The resonance model in amides: a combined crystallographic and ab initio investigation

Abstract

The resonance model in amides has been questioned based on the changes that occur during the rotation of the C–N bond. The geometrical changes, electron population and electrostatic potentials calculated during the rotation have been used to propose that the oxygen atom does not participate to a significant extent in the rotational barrier. Our results based on X-ray analysis and ab initio calculations reveal that the resonance model is adequate to explain the properties of amides and show the role that the oxygen atom plays in the rotation.