Target Analysis Resolves the Ground and Excited State Properties from Femtosecond Stimulated Raman Spectra

Target analysis is employed to resolve the ground and excited state properties from simultaneously measured Femtosecond Stimulated Raman Spectra (FSRS) and Transient Absorption Spectra (TAS). FSRS is a three-pulse technique, involving picosecond Raman pump pulses and femtosecond visible pump and probe pulses. The TAS are needed to precisely estimate the properties of the Instrument Response Function. The prezero “coherent artifact” present during the overlap of the three pulses is described by a damped oscillation with a frequency (ω – ωn) where ωn is a ground state resonance Raman frequency. Simultaneous target analysis of the FSRS and TAS allows the complete excited state dynamics to be resolved with a time resolution better than 100 fs. The model system studied is the carotenoid lycopene in tetrahydrofuran. The lycopene dynamics show a spectral evolution with seven states, including a biphasic cooling process during the S2–S1 internal conversion, multiple S1 lifetimes, and an S* state decaying with a lifetime of 7 ps.

Fit quality of TAS measured on a dedicated TA setup Figure S 2. Target analysis of TA of lycopene in THF with OD 480nm equal to 0.1 (in mOD) measured on a dedicated TA setup, note the qualitative and quantitative agreement.From left to right: data, fit and residual.In grey the estimated dispersion curves (the location of the maximum of the IRF).Note that the time axis is linear from -1 to 1 ps and logarithmic elsewhere.Three different samples of lycopene in THF have been measured with OD 480nm equal to 0.1, 0.3 and 1.0 (dataset 0, 1, and 2, respectively).Key: scaled data (grey, orange and cyan, in mOD), fit line in dashed black, red and blue.The green line represents the CA in THF measured with a pump power of 5 nJ per pulse, which was used in all experiments, and the fit of the CA is in dashed dark green.

Figure S 3 .
Figure S 3. Fit quality at 25 selected wavelengths (indicated in the title of each panel) of TA measured on a dedicated TA setup.

Figure S 4 .
Figure S 4. Overview of visible TA of lycopene in THF with OD 480nm equal to 0.1: Concentrations of the global analysis (A), EADS (B) and normalized EADS (E).Note that IRFAS have been used.Lifetimes : 71, 175 fs, 0.8, 3.3 and 5.9 ps, long lived.(C,F) are the DADS and normalized DADS.No trends in the residuals are visible in (D).The black dispersion curve in D indicates the wavelength dependence of the maximum of the IRF.(G-I) The singular value decomposition of the matrix of residuals: (G) first left singular vector, showing no trends (H) first right singular vector, showing dominant amplitude around 480 nm (I) screeplot of the singular values.(J-L) The singular value decomposition of the matrix of the data: (J) first four left singular vectors, (K) first four right singular vectors, (L) screeplot of the singular values.

Figure S 5 .
Figure S 5. Fit quality at 25 selected wavelengths of TA measured on the FSRS setup with OD 480nm equal to 1 (grey, in mOD), fit line in dashed black.

Figure S 6 .
Figure S 6. Global and target analysis of TAS of lycopene in THF with OD 480nm equal to 1. Concentrations (A,C) of a sequential scheme without losses (Figure 2A) and of a target kinetic scheme (Figure 2D).Legends in (A,C) indicate lifetimes and species, l.l. is long-lived; S1vh is very hot S1, S1h is hot S1, S1' is a more slowly decaying subpopulation of S1 with identical SADS, T is triplet.Estimated EADS (B) and SADS (D, both in mOD) using the kinetic schemes from Figure 2A and D.

Figure S 9 .
Figure S 9. Fit quality at 25 selected wavenumbers of TA of Stokes (grey) and Anti-Stokes (orange) in the FSRS regions, fit lines in dashed black and dashes red respectively.

Figure S 13 .
Figure S 13.Overview of Stokes FSRS of lycopene in THF: Concentrations of the global analysis (A), EADS (B) and normalized EADS (E).Note that IRFAS have NOT been used.Legend for all panels in (A).Lifetimes: 71, 175 fs, 0.8, 3.3 and 5.9 ps, long lived (cyan).(C,F) are the DADS and normalized DADS.Small trends in the residuals before time zero are visible in (D).The black dispersion curve in D indicates the wavenumber dependence of the maximum of the IRF.(G-I) The singular value decomposition of the matrix of residuals: (G) first left singular vector, showing only small trends (H) first right singular vector, showing dominant amplitude around 1700/cm (I) screeplot of the singular values.(J-L) The singular value decomposition of the matrix of the data: (J) first four left singular vectors, (K) first four right singular vectors, (L) screeplot of the singular values.

Figure S 16 .
Figure S 16.Overview of the damped oscillations attributed to the ν1 (A-C) and ν2 (D-F) bands of lycopene (A,D) damped cosines far away from resonance at frequencies indicated in the panel labels.(B,E) DOAS (C,F) Phase.No zero constraints are imposed on the DOAS.