Low temperature heat capacity and thermodynamic parameters of phase transitions of 4-nitro-4′-tert-butyl-diphenyl oxide

The low-temperature heat capacity of 4-nitro-4′-tert-butyl-diphenyl oxide was measured by vacuum adiabatic calorimetry over the temperature range (7-372) K. The temperature, the enthalpy and the entropy of fusion and the temperature, the jump of the heat capacity, and the range of devitrification of the glass-transition were determined. Heat capacity and main thermodynamic functions (changes of entropy, enthalpy, and Gibbs energy) in condensed state are tabulated as a function of temperature from 5 K to 370 K. The entropy of formation at T = 298.15 K of 4-nitro-4′-tert-butyl-diphenyl oxide in the crystal state was computed on the basis of the experimental results obtained.