Femtosecond experiments and absolute rate calculations on intervalence electron transfer of mixed-valence compounds

Tominaga, Kazuhiro; Kliner, Dahv A. V.; Johnson, Alan W.; Levinger, Nancy E.; Barbara, Paul F.

doi:10.1063/1.464344

Cited by 172 publications

(174 citation statements)

References 60 publications

Supporting

Mentioning

160

Contrasting

Order By: Relevance

“…[18][19][20][21][22] ͑3͔͒. A number of intramolecular ET systems have also been discovered by Barbara and co-workers [35][36][37][38][39][40][41][42][43] where ET occurs faster than the diffusive solvation rates. Since the contemporary ET theories can not explain these results, a twodimensional ET ͑2D-ET͒ model [44][45][46] is generally invoked to account the ultrafast nature of these ET reactions, where a solvent and an intramolecular coordinate is considered in a noncoupled manner to assist the ET process.…”

Section: Introductionmentioning

confidence: 93%

Ultrafast intermolecular electron transfer from orthomethoxyaniline to excited coumarin dyes

Pal

Shirota

Tominaga

et al. 1999

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

Ultrafast intermolecular electron transfer (ET) from orthomethoxyaniline (orthoanisidine, ANS) to a number of excited (S1) 4-trifluoromethyl-1,2-benzopyrones (coumarins) having differently substituted 7-amino group has been investigated by femtosecond fluorescence up-conversion technique. The ET dynamics in the present systems are nonsingle-exponential and occur faster than the diffusive solvation dynamics. The ET rates are largely dependent on the nature of the substituents at the 7-amino group of the coumarins. This dependence is well correlated with the free energy changes (ΔG0) for the ET reactions. The ET dynamics become slower on using deuterated ANS as the donor, where the amino group hydrogens of ANS are substituted by deuterium. The deuterium isotope effect, however, gradually reduces as the ET dynamics becomes faster. Conventional ET theories can not explain all the observations. The results are explained on the basis of the two-dimensional ET model, which considers the solvent coordinate and the intramolecular coordinate separately to depict the ET process. It is seen that in coumarin-ANS systems the ET occurs much faster than the coumarin-aniline systems. It is indicated that the electronic coupling matrix element, a parameter which determines the extent of interaction between the reactant and the product states in the ET process, is much larger in the present systems than for the coumarin-aniline systems. The deuterium isotope effect on the ET dynamics is explained in terms of the changes in the ΔG0 values on isotopic substitution of the solvent donors.

show abstract

Section: Introductionmentioning

confidence: 93%

Ultrafast intermolecular electron transfer from orthomethoxyaniline to excited coumarin dyes

Pal

Shirota

Tominaga

et al. 1999

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…In many DACs, the latter process, which corresponds to a CR is ultrafast and is thus the major deactivation pathway of the contact ion pair. [33][34][35][36][37][38][39][40][41][42][43][44][45][46] In the following, we will only consider the nonadiabatic reaction, and assume that the electronic transitions are only possible if the energies of the excited and ground states of the complex are equal, in accordance to the Franck-Condon principle. We will refer to these nuclear configurations as the TCR.…”

Section: Modelmentioning

confidence: 99%

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

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

“…are the relative amplitudes of the contribution of the medium modes with relaxation times s i , the index 1 standing for the inertial solvation mode [29,30],…”

Section: Hybrid Modelmentioning

confidence: 99%

The effect of excitation pulse carrier frequency on ultrafast charge recombination dynamics of excited donor–acceptor complexes

Ivanov

Belikeev

Федунов

et al. 2003

Chemical Physics Letters

View full text Add to dashboard Cite

The excitation of a charge transfer band by a laser pulse of finite duration and the ensuing charge recombination are calculated in the framework of the perturbation theory. The influence of the spectral characteristics of the laser pulse on the charge recombination dynamics is investigated for models including several nuclear modes that differ greatly in their timescales. It is shown that, in the area of applicability of the perturbation theory, the variation of the pulse carrier frequency inside the absorption band can significantly change the effective charge recombination rate constant.

show abstract

Femtosecond experiments and absolute rate calculations on intervalence electron transfer of mixed-valence compounds

Cited by 172 publications

References 60 publications

Ultrafast intermolecular electron transfer from orthomethoxyaniline to excited coumarin dyes

Ultrafast intermolecular electron transfer from orthomethoxyaniline to excited coumarin dyes

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

The effect of excitation pulse carrier frequency on ultrafast charge recombination dynamics of excited donor–acceptor complexes

Contact Info

Product

Resources

About