کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6661007 | 1426251 | 2013 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Structure and energetics correlations in some chlorohydroxypyridines
ترجمه فارسی عنوان
ساختار و ارتباطات انرژی در برخی از کلرو هیدروکسی پوریدین
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
چکیده انگلیسی
We have performed a study of the structure and energetics of some chlorohydroxypyridines based on experimental calorimetry techniques and high level ab initio computational calculations. The standard (p° = 0.1 MPa) molar enthalpies of formation of 2-chloro-3-hydroxypyridine (2-Cl-3-OHPy), 2-chloro-6-hydroxypyridine (2-Cl-6-OHPy) and 3-chloro-5-hydroxypyridine (3-Cl-5-OHPy) in the crystalline phase, at T = 298.15 K, were derived from the respective standard massic energies of combustion measured by rotating-bomb combustion calorimetry, in oxygen, at T = 298.15 K. The standard molar enthalpies of sublimation, at T = 298.15 K, were measured by Calvet microcalorimetry. From these experimentally determined enthalpic parameters we have derived the standard molar enthalpies of formation of the three compounds in the gaseous phase, at T = 298.15 K: 2-Cl-3-OHPy, â(76.8 ± 2.0) kJ · molâ1; 2-Cl-6-OHPy, â(105.0 ± 1.7) kJ · molâ1, 3-Cl-5-OHPy â(61.2 ± 2.4) kJ · molâ1. These values were compared with estimates obtained from very accurate computational calculations using the G3(MP2)//B3LYP composite method and appropriately chosen reactions. These calculations have also been extended to the remaining chlorohydroxypyridine isomers that were not studied experimentally. Based on B3LYP/6-31Gâ optimized geometries and calculated G3(MP2)//B3LYP absolute enthalpies some structure-energy correlations were discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Chemical Thermodynamics - Volume 62, July 2013, Pages 170-177
Journal: The Journal of Chemical Thermodynamics - Volume 62, July 2013, Pages 170-177
نویسندگان
Margarida S. Miranda, Maria Agostinha R. Matos, Victor M.F. Morais,