TEMPERATURE DEPENDENCE OF THE THERMODYNAMIC PARAMETERS OF COBALT(II) CLATHROCHELATE: X-RAY DIFFRACTION AND CALORIMETRIC CHARACTERISTICS OF THE LOW TEMPERATURE STRUCTURAL PHASE TRANSITION
The temperature dependence of heat capacity of the polycrystalline sample of cobalt(II) clathrochelate in a range of 6-300 K is studied. Based on the smoothed dependence <i>C</i><sub>p</sub>(<i>Т</i>), the entropy and enthalpy values in a temperature range of 8-300 K and their standard values at 298.15 K are calculated. In the <i>C</i><sub>p</sub>(<i>Т</i>) curve in a range of 50-70 K, a process is recorded whose entropy and enthalpy are 1.2 J·(K·mol<sup>-1</sup>) and 68 J·mol<sup>-1</sup> respectively. A comparison of the results with the data of a multitemperature X-ray diffraction study makes it possible to attribute this process to the structural phase transition.