کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5417999 | 1506959 | 2007 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Blue-shifting intramolecular CH â¯Â O(S) contacts in sterically strained systems
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A group of model systems which may form chelate-type structures with intramolecular CH â¯Â Y (Y = O, S) contact is investigated computationally. The existence of several conformers permits to identify a reference molecule without the CH â¯Â Y intramolecular contact and to establish the blue-shifting character of this interaction. The CH stretching frequency in chelate forms is found to increase with respect to its value in the reference system. A parallel decrease of the CH bond distance is also established. The blue-shifting character of the intramolecular CH â¯Â Y contact is interpreted in terms of the sterically enforced repulsion between the hydrogen atom in CH and the electron donor Y. This interpretation is supported by the negative (repulsive) estimates of the energy contribution due to CH â¯Â Y contacts.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 820, Issues 1â3, 15 October 2007, Pages 118-127
Journal: Journal of Molecular Structure: THEOCHEM - Volume 820, Issues 1â3, 15 October 2007, Pages 118-127
نویسندگان
MirosÅaw JabÅoÅski,