Elucidation of optical, thermal, morphological and antimicrobial efficacy of L-tryptophan hydrochloride single crystals

Abstract

An efficient semi-organic nonlinear optical single crystal of L-tryptophan hydrochloride (LTHC) of molecular formula C11H13N2O2Cl has been synthesized and its elemental composition was confirmed by EDS analysis. The crystallographic system and lattice parameters were found by single crystal XRD analysis which indicates the synthesized crystal corresponds to monoclinic system of space group P21 and its crystalline nature was identified by powder XRD analysis. The typical characteristic vibrational modes of the grown LTHC crystal were identified by FTIR spectral analysis. The grown crystal’s optical properties were analyzed by UV-Vis-NIR and Photoluminescence analyses. The wavelength dependent optical constants were also measured, and its refractive index at 532 nm was found to be 1.67. The grown crystal’s mechanical stability was determined with the help of Vicker’s hardness tester, which revealed that LTHC has soft material behaviour. TG-DTA-DSC tests were used to examine the thermal behaviour such as decomposition phenomena, phase transition, and melting point of the grown crystal, which revealed that it has high thermal stability up to 205 degrees. The dielectric behaviour, a.c. conductivity of LTHC crystal was studied by dielectric studies and its nonlinear efficiency was analyzed by Kurtz-Perry technique. The crystalline morphology of LTHC was examined by TEM and SEM analyses. Its optical damage property was analyzed by laser damage threshold analysis. The antimicrobial property of LTHC was also scrutinized against bacterial as well as fungal strains by Agar disk diffusion method. Finally, all these findings recommended that LTHC crystals could be useful in biomedical and nonlinear optics applications.