title: Vibrational spectroscopic investigations and computational study of 5-tert-butyl-N-(4-trifluoromethylphenyl)pyrazine-2-carboxamide.
abstract: Pyrazine and its derivatives form an important class of compounds present in several natural flavors and complex organic molecules. Quantum chemical calculations of the equilibrium geometry, harmonic vibrational frequencies, infrared intensities and Raman activities of 5-tert-Butyl-N-(4-trifluoromethylphenyl)pyrazine-2-carboxamide in the ground state were carried out by using density functional methods. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. Nonlinear optical behavior of the examined molecule was investigated by the determination of first hyperpolarizability. The calculated HOMO and LUMO energies show the chemical activity of the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated geometrical parameters are in agreement with that of similar derivatives. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis.
authors.affiliation: Department of Physics, St. Xavier's College, Vaikom, Kothavara, Kottayam, Kerala, India.
authors.forename: Tomy
authors.initials: T
authors.lastname: Joseph
authors.forename: Hema Tresa
authors.initials: HT
authors.lastname: Varghese
authors.forename: C
authors.initials: C
authors.lastname: Yohannan Panicker
authors.forename: K
authors.initials: K
authors.lastname: Viswanathan
authors.forename: Martin
authors.initials: M
authors.lastname: Dolezal
authors.forename: T K
authors.initials: TK
authors.lastname: Manojkumar
authors.forename: Christian
authors.initials: C
authors.lastname: Van Alsenoy
mesh_terms: D000577:Amides / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D017711:Nonlinear Dynamics; D011719:Pyrazines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration
chemical_list: C586040:5-tert-butyl-N-(4-trifluoromethylphenyl)pyrazine-2-carboxamide; D000577:Amides; D011719:Pyrazines
keywords: Carboxamide; FT-IR; FT-Raman; PED; Pyrazine