Crystal growth,thermal, optical and microhardness studies of tris (thiourea) zinc sulphate - a semiorganic NLO material

Tris (thiourea) zinc sulphate (ZTS), a semiorganic nonlinear optical (NLO) material has been synthesized at 30 °C. The solubility was determined in different solvents such as water, ethanol and water mixture of ethanol (1:1). Good quality single crystals with size 10 × 8 × 6 mm³ were grown by slow evaporation technique within three weeks with approximate growth rate of 0.5 mm/day. The grown crystals have been subjected to single crystal X-ray diffraction to determine the unit cell dimensions and morphology. The TGA and DTA reveal that the material has good thermal stability. The UV-Vis spectrum shows that the material has wide optical transparency in the entire visible region. The second harmonic generation was confirmed by Kurtz powder method. The birefringence of the crystal was measured in the visible region and it was found to vary with the wavelength. The microhardness test was carried out in (100) plane and the load dependent hardness was measured. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis,characterization and crystal structure of a porous crystalline material

An exploration of the nickel‐malate‐bpp system under hydrothermal conditions, has led to the isolation of a novel framework {[Ni(Hmal)(bpp)]·5H₂O}_n (1) (Hmal = malate dianion, bpp = 1,3‐bi(4‐pyridyl)propane). Single‐crystal X‐ray analyses reveal that it crystallizes in the orthorhombic space group Pccn. a = 21.141(3) Å, b = 10.4028(16) Å, c = 19.250(3) Å. The Ni(II) ions are linked into an extended helical chain via Hmal molecules. Further these chains are united together through the bridging bpp to form a 3D porous framework, which exhibits an unusual NbO‐type topological network. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal growth,characterization and Density functional theory computations of supramolecular N‐carbamothioyl acetamide

Single crystals of N‐carbamothioylacetamide (NCTA) were grown by slow evaporation technique at constant temperature. The structure is elucidated by single crystal XRD analysis. The studies reveal that the molecule is associated with accommodating weak C–O···H, N–H···O, N–H···S, C–H···N, C···C and H···H stacking interactions which are responsible for the formation and strengthening of supramolecular assembly. Inter‐ and intramolecular hydrogen bonding interactions exhibit supramolecular architecture in the crystal packing. Two different types of architecture, i.e., a column like packing, and cluster network type of infrastructure are observed. Hirshfeld surfaces and Fingerprint plots were used to locate and analyze the percentage of hydrogen bonding interactions. The various functional groups present in the molecule are confirmed by FT‐IR analysis. Density functional theory computations of the vibrational spectrum, molecular geometry, HOMO‐LUMO energy gaps, NBO and hyperpolarizability (β) were successfully evaluated. Facts concerning with the size, shape, charge density distribution and site of chemical reactivity of the molecule have been obtained by mapping electron density with electrostatic potential (ESP).     

Crystal growth,crystal structure and physical properties of polar orthorhombic tris(glycine) zinc chloride

Large single crystals of the polar (point group mm 2) compound tris(glycine) zinc chloride, (NH₃CH₂COO)₃ · ZnCl₂, were grown from aqueous solutions. The refractive indices were measured in the wavelength region from 365 nm to 1083 nm and an unpolarised absorption spectrum was recorded (transparency range from 260 to 1550nm). The phase matching conditions for second harmonic generation were analysed: both, type I (ss‐f) and type II (sf‐f) are possible in the red and near IR region. All five components of the piezoelectric tensor [d_ijk ] were determined; the maximum values of longitudinal and transverse piezoelectric effects are less than one half of d₁₁₁ of α‐quartz. In addition, a redetermination of the crystal structure (including location of H atoms) is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

DFT studies,Hirshfeld surface analysis and crystal structure of novel silver complex of sulfapyridine with secondary ligand pyridine

Silver complex of sulfapyridine has been synthesized and characterized by IR, NMR and PL. The crystal structure has been determined by X-ray diffraction technique. Silver complex of sulfapyridine with secondary ligand pyridine crystallizes in monoclinic space group P2₁/n with lattice parameter: a = 17.8075(4)Å, b = 10.7885(3)Å, c = 17.8075(4)Å, β = 94.12(1)Å and Z = 4. To study the nature of intermolecular interactions and their quantitative contributions towards the crystal packing, Hirshfeld surfaces and accordingly the fingerprint plot analysis have been performed. Molecular properties such as NBO analysis, Homo-Lumo energy calculation have been carried out by DFT method. Furthermore, the antimicrobial activity of silver complex of sulfapyridine and free ligand is studied by the dilution method.     

Crystal growth,thermal and optical studies of L‐histidine tetrafluoroborate: A semiorganic NLO material

L‐histidine tetrafluoroborate (L‐HFB), a semiorganic nonlinear optical (NLO) material has been synthesized and characterized by elemental analysis and FT–NMR spectroscopic studies. Solubility of L‐HFB has been determined in water and ethanol. The single crystals with dimensions 15 x 12 x 3 mm³ were grown by slow evaporation technique under two different pH conditions. The effect of pH on the morphology of the crystals have been studied. The grown crystals of both pH values has been subjected to single crystal X‐ray diffraction to determine the unit cell dimensions and morphology. The thermal stability has been analyzed by TGA and DTA. The microhardness test was carried out in (001) plane and the hardness coefficient was calculated. The birefringence values (Δ_n) were determined in the wavelength region 5540–6460 Å. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Linear trinuclear mixed valance MnIII-MnII-MnIII complex: Synthesis,crystal structure and characterization

A new linear trinuclear Mn^III-Mn^II-Mn^III complex 1 has been synthesized and characterized by elemental, spectral, X-ray and magnetic analysis. X-ray diffraction studies show that the central Mn^II ion is located at a crystallographic inversion center and is triply bridged to the terminal Mn^III ions through one methoxide, one syn-syn carboxylate and one hydroxyl oxygen bridges with the short Mn^III…Mn^II distance that is 3.047 Å. The intermolecular C-H…O, C-H…π and ring-metal interactions are observed in the hydrogen-bonded assembly of 1. Magnetic studies reveal that the mixed-valence complex 1 has S = 3/2 ground state with antiferromagnetic exchange interactions between Mn^II and Mn^III ions.     

