The singlet-oxygen-sensitized delayed fluorescence in mammalian cells: a time-resolved microscopy approach

2015 ◽  
Vol 14 (4) ◽  
pp. 700-713 ◽  
Author(s):  
Marek Scholz ◽  
Anna-Louisa Biehl ◽  
Roman Dědic ◽  
Jan Hála
Keyword(s):  
Excited State ◽  
Singlet Oxygen ◽  
Mammalian Cells ◽  
Delayed Fluorescence ◽  
Fibroblast Cells ◽  
Proof Of Concept ◽  
Time Resolved ◽  
Excited State Lifetimes ◽  
Kinetics Of

Microsecond kinetics of singlet-oxygen-sensitized delayed fluorescence (SOSDF) have been detected from individual living fibroblast cells as a proof-of-concept. These provide valuable information about excited state lifetimes and their changes during PDT-like treatment.

Efficient intersystem crossing using singly halogenated carbomethoxyphenyl porphyrins measured using delayed fluorescence, chemical quenching, and singlet oxygen emission

2015 ◽  
Vol 17 (43) ◽  
pp. 29090-29096 ◽  
Author(s):  
Dawn M. Marin ◽  
Sonia Payerpaj ◽  
Graham S. Collier ◽  
Angy L. Ortiz ◽  
Gaurav Singh ◽  
...  
Keyword(s):  
Excited State ◽  
Singlet Oxygen ◽  
State Formation ◽  
Delayed Fluorescence ◽  
Intersystem Crossing ◽  
Fluorescence Lifetimes ◽  
Triplet Excited State

Singly halogenated carbomethoxyphenylporphyrins show decreased singlet fluorescence lifetimes and increased rates of triplet excited state formation.

scholarly journals Excited States and Intermediates by Time-Resolved Infrared Spectroscopy

1999 ◽  
Vol 19 (1-4) ◽  
pp. 245-251 ◽  
Author(s):  
J. J. Turner ◽  
M. W. George ◽  
I. P. Clark ◽  
I. G. Virrels
Keyword(s):  
Infrared Spectroscopy ◽  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
Fast Time ◽  
Time Resolved ◽  
Excited Species ◽  
Charge Transfer Transitions ◽  
Time Resolved Infrared Spectroscopy ◽  
Kinetics Of

For coordination compounds containing CO or CN groups, fast time-resolved infrared spectroscopy (TRIR) provides a convenient method of probing excited states and intermediates. TRIR has proved particularly powerful for probing the structure and kinetics of organometallic intermediates. The interpretation is particularly straightforward when combined with IR data from matrix isolation experiments, although there can be some subtle differences. In excited state studies, shifts in ν(CO) and ν(CN) frequencies, from ground to excited state, are sensitive to the changes in electron distribution on excitation, thus allowing the distinction between charge-transfer and non-charge-transfer transitions. Subtle effects on excited state ν(CO) band positions occur with change from fluid to rigid solvent-“infrared rigidochromism”. There is often a change in ν(CO) band width on excitation; this can be interpreted in terms of specific interactions between the excited species and the solvent. This paper presents some of our recent work in this area.

Excited state lifetimes and energies of okenone and chlorobactene, exemplary keto and non-keto aryl carotenoids

2015 ◽  
Vol 17 (20) ◽  
pp. 13245-13256 ◽  
Author(s):  
Dariusz M. Niedzwiedzki ◽  
Laura Cranston
Keyword(s):  
Excited State ◽  
Photophysical Properties ◽  
Time Resolved ◽  
Excited State Lifetimes

Photophysical properties of two typical aryl carotenoids, okenone and chlorobactene, were studied with application of femtosecond and microsecond time-resolved absorption spectroscopies.

