Experimental and computational thermochemical studies of 9-R-xanthene derivatives (R=OH, COOH, CONH2)

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Vera L S Freitas (Author) FCUP; Jose R B Gomes (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP

Journal

Title: Journal of Chemical Thermodynamics

Vol. 54

Pages: 108-117

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 20 Citations

Scopus - 19 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-002-4AK

DOI: 10.1016/j.jct.2012.03.017

Abstract (EN): In the present work, the standard (p degrees = 0.1 MPa) molar enthalpies of formation of xanthydrol, 9-xanthenecarboxylic acid and 9-xanthenecarboxamide, in the gaseous state, at T = 298.15 K, were determined by experimental and computational studies. The experimental techniques used were the static-bomb combustion calorimetry, which enabled the determination of the standard molar enthalpy of formation, in the crystalline state, and the vacuum drop microcalorimetric and the Knudsen effusion techniques used to derive the enthalpy of sublimation. For comparison purposes, we performed standard ab initio molecular orbital calculations, using the G3(MP2)//B3LYP composite procedure, of the enthalpies of several homodesmotic reactions, allowing to extract the standard molar enthalpies of formation, in the gaseous state, of the three xanthene derivatives considered in this work. The calculated results are in good agreement with the experimental data.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10