INFRARED SPECTROSCOPIC AND CONFORMATIONAL STUDIES OF TRISUBSTITUTED UREAS CONTAINING CHLOROPHENYL GROUPS

Article abstract of DOI:10.1016/0022-2860(82)85229-0

The IR spectra, in the ν(N-H) region, of trisubstituted ureas R2UPhCl and RPhUPhCl containing a chlorophenyl group have been studied in order to examine the effects of the introduced chlorine atom.The out-trans-cis isomerism about the NH-CO rotational axis is discussed in reation to steric effect of the R2 group, Ph-Ph interaction and inter- and intra-molecular hydrogen bonding.In dilute solution, R2UPhCl exists in the trans or the out form, and RPhUPhCl in the cis form. o-Chlorophenyl derivatives show a monomeric ν(N-H) band at a wavenumber lower than that of the other derivatives and no associated ν(N-H) bands in concentrated or even in saturated solutions.Some of the derivatives are found to be in the same form in the solid state as in solution due to the retention of intra-molecular NH...Cl hydrogen bonding.