Conformational and vibrational analysis of 2,4-, 2,5- and 2,6-difluorobenzaidehydes by ab initio Hartree-Fock and density functional theory calculations


Saglam A., UCUN F.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES, cilt.63, ss.175-182, 2008 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 63
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1515/zna-2008-3-410
  • Dergi Adı: ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
  • Sayfa Sayısı: ss.175-182

Özet

The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments of the two planar O-cis and O-trans rotomers of 2,4-, 2,5- and 2,6-difluorobenzaidehyde have been calculated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with the 6-311++G(d,p) basis set level. The calculations were adapted to the CS symmetries of all the molecules. The O-trans rotomers with lower energy of all the compounds have been found as preferential rotomers in the ground state. The mean vibrational deviations between the vibrational frequency values of the two conformers of all the compounds have been shown to increase while the relative energies increase, and so it has been concluded that the higher the relative energy between the two conformers the bigger is the mean vibrational deviation.