Comparative Spectroscopic Studies on Pure, 10 and 50 mol% Glycine Mixed L-Valinium Picrate Crystals

Abstract

Nonlinear optical crystals of pure, 10 and 50 mol% glycine mixed L-valinium picrate have been grown from saturated aqueous solution by slow evaporation method at a temperature of 36℃ using a constant temperature bath of accuracy of ±0.01℃. The synthesized organic optical material has been purified by repeated recrystallization. The cell parameters were calculated using single crystal X-ray diffraction technique which confirmed the crystal system. Optical behavior was examined by UV-Vis-NIR spectrometer in the range from 190 nm to 1100 nm, which revealed the absence of absorption in the entire visible region. Functional groups and modes of vibration were identified by FT-IR spectrometer in the range between 400 cm -1 and 4000 cm -1 . The 1 H- and 13 C NMR spectra of grown crystals were recorded using D 2 O as solvent on a Bruker 300 MHz (Ultrashield) TM instrument at 23℃ (300 MHz for 1H NMR and 75 MHz for 13 C NMR) to confirm the molecular structure. The second harmonic generation conversion efficiency was investigated by Kurtz powder method using Nd: YAG laser as a source to explore the NLO characteristics.