INFRARED AND 1H-NMR STUDY OF MOLECULAR CONFORMATION OF SOME N,N'-ARYLALKYLUREAS

Article abstract of DOI:10.1016/0022-2860(84)85326-0

The 270 MHz 1H-NMR and IR spectra of several N,N'-arylalkylureas are analyzed 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 ot other N,N'-disubstituted ureas which are predominantly found in the trans-trans form.The influence of the N-substituent on hydrogen bonding and molecular conformation is emphasized.