Triplet energy transfer between bacteriochlorophyll and carotenoids in B850 light-harvesting complexes ofRhodobacter sphaeroides R-26.1

1994 ◽  
Vol 42 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Roya Farhoosh ◽  
Veeradej Chynwat ◽  
Ronald Gebhard ◽  
Johan Lugtenburg ◽  
Harry A. Frank
Keyword(s):  
Energy Transfer ◽  
Light Harvesting ◽  
Triplet Energy ◽  
Light Harvesting Complexes ◽  
Triplet Energy Transfer

Highly Efficient Light-Harvesting System Based on a Phosphorescent Acceptor Coupled with Dendrimer Donors via Singlet−Singlet and Triplet−Triplet Energy Transfer

2007 ◽  
Vol 19 (15) ◽  
pp. 3673-3680 ◽  
Author(s):  
Tae-Hyuk Kwon ◽  
Myoung Ki Kim ◽  
Jongchul Kwon ◽  
Dae-Yup Shin ◽  
Su Jin Park ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Light Harvesting ◽  
Triplet Energy ◽  
Highly Efficient ◽  
Triplet Energy Transfer

scholarly journals Bodipy–C60 triple hydrogen bonding assemblies as heavy atom-free triplet photosensitizers: preparation and study of the singlet/triplet energy transfer

2015 ◽  
Vol 6 (7) ◽  
pp. 3724-3737 ◽  
Author(s):  
Song Guo ◽  
Liang Xu ◽  
Kejing Xu ◽  
Jianzhang Zhao ◽  
Betül Küçüköz ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Energy Transfer ◽  
Visible Light ◽  
Light Harvesting ◽  
Heavy Atom ◽  
Intersystem Crossing ◽  
Triplet Energy ◽  
Triplet Energy Transfer

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

Carotenoids in photosynthesis

1978 ◽  
Vol 284 (1002) ◽  
pp. 569-579 ◽  
Keyword(s):  
Energy Transfer ◽  
Photosynthetic Bacteria ◽  
Light Harvesting ◽  
Protective Role ◽  
Reaction Centre ◽  
Triplet Energy ◽  
Photosynthetic Unit ◽  
Accessory Pigment ◽  
Light Harvesting Antenna ◽  
Triplet Energy Transfer

Carotenoids are usually considered to perform two major functions in photosynthesis. They serve as accessory light harvesting pigments, extending the range of wavelengths over which light can drive photosynthesis, and they act to protect the chlorophyllous pigments from the harmful photodestructive reaction which occurs in the presence of oxygen. Drawing upon recent work with photosynthetic bacteria, evidence is presented as to how the carotenoids are organized within both portions of the photosynthetic unit (the light harvesting antenna and the reaction centre) and how they discharge both their functions. The accessory pigment role is a singlet-singlet energy transfer from the carotenoid to the bacteriochlorophyll, while the protective role is a triplet-triplet energy transfer from the bacteriochlorophyll to the carotenoid.

scholarly journals Triplet–triplet energy transfer in the major intrinsic light-harvesting complex of Amphidinium carterae as revealed by ODMR and EPR spectroscopies

2010 ◽  
Vol 1797 (10) ◽  
pp. 1759-1767 ◽  
Author(s):  
Marilena Di Valentin ◽  
Enrico Salvadori ◽  
Giancarlo Agostini ◽  
Federico Biasibetti ◽  
Stefano Ceola ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Light Harvesting ◽  
Triplet Energy ◽  
Amphidinium Carterae ◽  
Light Harvesting Complex ◽  
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.

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