This dataset contains data published in an article understanding the role of vibronic coherence in ultrafast proton transfer. The following files are contained in the dataset with their description below:

• Source_Data_Main_text.xlsx
  • Tab 1 – Figure 1b contains the FTIR data of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The solvent spectrum is subtracted from this data. The w axis is in wavenumbers (cm ^-1) and the y-axis is in absorbance units.
  • Tab2– Figure 1bb contains the spectrum of the mid-IR probe. The x axis, w, is in wavenumbers (cm ^-1) and the y-axis is in intensity (arbitrary units).
  • Tab3– Figure 1c contains the transient infrared spectrum at a time delay of 10 picoseconds. The x axis, w3, is in wavenumbers (cm ^-1) and the y-axis is in differential absorbance, delta_A (mOD).
  • Tab 4 – Figure 2a contains the spectrum of the near UV pump pulses. The x axis, w, is in wavenumbers (cm ^-1) and the y-axis is in intensity (arbitrary units).
  • Tab5 – Figure 2aa contains the UV-Vis data of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The w axis is in wavenumbers (cm ^-1) and the y-axis is in normalized absorbance units.
  • Tab 6 -Figure 2b contains the 2D electronic-vibrational spectrum of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The spectrum is integrated over all the tau2 time-delays. It is plotted as a function of omega_1 in wavenumbers (cm ^-1) and omega_3 in wavenumbers (cm ^-1).
  • Tab 7 – Figure 3 a contains the 2D plot of the time-frequency analysis along the excited state emission region. It is plotted as a function of tau_1 center in femtoseconds (fs) and omega_3 in wavenumbers (cm ^-1).
  • Tab 8 -Figure 3 b contains the 2D plot of the time-frequency analysis along the excited state absorption region. It is plotted as a function of tau_1 center in femtoseconds (fs) and omega_3 in wavenumbers (cm ^-1).
  • Tab 9 – Figure 3c contains lineouts of the ω3 signal modulation at 1446 cm ^-1 as a function of time, tau1_center in fs, both in the excited state emission, ESE, (Fig. 3a) and excited state absorption, ESA, (Fig. 3b) regions. The fits of the data are shown as a function of tau1_fit in fs and normalized intensity in the ESE and ESA regions.
  • Tab 10 – Figure 4a showing low-frequency amplitude modulations in two-dimensional electronic–vibrational (2D EV) spectra show the amplitude of the coherent vibrational modes across all ω2 frequencies below the Nyquist limit. Showing the coherent vibrational amplitude in the ESE (ω1 = 24000–24700 cm ^-1, top panel) and ESA (ω1 = 25300–25800 cm ^-1, bottom panel) region coupled to the high-frequency vibration (ω3 =1446 cm ^-1). The w2_axis is in wavenumbers and the y-axis FT_amp and error_std are in arbitrary units
  • Tab 11 – Figure 4b Slice of 3D EV plot at w2 = 550 cm ^-1 as a function of w1 and w3 in wavenumbers.
  • Tab 12 – Figure 4c Slice of 3D EV plot at w2 = 770 cm ^-1 as a function of w1 and w3 in wavenumbers.
  • Tab 13 – Figure 4d Slice of 3D EV plot at w2 = 290 cm ^-1 as a function of w1 and w3 in wavenumbers.
• SI_Figures_Source_Data.xlsx
  • Tab1– SI_Fig-3 contains the following:
    • FTIR data of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The solvent spectrum is subtracted from this data. The Freq axis is in wavenumbers (cm ^-1) and the Exp (FTIR) y-axis is absorptivity (M ^-1 cm ^-1 units.
    • Calculated DFT frequencies of the same molecule. The Freq axis is in wavenumbers (cm ^-1) and the DFT (FTIR) y-axis is in D (10^{-40 esu}2cm^2)
  • Tab 2 – SI_Fig-4 contains the following:
    • FTIR data of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The Freq axis is in wavenumbers and the FTIR_gs-hbq_sub axis is in absorbance.
    • FTIR data of hydroxybenzo[h]quinoline (HBQ) in tetrachloroethylene (TCE). The Freq axis is in wavenumbers and the FTIR_gs-hbq axis is in absorbance.
    • FTIR data of tetrachloroethylene (TCE). The Freq axis is in wavenumbers and the FTIR_gs-TCE axis is in absorbance.
