Amide I vibrational dynamics of N-methylacetamide in polar solvents: the role of electrostatic interactions.

摘要: The vibrational frequency of the amide I transition peptides is known to be sensitive strength its hydrogen bonding interactions. In an effort account for interactions with solvents in terms electrostatics, we study dynamics coordinate N-methylacetamide prototypical polar solvents:  D2O, CDCl3, and DMSO-d6. These three have varying strengths, provide distinct solvent environments group. frequency−frequency correlation function, orientational relaxation rate vibration each are retrieved by using three-pulse photon echoes, two-dimensional infrared spectroscopy, pump−probe spectroscopy. Direct comparisons made molecular simulations. We find good quantitative agreement between experimentally simulated functions over all time scales when solute−solve...