Quantum chemical calculation (electronic and topologic) and experimental (FT-IR, FT-Raman and UV) analysis of isonicotinic acid N-oxide


KARACA Ç., ATAÇ A., Karabacak M.

Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, cilt.140, ss.85-95, 2015 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 140
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1016/j.saa.2014.12.084
  • Dergi Adı: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.85-95
  • Anahtar Kelimeler: Isonicotinic acid N-oxide, DFT, UV spectrum, Infrared and Raman spectra, HOMO-LUMO, Density of State
  • Manisa Celal Bayar Üniversitesi Adresli: Evet

Özet

In this work, the molecular conformation, vibrational and electronic analysis of isonicotinic acid N-oxide (iso-NANO) were presented in the ground state using experimental techniques (FT-IR, FT-Raman and UV) and density functional theory (DFT) employing B3LYP exchange correlation with the 6-311++G(d,p) basis set. The geometry optimization and energies associated possible two conformers (Rot-I and Rot-II) were computed. The vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The obtained structures were analyzed with the Atoms in Molecules (AIMs) methodology. The computational results diagnose the most stable conformer of iso-NANO as the Rot-I form. Total density of state (TDOS) and partial density of state (PDOS) and also overlap population density of state (OPDOS) diagrams analysis for the most stable conformer (Rot-I) were calculated using the same method. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated. As a result, the optimized geometry and calculated spectroscopic data show a good agreement with the experimental results.