Influence of spectral characteristics of the pump pulse on the transient absorption of donor–acceptor complexes in polar solvents

Федунов, Р. Г.; Ivanov, Anatoly I.

doi:10.1007/s10946-012-9269-8

Cited by 4 publications

(3 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simulated transient absorption spectra of DNXT in different solvents have been simulated on the approach elaborated in ref . This theory has already been approved for xanthione and xanthone derivatives as well as for pyrylium phenolate .…”

Section: Results and Discussionmentioning

confidence: 99%

Spectral Dynamics of Nitro Derivatives of Xanthione in Solutions

et al. 2019

View full text Add to dashboard Cite

Nitro derivatives of xanthione, 2,7-dinitro-9Hxanthene-9-thione and 2,4,7-trinitro-9H-xanthene-9-thione, have been first synthesized and their stationary and transient spectra have been measured. The stationary spectra show that the attachment of the nitro groups to the xanthione scaffold leads to strong quenching of S 2 → S 0 fluorescence and the decrease of the oscillator strength of the S 2 ← S 0 electronic transition. Analysis of the transient absorption spectra uncovers the ultrafast stimulated emission quenching from the second excited state, S 2 , in the both derivatives. A kinetic scheme has been suggested to rationalize the complex spectral dynamics of the transient absorption signal. The kinetic scheme is deduced from the analysis of the transient spectra and supported by the quantum-chemical calculations, which predict the existence of a dark state and S 2 state splitting into two close levels. The ultrafast transitions between S 2 state sublevels and the transition into the dark state play a crucial role in spectral dynamics. These new features discovered in the nitro derivatives of xanthione distinguish essentially their spectral dynamics from that observed in xanthione.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Spectral Dynamics of Nitro Derivatives of Xanthione in Solutions

et al. 2019

View full text Add to dashboard Cite

show abstract

“…One of the most important uncertainty is connected with the angle between reaction coordinates corresponding to different electronic transitions at the pump and probe stages. 61 An experimental observation of a positive hot GSA band in transient spectra has one more important aspect. Such an observation could clarify the mechanism of ultrafast charge recombination in excited donor−acceptor complexes that demonstrate unexpected dependence of the CR rate constant on the reaction free energy: 1,2 the logarithm of the charge recombination rate constant decreases monotonously, nearly linearly, with the increasing reaction exergonicity whereas the standard equilibrium Marcus nonadiabatic theory predicts a bell-shaped dependence.…”

Section: Discussionmentioning

confidence: 99%

“…A simulation of ESA and DSA can be fulfilled, but it requires too many fitting parameters. One of the most important uncertainty is connected with the angle between reaction coordinates corresponding to different electronic transitions at the pump and probe stages …”

Section: Discussionmentioning

confidence: 99%

Dynamics of Ground State Absorption Spectra in Donor–Acceptor Pairs with Ultrafast Charge Recombination

et al. 2015

View full text Add to dashboard Cite

A theoretical approach to simulation of the transient spectra in molecular systems with ultrafast photoinduced nonradiative electronic transitions is developed. The evolution of the excited and ground state populations as well as the nonradiative transitions between them are calculated in the framework of the stochastic multichannel point-transition model involving the reorganization of the medium and the intramolecular high frequency vibrational modes. Simulations of transient spectra of donor-acceptor pairs excited in the charge-transfer band that are accompanied by ultrafast charge recombination into the ground state demonstrate a possibility of positive band appearance in the transient absorption spectrum caused by those systems in the ground state, which returned there from the excited state. The region of the parameters of the donor-acceptor systems where a positive ground state absorption signal can be observed is discussed. A qualitative comparison of the simulated transient spectra with the experimental data on betaine-30 is presented.

show abstract