Ultrafast Excitation Transfer in Cy5 DNA Photonic Wires Displays Dye Conjugation and Excitation Energy Dependency

2020 ◽  
Vol 11 (10) ◽  
pp. 4163-4172 ◽  
Author(s):  
Richard J. Mazuski ◽  
Sebastián A. Díaz ◽  
Ryan E. Wood ◽  
Lawson T. Lloyd ◽  
William P. Klein ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Excitation Transfer ◽  
Energy Dependency ◽  
Photonic Wires

Design of Molecular Photonic Wires Based on Multistep Electronic Excitation Transfer

ChemPhysChem ◽  
2005 ◽  
Vol 6 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Philip Tinnefeld ◽  
Mike Heilemann ◽  
Markus Sauer
Keyword(s):  
Electronic Excitation ◽  
Excitation Transfer ◽  
Photonic Wires

Theory of excitation transfer in collisions between alkali atoms. I. Identical partners

1969 ◽  
Vol 47 (12) ◽  
pp. 1237-1248 ◽  
Author(s):  
E. I. Dashevskaya ◽  
A. I. Voronin ◽  
E. E. Nikitin
Keyword(s):  
Excitation Energy ◽  
Excited States ◽  
Cross Section ◽  
Electronic Excitation ◽  
Electronic States ◽  
Excitation Transfer ◽  
Electronic Excitation Energy ◽  
Alkali Atoms ◽  
The Cross

A mechanism is derived for nonresonant transfer of electronic excitation energy, induced in the process M*(2P3/2) + M(2S1/2) → M*(2P1/2) + M(2S1/2), where M and M* are identical alkali atoms in the ground and first excited states, respectively. Various types of interactions, responsible for the nonadiabatic combination of electronic states of the quasi molecule M2*, were considered, and their respective contributions to the cross section for excitation transfer were determined.

Low-Temperature Transient Optical Spectroscopy of Polydiacetylene DCHD: Evidence for a Distribution of Side Group Orientations

1995 ◽  
Vol 49 (3) ◽  
pp. 374-378 ◽  
Author(s):  
S. A. Hambir ◽  
G. J. Blanchard ◽  
G. L. Baker
Keyword(s):  
Low Temperature ◽  
Excitation Energy ◽  
Energy Dependence ◽  
Energy Barrier ◽  
Excitation Transfer ◽  
Population Recovery ◽  
Side Group ◽  
Polymer Backbone ◽  
Pump Probe ◽  
Multiple Conformers

We report on the transient optical response of the polydiacetylene DCHD at low temperature. Ultrafast pump-probe spectroscopic measurements reveal that excitation of the polymer N-methyl carbazolyl side group results in instantaneous (<10 ps) excitation transfer to the polymer backbone at 10 K. The slow population recovery signal seen subsequent to excitation transfer to the polymer backbone exhibits an excitation energy dependence that is indicative of the existence of multiple conformers. The energy barrier between these conformers is inferred to be <0.5 kcal/mol.

EXCITATION TRANSFER WITHIN THE OPTICALLY EXCITED DOUBLET Ē(2E) IN RUBY

1985 ◽  
Vol 46 (C7) ◽  
pp. C7-103-C7-107
Author(s):  
J. G.M. van Miltenburg ◽  
G. J. Jongerden ◽  
J. I. Dijkhuis ◽  
H. W. de Wijn
Keyword(s):  
Excitation 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.

scholarly journals Wavelength-Dependent Nonlinear Absorption in Palladium Nanoparticles

2021 ◽  
Vol 11 (4) ◽  
pp. 1640
Author(s):  
Chunyu Chen ◽  
Jun Wang ◽  
Yachen Gao
Keyword(s):  
Surface Plasmon Resonance ◽  
Excitation Energy ◽  
Systematic Study ◽  
Nonlinear Absorption ◽  
Palladium Nanoparticles ◽  
Excitation Wavelength ◽  
Saturated Absorption ◽  
Multi Wavelength ◽  
Resonant Region ◽  
Absorption Characteristics

This paper aims to study the nonlinear absorption characteristics of palladium nanoparticles (PdNPs) at off-resonant wavelengths. For this purpose, multi-wavelength (500–650 nm) nanosecond Z-scan technique was used. The experimental results indicate that saturated absorption (SA) and the transition from SA to reverse saturated absorption (RSA) can occur, and depends on the excitation wavelength and energy. When the excitation wavelength is constant, with the increase of excitation energy, PdNPs change from SA to RSA. When the excitation energy is constant, with the excitation wavelength approaching surface plasmon resonance (SPR), PdNPs change from SA to RSA. This phenomenon of SA and RSA under multi-wavelength excitation in the off-resonant region provides a supplement for the systematic study of the nonlinear absorption of PdNPs.

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