کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1250444 | 1495996 | 2012 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electron-induced phase transition in hydrogen-bonded anhydrous solid state 4-pyridone
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
Spectral studies of hydrogen bonded 4-pyridone crystal have demonstrated the existence of two anhydrous solid-state phases of the compound, namely the α and the β-phase. Hydrogen bonds in the high-temperature α-phase have been estimated to be 40% stronger than hydrogen bonds in the β-phase. It was proved that the crystals of the two polymorphs are identical with the crystals of the previously determined structures. The α polymorph is monoclinic while the β is orthorhombic. The mechanism of the phase transition 4-pyridone is proposed on the basis of the crystalline polarized IR spectra measured in the νOH and νOD band frequency ranges. It is connected with a partial change in the hydrogen bond nature, from the N+Hâ¯Oâ in the α-phase, to the NHâ¯O in the β-phase crystals. This involves small changes in the geometry of hydrogen bonds, which accompany the electron density redistribution in the hydrogen bonds during the phase transition.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Vibrational Spectroscopy - Volume 63, November 2012, Pages 440-450
Journal: Vibrational Spectroscopy - Volume 63, November 2012, Pages 440-450
نویسندگان
Henryk T. Flakus, Aleksandra Tyl,