کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5375487 | 1504297 | 2009 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
New insight into the structure, internal rotation barrier and vibrational analysis of 2-fluorostyrene
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The molecular structure of 2-fluorostyrene has been optimized at ab initio (MP2 and CCSD) and DFT levels (B3LYP, mPW1PW91) with different basis sets (6-31Gâ, 6-311++Gââ, cc-pVDZ). B3LYP predicts planar structures for both cis and trans conformers, the latter being more stable than the former. mPW1PW91, MP2 and CCSD calculations yield a quasi-planar conformation in agreement with XRD and microwave data. The vinyl-phenyl torsion barrier of 2-fluorostyrene has been calculated at B3LYP, mPW1PW91, MP2 and CCSD levels with 6-31Gâ basis set as well as at MP2/cc-pVDZ level. Results have been compared with experimental data from the vibronic spectrum of the jet-cooled compound through a deconvolution of the total electronic potential energy by a sixfold Fourier-type expansion. As a result, MP2/cc-pVDZ shows the best performance as regards the torsional barrier height for the trans form. The effects governing the torsion barriers and preferred conformations have been analyzed at mPW1PW91/6-31Gâ and MP2/cc-pVDZ levels. To achieve this, two different schemes, i.e. the total electron energy and the natural bond orbital, NBO, partition schemes have been used. The Atoms-in-Molecules (AIM) theory has been applied to the cis and trans conformers in order to detect intramolecular contacts. Furthermore, a twofold aimed analysis of the vibrational spectrum has been performed. First, to obtain a complete assignment nonexistent so far and second, to confirm the being of the predicted cis and trans forms in the liquid and solid states. New records of infrared and Raman spectra, and for the first time, the inelastic neutron scattering (INS) spectrum have been used. Moreover, the mPW1PW91/6-31Gâ harmonic force field has been scaled using a multiple scaling (SQM) force field procedure. To achieve this, the initial scale factors were refined in order to get the best possible fitting between the calculated and experimental frequencies attaining to a final rms deviation of 5Â cmâ1.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 361, Issues 1â2, 30 June 2009, Pages 94-105
Journal: Chemical Physics - Volume 361, Issues 1â2, 30 June 2009, Pages 94-105
نویسندگان
MarÃa Eugenia Tuttolomondo, Amparo Navarro, Tomás Peña, MarÃa Paz Fernández-Liencres, José Manuel Granadino-Roldán, Stewart F. Parker, Manuel Fernández-Gómez,