title: FT-IR and FT-Raman spectra of 5-fluoroorotic acid with solid state simulation by DFT methods.
abstract: FT-Raman and FT-IR studies of the biomolecule 5-fluoroorotic acid in the solid state were carried out. The unit cell found in the crystal was simulated as a tetramer form by density functional calculations. They were performed to clarify wavenumber assignments of the experimental observed bands in the spectra. Correlations with the molecule of uracil were made, and specific scale equations were employed to scale the wavenumbers of 5-fluoroorotic acid. Good reproduction of the experimental wavenumbers is obtained and the % error is very small in the majority of the bands. This fact confirms our simplified solid state model. The molecular structure was fully optimized using DFT and MP2 methods. The relative stability of both the syn and anti conformations was investigated, and the anti-form was found to be slightly more stable, by 7.49 kJ/mol at the MP2 level. The structures of all possible tautomeric forms were determined. The keto-form appeared as the most stable one. The NBO atomic charges and several thermodynamic parameters were also calculated.
authors.affiliation: Departamento de Química-Física I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid 28040, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Cuellar
authors.affiliation: Departamento de Química-Física I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid 28040, Spain. Electronic address: Alcolea@quim.uc.es.
authors.forename: M
authors.initials: M
authors.lastname: Alcolea Palafox
authors.affiliation: R D Foundation Group of Institutions, NH-58, Kadrabad, Modinagar, Ghaziabad, India; Indian Spectroscopy Society, KC 68/1, Old Kavinagar, Ghaziabad 201 002, India. Electronic address: v_krastogi@rediffmail.com.
authors.forename: V K
authors.initials: VK
authors.lastname: Rastogi
authors.affiliation: University of Würzburg, Institute for Physical and Theoretical Chemistry, Am Hubland, D-97074 Würzburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kiefer
authors.affiliation: University of Duisburg-Essen, Faculty of Chemistry, Universitätsstr. 5, D-45141 Essen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schlücker
authors.affiliation: Indian Spectroscopy Society, KC 68/1, Old Kavinagar, Ghaziabad 201 002, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Rathor
mesh_terms: D003198:Computer Simulation; D019281:Dimerization; D007536:Isomerism; D008958:Models, Molecular; D008968:Molecular Conformation; D009963:Orotic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration
chemical_list: D009963:Orotic Acid; C001242:5-fluoroorotic acid
keywords: 5-Fluoroorotic acid; FT-IR spectroscopy; FT-Raman spectroscopy; Tautomerization; Thermodynamic parameters; Vibrational wavenumbers