Triplet energy transfer mechanism in isotopic mixed molecular crystals

1976 ◽  
Vol 80 (20) ◽  
pp. 2196-2196 ◽  
Author(s):  
S. D. Colson ◽  
F. B. Tudron ◽  
R. E. Turner ◽  
V. Vaida
Keyword(s):  
Energy Transfer ◽  
Molecular Crystals ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Triplet Energy ◽  
Triplet Energy Transfer

scholarly journals Visible Light-Mediated [2+2] Cycloaddition for the Synthesis of Azetidines via Energy Transfer

2018 ◽  
Author(s):  
Marc R. Becker ◽  
Alistair D. Richardson ◽  
Corinna S. Schindler
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Functional Group ◽  
Transfer Mechanism ◽  
Synthetic Methods ◽  
Energy Transfer Mechanism ◽  
Triplet Energy ◽  
Mechanistic Investigations ◽  
Triplet Energy Transfer ◽  
Operational Simplicity

<p>Due to the lack of synthetic methods for their synthesis, azetidines are an underrepresented class of nitrogen-containing heterocycles. Herein, we describe the development of a mild, general protocol for the synthesis of azetidines relying on a visible light-mediated [2+2] cycloaddition between oximes and olefins catalyzed by an iridium photocatalyst. This approach is characterized by its operational simplicity, low catalyst loadings and functional group tolerance. Mechanistic investigations suggest that a triplet energy transfer mechanism is operative.<br></p>

scholarly journals Triplet Energy Transfer Mechanism of Ternary Organic Hybrid Thin Films of PFO/MEH-PPV/CsPbBr3 Perovskite Quantum Dots

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2094
Author(s):  
Bandar Ali Al-Asbahi ◽  
Saif M. H. Qaid ◽  
Hamid M. Ghaithan ◽  
Abdullah S. Aldwayyan
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Transfer Mechanism ◽  
Ternary Blend ◽  
Energy Transfer Mechanism ◽  
Triplet Energy ◽  
Blending Method ◽  
Donor And Acceptor ◽  
Hybrid Thin Films ◽  
Triplet Energy Transfer

The triplet energy transfer mechanism of novel poly(9,9-di-n-octylflourenyl-2,7-diyl) (PFO)/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)/CsPbBr3 perovskite quantum dot (PQD) hybrid thin films was comprehensively investigated. The concentrations of PFO and MEH-PPV in all the specimens were fixed, while the PQD content was varied with various weight ratios and premixed by a solution blending method before it was spin-coated onto glass substrates. The triplet non-radiative Förster resonance energy transfers (FRETs) in the PFO/MEH-PPV/PQDs ternary blend, the dual FRET from PFO to both PQDs and MEH-PPV, and the secondary FRET from PQDs to MEH-PPV were observed. The values of the Förster radius (Ro) of FRET from PFO to MEH-PPV in the presence of various PQD contents (Case I) increased from 92.3 to 104.7 Å, and they decreased gradually from 68.0 to 39.5 Å for FRET from PFO to PQDs in the presence of MEH-PPV (Case II). These Ro values in both cases confirmed the dominance of FRET in ternary hybrid thin films. Upon increasing the PQD content, the distance between the donor and acceptor molecules (RDA) and the conjugation length (Aπ) in both cases gradually decreased. The small values of Ro, RDA, and Aπ with a decrease in the energy transfer lifetime (τET) due to an increase in the PQD contents in both Cases I and II confirmed the efficient FRET in the hybrid. To prevent intermolecular transfer in PFO, the concentrations of MEH-PPV (Case I) and PQDs (Case II) should be decreased to a range of 0.57–0.39 mM and increased in the range of 1.42–7.25 mM.

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.

Energy transfer mechanism of supersonic jet noise through rectangular nozzles

2017 ◽  
Vol 65 (2) ◽  
pp. 110-120 ◽  
Author(s):  
Zhe Chen ◽  
Jiu-Hui Wu ◽  
A-Dan Ren ◽  
Xin Chen ◽  
Zhen Huang
Keyword(s):  
Energy Transfer ◽  
Supersonic Jet ◽  
Jet Noise ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Supersonic Jet Noise
Sign in / Sign up

Export Citation Format

Share Document