Thermal behaviour of hydrated and anhydrous Cucurbituril - A DSC, TG and calorimetric study in temperature range from 100 to 800 K

Thermal behaviour of differently hydrated Cucurbituril samples was studied using Differential Scanning Calorimetry and Thermogravimetry in the temperature range from 100 to 800 K. The enthalpy of reaction with water was measured by isothermal calorimetry at 298 K for anhydrous Cucurbituril and Cucurbituril . 8H(2)O. Two or three water molecules appear to be bonded stronger than the others. For these two subgroups of hydration water molecules, the respective bond energies were calculated as: (-22.5+/-2.5) kJ mol(-1) H2O and (-9.4+/-1.0) kJ mol(-1) H2O. (C) 1998 Elsevier Science B.V.