CALORIMETRIC BEHAVIOR OF ANHYDROUS BETA-CYCLODEXTRIN AT VERY-LOW TEMPERATURE

Heat capacities of anhydrous beta-cyclodextrin were measured between 1 0 K to 300 K using an adiabatic low-temperature calorimeter. Two disti nct types of thermal behaviour were observed in the temperature range 50-130 K, depending on the way the sample was cooled. In the absence o f hydration water molecules, we assumed that the two types of thermal behaviour could be attributed to freezing in more or less ordered stat es of the hydroxyl groups engaged in the intramolecular interglucose f lip-flop-type interactions.