Thermodynamic properties of 1,3,5-trithiane derived from solid phase heat capacity measurements by adiabatic calorimetry and DSC measurements in the melting range

The thermal properties of 1,3,5-trithiane were measured with adiabatic calorimetry and DSC between 15 and 500 K. It was necessary to purify the compound even as the stated purity of the commercial product was >99%. The impurity present triggers a reaction at the melting point. The absolute entropy at 298.15 K was measured to be (156.2±0.8) J K−1 mol−1, the enthalpy increment from 0 to 298.15 K is (22936±100) J mol−1. The enthalpy of melting was found to be (32.2±0.3) kJ mol−1, the fusion temperature 488.4 K. The molar heat capacity of the solid between 100 and 380 K can be described by a polynomial function Cp={24.17+0.4004T−9.9605.10−5T2} J K−1 mol−1, the standard deviation of this fit is 0.24 J K−1 mol−1.