Investigation of the Solvation Dynamics of an Organic Dye in Polar Solvents Using the Femtosecond Transient Grating Technique

Gumy, Jean-Claude; Nicolet, Olivier; Vauthey, Eric

doi:10.1021/jp992265+

Cited by 68 publications

(85 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In VaCN, the time constant for diffusive solvent relaxation amounts to 4.7 ps. 56 In acetonitrile, where the solvation time is much shorter, around 500 fs, 12 the wavelength dependence of the CR of both HMB/TCNE and IDU/ TCNE complexes was found to be hardly detectable, in agreement with the above model. Calculating the driving force for CR as ⌬GϭϪE ox (D)ϩE red (A), where E ox (D) and E red (A) are the oxidation and reduction potential of the donor and acceptor, respectively, results to ⌬GϭϪ1.35 and Ϫ1.59 eV for HMB/TCNE and IDU/TCNE, respectively.…”

Section: Resultssupporting

confidence: 71%

Effect of the excitation pulse carrier frequency on the ultrafast charge recombination dynamics of donor-acceptor complexes: Stochastic simulations and experiments

Федунов

Feskov

Ivanov

et al. 2004

The Journal of Chemical Physics

Self Cite

111

View full text Add to dashboard Cite

The influence of the excitation pulse carrier frequency on the ultrafast charge recombination dynamics of excited donor-acceptor complexes has been explored both theoretically and experimentally. The theoretical description involves the explicit treatment of both the optical formation of the nuclear wave packet on the excited free energy surface and its ensuing dynamics. The wave packet motion and the electronic transition are described within the framework of the stochastic point-transition approach. It is shown that the variation of the pulse carrier frequency within the absorption band can significantly change the effective charge recombination dynamics. The mechanism of this phenomenon is analyzed and a semiquantitative interpretation is suggested. The role of the vibrational coherence in the recombination dynamics is discussed. An experimental investigation of the ultrafast charge recombination dynamics of two donor-acceptor complexes in valeronitrile also is presented. The decays of the excited state population were found to be highly nonexponential, the degree of non-exponentiality depending on the excitation frequency. For one complex, the charge recombination dynamics was found to slow down upon increasing the excitation frequency, while the opposite behavior was observed with the other complex. These experimental observations follow qualitatively the predictions of the simulations.

show abstract

Section: Resultssupporting

confidence: 71%

Effect of the excitation pulse carrier frequency on the ultrafast charge recombination dynamics of donor-acceptor complexes: Stochastic simulations and experiments

Федунов

Feskov

Ivanov

et al. 2004

The Journal of Chemical Physics

Self Cite

111

View full text Add to dashboard Cite

show abstract

“…A considerable part of decay is not diffusive but rather inertial. [28][29][30][31] The initial relaxation, being inertial in nature, is described with a Gaussian autocorrelation function x 1 e -(t/τ 1 ) 2 . In this case, the solvent relaxation function becomes X(t) ) x 1 e -(t/τ 1 ) 2 + ∑ 2 N x i e -t/τ i.…”

Section: The Modelmentioning

confidence: 99%

Solvent and Spectral Effects in the Ultrafast Charge Recombination Dynamics of Excited Donor−Acceptor Complexes

Feskov¹,

Ionkin²,

Ivanov³

et al. 2008

J. Phys. Chem. A

Self Cite

132

View full text Add to dashboard Cite

The charge recombination dynamics of excited donor-acceptor complexes consisting of hexamethylbenzene (HMB), pentamethylbenzene (PMB), and isodurene (IDU) as electron donors and tetracyanoethylene (TCNE) as electron acceptor in various polar solvents has been investigated within the framework of the stochastic approach. The model accounts for the reorganization of intramolecular high-frequency vibrational modes as well as for the solvent reorganization. All electron-transfer energetic parameters have been determined from the resonance Raman data and from the analysis of the stationary charge transfer absorption band, while the electronic coupling has been obtained from the fit to the charge recombination dynamics in one solvent. It appears that nearly 100% of the initially excited donor-acceptor complexes recombine in a nonthermal (hot) stage when the nonequilibrium wave packet passes through a number of term crossings corresponding to transitions toward vibrational excited states of the electronic ground state. Once all parameters of the model have been obtained, the influence of the dynamic solvent properties (solvent effect) and of the carrier frequency of the excitation pulse (spectral effect) on the charge recombination dynamics have been explored. The main conclusions are (i) the model provides a globally satisfactory description for the IDU/TCNE complex although it noticeably overestimates the spectral effect, (ii) the solvent effect is quantitatively well described for the PMB/TCNE and HMB/TCNE complexes but the model fails to reproduce their spectral effects, and (iii) the positive spectral effect observed with the HMB/TCNE complex cannot be described within the framework of two-level models and the charge redistribution in the excited complexes should most probably be taken into account.

show abstract

“…After intramolecular vibrational relaxation in a few tens of fs, the vibrationally hot excited molecules cool down in a few ps by interaction with the surrounding medium. Solvent relaxation proceeds via both inertial motion occurring in about 100 fs and diffusive motion, which is viscosity dependent and takes place with a time constant of about 5 ps in the case of VaCN [15]. This implies that, for TMB-PMDA in VaCN, CR occurs while the excited complex is still hot and before the solvent has fully relaxed.…”

Section: Nonequilibrium Effects On the Free Energy Dependence Of Charmentioning

confidence: 99%

Ultrafast Photochemistry

Morandeira¹,

Fürstenberg²,

Nicolet³

et al. 2002

Chimia

Self Cite

View full text Add to dashboard Cite

show abstract

Investigation of the Solvation Dynamics of an Organic Dye in Polar Solvents Using the Femtosecond Transient Grating Technique

Cited by 68 publications

References 35 publications

Effect of the excitation pulse carrier frequency on the ultrafast charge recombination dynamics of donor-acceptor complexes: Stochastic simulations and experiments

Effect of the excitation pulse carrier frequency on the ultrafast charge recombination dynamics of donor-acceptor complexes: Stochastic simulations and experiments

Solvent and Spectral Effects in the Ultrafast Charge Recombination Dynamics of Excited Donor−Acceptor Complexes

Ultrafast Photochemistry

Contact Info

Product

Resources

About