Standard molar enthalpies of formation, vapour pressures, and enthalpies of sublimation of 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline

• Type: Article in International Scientific Journal
• Date: 2003

Authors

da Silva, MAVR (Author) FCUP; Lima, LMSS (Author) Other; Amaral, LMPF (Author) Other; Ana I M C L Lobo Ferreira (Author) Other; Jose R B Gomes (Author) Other

Journal

Title: Journal of Chemical Thermodynamics

Vol. 35

Pages: 1343-1359

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 55 Citations

Scopus - 56 Citations

Other information

Authenticus ID: P-000-FQP

DOI: 10.1016/s0021-9614(03)00109-5

Abstract (EN): The standard (p(o) = 0.1 MPa) molar enthalpies of formation for crystalline 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline were derived from the standard molar enthalpies of combustion, in oxygen, at the T = 298.15 K, measured by rotating bomb combustion calorimetry. The Knudsen mass-loss effusion technique was used to measure the vapour pressures of the crystals as function of temperature, and the standard molar enthalpies of sublimation, at T = 298.15 K, were derived by the Clausius-Clapeyron equation. Direct measurements of the standard molar enthalpies of sublimation, using Calvet microcalorimetry, for 2-chloro-4-nitroaniline and 2-chloro-5-nitroaniline confirmed the values derived from the Knudsen technique. [GRAPHICS] Additionally, standard enthalpies of formation were estimated by employing two different methodologies. One is based on the Cox scheme and the other one, much more accurate, is based on first-principles calculations. The theoretical calculations were performed at the AMI, B3LYP/6-31+G** and BP86/6-31+G** levels of theory. Estimated values are in good agreement with the reported experimental numbers.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 17