Combined experimental and computational study on the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one

• Type: Article in International Scientific Journal
• Date: 2011

Authors

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

Journal

Title: Journal of Chemical Thermodynamics

Vol. 43 No. 2

Pages: 635-644

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-002-S8M

DOI: 10.1016/j.jct.2010.11.006

Abstract (EN): The present work reports an experimental and computational study of the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one. The standard (p degrees = 0.1 MPa) massic energy of combustion, at T = 298.15K, of each compound was measured by rotating bomb combustion calorimetry, in oxygen that allowed the calculation of the respective standard molar enthalpy of formation, in the condensed phase, at T = 298.15 K. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by high-temperature Calvet microcalorimetry. From the combination of data obtained by both techniques we have calculated the standard molar enthalpies of formation, in the gaseous phase, at T =298.15 K. In addition, computational calculations were carried using the density functional theory with the B3LYP functional and the 6-31G* basis set and some correlations between structure and energetics were obtained for the keto and enol forms of both compounds. Using the G3(MP2)//B3LYP composite method and various appropriate reactions, the standard molar enthalpies of formation of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one, at T = 298.15 K. were computationally derived and compared with the experimental data. The aromaticity of 1,2-benzisothiazol-3(2H)-one, 1,4-benzothiazin-3(2H, 4H)-one and that of some related species was evaluated by analysis of nucleus independent chemical shifts (NICS).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10