Effect of strontium chloride on the optical and mechanical properties of γ–glycine crystals

Abstract

Single crystals of γ-glycine have been grown from aqueous solution in the presence of small amount of strontium chloride. Single crystal X-Ray diffraction analysis was used to measure the unit cell parameters and to confirm the crystal structure. The grown crystals have also been subjected to powder X-Ray diffraction study to identify the crystalline nature. The presence of all the functional groups of the γ-glycine has been confirmed by Fourier Transform Infrared (FTIR) spectral analysis. The presence of hydrogen and carbon in the glycine molecules was confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. Optical behavior of the crystal was studied using UV -Visible absorbance spectroscopy and second harmonic generation (SHG) studies. The SHG efficiency of γ-glycine is greater than that of standard potassium dihydrogen phosphate (KDP). Mechanical strength of the γ-glycine crystal has been determined by microhardness studies. Thermal stability of the grown crystal is probed using thermo gravimetric analysis and differential thermal analysis. Laser damage threshold value has been determined using Q-switched Nd:YAG laser operating at 1064 nm and with 13 ns pulse width in single shot mode.

Selective crystallization of gamma glycine for NLO applications using magnesium sulfate (MgSO4) as an additive

“…The unit cell program computed the lattice parameters for the grown γ-glycine crystal to be a = b = 7.057 Å, c = 5.501 Å, α = β = 90°, γ = 120°and unit cell volume V = 237 Å 3 . The computed results of XRD powder match well with the reported literature values [28][29][30][31][32]. The dominant or characteristic 100 % peak (2θ) of γ-glycine polymorph is positioned at ≈ 25°and its corresponding h k l plane is (1 1 0) plane.…”

“…The powdered glycine sample was transferred into a 25 mL volumetric flask and diluted with deionized water to a required volume. The filtered glycine sample was analyzed with ICP-OES system whose detection limit is 0.01 ppm [15,29]. The percentage of magnesium element present in the powdered glycine sample prepared at 3 g/100 mL concentration of MgSO 4 was found to be 0.04 ppm; γ-polymorph of glycine was later confirmed by SXRD, PXRD, NMR, TG-DTA and DSC studies.…”

“…The resonance signals situated at δ = 41.433 ppm and 172.412 ppm are attributed to methylene group CH 2 and carboxyl carbon group (COO − ), respectively. Anbuchezhiyan et al [29] reported that the effect of strontium chloride on γ-glycine molecule produced resonance signals δ = 3.3 ppm and 4.633 ppm in proton 1 H NMR and δ = 41.35 ppm and 172.37 ppm, respectively, in 13 C NMR spectra. In the present NMR investigation, the observed NMR resonance signal chemical shifts are in line with Anbuchezhiyan et al [29] with a slight increment in chemical shift ppm values (Table 1).…”

“…Anbuchezhiyan et al [29] reported that the effect of strontium chloride on γ-glycine molecule produced resonance signals δ = 3.3 ppm and 4.633 ppm in proton 1 H NMR and δ = 41.35 ppm and 172.37 ppm, respectively, in 13 C NMR spectra. In the present NMR investigation, the observed NMR resonance signal chemical shifts are in line with Anbuchezhiyan et al [29] with a slight increment in chemical shift ppm values (Table 1). This increase in chemical shift values may be due to the presence of magnesium species in the γ-glycine salt.…”

“…From the thorough literature study of glycine polymorphs it was concluded that metastable αpolymorphic form of glycine produces spontaneously in pure aqueous solutions whereas the most thermodynamically stable form γ-glycine can be obtained in acidic or basic solution, low pH or high pH solutions or in the presence of inorganic salts or tailor made additives [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][19][20][21][22]. In recent times, γ-glycine single crystals have grown in the presence of potassium chloride [31], magnesium chloride [15], phosphoric acid [16], ammonium acetate [17], ammonium carbonate [18], zinc acetate [23], strontium chloride [29], cesium chloride [30] and ammonia solutions [24]. In the present research article, we report the growth and characterization of γ-glycine crystal grown from a mixture of water and magnesium sulfate solvent by slow solvent evaporation procedure.…”