The 1H NMR spectra of N-(2-pyridyl), N′-(3-pyridyl) ureas and N-(2-pyridyl), N′-(4-pyridyl) ureas in CDCl3 and (CD3) 2CO have been assigned with the aid of COSY and NOE experiments and chemical shift and coupling constant correlations. The 13C NMR spectra in CDCl3 were analysed utilizing the HETCOR and proton coupled spectra. The 1H NMR spectra, NOE effects and MINDO/3 calculations have been utilized to show that the ...