title: FT-IR, FT-Raman, ab initio and DFT structural and vibrational frequency analysis of 6-aminopenicillanic acid.
abstract: Quantum mechanical calculations of energies, geometries and vibrational wavenumbers of 6-aminopenicillanic acid were carried out by using ab initio HF and density functional theory (DFT/B3LYP) methods with 6-311G(d,p) basis set. The optimized geometrical parameters obtained by HF and DFT calculations are in good agreement with experimental X-ray data. A detailed interpretation of the infrared spectra has also been reported. The theoretical IR and Raman spectrograms have been constructed and compared with the experimental FT-IR and FT-Raman spectra. The differences between the observed and scaled wavenumber values of most of the fundamentals are very small. The thermodynamic parameters have also been computed.
authors.affiliation: Department of Chemistry, Periyar Maniammai University, Vallam, Thanjavur, India.
authors.forename: J
authors.initials: J
authors.lastname: Swaminathan
authors.forename: M
authors.initials: M
authors.lastname: Ramalingam
authors.forename: V
authors.initials: V
authors.lastname: Sethuraman
authors.forename: N
authors.initials: N
authors.lastname: Sundaraganesan
authors.forename: S
authors.initials: S
authors.lastname: Sebastian
authors.forename: M
authors.initials: M
authors.lastname: Kurt
mesh_terms: D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013816:Thermodynamics; D014732:Vibration
chemical_list: D010397:Penicillanic Acid; C004408:aminopenicillanic acid