Laser Photolysis and Pulse Radiolysis Investigations on the Triplet Energy Transfer in Aromatic Donor-Acceptor Systems

1985 ◽  
Vol 89 (10) ◽  
pp. 1036-1041 ◽  
Author(s):  
O. Brede ◽  
R. Mehnert ◽  
W. Naumann ◽  
J. Teply
Keyword(s):  
Energy Transfer ◽  
Pulse Radiolysis ◽  
Laser Photolysis ◽  
Triplet Energy ◽  
Aromatic Donor ◽  
Donor Acceptor ◽  
Triplet Energy Transfer

Triplet-Triplet Energy Transfer Controlled by the Donor-Acceptor Distance in Rigidly Held Palladium-Containing Cofacial Bisporphyrins

2005 ◽  
Vol 11 (11) ◽  
pp. 3469-3481 ◽  
Author(s):  
Sébastien Faure ◽  
Christine Stern ◽  
Enrique Espinosa ◽  
Jasmin Douville ◽  
Roger Guilard ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Triplet Energy ◽  
Donor Acceptor ◽  
Triplet Energy Transfer

scholarly journals Shallow distance-dependent triplet energy migration mediated by endothermic charge-transfer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Runchen Lai ◽  
Yangyi Liu ◽  
Xiao Luo ◽  
Lan Chen ◽  
Yaoyao Han ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Semiconductor Nanocrystals ◽  
Electronic Coupling ◽  
Alternative Mechanism ◽  
Acceptor Pair ◽  
Triplet Energy ◽  
Distance Dependence ◽  
Donor Acceptor ◽  
Triplet Energy Transfer

AbstractConventional wisdom posits that spin-triplet energy transfer (TET) is only operative over short distances because Dexter-type electronic coupling for TET rapidly decreases with increasing donor acceptor separation. While coherent mechanisms such as super-exchange can enhance the magnitude of electronic coupling, they are equally attenuated with distance. Here, we report endothermic charge-transfer-mediated TET as an alternative mechanism featuring shallow distance-dependence and experimentally demonstrated it using a linked nanocrystal-polyacene donor acceptor pair. Donor-acceptor electronic coupling is quantitatively controlled through wavefunction leakage out of the core/shell semiconductor nanocrystals, while the charge/energy transfer driving force is conserved. Attenuation of the TET rate as a function of shell thickness clearly follows the trend of hole probability density on nanocrystal surfaces rather than the product of electron and hole densities, consistent with endothermic hole-transfer-mediated TET. The shallow distance-dependence afforded by this mechanism enables efficient TET across distances well beyond the nominal range of Dexter or super-exchange paradigms.

Enhancing triplet sensitization ability of donor–acceptor dyads via intramolecular triplet energy transfer

2020 ◽  
Vol 8 (10) ◽  
pp. 3536-3544
Author(s):  
Shanshan Liu ◽  
Xiangyang Wang ◽  
Heyuan Liu ◽  
Li Shen ◽  
Dezhi Zhao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Triplet Energy ◽  
Donor Acceptor ◽  
Triplet Energy Transfer

Efficient intramolecular triplet–triplet energy transfer is beneficial for improving the upconversion efficiency when the donor–acceptor system is adopted as a triplet donor.

Intramolecular Triplet Energy Transfer in Donor–Acceptor Molecules Linked by a Crown Ether Bridge

2006 ◽  
Vol 12 (20) ◽  
pp. 5238-5245 ◽  
Author(s):  
Xiao-He Xu ◽  
Xiao-Gang Fu ◽  
Li-Zhu Wu ◽  
Bin Chen ◽  
Li-Ping Zhang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Crown Ether ◽  
Triplet Energy ◽  
Ether Bridge ◽  
Donor Acceptor ◽  
Triplet Energy Transfer ◽  
Acceptor Molecules

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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