Analysis of vibrational spectra and nonlinear optical properties of organic molecule l-alaninium formate

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 86; pp. 174 - 180
• Main Authors: Jesintha John, C., Xavier, T.S., Amalanathan, M., Hubert Joe, I., Rastogi, V.K.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.02.2012
• Subjects: Absorption; Alanine - chemistry; Density functional theory; Electronic spectra; First order hyperpolarizability; Formates - chemistry; Kinetics; Molecular Conformation; Nonlinear Dynamics; Optical Phenomena; Particle Size; Second harmonic generation; Solvents; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Vibration; Vibrational spectra; First order hyperpolarizability; Second harmonic generation; Density functional theory; Vibrational spectra; Electronic spectra
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2011.09.070

Vibrational and electronic spectra of the crystallized nonlinear optical molecule l-alaninium formate have been recorded and analyzed. The equilibrium geometry, vibrational wavenumbers, and the first order hyperpolarizability of the crystal have been calculated with the help of density functional theory computations. The N–H⋯O bond distance shows the presence of intramolecular hydrogen bonding and the result is confirmed by the natural bond orbital analysis. The HOMO–LUMO energy gap and the first order hyperpolarizability was calculated and it supports the nonlinear optical activity of the l-alaninium formate crystal. [Display omitted] ► The growth and the vibrational spectral analysis of LAF crystals taken up to understand the NLO activity. ► Hydrogen bonding and charge transfer interactions are also analyzed. ► The calculated first hyperpolarizability of BPH is found to be 2.84 × 10 −30 esu, which is 2 times that of KDP. ► The red shifting of O–H stretching wavenumber confirms the intramolecular O–H⋯O hydrogen bonding. Vibrational and electronic spectra of the crystallized nonlinear optical molecule l-alaninium formate have been recorded and analyzed. The equilibrium geometry, vibrational wavenumbers, and the first order hyperpolarizability of the crystal have been calculated with the help of density functional theory computations. The N–H⋯O bond distance shows the presence of intramolecular hydrogen bonding and the result is confirmed by the natural bond orbital analysis. The HOMO–LUMO energy gap and the first order hyperpolarizability was calculated and it supports the nonlinear optical activity of the l-alaninium formate crystal.