2D vibrational spectroscopy is applied to investigate the equilibrium dynamics of hydrogen bonding of N-methylacetamide (NMA) dissolved in methanol-d4. For this particular solute-solvent system, roughly equal populations are found for two conformers of the solute-solvent complex, one of which forms a hydrogen bond from the C=O group of NMA to the surrounding solvent, and one of which does not. Using time-resolved 2D-IR spectroscopy on the amide I band of NMA, the exchange between both conformers is resolved. Equilibration of each conformer is completed after 4.5 ps, while the formation and breaking of the hydrogen bond occurs on a slower, 10-15 ps time scale. This interpretation is supported by classical molecular-dynamics simulations of NMA in methanol. The calculations predict a 64% population of the hydrogen-bonded conformer and an average hydrogen-bond lifetime of ≈12 ps. © 2001 Elsevier Science B.V.
CITATION STYLE
Woutersen, S., Mu, Y., Stock, G., & Hamm, P. (2001). Hydrogen-bond lifetime measured by time-resolved 2D-IR spectroscopy: N-methylacetamide in methanol. Chemical Physics, 266(2–3), 137–147. https://doi.org/10.1016/S0301-0104(01)00224-5
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