Nuts and Bolts of Excitation Energy Migration and Energy Transfer

2007 ◽  
pp. 83-105 ◽  
Author(s):  
Robert M. Clegg
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Energy Migration

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.

Thymine Dimerization Induced by Oxidative DNA Lesions and Epigenetic Intermediates via Triplet-Triplet Energy Transfer

2020 ◽  
Author(s):  
Mauricio Lineros-Rosa ◽  
Antonio Francés-Monerris ◽  
Antonio Monari ◽  
Miguel Angél Miranda ◽  
Virginie Lhiaubet-Vallet
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Transient Absorption ◽  
Theoretical Calculations ◽  
Dna Lesions ◽  
Transient Absorption Spectroscopy ◽  
Triplet Energy ◽  
Pyrimidine Dimers ◽  
Triplet Energy Transfer ◽  
Dna Nucleobases

Interaction of nucleic acids with light is a scientific question of paramount relevance not only in the understanding of life functioning and evolution, but also in the insurgence of diseases such as malignant skin cancer and in the development of biomarkers and novel light-assisted therapeutic tools. This work shows that the UVA portion of sunlight, not absorbed by canonical DNA nucleobases, can be absorbed by 5-formyluracil (ForU) and 5-formylcytosine (ForC), two ubiquitous oxidative lesions and epigenetic intermediates present in living beings in natural conditions. We measure the strong propensity of these molecules to populate triplet excited states able to transfer the excitation energy to thymine-thymine dyads, inducing the formation of the highly toxic and mutagenic cyclobutane pyrimidine dimers (CPDs). By using steady-state and transient absorption spectroscopy, NMR, HPLC, and theoretical calculations, we quantify the differences in the triplet-triplet energy transfer mediated by ForU and ForC, revealing that the former is much more efficient in delivering the excitation energy and producing the CPD photoproduct. Although significantly slower than ForU, ForC is also able to harm DNA nucleobases and therefore this process has to be taken into account as a viable photosensitization mechanism. The present findings evidence a rich photochemistry crucial to understand DNA photodamage and of potential use in the development of biomarkers and non-conventional photodynamic therapy agents.

scholarly journals An Effective Potential for Frenkel Excitons

2020 ◽  
Author(s):  
Bartosz Błasiak ◽  
Wojciech Bartkowiak ◽  
Robert Władysław Góra
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Efficient Method ◽  
Effective Potential ◽  
Excitation Energy Transfer ◽  
Computationally Efficient ◽  
Frenkel Excitons

Excitation energy transfer (EET) is a ubiquitous process in life and materials sciences. Here, a new and computationally efficient method of evaluating the electronic EET couplings between interacting chromophores is...

scholarly journals Excitation Energy Transfer from Rhodamine 6G to Photochromic Fulgide

2014 ◽  
Vol 26 (23) ◽  
pp. 8229-8233
Author(s):  
Rabab Sharaf Jassas ◽  
Samy Abdullah El-Daly ◽  
Abdullah M. Asiri ◽  
Salman A Khan
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Rhodamine 6G ◽  
Excitation Energy Transfer
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