ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Low-Temperature Heat Capacity and Thermodynamic Properties of Crystalline 2-Chloro-5-trichloromethylpyridine

L. G. Kong, Z. C. Tan, W. Zhang, F. Xu, M. H. Wang, X. H. Bao, T. Zhang, and L. X. Sun

Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China

E-mail: tzc@dicp.ac.cn

Received: 30 May 2003

Abstract: The low-temperature heat capacities of 2-chloro-5-trichloromethylpyridine were measured with a high-precision automated adiabatic calorimeter in the temperature range from 80 K to 345 K. A solid-liquid phase transition was observed from 318.57 K to 327.44 K with peak temperature 324.67 K; the molar enthalpy and entropy of phase transition, ΔH_m and ΔS_m, were determined to be 14.50 ± 0.02 kJ mol⁻¹ and 44.66 ± 0.07 kJ K⁻¹ mol⁻¹, respectively. The thermal stability was investigated through thermogravimetric analysis (TG). The TG and DTG results reveal that 2-chloro-5-trichloromethylpyridine starts to lose mass at 332 K due to evaporation and completely changes into vapour at 483 K under the present experimental conditions.

Full paper in Portable Document Format: 585a295.pdf

Chemical Papers 58 (5) 295–298 (2004)