Triplet energy transfer. IX. Nonlinear quenching and variable excited state lifetimes in the photochemistry of mixed chromophores

1974 ◽  
Vol 96 (11) ◽  
pp. 3668-3670 ◽  
Author(s):  
Peter J. Wagner ◽  
Takayuki Nakahira
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Triplet Energy ◽  
Excited State Lifetimes ◽  
Triplet Energy Transfer

scholarly journals Sensitization of ultra-long-range excited-state electron transfer by energy transfer in a polymerized film

2012 ◽  
Vol 109 (38) ◽  
pp. 15132-15135 ◽  
Author(s):  
Akitaka Ito ◽  
David J. Stewart ◽  
Zhen Fang ◽  
M. Kyle Brennaman ◽  
Thomas J. Meyer
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Excited State ◽  
Charge Transfer ◽  
Long Range ◽  
Methyl Viologen ◽  
Polymer Network ◽  
Triplet Energy ◽  
Ligand Charge Transfer ◽  
Triplet Energy Transfer

Distance-dependent energy transfer occurs from the Metal-to-Ligand Charge Transfer (MLCT) excited state to an anthracene-acrylate derivative (Acr-An) incorporated into the polymer network of a semirigid poly(ethyleneglycol)dimethacrylate monolith. Following excitation, to Acr-An triplet energy transfer occurs followed by long-range, Acr-3An—Acr-An → Acr-An—Acr-3An, energy migration. With methyl viologen dication (MV2+) added as a trap, Acr-3An + MV2+ → Acr-An+ + MV+ electron transfer results in sensitized electron transfer quenching over a distance of approximately 90 Å.

Combined Picosecond Time-Resolved UV–Vis and NMR Techniques Used for Investigation of the Excited State Intramolecular Triplet–Triplet Energy Transfer

2019 ◽  
Vol 123 (32) ◽  
pp. 6978-6985 ◽  
Author(s):  
Jacek Dobkowski ◽  
Alexandr Gorski ◽  
Michał Kijak ◽  
Mariusz Pietrzak ◽  
Kipras Redeckas ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Triplet Energy ◽  
Time Resolved ◽  
Nmr Techniques ◽  
Triplet Energy Transfer

Preparation of Bodipy–ferrocene dyads and modulation of the singlet/triplet excited state of bodipy via electron transfer and triplet energy transfer

2016 ◽  
Vol 4 (14) ◽  
pp. 2843-2853 ◽  
Author(s):  
Xueyan Wu ◽  
Wenting Wu ◽  
Xiaoneng Cui ◽  
Jianzhang Zhao ◽  
Mingbo Wu
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Excited State ◽  
Excited States ◽  
Singlet Excited State ◽  
Triplet Excited State ◽  
Triplet Energy ◽  
Triplet Excited States ◽  
Triplet Energy Transfer

Bodipy–ferrocene dyads were prepared for reversible electrochemical switching of the singlet excited state (fluorescence), as well as the triplet excited states of Bodipy.

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.

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