
Triplet Energy Transfer ◽  
Triplet Triplet Annihilation

H2O2-activatable TTA upconversion was achieved with non-fluorescent 9,10-bis(diphenylphosphino)anthracene as a triplet acceptor/emitter, which can be oxidized to a fluorescent product by H2O2.

scholarly journals A postsynthetically 2’-“clickable” uridine with arabino configuration and its application for fluorescent labeling and imaging of DNA

2017 ◽  
Vol 13 ◽  
pp. 127-137 ◽  
Author(s):  
Heidi-Kristin Walter ◽  
Bettina Olshausen ◽  
Ute Schepers ◽  
Hans-Achim Wagenknecht
Keyword(s):  
Energy Transfer ◽  
Solid Phase ◽  
Fluorescent Labeling ◽  
Fluorescent Imaging ◽  
Quantum Yields ◽  
Color Contrast ◽  
Styryl Dyes ◽  
Fluorescence Quantum Yields ◽  
Color Changes ◽  
Emission Color

The arabino-configured analog of uridine with a propargyl group at the 2’-position was synthesized and incorporated into DNA by solid-phase chemistry. The fluorescence quantum yields of DNA strands that were postsynthetically modified by blue and green emitting cyanine-styryl dyes were improved due to the arabino-configured anchor. These oligonucleotides were used as energy transfer donors in hybrids with oligonucleotides modified with acceptor dyes that emit in the yellow-red range. These combinations give energy transfer pairs with blue–yellow, blue–red and green–red emission color changes. All combinations of arabino- and ribo-configured donor strands with arabino- and ribo-configured acceptor strands were evaluated. This array of doubly modified hybrids was screened by their emission color contrast and fluorescence quantum yield. Especially mixed combinations, that means donor dyes with arabino-configured anchor with acceptor dyes with ribo-configured anchor, and vice versa, showed significantly improved fluorescence properties. Those were successfully applied for fluorescent imaging of DNA after transport into living cells.

scholarly journals Stereoselectivity of Electron and Energy Transfer in the Quenching of (S/R)-Ketoprofen-(S)-Tryptophan Dyad Excited State

2020 ◽  
Vol 21 (15) ◽  
pp. 5370
Author(s):  
Aleksandra A. Ageeva ◽  
Simon V. Babenko ◽  
Ilya M. Magin ◽  
Victor F. Plyusnin ◽  
Polina S. Kuznetsova ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Fluorescence Quenching ◽  
Resonance Energy Transfer ◽  
Practical Interest ◽  
Resonance Energy ◽  
High Sensitivity ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Trp Fluorescence

Photoinduced elementary processes in chiral linked systems, consisting of drugs and tryptophan (Trp) residues, attract considerable attention due to several aspects. First of all, these are models that allow one to trace the full and partial charge transfer underlying the binding of drugs to enzymes and receptors. On the other hand, Trp fluorescence is widely used to establish the structure and conformational mobility of proteins due to its high sensitivity to the microenvironment. Therefore, the study of mechanisms of Trp fluorescence quenching in various systems has both fundamental and practical interest. An analysis of the photo-chemically induced dynamic nuclear polarization (CIDNP) and Trp fluorescence quenching in (R/S)-ketoprofen-(S)-tryptophan ((S/R)-KP-(S)-Trp) dyad carried out in this work allowed us to trace the intramolecular reversible electron transfer (ET) and obtain evidence in favor of the resonance energy transfer (RET). The fraction of dyad’s singlet excited state, quenched via ET, was shown to be 7.5 times greater for the (S,S)-diastereomer than for the (R,S) analog. At the same time, the ratio of the fluorescence quantum yields shows that quenching effectiveness of (S,S)-diastereomer to be 5.4 times lower than for the (R,S) analog. It means that the main mechanism of Trp fluorescence quenching in (S/R)-KP-(S)-Trp dyad is RET.

scholarly journals 1,4-Bis (β-Pyridyl-2-Vinyl) Benzene (P2VB) and 2,5-Distyryl-pyrazine (DSP) as Blue Laser Dyes

1985 ◽  
Vol 5 (4) ◽  
pp. 223-230 ◽  
Author(s):  
E. M. Ebeid ◽  
M. M. F. Sabry ◽  
S. A. El-Daly
Keyword(s):  
Energy Transfer ◽  
Laser Excitation ◽  
Blue Laser ◽  
Quantum Yields ◽  
Nitrogen Laser ◽  
Laser Dyes ◽  
Energy Transfer Mechanism ◽  
Fluorescence Quantum Yields ◽  
Critical Transfer Distance