  • Tab 3 – SI_Fig-5 contains thepump pulse fluence dependence of the transient IR signal:
    • The transient IR signal as a function of MIR Frequency (w) in wavenumbers of fluence (1 uJ, 0.93 uJ, 0.79 uJ, 0.57 uJ, and 0.31 uJ ). uJ represents micro Joule, energy of the pump pulse at 1 kHz.
    • Linear dependence of the pump power. The excited state absorption peak at 1446 cm ^-1 at a 2 ps pump-probe delay. The x-axis is in Pulse Energy in uJ and the y-axis is in delta_A.
  • Tab 4 – SI Fig 6 contains the following:
    • pump pulse time autocorrelation trace after phase cycling subtraction with x-axis of tau_1 in fs and the y-axis in relative intensity
    • Frequency domain pump pulse spectrum with x-axis of Freq in cm ^-1 and y-axis in relative intensity.
  • Tab 5 – SI Fig 7 showing (a) UV-Vis absorption of HBQ and the pump spectrum used in 2D EV measurements. The dotted line shows the absorption strength at frequencies where ESE (24500 cm ^-1) and ESA (25600 cm ^-1) were observed. (b) 2D EV signal amplitude as a function of 𝜔3, comparing the signal strength in the ESE and ESA regions.
    • GS_UV_Vis_cm – x-axis in cm ^-1
    • GS_UV_Vis_abs_N – y-axis in normalized absorbance
    • w3 in cm ^-1
    • ESA and ESE y-axes in delta_A
  • Tab 6 – SI-Fig 9 showing (a) Sliding double-sided hyper tangent filter with a full width at half maximum (FWHM) of 5.5 fs applied to the autocorrelation signal to extract τ1-resolved information.(b) Signal modulation as a function of τ1,center, observed at 𝜔3 = 1446 cm ^-1 and 𝜔1 = 24000–24700 cm ^-1 (ESE region), 𝜔3 = 1446 cm ^-1 and 𝜔1 = 25300–25800 cm ^-1 (ESA region), with the fitted curves. (c) Fourier transform of the signal modulation in (b) for the case of ESE, indicating the contribution of low-frequency modes down to 500 cm ^-1 in the vibronic coherence transfer, with broad peaks between 600-900 cm ^-1 and 1350-1450 cm ^-1. (d) Signal modulation as a function of τ1,center, observed at 𝜔3 = 1386 cm ^-1 and 𝜔1 = 24000–24700 cm ^-1 (ESE region), 𝜔3 = 1386 cm ^-1 and 𝜔1 = 25300–25800 cm ^-1 (ESA region), with the fitted curves.
    • Tau_1 in fs
    • Amplitude in arbitrary units
    • Tau_1 center in fs
    • Freq in cm ^-1
  • Tab 7 – SI Fig 10 showing the effect of the Window Function Width on Signal Modulation.
    • Tau1_center in fs
    • ESE and ESA signals in arbitrary unit.
  • Tab 8 – SI Fig 11 showing (a) Energy level diagram and model illustrating the experimental observations. Electronic excitation at ω1,ESA is non-adiabatically coupled to the K* state with a time-independent coupling constant of 336±47 cm ^-1, allowing excitation at lower frequency at ω1,ESE. This additionally resulted in a time-dependent signal modulation through a high-frequency vibration (ωp), facilitating coherence transfer to a vibrationally excited keto state. The right panel shows two diabatic potential energy surfaces of E* and K*, vibronically coupled through a high-frequency coherent vibrational motion (ωp = 1375±50 cm ^-1), which periodically modulates the vibronic coupling, and dephases as the proton transfer completes. (b) Bottom Panel: Experimental and simulated signal modulation as a function of τ1. The experimental signal is scaled to match the simulated signal modulation obtained from the differential equation, representing non-adiabatic proton transfer. Top panel: Amplitude of the Fourier Transform of the signal modulation, both in the under sampling and over sampling frequency regime, showing negligible impact of under sampling in our experiments and simulations. (c) Fourier transformed signal modulation as a function of the center of the Fourier filter both at the ESA and ESE regions for experimental and simulated data, along with their fits.
    • Freq in cm ^-1
  • Tab 9 – Figure SI-12 showing amplitude of the coherent oscillations at ω2 frequencies of (a) 90 cm ^-1 , (b) 205 cm ^-1 , (c) 450 cm ^-1 , (d) 850 cm ^-1, (e) 1000 cm ^-1, (f) 1220 cm ^-1, on top of the (ω1-ω3) 2D-EV plot, demonstrating that these modes have localized amplitude in the ESA (near ω1=25500 cm ^-1) region. Note that w1 and w3 are in cm ^-1.
