کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1408067 | 1501904 | 2007 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Molecular structure, hydrogen bonding, basicity and spectroscopic properties of 3-hydroxypyridine betaine hydrochloride monohydrate
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The effect of hydrogen bonding, inter- and intramolecular electrostatic interactions on the structure of 3-hydroxy-pyridine betaine hydrochloride monohydrate (1-carboxymethyl-3-hydroxypyridinium chloride monohydrate), 3-HO-PBH·Cl·H2O, has been studied by X-ray diffraction, 1H and 13C NMR and FTIR spectroscopies, and by the B3LYP/6-31G(d,p) calculations. In the crystal, the Clâ anion is connected with protonated betaine via the hydrogen bond, OCOHâ¯Clâ = 2.993(2) Ã
and with neighboring H2O molecules via the 3.111(1) and 3.578(1) Ã
bonds, while the 3-OH group interacts with water molecule by the hydrogen bond of 2.566(2) Ã
, forming an aggregate along the [b] direction. The water molecule additionally forms hydrogen bonds of 2.888(3) Ã
to the CO bond of OCOH group. On recrystallization the 1:1 complex slowly converts into the 2:1 complex, bis(3-hydroxy-pyridine betaine) hydrochloride, [bis(1-carboxymethyl-3-hydroxypyridinium) chloride], [(3-HO-PB)2H·Cl]. The geometries of 3-HO-PBH·Cl·H2O in the gas phase (vacuum), DMSO and water solutions have been optimized by the B3LYP/6-31G(d,p) level of theory using the COSMO model. Good linear correlations between 13C and 1H experimental chemical shifts and GIAO/ B3LYP/6-31G(d,p) calculated magnetic isotropic shielding tensors (Ï) have been obtained. The FTIR spectrum of the 1:1 complex shows a broad and intense absorption in the 3100-2500 cmâ1 region due to the stretching vibration of hydrogen bonds between the Clâ anion and COOH, OH substituents and H2O molecules, and the νCO band at 1739 cmâ1. The spectrum of the 2:1 complex shows an additional broad absorption in the 1900-800 cmâ1 region due to the OH·O hydrogen bonds between COO groups.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 832, Issues 1â3, 30 April 2007, Pages 63-72
Journal: Journal of Molecular Structure - Volume 832, Issues 1â3, 30 April 2007, Pages 63-72
نویسندگان
P. BarczyÅski, A. Komasa, A. Katrusiak, Z. Dega-Szafran, M. Szafran,