Investigations on the growth, optical behaviour and factor group of an NLO crystal: L‐alanine alaninium nitrate

Abstract

Amino acid family crystals exhibit excellent nonlinear and electro-optical properties. L-alanine alaninium nitrate (LAAN) single crystal belonging to the amino acid group was grown by slow cooling solution growth technique. The High resolution X-ray diffraction (HRXRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, UV-Vis., Photoluminescence (PL) and Factor group analyses were carried out. The factor group analysis reveals 183 internal vibrations for the title compound. The second harmonic generation property was tested by Kurtz-Perry powder technique.

Growth and Characterisation of Nonlinear Optical Single Crystals of L-Alaninium Oxalate

“…The maximum intensity peak at 440nm is due to the protonation of amino group to the carboxyl group. The lowering of photoluminescence intensity at higher wavelength region may be attributed to a relatively low barrier for rotation of the carboxyl group around the central C-C bond [19]. …”

Comments on papers reporting IR‐spectra and other data of alleged L‐alanine alaninium nitrate and L‐alanine sodium nitrate crystals

“…After discovering the first respective dimeric cation in the structure of L-Phenylalanine L-Phenylalaninium formate [5], similar dimeric arrangements were found also for other amino acids and represent an interesting class of crystals from a crystallochemical point of view. Aravindan et al [6] decided to grow and investigate crystals of (A·HA·NO 3 ) as a nonlinear optical (NLO) material. However, analysis of this paper shows that the results presented in this paper are questionable.…”

Studies on structure, growth and characterization of third order nonlinear optical 2-amino-5-chloropyridinium-4-amino benzoate single crystal

“…The occurrence of the intensive peak positioned at 440 nm is due to protonation of the amine group attached to the pyridinium ring moiety to the carboxyl group of the acid. The diminishing intensity at higher wavelength region of PL spectrum may be possibly due to the large barrier for rotation of COOH group around C-C bond present in PABA [26].…”