DENSITY FUNCTIONAL THEORY STUDY OF THE ROTATIONAL BARRIERS, CONFORMATIONAL PREFERENCE, AND VIBRATIONAL SPECTRA OF 2-FORMYLFURAN AND 3-FORMYLFURAN
Y. Umar1, J. Tijani2
1Department of Chemical and Process Engineering Technology, Jubail Industrial College, Jubail Industrial City, Saudi Arabia
umar_y@jic.edu.sa
2Department of General Studies, Jubail Industrial College, Jubail Industrial City, Saudi Arabia
Ключевые слова: density functional theory, rotational barrier, vibrational wavenumber, conformational preference, infrared spectra, geometry optimization, solvent effect, formylfuran, furan carbaxaldehyde, polarizable continuum model
Страницы: 1369-1376
Подраздел: ИССЛЕДОВАНИЕ СТРОЕНИЯ МОЛЕКУЛ ФИЗИЧЕСКИМИ МЕТОДАМИ
Аннотация
The torsional potentials, molecular structures, conformational stability, and vibrational wavenumbers for the rotational isomers of 2-formylfuran and 3-formylfuran are computed using the density functional theory (B3LYP) method with the 6-31+G* basis set. All structures are fully optimized and the optimized geometries, rotational constants, dipole moments, and energies are presented. From the computations, both 2-formylfuran and 3-formylfuran are predicted to exist predominantly in trans conformation with a cis-trans rotational barrier of 11.19 kcal/mol and 8.10 kcal/mol, respectively. The vibrational wavenumbers and the corresponding vibrational assignments of the molecules in the Cs symmetry are examined and the infrared spectra of the molecules are simulated using the wavenumbers and the corresponding intensities obtained from the computations. The effect of solvents on the conformational stability of all the molecules in nine different solvents (heptane, chloroform, tetrahydrofuran, dichloroethane, acetone, ethanol, methanol, dimethylsulfoxide, and water) is investigated. The integral equation formalism in the polarizable continuum model (IEF-PCM) is used for all solution phase computations.
DOI: 10.15372/JSC20150711 |
