Acrylamide Conformers: A Revision of Published Density Functional Theory Studies

TL;DR

This study revises the conformational landscape of acrylamide using high-precision DFT calculations, confirming three stable conformers and their transition states, and providing detailed spectral and structural data.

Contribution

It clarifies the number of stable acrylamide conformers, verifying three with high-precision DFT, and updates previous literature that reported only two or three conformers.

Findings

Confirmed three stable conformers of acrylamide

Identified transition state barriers between conformers

Provided detailed vibrational spectra and atomic charges

Abstract

Acrylamide, with PubChem identifier CID=6579 is broadcasted to have four stable conformers contrasting with several journal publications characterizing only two or three. In this revision summary the discrepancy is clarified. Through very high precision density functional theory (DFT) calculations, three stable conformers and the three transition state barriers existing between them are verified to exist and validated with our own DFT calculations The most stable conformer is a planar molecular structure termed "sys" or "trans" in the literature. Meanwhile, a less stable structure termed "skew" pertains to two 3-dimensional structures that are energy-degenerate, but differ in their structure for being mirrored images of each other. Vibrational spectra, partial atomic charges, Cartesian coordinates, and Intrinsic Reaction Coordinate paths are summarized and recalculated with DFT at the $\omega$B97XD/Def2TZVPP level for the three stable acrylamide isomers: the sys/trans lowest in energy structure, and the two skew mirrored structures.