کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9591711 1507012 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Intramolecular dative bonds involving boron with oxygen and nitrogen in boronic acids and esters: a computational study
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Intramolecular dative bonds involving boron with oxygen and nitrogen in boronic acids and esters: a computational study
چکیده انگلیسی
The differential affinity of boron towards the oxygen and nitrogen lone pairs of electrons in 2-aminocarbonyl-phenylboronic acid (2-AC-PBA) and its corresponding ester, ethanediol (2-aminocarbonyl) phenylboronate (ED-2-AC-PB), has been investigated computationally using both density functional theory and second-order Møller-Plesset perturbation theory. In vacuo, the optimized boron-oxygen or boron-nitrogen distances in conformers of 2-AC-PBA, that involve either an intramolecular five-membered (:OC-CC-B) or (:N-C-CC-B) ring motif, are long, ∼2.4-3.0 Å, and the calculated charge distribution and 11B chemical shifts for these structures are not indicative of the presence of a B-O or B-N dative bond. In a variety of solvents, however, the optimized B-O or B-N distances from self-consistent reaction field calculations are much shorter, ∼1.7-1.8 Å, and the charge distribution and 11B chemical shifts are consistent with the formation of dative bonds. The results for the ester ED-2-AC-PB are similar, although a conformer with a B-N dative bond is also found in vacuo. The calculations show that conformers with the (:OC-CC-B) ring motif are consistently lower in energy than the corresponding conformers with the (:N-C-CC-B) ring motif, both in vacuo and in solution.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 723, Issues 1–3, 20 May 2005, Pages 147-157
نویسندگان
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