Phase Transitions in Some Hydrogen-Bonded Molecules

✍ Scribed by Abdel-Kader, M.M. ;Gwaily, S.E. ;El Zayat, M.Y.

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 130 KB
• Volume: 191
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200205)191:1<49::aid-pssa49>3.0.co;2-e

✦ Synopsis

Subject classification: 64.70.Kb; 65.40.-b; S12

The calorimetric parameters including the heat capacity, thermal conductivity and thermal diffusivity are measured and/or determined as a function of temperature (310 K < T < 400 K) for two hydrogen-bonded molecules, namely anthralinic acid C 6 H 4 COOHNH 2 and p-nitrophenol C 6 H 4 NO 2 OH. It seems likely that the first compound undergoes a structural phase transition around 354 K whereas for the second compound the transition temperature is 336 K. Furthermore, the order of magnitude of the above-mentioned parameters suggests that the two compounds under current investigation behave as poorly conducting materials. The thermogravimetric analysis (TGA) for the two compounds was carried out. An interpretation of our data has been outlined on the basis of the crystal structure including the arrangement of the hydrogen bonding system in each compound.