The influence of the halogen size in the volatility and melting of methyl p-halobenzoic esters and of their parent acids

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Ana R R P Almeida (Author) Other; Manuel J S Monte (Author) FCUP

Journal

Title: Journal of Chemical Thermodynamics

Vol. 57

Pages: 160-168

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 26 Citations

Scopus - 27 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-002-13K

DOI: 10.1016/j.jct.2012.07.027

Abstract (EN): The vapour pressures of the condensed phases of the methyl esters of p-halobenzoic acids were measured over wide temperature ranges. The results enabled the determination of the standard molar entropies and enthalpies of sublimation and of vapourisation, at T = 298.15 K, of these four compounds. The temperatures and molar enthalpies of fusion were determined using differential scanning calorimetry and were compared with the values derived from the vapour pressure measurements. Temperature and enthalpy of fusion of p-chlorobenzoic acid were also measured using DSC. The enthalpies of the intermolecular hydrogen bonds O-H center dot center dot center dot O formed in the crystals of the parent halobenzoic acids were calculated. From the available results for these compounds and from the ones determined in this work, several correlations involving thermodynamic properties of sublimation and fusion as well as the volume of the halogen substituent were derived.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9