Journal of Physical Chemistry A, Vol.106, No.38, 8870-8875, 2002
Dynamics of an inclusion complex of dichloromethane and cryptophane-E
The dynamic properties of the guest-host complex between cryptophane-E and dichloromethane have been studied in tetrachloroethane solution, using proton and carbon-13 NMR, and in the solid state by means of deuteron NMR. The exchange of dichloromethane guest between the free state in the bulk solution and the bound state within the host cavity is slow, on the time scale of seconds, similarly to the earlier studied complex between cryptophane-E and chloroform. The reorientational dynamics of complexed dichloromethane is very fast and is only weakly affected by the reorientation of the guest-host complex as a whole. This result is very different from the case of chloroform inside of the cryptophane cavity. These different pictures of the reorientation of the two chloromethane guests are also nicely reflected in the solid-state deuteron NMR spectra of deuterated guest molecules.