Related Experiment Video
Updated: Mar 3, 2026

Author Spotlight: In Silico Creation and Impact of Carbonylated Amino Acids on Protein Structure and Function
Published on: April 26, 2024
Probing the dynamics of N-methylacetamide in methanol via ab initio molecular dynamics
Vivek K Yadav1, Michael L Klein
1ICMS, Department of Chemistry, Temple University, Philadelphia, 19122, USA. mlklein@temple.edu.
Abstract:
Two-dimensional infrared (2D IR) spectroscopy of amide 1 vibrational bands provides a valuable probe of proteins as well as molecules such as N-methylacetamide (NMA), which present peptide-like H-bonding possibilities to a solvent. To assist in rationalizing a large body of experimental 2D IR data on NMA in both aqueous and non-aqueous solvents, we have performed an ab initio molecular dynamics simulation of NMA in methanol. Our study enables us to compare and contrast our findings with earlier calculations on NMA in water, and thereby explore the effect of solvent on the structural and dynamical properties of the NMA solute. We explicitly focus on the dynamics associated with the amide mode I (mainly C[double bond, length as m-dash]O stretch) and amide mode A (mainly N-H stretch) and its interaction with solvent through hydrogen bonding. Our results show that NMA exhibits faster hydrogen bond dynamics in methanol than in water, with an accompanying blue shift of the vibrational frequencies with respect to water. The observed faster diffusion of NMA in methanol signifies a weakening of hydrogen bonding between solute and solvent compared with water.
More Related Videos
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Amides to Carboxylic Acids: Hydrolysis
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
¹H NMR of Labile Protons: Temporal Resolution
The –OH proton in alcohols typically appears in the range of δ 2 to 5 ppm but can vary depending on the specific...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Mass Spectrometry of Amines

