Vibrational spectroscopic study, charge transfer interaction and nonlinear optical properties of L-asparaginium picrate: a density functional theoretical approach.
Single crystals of L-asparaginium picrate (LASP) were grown by slow evaporation technique at room temperature and were the subject of an X-ray powder diffraction study to confirm the crystalline nature of the synthesized compound. FT-IR and Raman spectra were recorded and analyzed with the aid of the density functional theory (DFT) calculations in order to make a suitable assignment of the observed bands. The optimum molecular geometry, normal mode wavenumbers, infrared and Raman intensities and the first hyperpolarizability were investigated with the help of B3LYP method using 6-31G(d) basis set. The theoretical FT-IR and Raman spectra of LASP were simulated and compared with the experimental data. A good agreement was shown and a reliable vibrational assignment was made. Natural bond orbital (NBO) analysis was carried out to demonstrate the various inter and intramolecular interactions that are responsible for the stabilization of the title compound leading to high NLO activity. A study on the electronic properties was performed by time-dependent DFT (TD-DFT) approach. The lowering in the HOMO and LUMO energy gap explains the eventual charge transfer interactions that take place within the molecules.
Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP 802, 3000 Sfax, Tunisia. Electronic address: nabil.elleuch@gmail.com.
Nabil
N
Elleuch
Laboratoire des Sciences des Matériaux et d'Environnement, Université de Sfax, Faculté des Sciences, BP 1171, 3000 Sfax, Tunisia.
Walid
W
Amamou
Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP 802, 3000 Sfax, Tunisia.
Ali
A
Ben Ahmed
Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP 802, 3000 Sfax, Tunisia.
Younes
Y
Abid
Laboratoire de Physique Appliquée (LPA), Université de Sfax, Faculté des Sciences, BP 802, 3000 Sfax, Tunisia.
Habib
H
Feki
D001216:Asparagine / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010851:Picrates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods
D010851:Picrates; D001216:Asparagine
Charge transfer; DFT; First hyperpolarizability; NBO analysis; Vibrational spectra; l-Asparaginium picrate