The experimental results for DABCO-2,2 and DABCO-6.6 differ from those for DABCO and bromoethyl-DABCO. However, also these molecules do not form inclusion complexes. Due to the ion-dipole interactions between the carbonyl groups and the positively charged nitrogen atom the ethyl and hexyl substituents have to be located inside the cavity of CB . Therefore, the alkyl substituents replace some water molecules from the cavity. Calculations show that three or four water molecules are located inside the cavity . Without some detailed knowledge about the number of water molecules inside the cavity, no further discussion of the thermodynamic values is possible at the moment. This interpretation is supported by the results obtained for the complexation of hexylamine (log K = 3.83 [L mol -1 ], -ΔH = 22.1 [kJ mol -1 ], TΔS = 0.9 [kJ mol -1 ]