Excited state dynamics of the astaxanthin radical cation

Amarie, Sergiu; Förster, Ute; Gildenhoff, Nina; Dreuw, Andreas; Wachtveitl, Josef

doi:10.1016/j.chemphys.2010.01.017

Cited by 25 publications

(23 citation statements)

References 55 publications

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“…In fact, our results nicely corroborate femtosecond pump-probe experiments on AXT Å+ [34], since for an explanation of the observed excited state dynamics, three excited electronic states are needed. Upon excitation into the D 3 state, excited AXT Å+ molecules decay rapidly within about 100 fs into the D 2 state, from where they further decay into the D 1 state within less than a picosecond.…”

Section: Charge Difference Cation-neutralsupporting

confidence: 87%

“…The computed excitation wavelengths of the D 1 and D 3 states of 1333 and 810 nm are in nice agreement with experimental values of 1300 and 870 nm in chloroform, respectively. The state ordering is also in agreement with pump-probe experiments on AXT Å+ , in which it is demonstrated that the initial excited state population of D 3 decays rapidly into D 2 and finally via D 1 back to the ground state [34]. Mulliken atomic charge analysis has been used to investigate how the positive charge is moved upon excitation into the vertical excited states.…”

Section: Discussionsupporting

confidence: 66%

“…Frontier orbitals of the AXT radical cation as obtained by DFT/B3LYP/6-31G*. ment with experimental findings, since a weak absorption band of AXT Å+ could be identified around 1300 nm in the near-IR region of the absorption spectrum in chloroform [34]. In the molecular orbital picture, the D 1 state is best represented by a linear combination of two almost equally weighted Slater determinants: one in which an a-electron is excited from the SOMO to the LUMO and one in which a b-electron is excited from the HOMO to the SOMO ( Table 1, Fig.…”

Section: Excited State Properties Of the Astaxanthin Radical Cationmentioning

confidence: 77%

“…The computed excitation energy is 1.54 eV corresponding to an excitation wavelength of 810 nm (Table 1). Experimentally this main absorption band has been found at 870 nm in acetone [34]. The wavefunction of the D 3 state is best characterized by the same determinants like the D 1 state, i.e.…”

Section: Charge Difference Cation-neutralmentioning

confidence: 95%

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Excited state properties of the astaxanthin radical cation: A quantum chemical study

2010

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Section: Charge Difference Cation-neutralsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 66%

Section: Excited State Properties Of the Astaxanthin Radical Cationmentioning

confidence: 77%

Section: Charge Difference Cation-neutralmentioning

confidence: 95%

See 2 more Smart Citations

Excited state properties of the astaxanthin radical cation: A quantum chemical study

2010

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“…[7][8][9][10][11] Vauthey and coworkers have exploited liquid solutions of a neutral organic precursor compound serving as an electron donor in the presence of an electron acceptor. In solution, the radicals were generated in situ either by chemical, electrochemical, or photochemical means and conventional pumpprobe or transient grating techniques were applied.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast primary processes of the stable neutral organic radical, 1,3,5-triphenylverdazyl, in liquid solution

Weinert

Wezisla

Lindner

et al. 2015

Phys. Chem. Chem. Phys.

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Femtosecond spectroscopy with hyperspectral white-light detection was used to elucidate the ultrafast primary processes of the thermodynamically stable organic radical, 1,3,5-triphenylverdazyl, in liquid acetonitrile solution at room temperature. The radical was excited with optical pulses having a duration of 39 fs and a center wavelength of 800 nm thereby accessing its energetically lowest electronically excited state (D1). The apparent spectrotemporal response is understood in terms of an ultrafast primary D1-to-D0 internal conversion that generates the electronic ground state of the radical in a highly vibrationally excited fashion within a few hundred femtoseconds. The replenished electronic ground state subsequently undergoes vibrational cooling on a time scale of a few picoseconds. The instantaneous absorption spectra of the radical derived from the femtosecond pump-probe data are analyzed within the Sulzer-Wieland formalism for calculating the electronic spectra of "hot" polyatomic molecules. The pump-probe spectra together with transient anisotropy data in the region of the D0 → D1 ground-state bleach gives evidence for an additional transient absorption that arises from a dark excited state, which gains oscillator strength with increasing vibrational excitation of the radical by virtue of vibronic coupling.

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A Mitochondrion‐Localized Two‐Photon Photosensitizer Generating Carbon Radicals Against Hypoxic Tumors

et al. 2020

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The efficacy of photodynamic therapyi st ypically reliant on the local concentration and diffusion of oxygen. Due to the hypoxic microenvironment found in solid tumors, oxygen-independent photosensitizers are in great demand for cancer therapy. We herein report an iridium(III) anthraquinone complex as am itochondrion-localized carbon-radical initiator.I ts emission is turned on under hypoxic conditions after reduction by reductase.F urthermore,i ts two-photon excitation properties (l ex = 730 nm) are highly desirable for imaging.U pon irradiation, the reduced form of the complex generates carbon radicals,l eading to al oss of mitochondrial membrane potential and cell death (IC 50 light = 2.1 mm,IC 50 dark = 58.2 mm,P I= 27.7). The efficacy of the complex as aP DT agent was also demonstrated under hypoxic conditions in vivo. To the best of our knowledge,i ti st he first metal-complexbased theranostic agent which can generate carbon radicals for oxygen-independent two-photon photodynamic therapy.

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Excited state dynamics of the astaxanthin radical cation

Cited by 25 publications

References 55 publications

Excited state properties of the astaxanthin radical cation: A quantum chemical study

Excited state properties of the astaxanthin radical cation: A quantum chemical study

Ultrafast primary processes of the stable neutral organic radical, 1,3,5-triphenylverdazyl, in liquid solution

A Mitochondrion‐Localized Two‐Photon Photosensitizer Generating Carbon Radicals Against Hypoxic Tumors

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