Intramolecular triplet energy transfer. 3. A carbazole-naphthalene system having short chain length methylene spacer units

1993 ◽  
Vol 97 (37) ◽  
pp. 9270-9273 ◽  
Author(s):  
Gregory W. Haggquist ◽  
Hideaki Katayama ◽  
Akira Tsuchida ◽  
Shinzaburo Ito ◽  
Masahide Yamamoto
Keyword(s):  
Energy Transfer ◽  
Chain Length ◽  
Short Chain ◽  
Triplet Energy ◽  
Short Chain Length ◽  
Triplet Energy Transfer

Triplet energy transfer of the intramolecular system having benzophenone and dibenz[b,f]azepine at the chain ends: chain length dependence

1991 ◽  
Vol 95 (9) ◽  
pp. 3480-3486 ◽  
Author(s):  
Hideaki Katayama ◽  
Shogo Maruyama ◽  
Shinzaburo Ito ◽  
Yoshinobu Tsujii ◽  
Akira Tsuchida ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Chain Length ◽  
Triplet Energy ◽  
Length Dependence ◽  
Triplet Energy Transfer

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.

Degrees of order of solubilized alkanes, alcohols, carboxylates, and carboxylic acids in oriented lyomesophases

1977 ◽  
Vol 55 (12) ◽  
pp. 2404-2410 ◽  
Author(s):  
Douglas M. Chen ◽  
Fred Y. Fujiwara ◽  
Leonard W. Reeves
Keyword(s):  
Carboxylic Acids ◽  
Chain Length ◽  
Linear Increase ◽  
Short Chain ◽  
Appreciable Amount ◽  
Linear Region ◽  
Short Chain Length ◽  
Chain Lengths ◽  
Degree Of Order ◽  
Limiting Value

The degree of order of solubilized molecules and ions in oriented lyomesophases has been determined at specifically deuterated C—D bond axes from the quadrupole splitting of the deuterium magnetic resonance. Mixtures at low concentration of specifically deuterated alkanes, alcohols, carboxylic acids, and carboxylates of different chain length have been observed in host cationic and anionic lyomesophases. The degree of order of a given C—D position in alcohols increases strongly with chain length up to a length comparable with the host detergent. A broad series of carboxylic acids and carboxylate ions from C2 to C16 have been deuterated in the α position. The α-C—D bond axis in the solubilisate increases in order with chain length, the anion having lower order than the parent acid. An accurately linear increase in the degree of order of the α position is observed for intermediate chain lengths. At chain lengths approximately equal to the host chain lengths the α position reaches a limiting value in the degree of order and further segments do not influence the order. At short chain lengths the degree of order is less than that predicted from extrapolation of order in the linear region. This has been interpreted in terms of distribution into the aqueous compartment by the solubilisates of short chain length. Acetic acid and the acetate, propionate, butanoate, and pentanoate ions spend an appreciable amount of time in the aqueous region. An estimate has been made of these distributions based on reasonable assumptions.

Triplet energy transfer in conjugated polymers. II. A polaron theory description addressing the influence of disorder

2008 ◽  
Vol 78 (4) ◽  
Author(s):  
Ivan I. Fishchuk ◽  
Andrey Kadashchuk ◽  
Lekshmi Sudha Devi ◽  
Paul Heremans ◽  
Heinz Bässler ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Conjugated Polymers ◽  
Triplet Energy ◽  
Polaron Theory ◽  
Triplet Energy Transfer

Triplet Energy Transfer Insight in Coordination of Unsaturated Hydrocarbons by d0Bent Metallocenes (Zr, Hf)

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

Triplet-Triplet Energy Transfer from a UV-A Absorber Butylmethoxydibenzoylmethane to UV-B Absorbers

2014 ◽  
Vol 90 (3) ◽  
pp. 511-516 ◽  
Author(s):  
Azusa Kikuchi ◽  
Nozomi Oguchi-Fujiyama ◽  
Kazuyuki Miyazawa ◽  
Mikio Yagi
Keyword(s):  
Energy Transfer ◽  
Triplet Energy ◽  
Triplet Energy Transfer
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