Amino acids-precursors for synthesizing nonlinear optical materials

Abstract

Some new nonlinear optical materials were synthesized from amino acids l-arginine and l-valine and single crystals were grown from their aqueous solution by solvent evaporation method at constant temperature and slow cooling method. The synthesized materials were identified by carbon, hydrogen, nitrogen (CHN) test and single crystal X-ray diffraction (XRD) analysis. The grown crystals were characterized by measuring their thermal, optical and mechanical properties by Differential Thermal Analysis (DTA), Thermo Gravimetric Analysis (TGA), powder second harmonic generation (SHG) efficiency, damage threshold and microhardness measurements. Our study shows that halides of l-arginine and l-valine are promising Nonlinear Optical (NLO) materials having Second Harmonic Generation (SHG) efficiency, mechanical and thermal stability greater than other semi-organic NLO materials. But among the halide salts, l-valine hydrobromide (LVHBr) emerged as most promising NLO materials as far as SHG efficiency, and damage threshold are concerned.