Kinetics of Photon Upconversion in Ionic Liquids: Time-Resolved Analysis of Delayed Fluorescence

2013 ◽  
Vol 117 (17) ◽  
pp. 5180-5187 ◽  
Author(s):  
Yoichi Murakami ◽  
Hitomi Kikuchi ◽  
Akio Kawai
Keyword(s):  
Ionic Liquids ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Kinetics Of

Triplet-State Kinetics of 2,5 Diphenyloxazole (PPO)

1988 ◽  
Vol 42 (1) ◽  
pp. 27-31
Author(s):  
A. N. Dharamsi ◽  
Shawpin Jong
Keyword(s):  
Excited State ◽  
Triplet State ◽  
Absorption Spectra ◽  
Rate Constants ◽  
Intersystem Crossing ◽  
Time Resolved ◽  
Probe Technique ◽  
Pump And Probe ◽  
Kinetics Of ◽  
Triplet Absorption

Time-resolved excited-state triplet-triplet absorption spectra were measured for solutions of 2,5 diphenyloxazole (PPO) in various solvents, with the use of a pump and probe technique. The rate constants for intersystem crossing, triplet deactivation by oxygen, and triplet-triplet self-quenching are obtained. The latter two rate constants are substantially larger than the corresponding rate constants for 2-(1 naphthyl)-5-phenyloxazole-αNPO.

scholarly journals Characterization of Excited States in a Multiple-Resonance-Type Thermally Activated Delayed Fluorescence Molecule Using Time-resolved Infrared Spectroscopy

2021 ◽  
Author(s):  
Yuushi Shimoda ◽  
Masaki Saigo ◽  
Tomohiro Ryu ◽  
Takumi Ehara ◽  
Kiyoshi Miyata ◽  
...  
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Potential Surfaces ◽  
Time Resolved ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Multiple Resonance ◽  
Time Resolved Infrared Spectroscopy

We have investigated the correlation between the photophysical properties and the excited-state detailed characteristics in a multiple-resonance-type thermally activated delayed fluorescence (TADF) molecule, DABNA-1, using time-resolved infrared vibrational spectroscopy. In comparison of the distinctive vibrational spectra in the fingerprint region, 1000 - 1700 cm<sup>-1</sup>, to the simulated spectra by density functional theory calculations, we found the best calculation condition. On the basis of the calculations, we determined the excited-state geometries and molecular orbitals of the lowest excited singlet (S<sub>1</sub>) and triplet (T<sub>1</sub>) states as well as the ground state (S<sub>0</sub>). We revealed that the similarity of the potential surfaces between T<sub>1</sub> and S<sub>0</sub> suppresses the nonradiative decay and causes the high fluorescence quantum yield via TADF process.

Microscopic time-resolved imaging of singlet oxygen by delayed fluorescence in living cells

2017 ◽  
Vol 16 (11) ◽  
pp. 1643-1653 ◽  
Author(s):  
Marek Scholz ◽  
Roman Dědic ◽  
Jan Hála
Keyword(s):  
Singlet Oxygen ◽  
Living Cells ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Microscopic Imaging ◽  
Time Resolved Imaging ◽  
In Cells

Singlet Oxygen Feedback Delayed Fluorescence (SOFDF) is a novel semi-direct modality for microscopic imaging of singlet oxygen in cells. SOFDF enables time-resolved experiments and it can be much stronger than the singlet oxygen phosphorescence.

scholarly journals Quantum-chemistry-aided ligand engineering for potential molecular switches: changing barriers to tune excited state lifetimes

2020 ◽  
Vol 56 (79) ◽  
pp. 11831-11834
Author(s):  
Dorottya Sárosiné Szemes ◽  
Tamás Keszthelyi ◽  
Mariann Papp ◽  
László Varga ◽  
György Vankó
Keyword(s):  
Excited State ◽  
Quantum Chemistry ◽  
Energy Barrier ◽  
Molecular Switches ◽  
Iron Complex ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Singlet States ◽  
Excited State Lifetimes

DFT predicts the ability to tune the energy barrier between the quintet and singlet states of an iron complex, and thus the quintet lifetime, with selected substituents on the ligand; this prediction is confirmed by time-resolved spectroscopy.

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