Heat capacity of methacetin in a temperature range of 6 to 300 K
- 81 Downloads
Heat capacity of methacetin (N-(4-methoxyphenyl)-acetamide) has been measured in the temperature range 5.8–300 K. No anomalies in the C p(T) dependence were observed. Thermodynamic functions were calculated. At 298.15 K, the values of entropy and enthalpy are equal to 243.1 J K−1 mol−1 and 36360 J mol−1, respectively. The heat capacity of methacetin in the temperature range 6–10 K is well fitted by Debye equation C p = AT 3. The thermodynamic data obtained for methacetin are compared with those for the monoclinic and orthorhombic polymorphs of paracetamol.
KeywordsAdiabatic calorimetry Methacetin Heat capacity Molecular crystals Thermodynamic functions
The authors are grateful to Dr. T. Drebushchak for X-ray characterization of the sample. The study was supported by the Integration Project 109 of the Siberian Branch of the Russian Academy of Sciences.
- 13.Boldyreva EV, Shakhtshneider TP, Ahsbahs H, Uchtmann H, Burgina EB, Baltakhinov VP. The role of hydrogen bonds in the pressure-induced structural distortion of 4-hydroxyacetanilide crystals. Polish J Chem. 2002;76:1333–46.Google Scholar
- 15.Kolesov BA, Mikhailenko MA, Boldyreva EV. Dynamics of intermolecular hydrogen bonds in the polymorphs of paracetamol in relation to crystal packing and conformational transitions: a variable-temperature polarized Raman spectroscopy study. Phys Chem Chem Phys. 2011; (submitted).Google Scholar
- 17.Paukov IE, Kovalevskaya YuA, Boldyreva EV. Low-temperature heat capacity of l- and dl-phenylglycines. J Therm Anal Calorim. 2010. doi: 10.1007/s10973-009-0665-4.