Experimental and computational study of the thermochemistry of the fluoromethylaniline isomers

• Type: Article in International Scientific Journal
• Date: 2007

Authors

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

Journal

Title: Journal of Physical Chemistry B

Vol. 111

Pages: 6444-6451

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 9 Citations

Other information

Authenticus ID: P-004-9CW

DOI: 10.1021/jp071232o

Abstract (EN): The standard (p(o) = 0.1 MPa) molar enthalpies of formation in the condensed phase of seven isomers of fluoromethylaniline were derived from the standard molar energies of combustion, in oxygen, to yield CO2(g), N-2(g) and HF center dot 10H(2)O(l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies of vaporization or sublimation of these compounds, also at T = 298.15 K, were determined using Calvet microcalorimetry, while the enthalpies of fusion of the solid compounds were determined by differential scanning calorimetry. The standard molar enthalpies of formation in the gaseous phase, at T = 298.15 K, were derived from the former two experimental quantities. G3MP2//B3LYP calculations were performed for all possible fluoromethylanilines allowing the estimation of data for the isomers that were not studied experimentally. The Cox scheme was applied with two different approaches for the estimation of the standard molar enthalpies of formation of all the isomers studied, and this led to the conclusion that the literature values for the enthalpies of formation of the meta and para isomers of methylaniline seem to be not reliable. Further G3MP2//B3LYPs calculations on the methylaniline isomers yielded new values for the standard molar enthalpies of formation of the isomers of methylaniline, which have been tested under the Cox scheme, resulting in better estimates.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8