Nuclear magnetic resonance studies of urea and thiourea adducts

The ‘wide-line’ proton magnetic resonance spectra of n-tridecane and n-hexadecane and their urea adducts have been examined from 77°K to 298°K. The results show that the enclosed component is capable of a considerable degree of molecular motion. Estimates of the energy barriers involved support the idea that the interaction between the urea cage and the adducted hydrocarbon is only slight. The thiourea adducts of some cyclic hydrocarbons have also been examined.