Abstract The 270 MHz 1 H-NMR and IR spectra of several N, N′-arylalkylureas are analysed in terms of their conformational properties. For most systems, the—NHCONH— group adopts a less energetic trans—cis conformation which is stabilized by unsymmetric intramolecular hydrogen bonding of lower polarizability, in contrast to other N, N′- disubstituted ureas which are predominantly found in the trans—trans form. The influence ...
