کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
216334 1426277 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Combined experimental and computational study on the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Combined experimental and computational study on the energetics of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one
چکیده انگلیسی

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° = 0.1 MPa) massic energy of combustion, at T = 298.15 K, 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).

Research highlights
► The standard molar enthalpies of formation and sublimation of 1,2-benzisothiazol-3(2H)-one and 1,4-benzothiazin-3(2H, 4H)-one were determined.
► Computational calculations predict that keto tautomers are more stable than the enol ones.
► G3(MP2)//B3LYP calculations allowed estimation of the standard enthalpies of formation.
► The aromaticity of both compounds was evaluated by analysis of NICS values.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Chemical Thermodynamics - Volume 43, Issue 5, May 2011, Pages 635–644
نویسندگان
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