Low-Temperature Heat Capacities and Thermodynamic Properties of a New Complex [Na(H2O)2]6[MoCo6O12(H2O)12]•4.3H2O(s)

A new complex [Na (H2O)2]6[MoCo6O12(H2O)12]·4.3H2O(s) was synthesized and determined by X-ray crystallography. Low-temperature heat capacities of the compound was measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 380 K. An obvious dehydration process was found in the heat capacity curve of the title compound. The temperature, enthalpy and entropy of the dehydration process were determined to be (370.266±0.292) K, (187.455±0.354) kJ·mol-1, (50.627±0.078) J·K-1·mol-1 by three series of repeated heat capacity measurements in the region of thermal decomposition.