title: A complete assignment of the vibrational spectra of 2-furoic acid based on the structures of the more stable monomer and dimer.
abstract: The structural and vibrational properties of cyclic dimer of 2-furoic acid (2FA) were predicted by combining the available experimental infrared and Raman spectra in the solid phase and ab initio calculations based on density functional theory (DFT) with Pople's basis sets. The calculations show that there are two cyclic dimers for the title molecule that have been theoretically determined in the gas phase, and that only one of them, cis conformer, is present in the solid phase. The complete assignment of the 66 normal vibrational modes for the cis cyclic dimer was performed using the Pulay's Scaled Quantum Mechanics Force Field (SQMFF) methodology. Four strong bands in the infrared spectrum at 1583, 1427, 1126 and 887 cm(-1) and the group of bands in the Raman spectrum at 1464, 1452, 1147, 1030, 885, 873, 848, 715 and 590 cm(-1) are characteristic of the dimeric form of 2FA in the solid phase. In this work, the calculated structural and vibrational properties of both dimeric species were analyzed and compared between them. In addition, three types of atomic charges, bond orders, possible charge transfer, topological properties of the furan rings, Natural Bond Orbital (NBO) and Atoms in Molecules (AIM) theory calculations were employed to study the stabilities and intermolecular interactions of the both dimers of 2FA.
authors.affiliation: Quantum Physics Laboratory, Faculty of Sciences of Monastir, Monastir 5000, Tunisia.
authors.forename: Houcine
authors.initials: H
authors.lastname: Ghalla
authors.affiliation: Quantum Physics Laboratory, Faculty of Sciences of Monastir, Monastir 5000, Tunisia.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Issaoui
authors.affiliation: Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, (4000), San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Castillo
authors.affiliation: Cátedra de Química General, Instituto de Química Inorgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, (4000), San Miguel de Tucumán, Tucumán, Argentina. Electronic address: sbrandan@fbqf.unt.edu.ar.
authors.forename: Silvia Antonia
authors.initials: SA
authors.lastname: Brandán
authors.affiliation: Institute of Chemistry, University of Silesia, 9 Szkolna Street, Pl-40-006 Katowice, Poland.
authors.forename: Henryk T
authors.initials: HT
authors.lastname: Flakus
mesh_terms: D019281:Dimerization; D005663:Furans / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D005663:Furans; C060089:2-furoic acid
keywords: 2-Furoic acid; DFT calculations; Intermolecular hydrogen bond; Molecular structure; Vibrational spectra