title: Infrared, Raman and NMR spectra, conformational stability and vibrational assignment of 7,8-Dihydroxy-4-Methylcoumarin.
abstract: We report a combined some (infrared, Raman and NMR) spectroscopic and quantum chemistry study on 7,8-Dihydroxy-4-Methylcoumarin molecule (78D4MC). The Raman and IR spectra of 78D4MC molecule were recorded and analyzed in the region 3500-50 cm(-1) and 4000-400 cm(-1), respectively. Potential energy scans were performed at the MMFF level of theory. All possible conformers, which are results at the MMFF level theory, were re-computed at the B3LYP functional with cc-pVDZ basis set. The optimized geometrical parameters, harmonic vibrational wavenumbers and NMR chemical shifts of the most stable conformer were calculated at the B3LYP/6-311G(d,p), cc-pVTZ and cc-pVQZ level in the proximity of the isolated molecule. DFT calculations were combined with Pulay's scaled quantum mechanics force field (SQMFF) methodology in order to fit the theoretical wavenumbers to the experimental ones.
authors.affiliation: Department of Physics, Ahi Evran University, 40040 Kirsehir, Turkey. Electronic address: yusuferdogdu@gmail.com.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Erdogdu
authors.affiliation: Department of Physics, Gazi University, 06100 Ankara, Turkey.
authors.forename: Semran
authors.initials: S
authors.lastname: Saglam
mesh_terms: D003374:Coumarins / Q000737:chemistry*; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013816:Thermodynamics; D014732:Vibration
chemical_list: C114368:7,8-dihydroxy-4-methylcoumarin; D003374:Coumarins
keywords: 7,8-Dihydroxy-4-Methylcoumarin; DFT; FT-IR spectra; FT-Raman spectra; NMR spectra