Evidence for migration of molecules into the tunnel structure of urea inclusion compounds

It is shown by high-resolution solid state 13C NMR spectroscopy and optical microscopy that n-decane molecules can migrate from the liquid phase into the tunnel structure of the 1,8-dichlorooctane–urea inclusion compound without loss of single crystal integrity; this result provides strong evidence to suggest that urea inclusion compounds possess an open host structure, and has important implications with regard to potential applications of these inclusion compounds.