Improved model on fluorescence decay in singlet fission materials

2019 ◽  
Vol 21 (4) ◽  
pp. 2153-2165
Author(s):  
Fang-qi Hu ◽  
Qing Zhao ◽  
Xu-biao Peng
Keyword(s):  
Experimental Data ◽  
Fluorescence Decay ◽  
Singlet Fission ◽  
Dynamics Model ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fission Process ◽  
Improved Model

A comprehensive dynamics model on singlet fission process is presented, giving a more consistent fitting on the time-resolved fluorescence decay experimental data in singlet fission materials.

scholarly journals Architecture of Polyglutamine-containing Fibrils from Time-resolved Fluorescence Decay

2014 ◽  
Vol 289 (39) ◽  
pp. 26817-26828 ◽  
Author(s):  
Christoph Röthlein ◽  
Markus S. Miettinen ◽  
Tejas Borwankar ◽  
Jörg Bürger ◽  
Thorsten Mielke ◽  
...  
Keyword(s):  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Maximum likelihood method for the analysis of time-resolved fluorescence decay curves

1991 ◽  
Vol 20 (5) ◽  
pp. 247-262 ◽  
Author(s):  
?eljko Bajzer ◽  
Terry M. Therneau ◽  
Joseph C. Sharp ◽  
Franklin G. Prendergast
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Method ◽  
Fluorescence Decay ◽  
Likelihood Method ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Time-resolved Fluorescence Decay Study of Hematoporphyrin Derivative

1991 ◽  
Vol 8 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Liu Wenqing ◽  
Xia Yuxing ◽  
Liu Songhao ◽  
Ramponi R ◽  
Cubeddu R
Keyword(s):  
Fluorescence Decay ◽  
Hematoporphyrin Derivative ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Decay Study

scholarly journals Interaction of heparin with internally quenched fluorogenic peptides derived from heparin-binding consensus sequences, kallistatin and anti-thrombin III

2002 ◽  
Vol 366 (2) ◽  
pp. 435-446 ◽  
Author(s):  
Daniel C. PIMENTA ◽  
Iseli L. NANTES ◽  
Eduardo S. de SOUZA ◽  
Bernard Le BONNIEC ◽  
Amando S. ITO ◽  
...  
Keyword(s):  
Binding Sites ◽  
Fluorescence Decay ◽  
Heparin Binding ◽  
Cd Spectra ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Kd Values ◽  
Donor Acceptor ◽  
Peptide Complexes ◽  
Α Helix

Internally quenched fluorogenic (IQF) peptides bearing the fluorescence donor/acceptor pair o-aminobenzoic acid (Abz)/N-(2,4-dinitrophenyl)ethylenediamine (EDDnp) at N- and C-terminal ends were synthesized containing heparin-binding sites from the human serpins kallistatin and antithrombin, as well as consensus heparin-binding sequences (Cardin clusters). The dissociation constant (Kd), as well as the stoichiometry for the heparin–peptide complexes, was determined directly by measuring the decrease in fluorescence of the peptide solution. Experimental procedures were as sensitive as those used to follow the fluorescence change of tryptophan in heparin-binding proteins. The conformation of the peptides and the heparin–peptide complexes were obtained from measurements of time-resolved fluorescence decay and CD spectra. Kallistatin (Arg300–Pro319)-derived peptide (HC2) and one derived from antithrombin III helix D [(AT3D), corresponding to Ser112–Lys139], which are the heparin-binding sites in these serpins, showed significant affinity for 4500Da heparin, for which Kd values were 17nM and 100nM respectively. The CD spectra of the heparin–HC2 peptide complex did not show any significant α-helix content, different from the situation with peptide AT3D, for which complex-formation with heparin resulted in 24% α-helix content. The end-to-end distance distribution and the time-resolved fluorescence-decay measurements agree with the CD spectra and Kd values. The synthetic α-methyl glycoside pentasaccharide AGA∗IAM (where A represents N,6-O-sulphated α-d-glucosamine; G, β-d-glucuronic acid; A∗, N,3,6-O-sulphated α-d-glucosamine; I, 2-O-sulphated α-l-iduronic acid; and AM, α-methyl glycoside of A) also binds to AT3D and other consensus heparin-binding sequences, although with lower affinity. The interaction of IQF peptides with 4500Da heparin was displaced by protamine. In conclusion, IQF peptides containing Abz/EDDnp as the donor/acceptor fluorescence pair are very promising tools for structure–activity relationship studies on heparin–peptide complexes, as well as for the development of new peptides as heparin reversal-effect compounds.

scholarly journals Mechanisms of fluorescence decays of colloidal CdSe–CdS/ZnS quantum dots unraveled by time-resolved fluorescence measurement

2015 ◽  
Vol 17 (41) ◽  
pp. 27588-27595 ◽  
Author(s):  
Hao Xu ◽  
Volodymyr Chmyrov ◽  
Jerker Widengren ◽  
Hjalmar Brismar ◽  
Ying Fu
Keyword(s):  
Quantum Dots ◽  
Radiative Recombination ◽  
Energy Relaxation ◽  
Fluorescence Decay ◽  
Fluorescence Measurement ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Decay Spectrum

The fluorescence decay spectrum of colloidal CdSe-based quantum dots is characterized by energy relaxation and radiative recombination of photoexcited excitons.

