کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1410437 1501869 2009 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A theoretical IR spectroscopic study based on DFT calculations for free mn-15S2O3 maleonitrile-dithiacrown ether compound
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
A theoretical IR spectroscopic study based on DFT calculations for free mn-15S2O3 maleonitrile-dithiacrown ether compound
چکیده انگلیسی

The theoretically possible stable conformers of free mn-15S2O3 maleonitrile-dithiacrown ether molecule were searched by means of a conformational study which consists of molecular dynamics and energy minimization calculations performed with MM2 force field and successive geometry optimization + frequency calculations performed first at B3LYP/3-21G and then at B3LYP/6-31G(d) levels of theory. The obtained calculation results have clearly indicated that the free molecule in electronic ground state is very flexible and accordingly has many possible stable conformers of different conformational properties at room temperature; among them, the one having a macrocyclic ring structure in which all of the ether units oriented toward the center of the ring was determined the energetically most preferable conformer. In addition, the equilibrium geometrical parameters, vibrational normal modes and associated IR spectral data of the determined most stable three conformers of the molecule were calculated at B3LYP/6-31+G(d) and B3LYP/6-31++G(d,p) levels of theory. A successful assignment of the fundamental bands observed in the recorded experimental solid phase and solution phase IR spectra of the molecule was achieved in the light of the theoretical data obtained from these DFT calculations. To fit the calculated harmonic wavenumbers to the experimental ones, two different scaling procedures, referred to as “Scaled Quantum Mechanical Force Field (SQM FF) methodology” and “Scaling wavenumbers with empirical dual scale factors”, were proceeded independently.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 919, Issues 1–3, 17 February 2009, Pages 128–139
نویسندگان
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