Solutions of P2VB and DSP in dimethyl-sulphoxide (DMSO) of concentration ca. 10–3 M/l act as laser dyes on pumping with nitrogen laser. P2VB and DSP are lasing in the ranges 390–440 nm (λmax = 416 nm) and 435–465 nm (λmax = 447 nm) respectively. An equimolar mixture of P2VB and DSP behaves as an energy transfer dye laser (ETDL) and is lasing in the range 429–455 nm (λmax = 438 nm). Such ETDL system obeys a long range coulombic energy transfer mechanism with a critical transfer distance R0 = 7.5 nm.The fluorescence quantum yields of both dyes have been measured, and in DMSO φf = 0.46 and 0.35 for P2VB and DSP respectively.Both dyes show a remarkable photostability upon nitrogen laser excitation. This has been attributed to the role of the 337 nm light in inducing a back photo-chemical reaction of the initially formed photoproducts consisting mainly of photo-oligomers and cis-photoisomers.

Visible and Near-Infrared Fluorescence of Crude Oils

1995 ◽  
Vol 49 (6) ◽  
pp. 754-764 ◽  
Author(s):  
Taggart D. Downare ◽  
Oliver C. Mullins
Keyword(s):  
Energy Transfer ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Crude Oils ◽  
Excitation Wavelength ◽  
Fluorescence Emission Spectra ◽  
Fluorescence Quantum Yields ◽  
Oil Type

Fluorescence emission spectra and absolute quantum yields have been measured for ten diverse crude oils at various concentrations over a broad range of excitation and emission wavelengths in the visible and the near-infrared. Energy transfer produces large red shifts and large widths in the fluorescence emission spectra for shorter wavelength excitation particularly for heavier crude oils. However, the effects of energy transfer are nearly absent for near-infrared excitation; all crude oils exhibit nearly the same emission spectra for long wavelength excitation. In addition, the fraction of emission resulting from collisional energy transfer relative to nascent emission is almost independent of oil type; it is governed by quantum yield characteristics. Absolute fluorescence quantum yields of ten crude oils (and three rhodamine dyes for validation) were measured with respect to scattering of latex microspheres in distilled water. Fluorescence quantum yields vary systematically with crude oil type as well as excitation wavelength; quantum yields are lower for high fluorophore concentrations (heavy crude oils) and for longer wavelength excitation. Stern-Volmer analyses of the quantum yields indicate that simple models apply and show the relative quenching rates for different excitation wavelengths.

scholarly journals High-performance quasi-2D perovskite light-emitting diodes: from materials to devices

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Li Zhang ◽  
Changjiu Sun ◽  
Tingwei He ◽  
Yuanzhi Jiang ◽  
Junli Wei ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Structural Characteristics ◽  
Quantum Yields ◽  
Research Directions ◽  
Light Emitting ◽  
Perovskite Materials ◽  
Quantum Confinement Effects ◽  
Semiconducting Properties

AbstractQuasi-two-dimensional (quasi-2D) perovskites have attracted extraordinary attention due to their superior semiconducting properties and have emerged as one of the most promising materials for next-generation light-emitting diodes (LEDs). The outstanding optical properties originate from their structural characteristics. In particular, the inherent quantum-well structure endows them with a large exciton binding energy due to the strong dielectric- and quantum-confinement effects; the corresponding energy transfer among different n-value species thus results in high photoluminescence quantum yields (PLQYs), particularly at low excitation intensities. The review herein presents an overview of the inherent properties of quasi-2D perovskite materials, the corresponding energy transfer and spectral tunability methodologies for thin films, as well as their application in high-performance LEDs. We then summarize the challenges and potential research directions towards developing high-performance and stable quasi-2D PeLEDs. The review thus provides a systematic and timely summary for the community to deepen the understanding of quasi-2D perovskite materials and resulting LED devices.

Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽  
2021 ◽  
Author(s):  
Xianglong Chu ◽  
Yadi Niu ◽  
Chen Ma ◽  
Xiaodong Wang ◽  
Yunliang Lin ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Cross Coupling Reaction ◽  
Color Tunable ◽  
Palladium Catalyzed ◽  
Structure Relationship ◽  
High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

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