scholarly journals Migration of Excitation Energy in Furocoumarins

2021 ◽  
Vol 9 ◽  
Author(s):  
O.N. Tchaikovskaya ◽  
N.G. Dmitrieva ◽  
E.N. Bocharnikova ◽  
V.S. Chaidonova ◽  
P.V. Avramov
Keyword(s):  
Quantum Chemistry ◽  
Excitation Energy ◽  
Pulse Duration ◽  
Absorption Spectroscopy ◽  
Electron Spectroscopy ◽  
Emission Wavelength ◽  
Triplet States ◽  
Stationary Electron ◽  
Fluorescence And Phosphorescence ◽  
Triplet Transition

The migration of excitation energy of a number of psoralen compounds has been studied. For this, the methods of induced absorption spectroscopy, stationary electron spectroscopy, fluorescence and phosphorescence, as well as quantum chemistry were used. A comparative photostability of psoralen was achieved by exposure to a XeCl excilamp irradiation (emission wavelength λem = 308 nm) with parameters Δλ = 5–10 nm, Wpeak = 18 mW/cm2, p = 8.1 J/cm3, f = 200 kHz, pulse duration 1 μs. It was found that the singlet-triplet transition played a major role in the migration of excitation energy into triplet states. Among all tested compounds, substances with an OCH3-group in the structure have the strongest effect on the spectral-luminescent characteristics.

A practical method for determining film thickness using X-ray absorption spectroscopy in total electron yield mode

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Noritake Isomura ◽  
Keiichiro Oh-ishi ◽  
Naoko Takahashi ◽  
Satoru Kosaka
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Absorption Spectroscopy ◽  
Electron Spectroscopy ◽  
Practical Method ◽  
Decay Length ◽  
Total Electron ◽  
X Ray ◽  
Logarithmic Equation ◽  
X Ray Absorption

Thin films formed on surfaces have a large impact on the properties of materials and devices. In this study, a method is proposed using X-ray absorption spectroscopy to derive the film thickness of a thin film formed on a substrate using the spectral separation and logarithmic equation, which is a modified version of the formula used in electron spectroscopy. In the equation, the decay length in X-ray absorption spectroscopy is longer than in electron spectroscopy due to a cascade of inelastic scattering of electrons generated in a solid. The modification factor, representing a multiple of the decay length, was experimentally determined using oxidized Si and Cu with films of thickness 19 nm and 39 nm, respectively. The validity of the proposed method was verified, and the results indicated that the method can be used in the analysis of various materials with thin films.

Depolarization of Photoluminescence of Isotropic Solutions Produced by Excitation Energy Migration

1987 ◽  
Vol 42 (8) ◽  
pp. 813-818
Author(s):  
A. Kawski ◽  
J. Kamiński
Keyword(s):  
Experimental Data ◽  
Energy Transfer ◽  
Excitation Energy ◽  
Master Equation ◽  
Shell Model ◽  
Excitation Energy Transfer ◽  
Critical Distance ◽  
Energy Migration ◽  
Isotropic Solution ◽  
Fluorescence And Phosphorescence

A theory of the excitation energy transfer between like molecules in isotropic solution based on a centre or shell model of a primarily excited luminescent molecule and on the extended Förster “excitation master equation” has been elaborated. Fluorescence and phosphorescence depolarization are shown to be governed by singlet-singlet energy migration and described by the same expression. The comparison of the theoretical curve with the experimental data obtained by Gondo et al. (1975) for benzo[f]quinoline in ethanol glass at 77 K results in the following critical distance R0 for the excitation energy migration: 21.5 Å for fluorescence and phosphorescence, respectively.

scholarly journals Polyphenylsilole multilayers – an insight from X-ray electron spectroscopy and density functional theory

2015 ◽  
Vol 17 (46) ◽  
pp. 31117-31124 ◽  
Author(s):  
Katharina Diller ◽  
Yong Ma ◽  
Yi Luo ◽  
Francesco Allegretti ◽  
Jianzhao Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Silicon Atom ◽  
Absorption Spectroscopy ◽  
Electron Spectroscopy ◽  
Density Functional ◽  
Functional Theory ◽  
X Ray ◽  
Photoelectron And Absorption Spectroscopy

Two polyphenylsilole compounds are characterised using X-ray photoelectron and absorption spectroscopy and density functional theory. In both compounds the positive silicon atom is flanked by two negatively charged carbon atoms.

Deexcitation electron spectroscopy of core‐excited NO as a function of excitation energy

1994 ◽  
Vol 101 (2) ◽  
pp. 998-1005 ◽  
Author(s):  
T. X. Carroll ◽  
M. Coville ◽  
P. Morin ◽  
T. D. Thomas
Keyword(s):  
Excitation Energy ◽  
Electron Spectroscopy

scholarly journals Complexes trans-Pt(BODIPY)X(PEt3)2: excitation energy-dependent fluorescence and phosphorescence emissions, oxygen sensing and photocatalysis

2016 ◽  
Vol 45 (25) ◽  
pp. 10420-10434 ◽  
Author(s):  
Peter Irmler ◽  
Rainer F. Winter
Keyword(s):  
Excitation Energy ◽  
Oxygen Sensing ◽  
Single Component ◽  
Quantum Yields ◽  
Dual Fluorescence ◽  
Anionic Ligand ◽  
Energy Dependent ◽  
Fluorescence And Phosphorescence

Complexes trans-Pt(BODIPY)X(PEt3)2 exhibit dual fluorescence and phosphorescence emissions, whose intensities are modulated by the anionic ligand X− and the excitation wavelengths. They constitute efficient single-component 3O2 sensors and photocatalysts for aereal photooxidations with quantum yields near unity.

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