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
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Accurate calculation of N1s and C1s core electron binding energies of substituted pyridines. Correlation with basicity and with Hammett substituent constants
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 ΔEKS (PW86x-PW91c/TZP+Crel)//HF/6-31G∗. Average absolute deviation of calculated core electron binding energy shifts at N atom in substituted pyridines from experiment was 0.08 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 1–3, 30 August 2008, Pages 33-38
نویسندگان
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