This dataset contains the time-resolved transient IR spectra (TRIR spectra for short) supporting the paper "Direct observation of two-channel photodissociation of carbon monoxide from the hemoglobin subunits" by Lepeshkevich et. al, Nature Communications, 2025. The DOI and the page numbers for that paper are not available at the time this Read_Me file is written.

Should the ground-state UV-Visible absorption spectra or ground-state FTIR spectra (in the C=O stretch vibration spectral range) be required, those are shown on Fig. 1b and in the insets to Fig. 5 and Fig. 6, respectively, and the source data can be found in the "Source Data" file available from the journal website (alongside the Supplementary Information file).

The TRIR spectra in this data set are arranged in folders, each folder corresponds to a specific sample (either alpha or beta carbonmonoxy chains of HbCO) and specific experiment conditions (polarization of the probe beam with respect to the pump beam, and the spectral range of mid-IR probing).
For example, the folder named "alpha CO_magic angle_1751-2002 cm-1" contains the TRIR spectra obtained for carbonmonoxy alpha chains at "Magic angle" polarization (which is 54.7 degree) and in the spectra probe range of 1751-2002 cm-1 at a number of time delays.

Each folder contains the text files (in .txt format, Tab-delimited). Each .TXT file corresponds to the transient IR spectrum obtained at the specific time delay (the time delay between the pump and the probe is indicated in the name of the text file in picoseconds in square brackets). 
For example, the file named "alpha CO_magic angle [ps 1.5e+05] 1751-2002 cm-1.TXT" contains the TRIR spectrum for carbonmonoxy alpha chains taken at "Magic angle" polarization at 1.5e+05 ps time delay (i.e. at 150 ns) within the probe range of 1751-2002 cm-1.

In each file there are two columns, the first column contains the wavenumbers (the spectral position of the data point), and the second column contains the difference optical density value at this data point. Occasionally "NAN" ("not a number") or "Inf" ("infinite value") can appear instead of difference optical density values for some spectral points. This sometimes happens near the edge of the spectral window where the probe light intensity is lower, as signal referencing is applied during data acquisition. Those data points can be ignored.