  • Tab10– Figure SI 13 contains (a) 2D EV absorption map as a function of excitation frequency (ω1) and MIR probe frequency (ω3). (b) Background signals are calculated as (signal ≤5% max) using the data from plot in (a) and shown as contour. The shaded regions were determined using a logical function and do not correspond to any units.(c) The solid line represents the average error ω2 spectrum and the shaded areas represent ± 1 standard deviation from the mean. This shaded error plots are shown in the main figures on top of the coherent signal amplitude. Note that w1, w2, and w3 are in cm ^-1.
  • Tab 11 – Figure SI 14 showing (a-c) The 2DEV(ω₁, τ₂, ω₃) data for fixed ω₃ values corresponding to the high-frequency vibrational modes at 1350 cm ^-1, 1380 cm ^-1, and 1446 cm ^-1. (d–f) Showing the corresponding 2DEV (ω₁, τ₂, ω₃) datasets after subtraction of the population decay from Figures (a-c). (g-i) Full map of (ω1- ω2) correlation along all three high-frequency (ω3) vibrational coordinates. (g) 1446 cm ^-1, (h) 1386 cm ^-1, (i) 1350 cm ^-1. These plots were obtained by Fourier transforming the residual along τ2 for each ω1 frequencies at select ω3 frequency. Note the presence of several low-frequency modes near ω1 = 25500 cm ^-1. Note that t2 is in fs and w1, w2, and w3 are in cm ^-1.
  • Tab 12 – Figure SI 15 showing coherent low-frequency (ω2) vibrational motions across all the observed fingerprint high-frequency coordinates, their dephasing, and vibrational cooling. (a, c, e) Fourier transform amplitude vs ω2 plots for all the high-frequency modes 1446 cm ^-1 (a), 1386 cm ^-1 (c), 1350 cm ^-1 (e) during the first 600 fs pump-probe delay time. These amplitudes were obtained at the ESA region along the excitation frequency (25500 cm ^-1). The solid, redline reveals 10 resolved low-frequency vibrational coupling that are above the noise (orange solid line), the standard errors are shown as corresponding shaded regions. (b, d, f) Represents the time-frequency analysis of the ω2 vibrations using a gaussian window function with FWHM of 0.3 ps. Showing the dephasing and vibrational cooling of the modes as a function of time. Note that t2 is in fs and w1, w2, and w3 are in cm ^-1.
  • Tab 13 – Figure SI 16 showing (a) Time-frequency analysis of the ω2 vibrations as a function of time, showing the dephasing and blue shifts of vibrational frequencies. (b) Shows the similar time-frequency analysis for the background region, as described in Supplementary Figure 11. This shows the amplitude of the error propagation following the Fourier transform. The maximum amplitude of the error is less than by a factor of 4 compared to the signal observed in (a). Note that t2 is in fs and w1, w2, and w3 are in cm ^-1.
  • Tab 14 – Figure SI 17 showing the effect of temporal window function on the time-frequency analysis of the ω2 vibrations using (a) Gaussian window function (FWHM = 300 fs), as described in the main manuscript. (b) Rectangular filter (double sided hyper-tangent with a flat top, FWHM = 400 fs) (c) Double sided-hyperbolic tangent filter (FWHM = 300 fs). Note that t2,center is in fs and w1, w2, and w3 are in cm ^-1.
  • Tab 15 – Figure SI 18 showing the effect of the width of the gaussian filter on the time-frequency analysis. (a) 200 fs, (b) 300 fs, (c) 400 fs, and (d) 500 fs.). Note that t2,center is in fs and w1, w2, and w3 are in cm ^-1.
  • Supplementary_data.zip
    • Gaussian_Files - Contains the output files for the frequency calculations of the enol form of hydroxybenzo[h]quinoline (HBQ) in the ground electronic state. Contains the output files for the frequency calculations of the keto form of hydroxybenzo[h]quinoline (HBQ) in the excited electronic state.
    • GS_HBQ - contains .txt files of the FTIR data and the UV-vis data of 50 mM of hydroxybenzo[h]quinoline (HBQ) dissolved in tetrachloroethylene (TCE).
    • EV2D_all_data.mat: contains 2D EV data following fourier transform of t1 as a function of w1 and w3 and t2.