title: Spectroscopic (FT-IR, FT-Raman), first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 5-tert-Butyl-6-chloro-N-[(4-(trifluoromethyl)phenyl]pyrazine-2-carboxamide.
abstract: The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 5-tert-Butyl-6-chloro-N-[(4-(trifluoromethyl)phenyl]pyrazine-2-carboxamide have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. From the NBO analysis it is evident that the increased electron density at the nitrogen, carbon atoms leads to the elongation of respective bond length and a lowering of the corresponding stretching wave number. The calculated geometrical parameters are in agreement with that of similar derivatives. The calculated first hyperpolarizability is high and the calculated data suggest an extended π-electron delocalization over the pyrazine ring and carboxamide moiety which is responsible for the nonlinearity of the molecule.
authors.affiliation: Department of Chemistry, Mar Ivanios College, Nalanchira, Trivandrum, Kerala, India.
authors.forename: J B
authors.initials: JB
authors.lastname: Bhagyasree
authors.affiliation: Department of Physics, Fatima Mata National College, Kollam, Kerala, India.
authors.forename: Hema Tresa
authors.initials: HT
authors.lastname: Varghese
authors.affiliation: Department of Physics, TKM College of Arts and Science, Kollam, Kerala, India. Electronic address: cyphyp@rediffmail.com.
authors.forename: C Yohannan
authors.initials: CY
authors.lastname: Panicker
authors.affiliation: Department of Chemistry, University of Antwerp, B2610 Antwerp, Belgium.
authors.forename: Christian
authors.initials: C
authors.lastname: Van Alsenoy
authors.affiliation: Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
authors.forename: Abdulaziz A
authors.initials: AA
authors.lastname: Al-Saadi
authors.affiliation: Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, Hradec Kralove 50005, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Dolezal
authors.affiliation: Department of Chemistry, Mar Ivanios College, Nalanchira, Trivandrum, Kerala, India.
authors.forename: Jadu
authors.initials: J
authors.lastname: Samuel
mesh_terms: D004583:Electrons; D008968:Molecular Conformation; D011719:Pyrazines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D011719:Pyrazines
keywords: Carboxamide; FT-IR; FT-Raman; PED; Pyrazine