scholarly journals Studies on Triplet Energy Transfer by Means of an Emission-Absorption Flash Technique. II. Mixed Triplet-Triplet Annihilation in Ethanol

1971 ◽  
Vol 44 (6) ◽  
pp. 1527-1534 ◽  
Author(s):  
Koichi Kikuchi ◽  
Hiroshi Kokubun ◽  
Masao Koizumi
2020 ◽  
Vol 22 (32) ◽  
pp. 17807-17813
Author(s):  
Toshiko Mizokuro ◽  
Aizitiaili Abulikemu ◽  
Kengo Suzuki ◽  
Yusuke Sakagami ◽  
Ritsuki Nishii ◽  
...  

Photon upconversion and the triplet energy transfer dynamics were studied for sensitizer-fixed nanoporous glass immersed in emitter solution.


2019 ◽  
Vol 55 (84) ◽  
pp. 12611-12614 ◽  
Author(s):  
Haruki Minami ◽  
Takuya Ichikawa ◽  
Kazuki Nakamura ◽  
Norihisa Kobayashi

Electrochemically triggered upconverted luminescence through triplet–triplet energy transfer (TTET) and subsequent triplet–triplet annihilation upconversion (TTA-UC) is observed for the first time.


1986 ◽  
Vol 41 (7) ◽  
pp. 971-973
Author(s):  
Maximilian Zander

P-tvpe Delayed Fluorescence o f 1-Naphthyl-9-carbazyl-methane At 77 K 1-naphthyl-9-carbazyl-methane adsorbed on filter paper shows predominantly delayed fluorescence o f the carbazole chromophore. The experimental findings are in agreement with the assumption that the carbazole chromophore after excitation by light absorption becomes first deactivated by intramolecular triplet-triplet energy transfer and then re-excited in a two-step mechanism including intermolecular naphthalene triplet-triplet annihilation and intramolecular singlet-singlet energy transfer from the naphthalene to the carbazole chromophore.


2015 ◽  
Vol 51 (62) ◽  
pp. 12403-12406 ◽  
Author(s):  
Renjie Tao ◽  
Jianzhang Zhao ◽  
Fangfang Zhong ◽  
Caishun Zhang ◽  
Wenbo Yang ◽  
...  

H2O2-activatable TTA upconversion was achieved with non-fluorescent 9,10-bis(diphenylphosphino)anthracene as a triplet acceptor/emitter, which can be oxidized to a fluorescent product by H2O2.


RSC Advances ◽  
2015 ◽  
Vol 5 (86) ◽  
pp. 70640-70648 ◽  
Author(s):  
Shuai Yu ◽  
Yi Zeng ◽  
Jinping Chen ◽  
Tianjun Yu ◽  
Xiaohui Zhang ◽  
...  

A triplet–triplet annihilation upconversion system with a short-lived triplet state photosensitizer was constructed and enhanced by the design of intramolecular triplet–triplet energy transfer.


2020 ◽  
Author(s):  
Mauricio Lineros-Rosa ◽  
Antonio Francés-Monerris ◽  
Antonio Monari ◽  
Miguel Angél Miranda ◽  
Virginie Lhiaubet-Vallet

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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