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ABSTRACT: Structural varieties of L-arginine trifluoroacetate (abbreviated as LATF) and L-arginine bis(trifluoroacetate), LABTF, in the solid state compounds were observed and analyzed by the nuclear magnetic resonance (NMR) spectroscopy. The guanidinium-carboxylate interaction plays an important role involving in the crystal structure construction. Conformational changes of L-Arg(+) and L-Arg(2+) cations result from the intrinsic structural difference by hydrogen bonding and electrostatic interactions. The low-temperature structure of its crystalline salt, L-arginine bis(trifluoroacetate), was determined to describe the hydrogen bonding interactions. In comparison with the crystal structure at room temperature, the low-temperature L-Arg(2+) cations present tiny conformational difference and the rotational disorder of CF(3) group disappears. FT-IR and Raman spectra were investigated and hydrogen bonding interactions were analyzed on the basis of its vibrational spectra. Results indicate that this type interaction is greatly contributive to the structural features and vibrational spectral properties.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 07/2011; 83(1):39-45. · 2.10 Impact Factor
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ABSTRACT: Fourier transform infrared and Raman spectra of the nonlinear optical crystal, L-arginine trifluoroacetate (L-arginine.CF3COOH, abbreviated as LATF) have been calculated by the first-principles calculation and investigated in experiment. The calculated results are slightly different from those experimental values because of the distinction resulted from the intermolecular hydrogen bonds. The role of this type of intermolecular interaction on the crystal vibrational spectra and nonlinear optical properties has been discussed. The absorption-edge on the IR side has been estimated by the theoretical approach on basis of the calculated infrared spectrum, which will be meaningful for further research on NLO crystal.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 03/2008; 71(2):663-8. · 2.10 Impact Factor
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ABSTRACT: Single crystal growth of the organic nonlinear optical crystal, L-arginine trifluoroacetate (L-Arg·CF3COOH, abbreviated as LATF) is reported. Low temperature solution growth method is employed for the growth of bulk single crystals. The cell parameters are verified by single crystal diffraction. Fourier transform infrared (FT-IR) and Fourier transform Raman analysis are used to confirm the presence of various functional groups in the grown crystal. The thermal properties of the grown crystals are studied by thermogravimetric analysis and differential scanning calorinetry analysis (TGA/DSC). Second harmonic generation (SHG) measurement confirms the NLO properties of the grown crystal. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal Research and Technology 07/2007; 42(8):812 - 816. · 0.95 Impact Factor
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ABSTRACT: Single crystals of nonlinear optical material, L-arginine trifluoroacetate (abbreviated as LATF), were grown from an aqueous solution by the low temperature solution growth method. The cell parameters of the grown crystal were determined by the X-ray powder diffraction analysis. Atomic force microscopy (AFM) was used to investigate the surface morphology of {101} cleavage faces of LATF. Straight steps and two-dimensional nuclei were observed. Liquid inclusions and impurities as defects for revealing macrosteps were demonstrated. The molecular structure and crystal structure correlative with surface morphology were discussed.
Surface Review and Letters (SRL). 01/2007; 14(03):439-444.
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ABSTRACT: Transparent glass-ceramics containing Co2+:ZnAl2O4 nanocrystals were obtained by the sol–gel process for the first time. The gels of composition 89SiO2–5.9Al2O3–4.9ZnO–0.2CoO (ZAS) were prepared at room temperature, and heat-treated at different temperatures. The microstructure and optical properties of the heated samples were studied by using X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared spectroscopy, and optical absorption spectra. Co2+:ZnAl2O4 nanocrystals were precipitated from ZAS system and dispersed in the SiO2-based glass during heat-treatment in the temperature range 900–1100 °C. Co2+ ions were located in tetrahedral sites in ZnAl2O4 nanocrystals. The Co2+:ZnAl2O4 crystallite size was in the range of 4–15 nm.
Materials Research Bulletin.
