Quenching of the Yt-Base Fluorescence by Heavy-Atom Induced Intermoleeular Singlet-Triplet Energy Transfer

1981 ◽  
Vol 36 (1) ◽  
pp. 76-77 ◽  
Author(s):  
I. Gryczyński ◽  
A. Kawski ◽  
S. Paszyc ◽  
T. Skowyra

Quenching of the Yt-base fluorescence by a series of halogen derivatives of benzene and naphthalene was measured in dioxane. For the naphthalene derivatives, the presence of the heavy atom in the acceptor molecule was found to affect strongly the fluorescence quenching rate constant, whereas no such effect was observed for the benzene derivatives. The fact is explained with the assumption of a singlet-triplet energy transfer from the Yt- base molecules to the naphthalene derivatives

2015 ◽  
Vol 6 (7) ◽  
pp. 3724-3737 ◽  
Author(s):  
Song Guo ◽  
Liang Xu ◽  
Kejing Xu ◽  
Jianzhang Zhao ◽  
Betül Küçüköz ◽  
...  

Hydrogen bonding-mediated supramolecular triplet photosensitizers with easily interchangeable visible light-harvesting Bodipy modules and the fullerene intersystem crossing module were devised.


2003 ◽  
Vol 75 (8) ◽  
pp. 1061-1068 ◽  
Author(s):  
Piotr Piotrowiak ◽  
Kurt Deshayes ◽  
Zinaida S. Romanova ◽  
Cynthia Pagba ◽  
Sarmimala Hore ◽  
...  

Encapsulation of chromophores within Cram-type hemicarcerands allowed the investigation of fundamental photophysical phenomena, such as long-range triplet energy transfer, electron transfer, and the remote heavy atom effect. Furthermore, novel water-soluble hemicarcerands are being used to develop unique hybrid materials composed of semiconductor nanoparticles and host–guest assemblies. Photoinduced charge injection from the “incarcerated” guest into the conduction band of the semiconductor has been demonstrated.


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.


2008 ◽  
Vol 78 (4) ◽  
Author(s):  
Ivan I. Fishchuk ◽  
Andrey Kadashchuk ◽  
Lekshmi Sudha Devi ◽  
Paul Heremans ◽  
Heinz Bässler ◽  
...  

2007 ◽  
Vol 111 (43) ◽  
pp. 10928-10937 ◽  
Author(s):  
Galina V. Loukova ◽  
Svetlana E. Starodubova ◽  
Vyatcheslav A. Smirnov

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