Energetics of Coumarin and Chromone

• Type: Article in International Scientific Journal
• Date: 2009

Authors

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

Journal

Title: Journal of Physical Chemistry B

Vol. 113

Pages: 11216-11221

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 25 Citations

Scopus - 22 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-GS5

DOI: 10.1021/jp9026942

Abstract (EN): Condensed phase standard (p degrees = 0.1 MPa) molar enthalpies of formation for coumarin and chromone were derived from the standard molar enthalpies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: coumarin, -(163.4 +/- 3.3) kJ(.)mol(-1), and chromone, -(126.1 +/- 2.5) kJ(.)mol(-1). The temperatures of fusion, T(fusion), and fusion enthalpies, at T = T(fusion), were also reported. Additionally, theoretical calculations were done using different methods: DFT/B3LYP, MCCM (MC-UT/3 and MC-QCISD/3), and also the more accurate G3MP2 method. Good agreement between experimental and theoretical data was achieved. Some correlations between structure and energy were also made, and the aromaticity of the compounds was evaluated by the nucleus independent chemical shifts (NICS).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6