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ABSTRACT: A novel organic nonlinear optical crystal, l-histidine trifluoroacetate (LHTF), has been prepared, and single crystals had been grown by the controlled evaporation of the aqueous solution. Its solubility curve was determined gravimetrically. The structural, physicochemical properties of the grown crystals were characterized by X-ray powder diffraction, infrared spectroscopy and thermal analysis. Density functional theory at the B3LYP/6-31G (d, p) level had been used to compute the first-order hyperpolarizability of LHTF. The optical transmission spectrum and second-harmonic generation were investigated to study its linear and nonlinear optical properties.
Journal of Crystal Growth.
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ABSTRACT: A novel potentially useful organometallic nonlinear optical crystal, manganese mercury thiocyanate-bis(N-methylformamide), MnHg(SCN)4(C2H5NO)2 (MMTN) has been prepared, and large highly-optical quality single crystals with dimensions up to 29×28×14 mm3 have been grown. The structural characterization, thermal and optical properties of the grown crystals are investigated. The growth morphology was obtained by indexing the X-ray powder diffraction data and compared with that deducing from the single crystal structure data using the Bravais–Friedel–Donnay–Harker model. The thermal analysis reveals that MMTN crystal possesses good physicochemical stability. The specific heat of the crystal is 635.1 J mol−1 K−1 at 300 K. The thermal expansion coefficient along the a, b, and c axis is α1=6.18×10−5 K−1, α2=3.91×10−5 K−1 and α3=9.53×10−6 K−1, respectively. The laser damage threshold of MMTN crystal is about 225.7 MW/cm2 with pulse width of 18 ns at 1064 nm. The powder second harmonic efficiency of the crystal is about 1.1 pm/V and the UV transparency cutoff is 354 nm, which are interpreted on the basis of the crystal structure with the Molecular Orbital theory using a GAUSSIAN03 program.
Physica B Condensed Matter 405(4):1071-1080. · 1.06 Impact Factor
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ABSTRACT: The organic nonlinear optical crystal of amino-carboxyl acid family, l-lysinium trifluoroacetate (abbreviated as LLTF) was successfully grown from its aqueous solution by the temperature-lowering technique. Its growth morphology was investigated based on the X-ray single-crystal diffraction data and the growth habits were studied using the micro-crystallization method. The metastable zonewidth and induction period were determined for the aqueous solution growth of LLTF. The surface free energy values were calculated from the experimental data. Nucleation kinetics and fundamental growth parameters such as critical radius, critical free energy and volume free energy change were also evaluated. Crystals of LLTF were obtained by the optimized nucleation parameters.
Journal of Crystal Growth 311(13):3455-3460. · 1.73 Impact Factor
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ABSTRACT: A novel organic crystal, l-arginine 4-nitrophenolate 4-nitrophenol dehydrate (LAPP), synthesized and grown from aqueous solution, is presented. X-ray single diffraction shows that LAPP belongs to the monoclinic crystallographic system with space group P21. FT-IR and UV/vis/NIR transmission spectra have been employed to characterize the crystal. The computational calculation based on the density functional theory at the B3LYP/6-31G (d, p) level has been used to compute the first-order hyperpolarizability of LAPP relating to different molecular models. The morphology, nonlinear characteristic and thermal stability of the crystal have also been investigated.Highlights► Novel optical crystal has been grown in aqueous solution. ► Optical and chemical properties of the crystal have been characterized. ► Computational modeling is employed in different molecular models. ► Crystal is as high as urea in the SHG efficiency and is phase-matchable.
Journal of Crystal Growth 327(1):133-139. · 1.73 Impact Factor
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ABSTRACT: Fourier transform infrared and Raman spectra of the nonlinear optical crystal, l-arginine trifluoroacetate (l-arginine·CF3COOH, abbreviated as LATF) have been calculated by the first-principles calculation and investigated in experiment. The calculated results are slightly different from those experimental values because of the distinction resulted from the intermolecular hydrogen bonds. The role of this type of intermolecular interaction on the crystal vibrational spectra and nonlinear optical properties has been discussed. The absorption-edge on the IR side has been estimated by the theoretical approach on basis of the calculated infrared spectrum, which will be meaningful for further research on NLO crystal.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 71(2):663-668. · 2.10 Impact Factor
