title: Theoretical investigations on the molecular structure, vibrational spectral, HOMO-LUMO and NBO analysis of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol.
abstract: The experimental FT-IR and FT-Raman spectra of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol have been recorded. Quantum chemical calculations of geometry and vibrational wavenumbers of 9-[3-(Dimethylamino)propyl]-2-trifluoro-methyl-9H-thioxanthen-9-ol are carried out theoretically. Four possible stable conformations of the title compound were determined. In terms of the conformational analysis, one of the most interesting structural features of the title compound is the intra molecular OH⋯N hydrogen bond. The barrier of planarity between the most stable and planar form is also predicted. The optimized geometrical parameters obtained by B3LYP method show a good agreement with XRD data. The difference between the observed and theoretical wavenumbers is very small. The complete assignments were performed on the basis of potential energy distribution of the vibrational modes calculated theoretically. The calculated HOMO and LUMO energies allow the calculation of atomic and molecular properties and they also showed that charge transfer occurs in the molecule. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. As seen from the MEP map, negative potential regions are over the hydroxyl group and positive potential regions are over the methyl groups.
authors.affiliation: Department of Physics, Fatima Mata National College, Kollam, Kerala, India.
authors.forename: Y Sheena
authors.initials: YS
authors.lastname: Mary
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 Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570006, India.
authors.forename: T S
authors.initials: TS
authors.lastname: Yamuna
authors.affiliation: Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570006, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Siddegowda
authors.affiliation: Department of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570006, India.
authors.forename: H S
authors.initials: HS
authors.lastname: Yathirajan
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: Department of Chemistry, University of Antwerp, B2610 Antwerp, Belgium.
authors.forename: Christian
authors.initials: C
authors.lastname: Van Alsenoy
mesh_terms: D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D055672:Static Electricity; D013892:Thioxanthenes / Q000737:chemistry*; D014732:Vibration
chemical_list: C000595975:9-(3-(dimethylamino)propyl)-2-trifluoro-methyl-9H-thioxanthen-9-ol; D013892:Thioxanthenes
keywords: FT-IR; FT-Raman; Hyperpolarizability; MEP; Thioxanthene