Solute-solvent interactions in dilute aqueous solution of some alkylureas and diazolidin-2-one

The integral heats of solution of urea, methylurea, 1,3 d$\text{i}$ methylurea, N,N,N′,N′ tetramethylurea, 1,3 diazolidin-2-one and N,N dimethyl 1,3 diazolidin-2-one have been measured at 298.15K.The results are interpreted qualitatively in terms of intercomponent molecular interaction and hydrophobic stabilisation of the water structure by the solute molecules.The obtained results indicate that the geometry, the number of hydrogen atoms and the number of alkyl groups have an important action on these two effects.A structural model between five water molecules bonded to 1,3 diazolidin-2-one is proposed by a diffractometric analysis on an aqueous solution 2 M of this compound.