Experimental and computational thermochemistry of 1,4-benzodioxan and its 2-R derivatives

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Agostinha A R Matos (Author) FCUP; Clara C S Sousa (Author) Other; Victor M F Morais (Author) ICBAS

Journal

Title: Journal of Chemical Thermodynamics

Vol. 40

Pages: 1485-1489

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 3 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-003-VW0

DOI: 10.1016/j.jct.2008.06.003

Abstract (EN): The standard molar energies of combustion, at T = 298.15 K, of crystalline 1,4-benzodioxan-2-carboxylic acid and 1,4-benzodioxan-2-hydroxymethyl were measured by static bomb calorimetry in an oxygen atmosphere. The standard molar enthalpies of sublimation, at T = 298.15 K, were obtained by Calvet microcalorimetry. These values were used to derive the standard molar enthalpies of formation of the compounds in the gas phase at T = 298.15 K: 1,4-benzodioxan-2-carboxylic acid -(547.7 +/- 3.0)kJ.mol(-1) and 1,4-benzodioxan-2-hydroxymethyl -(374.2 +/- 2.3)kJ.mol(-1). In addition, density functional theory calculations using the B3LYP hybrid exchange-correlation energy functional with extended basis sets, 6-31IG(center dot center dot) and cc-pVTZ, have been performed for the compounds studied. We have also tested two more accurate computational procedures involving multiple levels of electron structure theory in order to get reliable estimates of the thermochemical parameters of the compounds studied. The agreement between experiment and theory gives confidence to estimate the enthalpies of formation of other 2-R derivatives of 1,4-benzodioxan (R = -CH(2)COOH, -OH, -COCH(3), -CHO, -CH(3), -CN, and -NO(2)).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5