Molecular structure, NLO, MEP, NBO analysis and spectroscopic characterization of 2,5-dimethylanilinium dihydrogen phosphate with experimental (FT-IR and FT-Raman) techniques and DFT calculations.

Single crystals of 2,5-dimethylanilinium dihydrogen phosphate were grown by slow evaporation method at room temperature. The synthesized compound was characterized by powder X-ray diffraction analysis to confirm its crystalline nature. 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. Theoretical 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.

Molecular structure, vibrational spectra and nonlinear optical properties of 2,5-dimethylanilinium chloride monohydrate: a density functional theory approach.

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.

Vibrational spectral studies and non-linear optical properties of L-leucine L-leucinium picrate: a Density Functional Theory approach.

Single crystals of l-leucine l-leucinium picrate 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) basis set. Good consistency is found between the calculated results and the experimental structure, IR, and Raman spectra. The detailed interpretation of the vibrational modes was carried out. The natural bond orbital (NBO) analysis, confirms the occurrence of intermolecular hydrogen bonds that are responsible for the stabilization of the title compound, 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.