Spectroscopic investigation, natural bond orbital analysis, HOMO-LUMO and thermodynamic functions of 2-tert-butyl-5-methyl anisole using DFT (B3LYP) calculations

Balachandran V., Santhi G., Karpagam V., Revathi B., Karabacak M.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, cilt.136, sa.PB, ss.451-463, 2015 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 136 Sayı: PB
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1016/j.saa.2014.09.057
  • Dergi Adı: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.451-463
  • Anahtar Kelimeler: Vibrational spectra, DFT, 2-tert-butyl-5-methyl anisole, NBO, HOMO-LUMO, Thermodynamic functions
  • Manisa Celal Bayar Üniversitesi Adresli: Evet

Özet

The optimized molecular structure and corresponding vibrational assignments of 2-tert-butyl-5-methyl anisole (TBMA) have been investigated using density functional theory (DFT)/B3LYP with 6-31G(d,p) and 6-311++G(d,p) basis sets investigation of the relative orientation of the methoxy group has shown two conformers (O-cis) and (O-trans) exist. The vibrational analysis of the stable conformer of the title compound is performed by means of infrared absorption and Raman spectroscopy in combination with theoretical simultaneously. The natural bond orbital (NBO) analysis is useful to understand the intra-molecular hyper conjugative interaction lone pair and π∗(CC), σ∗(CH) bond orbital. HOMO and LUMO energies show that charge transfer occurs in the molecule, therefore; HOMO, LUMO and molecular electrostatic potential (MEP) were calculated and analyzed. 1H and 13C NMR spectra by using gauge including atomic orbital (GIAO) method of studied compound were compared with experimental data. The thermodynamic functions of TBMA were calculated by B3LYP/6-311+G(d,p) basis set.