کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5417550 | 1506938 | 2008 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Accurate calculation of N1s and C1s core electron binding energies of substituted pyridines. Correlation with basicity and with Hammett substituent constants
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
Substituent shifts of the energetics of four related ionization processes of pyridines and benzoic acids (Fig. 1) were investigated. The first process is core-electron ionization of gas-phase pyridines (Fig. 1A), while the second concerns gas-phase acid-base reaction between a substituted pyridine and a conjugated acid (Fig. 1B), and the third and fourth processes are the acid dissociation of substituted benzoic acids in aqueous solution (Fig. 1C) and in vacuum (Fig. 1D), respectively. Core-electron binding energies for the first process were calculated using density-functional theory with the scheme ÎEKS (PW86x-PW91c/TZP+Crel)//HF/6-31Gâ. Average absolute deviation of calculated core electron binding energy shifts at N atom in substituted pyridines from experiment was 0.08Â eV. The shift at N coincides highly with that at a ring carbon atom. The four shifts corresponding to the four processes shown in Figs. 1A-D correlate strongly with one another, with numerical values fairly close to each other when expressed in unit of electron volts.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 863, Issues 1â3, 30 August 2008, Pages 33-38
Journal: Journal of Molecular Structure: THEOCHEM - Volume 863, Issues 1â3, 30 August 2008, Pages 33-38
نویسندگان
Yuji Takahata, Carl E. Wulfman, Delano P. Chong,