Luminescence and triplet energy transfer in mixed crystals. II. Three component systems

Triplet-triplet energy transfer between two guest molecules in a host crystal has been studied by observing the temperature and concentration dependence of the phosphorescence of the donor guest molecule. The results are interpreted in terms of transfer via the host triplet exciton band.

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Luminescence and triplet energy transfer in mixed crystals. I. Two-component systems

Australian Journal of Chemistry ◽

10.1071/ch9692061 ◽

1969 ◽

Vol 22 (10) ◽

pp. 2061 ◽

Cited By ~ 3

Author(s):

KR Adam ◽

MF O'Dwyer

Keyword(s):

Energy Transfer ◽

Delayed Fluorescence ◽

Mixed Crystals ◽

Temperature Dependent ◽

Triplet Energy ◽

Component Systems ◽

Two Component ◽

Two Component Systems ◽

Quantitative Results ◽

Triplet Energy Transfer

Quantitative results are given for the temperature dependence of the intensities and decays of phosphorescence and delayed fluorescence in a number of two-component organic mixed crystals. These results are interpreted in terms of a kinetic model. For low guest concentrations, the guest phosphorescence decay is found to be first order and strongly temperature dependent with an activation energy different from that involved in energy transfer to the host triplet exciton level.

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Intermolecular Triplet Energy Transfer in Naphthalene–Pentacene Mixed Crystals via Higher Excited Triplet States

physica status solidi (b) ◽

10.1002/pssb.2220510116 ◽

1972 ◽

Vol 51 (1) ◽

pp. 155-159 ◽

Cited By ~ 2

Author(s):

G. Vaubel ◽

L. Peter

Keyword(s):

Energy Transfer ◽

Mixed Crystals ◽

Triplet States ◽

Triplet Energy ◽

Excited Triplet ◽

Triplet Energy Transfer ◽

Excited Triplet States

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Triplet energy transfer and triplet exciton recycling in singlet fission sensitized organic heterojunctions

Organic, Hybrid, and Perovskite Photovoltaics XVIII ◽

10.1117/12.2273804 ◽

2017 ◽

Author(s):

Ajay Pandey ◽

Tasnuva Hamid ◽

Soniya D. Yambem ◽

Ross Crawford ◽

Jonathan Roberts

Keyword(s):

Energy Transfer ◽

Triplet Exciton ◽

Singlet Fission ◽

Triplet Energy ◽

Triplet Energy Transfer ◽

Organic Heterojunctions

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Thymine Dimerization Induced by Oxidative DNA Lesions and Epigenetic Intermediates via Triplet-Triplet Energy Transfer

10.26434/chemrxiv.12782270 ◽

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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