کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1237447 968893 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Analysis of vibrational spectra of 3-halo-1-propanols CH2XCH2CH2OH (X is Cl and Br)
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Analysis of vibrational spectra of 3-halo-1-propanols CH2XCH2CH2OH (X is Cl and Br)
چکیده انگلیسی

The conformational stability and the three rotor internal rotations in 3-chloro- and 3-bromo-1-propanols were investigated by DFT-B3LYP/6-311 + G** and ab initio MP2/6-311 + G**, MP3/6-311 + G** and MP4(SDTQ)//MP3/6-311 + G** levels of theory. On the calculated potential energy surface twelve distinct minima were located all of which were not predicted to have imaginary frequencies at the B3LYP level of theory. The calculated lowest energy minimum in the potential curves of both molecules was predicted to correspond to the Gauche–gauche–trans (Ggt) conformer in excellent agreement with earlier microwave and electron diffraction results. The equilibrium constants for the conformational interconversion of the two 3-halo-1-propanols were calculated at the B3LYP/6-311 + G** level of calculation and found to correspond to an equilibrium mixture of about 32% Ggt, 18% Ggg1, 13% Tgt, 8% Tgg and 8% Gtt conformations for 3-chloro-1-propanol and 34% Ggt, 15% Tgt, 13% Ggg1, 9% Tgg and 7% Gtt conformations for 3-bromo-1-propanol at 298.15 K. The nature of the high energy conformations was verified by carrying out solvent experiments using formamide (ɛ = 109.5) and MP3 and MP4//MP3 calculations. The vibrational frequencies of each molecule in its three most stable forms were computed at the B3LYP level and complete vibrational assignments were made based on normal coordinate calculations and comparison with experimental data of the molecules.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 71, Issue 3, 1 December 2008, Pages 1095–1101
نویسندگان
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