title: Molecular structure, vibrational spectra and nonlinear optical properties of 2,5-dimethylanilinium chloride monohydrate: a density functional theory approach.
abstract: Single crystals of 2,5-dimethylanilinim chloride monohydrate were grown by slow evaporation at room temperature and were characterized by X-ray powder diffraction study to confirm the crystalline nature of the synthesized compound. The optimized molecular structure, vibrational spectra and the optical properties were calculated by the density functional theory (DFT) method using the B3LYP function with the 6-31G(d,p) basis set. Simulation of infrared and Raman spectra led to excellent overall agreement with the observed spectral patterns. The complete assignments of the vibrational spectra were carried out with the aid of potential energy distribution (PED). The stability of the molecule arising from hyperconjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis leading to high nonlinear optical (NLO) activity. The lowering in the HOMO and LUMO energy gap explains the eventual charge transfer interactions that take place within the molecules.
authors.affiliation: Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP.1171, 3000 Sfax, Tunisia. Electronic address: sameh_guidara@yahoo.fr.
authors.forename: Sameh
authors.initials: S
authors.lastname: Guidara
authors.affiliation: Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP.1171, 3000 Sfax, Tunisia.
authors.forename: Ali Ben
authors.initials: AB
authors.lastname: Ahmed
authors.affiliation: Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP.1171, 3000 Sfax, Tunisia.
authors.forename: Younes
authors.initials: Y
authors.lastname: Abid
authors.affiliation: Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP.1171, 3000 Sfax, Tunisia.
authors.forename: Habib
authors.initials: H
authors.lastname: Feki
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D003460:Crystallization; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction
chemical_list: D000814:Aniline Compounds
keywords: 2,5-Dimethylanilinium chloride monohydrate; HOMO–LUMO; NBO analysis; NLO; Vibrational analysis