The dataset contains the numerical data used to produce figures 2-14 and S1-S8 (Figure 1 is purely schematic and is uploaded as a tif file for completeness - it does not contain any new data.  These files contain the transient UV-visible, X-ray absorption, and X-ray emission data that were used to characterize the dynamics of methyl cobalamin at neutral pH and to compare this to adenosyl cobalamin.  Details of data collection and reduction are provided in the associated manuscript. Data files are all text files which contain tab-delimited columns of data corresponding to each figure in the manuscript 

Figure 1. UV-visible absorption spectrum of MeCbl at pH 7. The vertical lines indicate the center wavelength for pulses used to excited the MeCbl samples for UV-visible transient absorption (blue, 270 nm, 407 nm, and 540 nm), X-ray emission (red, 400 nm and 550 nm) and X-ray absorption (green, 520 nm). 

Figure 2. Optical transient absorption results following excitation of MeCbl in water (pH ~7) at 540 nm. 

Figure 3. Time resolved difference spectra and estimated excited state UV-visible spectra for the initial excited state, A, following excitation of MeCbl. 

Figure 4. Estimated excited state UV-visible spectra for MeCbl. 

Figure 5. Species associated difference spectra obtained from a global analysis of transient absorption data following excitation at 400 nm and 270 nm. 

Figure 6. Isotropic XANES difference spectrum of MeCbl as a function of time delay following excitation at 520 nm.

Figure 7. Ground state XANES spectrum of MeCbl (GS black) and estimated excited state spectra.

Figure 8. Decomposition of the transient XANES signal at key energies following excitation of MeCbl. 

Figure 9. Time-resolved X-ray emission spectra and X-ray absorption spectra for MeCbl.

Figure 10. Left: Evolution associated difference spectra obtained from a fit to the transient XES spectra.

Figure 11. (a) Difference spectra obtained at the indicated time delays following excitation of MeCbl at 400 nm. 

Figure 12. Comparison of experimental difference spectra and estimated excited state spectra for MeCbl with simulated spectra.

Figure 13. (a) Comparison of the valence-to-core spectrum of MeCbl with a TD-DFT simulation of the transitions involved. 

Figure 14. Fit of the XANES difference spectra of MeCbl averaged over select energy regions to a displaced step function convoluted with a Gaussian. 

Figure S1. Contour surface plot of the broadband transient absorption difference spectrum of base-on MeCbl following excitation at 560 nm.

Figure S2. Comparison of experimental and fit difference spectra for select time delays

Figure S3. Fits at select energies in the Ka1 and Kb2 emission bands.

Figure S4. Fits at select energies in the Kb and valence-to-core (lower right) emission bands.

Figure S5. Comparison of exponential and displaced rise fits to the XAS pre-edge transient averaged around 7.714 keV. 

Figure S6. Comparison of the exponential fit to the data in the pre-edge region. 

Figure S7. Comparison of calculated ground state valence-to-core emission spectra for the parameters used in the XANES simulations.