کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1252058 | 970965 | 2010 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Infrared, Raman and temperature-dependent NMR spectra, vibrational assignments, normal coordinate analysis, and DFT calculations of benzoxazoline-2-thione
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The tautomerism of benzoxazoline-2-thione (BOT; thio-keto) and 2-mercaptobenzoxazole (MBO; thio-enol) has been thoroughly investigated by means of Raman (3600-100 cmâ1), infrared (4000-200 cmâ1), 1H and 13C NMR spectra and X-ray powder diffraction (XRD). In addition, temperature-dependent 1H NMR spectra from â90 to +90 °C were acquired. To complement experimental results with theoretical predictions, we performed Density Functional Theory (DFT) calculations utilizing B3LYP, B3PW91 and SVWN methods at 6-31G(d) basis set. Both computational and spectral results were in favor of thio-keto BOT structure with no evidence for the existence of thio-enol (MBO) tautomer which firmly eliminates the possibility of an existing equilibrium between keto and enol forms. Moreover the dimerization percentage of thio-keto benzoxazoline-2-thione (BOT) and benzothiazoline-2-thione (BTT) were found to be 11.9% and 2.5%, respectively which favors strong hydrogen bonding interactions in BOT. Aided by normal coordinate analysis, force constants in internal coordinates and potential energy distributions (PEDs), a complete vibrational assignment for all fundamentals was obtained. The results are compared with the sulfur analogue, benzothiazoline-2-thione (BTT) whenever appropriate.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Vibrational Spectroscopy - Volume 52, Issue 2, 18 March 2010, Pages 128-136
Journal: Vibrational Spectroscopy - Volume 52, Issue 2, 18 March 2010, Pages 128-136
نویسندگان
Tarek A. Mohamed, Ahmed M. Mustafa, Wajdi M. Zoghaib, Mahmoud S. Afifi, Rabei S. Farag, Yehia Badr,