A. Bazyleva, A. Blokhin, G. J. Kabo
Jul 1, 2005
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0
Influential Citations
20
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Journal
The Journal of Chemical Thermodynamics
Abstract
Abstract The heat capacities of 1-bromoadamantane in the condensed state were measured in calorimeters of two types: an adiabatic vacuum calorimeter was used in the temperature range from (6 to 320) K and a differential scanning calorimeter of the heat bridge type – between T = (290 and 430) K. Three solid-to-solid phase transitions and fusion were found to occur in the mentioned temperature range. The thermodynamic parameters of the solid-to-solid phase transitions were determined by the adiabatic calorimetry and of the crII → crI transition and fusion – in the scanning calorimeter. The molar thermodynamic functions of 1-bromoadamantane in the crystalline and liquid states were obtained. The two-stage development of the orientational disorder in the crystalline phases up to the formation of the plastic crystals was established for the compound under study. Thermal behaviour of adamantane and 1-haloadamantanes and parameters of orientational disorder in their isotropic plastic crystals were discussed.