As already mentioned the DABCO molecule is not enclosed inside the cavity of CB . Even no threading is observed with the dumbbell molecules composed of two DABCO molecules connected by alkyl chains. From the complex formation between CB and spermine it is known that four CH2-groups between the NH-groups are optimal for the formation of a strong complex . Varying the number of CH2-groups between the DABO end groups from three to seven has no influence upon the stability constants measured. Thus, no threading takes place.