Dynamics of the time-resolved stimulated Raman scattering spectrum in presence of transient vibronic inversion of population on the example of optically excited trans-β-apo-8'-carotenal

T M Kardaś; B Ratajska-Gadomska; A Lapini; E Ragnoni; R Righini; M Di Donato; P Foggi; W Gadomski

doi:10.1063/1.4879060

Dynamics of the time-resolved stimulated Raman scattering spectrum in presence of transient vibronic inversion of population on the example of optically excited trans-β-apo-8'-carotenal

J Chem Phys. 2014 May 28;140(20):204312. doi: 10.1063/1.4879060.

Authors

T M Kardaś¹, B Ratajska-Gadomska¹, A Lapini², E Ragnoni², R Righini², M Di Donato², P Foggi², W Gadomski¹

Affiliations

¹ Department of Chemistry, University of Warsaw, Zwirki Wigury 101, 02-089 Warsaw, Poland.
² European Laboratory for Non-linear Spectroscopy (LENS), Universit`a di Firenze, Via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.

PMID: 24880285
DOI: 10.1063/1.4879060

Abstract

We have studied the effect of transient vibrational inversion of population in trans-β-apo-8(')-carotenal on the time-resolved femtosecond stimulated Raman scattering (TR-FSRS) signal. The experimental data are interpreted by applying a quantum mechanical approach, using the formalism of projection operators for constructing the theoretical model of TR-FSRS. Within this theoretical frame we explain the presence of transient Raman losses on the Stokes side of the TR-FSRS spectrum as the effect of vibrational inversion of population. In view of the obtained experimental and theoretical results, we conclude that the excited S2 electronic level of trans-β-apo-8(')-carotenal relaxes towards the S0 ground state through a set of four vibrational sublevels of S1 state.