Torsional barriers around N-C ligations: a NMR study and molecular model

Protons and carbon-13 NMR spectra of four carbon anhydride derivatives have shown double-dealing of some signals. This phenomenon, called atropoisomery, is due the obstructed rotation around carbon-nitrogen ligation and the existing rotational conformers presenting some distinct chemical shifts. The present work shows a profound research about atropoisomers' structures using molecular model and nuclear magnetic resonance and a complete assignment of all variable temperature spectra