کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5395059 | 1505654 | 2011 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
On the basicity and Ï-electron delocalization of 'hexaazabenzene' N6 - Quantum-chemical studies
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The HF, MP2, and DFT structures of neutral (N6) and monoprotonated (N6H+) hexazine, nitrogen analogues of benzene, were discussed. For neutral N6, the extended geometry-based HOMED (harmonic oscillator model of electron delocalization) index, being a measure of Ï-electron delocalization, is close to that of benzene. Protonation of one N atom in planar N6 has no important effect on the HOMED value. Contrary to benzene, planar N6H+ does not lose its aromatic character. Ï-Electrons of the ring are not engaged in the formation of the NH bond. The proton affinity (PA) of N6 seems to be considerably lower than that of benzene (by ca. 16 kcal molâ1 at the G2 level), indicating great NN lone pairs repulsion and electron-withdrawing effects of the N-aza groups (ca. 12 kcal molâ1 for each N atom).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computational and Theoretical Chemistry - Volume 971, Issues 1â3, 15 September 2011, Pages 38-41
Journal: Computational and Theoretical Chemistry - Volume 971, Issues 1â3, 15 September 2011, Pages 38-41
نویسندگان
Ewa D. RaczyÅska,