کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
217048 1426308 2008 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Experimental and computational thermochemistry of 1,4-benzodioxan and its 2-R derivatives
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Experimental and computational thermochemistry of 1,4-benzodioxan and its 2-R derivatives
چکیده انگلیسی

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, 6-311G∗∗ 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 = –CH2COOH, –OH, –COCH3, –CHO, –CH3, –CN, and –NO2).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Chemical Thermodynamics - Volume 40, Issue 10, October 2008, Pages 1485–1489
نویسندگان
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