Long-lived Triplet Excitons Formed by Exergonic Intramolecular Singlet Fission of an Adamantane-linked Tetracene Dyad

2019 ◽  
Author(s):  
Yasunori Matsui ◽  
Shuhei Kawaoka ◽  
Hiroki Nagashima ◽  
Tatsuo Nakagawa ◽  
Naoki Okamura ◽  
...  
Keyword(s):  
Conformational Dynamics ◽  
High Energy ◽  
Fluorescence Decay ◽  
Singlet Fission ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
Triplet Pair ◽  
Electron Paramagnetic ◽  
Effective Conservation ◽  
Moderate Interaction

<div>An adamantane-linked tetracene dyad (Tc–Ad–Tc) undergoes exergonic intramolecular singlet fission (SF), producing longlived (τ = 175 μs) and high-energy (2 x 1.03 eV) multiexcitons. Timeresolved absorption, fluorescence decay, and electron paramagnetic resonance (EPR) spectroscopic analysis revealed that the long-lived triplet species is generated in this system via correlated triplet pair having singlet and quintet characteristics. Time-resolved EPR analysis revealed that conversion of <sup>1</sup>(<sup>3</sup>Tc–Ad–<sup>3</sup>Tc)* -> <sup>5</sup>(<sup>3</sup>Tc–Ad–<sup>3</sup>Tc)* requires small conformational dynamics accompanied by molecular motion. Analysis of the geometries of the quintet states shows that formation of the long-lived multiexciton is enabled by precise and close alignment of the tetracene moieties, which leads to their moderate interaction in the singlet excited state, while triplet–triplet annihilation is prevented by quintet generation. The presence of aliphatic linkages, like the rigid adamantane group, might enable effective conservation of intrinsic S<sub>1</sub> and T<sub>1</sub> levels of the original monomers, and moderate bridge-mediated σ–π interaction leading to exergonic intramolecular SF involving <sup>1</sup>Tc*–Ad–Tc -> <sup>1</sup>(<sup>3</sup>Tc–Ad–<sup>3</sup>Tc)*.</div><div><br></div>

Pad�-Laplace method for the analysis of time-resolved fluorescence decay curves

1990 ◽  
Vol 18 (2) ◽  
Author(s):  
Z. Bajzer ◽  
J.C. Sharp ◽  
S.S. Sedarous ◽  
F.G. Prendergast
Keyword(s):  
Fluorescence Decay ◽  
Laplace Method ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Monitoring Supramolecular Self-Assembly using Time-Resolved Fluorescence Spectroscopy

2011 ◽  
Vol 64 (6) ◽  
pp. 825 ◽  
Author(s):  
Scott C. McLean ◽  
Colin A. Scholes ◽  
Trevor A. Smith ◽  
Michelle L. Gee
Keyword(s):  
Fluorescence Spectroscopy ◽  
Self Assembly ◽  
Supramolecular Structure ◽  
Micelle Formation ◽  
Fluorescence Decay ◽  
Distribution Analysis ◽  
Time Resolved Fluorescence ◽  
Decay Kinetics ◽  
Time Resolved ◽  
Relative Population

Time-resolved fluorescence spectroscopy is used to observe subtleties in supramolecular structure during the self-assembly of polymers in solution. Lifetime distribution analysis of the fluorescence decay kinetics of the solvent-sensitive fluorescent probe 1-anilino-8-naphthalene sulfonic acid associated with the di-block copolymer poly(2-vinylpyridine)41–poly(ethylene oxide)204 (P2VP-PEO) as it self-assembles enabled identification of three microdomains, distinguishable on the basis of micropolarity. These microdomains can be assigned to different supramolecular substructures: the micelle corona (high polarity), the micelle core and the P2VP globule (both low polarity), and the core–corona interface and the globule–PEO junction (both intermediate polarity). Changes in the relative population distributions of these sub-structures as a function of P2VP-PEO pinpoint the onset of micellization corresponding to the critical micelle concentration (CMC) of the copolymer, but indicate significant variation in supramolecular structure, including micelle formation, well below the CMC. This suggests that supramolecular self-assembly in polymeric systems has characteristics of a second order phase transition.

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