Synthesis,characterization, and crystal structure analysis of 2-(2-hydroxy-3-methoxyphenyl)-1-(4-chlorophenyl)-4,5-diphenyl-1h-imidazole

The substituted imidazole C₂₈H₂₁ClN₂O₂, was prepared via multicomponent reactions and the product crystallized using dimethylformamide. The structure of the compound was established by elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-visible, proton nuclear magnetic resonance spectroscopy, and single-crystal X-ray diffraction. The molecule is crystallized in the tetragonal crystal system with the space group P4₃2₁2 and with unit cell parameters a = 12.246(4) Å, b = 12.246(4) Å, c = 31.781(2) Å, and Z = 8. The molecular and crystal structures of the title molecule are stabilized by the intramolecular interactions, O-H···N and C-H···N, and intermolecular interaction, C-H···O.     

Crystallization and characterization of nonlinear optical l‐histidinium dihydrogen orthophosphate orthophosporic acid single crystal

L‐histidinium dihydrogen orthophosphate orthophosporic acid (abbreviated as LHP) with molecular formula C₆H₁₀N₃O₂⁺·H₂PO₄^‐·H₃PO₄ was successfully grown by slow evaporation technique from aqueous solution. The crystal was characterized by X‐ray diffractometry (XRD), UV‐Vis‐NIR, TGA, DTA, microhardness and solubility studies. The dielectric constant and dielectric loss of the crystal were studied as function of frequency. Photoconductivity studies were also carried out on the sample. The SHG efficiency of the crystal is studied using the Kurtz and Perry technique. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Benztropine mesylate: crystal structure and kinetics of dehydration

The crystal structure of benztropine mesylate has been determined. It is orthorhombic, Pbca, with a = 12. 885(8)Å, b = 32.012(9)Å, and c = 10.027(3) Å. It exhibits similar packing to that seen in the previously reported crystal structure of benztropine mesylate monhydrate. X-ray powder diffraction patterns have been used to identify the anhydrous and monohydrate forms. The dehydration of the monohydrate follows a first-order reaction mechanism with activation energy of 92(8) kJ mol^–1.     

Crystal structure and physical characterization of neotame methanol solvate

The crystal structure of the methanol solvate (empirical formula: 2C₂₀H₃₀N₂O₅·3CH₃OH) of a new dipeptide sweetener, neotame (N-(3,3-dimethylbutyl)-L--aspartyl-L-phenylalanine 1-methyl ester), has been determined. Crystal data: a = 9.8989(1), b = 18.1331(1), c = 27.5725(1) Å, orthorhombic, space group P2₁2₁2₁, with Z = 4. Each unit cell includes 8 neotame and 12 methanol molecules. Disorder exists in one neotame molecule and one methanol molecule. The crystals were characterized by the following techniques: hot-stage microscopy (HSM), Karl-Fischer titrimetry (KFT), powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), ¹³C solid-state nuclear magnetic resonance (SSNMR) spectroscopy. Under HSM at a heating rate of 10°C/min in silicone oil, the sample melts at 64–84°C and liberates bubbles at 71–86°C. DSC in open pans shows two overlapping endotherms at 56 and 71°C, probably due to melting and desolvation, respectively. TGA in open pans shows 5.9% weight loss due to desolvation below 70°C. Under house vacuum (23 mm Hg) over phosphorus pentoxide at 23°C, the methanol solvate produces pure amorphous anhydrate, which converts to crystalline neotame monohydrate in the presence of moisture.     

Crystal growth and structure of KBi(WO4)2 single crystals

Potassium bismuth tungstate [KBi(WO₄)₂] single crystals have been grown by the top‐seeded solution growth technique. Bulk crystal with dimensions up to several centimeters is obtained for the first time. Several self‐flux systems have been used for the growth from the solution and the experiments using K₂W₂O₇ as a solvent are detailed. Powder and single crystal X‐ray diffraction of this crystal are reported. The structure refinement shows that KBi(WO₄)₂ crystallizes in the monoclinic space group C2/c, with a=10.837(3), b=10.586(3), c=7.622(2)Å, β=130.860(3)°, V=661.4(3)ų, and Z=4. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal growth,structure and spectroscopic studies of a novel organic single crystal: L‐lysine p‐nitrophenolate monohydrate (LLNP)

A novel organic crystal, L‐lysine p‐nitrophenolate monohydrate (LLNP) has been grown successfully from an aqueous solution by the slow cooling method. Transparent single crystal of dimensions 22 × 12 × 12 mm³ has been obtained. The single crystal X‐ray diffraction has shown that LLNP belongs to the orthorhombic crystallographic system with space group P2₁2₁2₁. The functional groups and vibrational frequencies of the crystal have been identified using IR and Raman spectra. The proton and carbon configurations have been confirmed through ¹H‐NMR and ¹³C‐NMR spectra analyses. The UV‐Vis‐NIR transmittance spectrum for LLNP crystal has been recorded in the range from 200 to 2500 nm. The second harmonic generation (SHG) intensity of LLNP has been measured by powder SHG method and found to be as 4.2 times as that of KDP. The thermal properties have been studied by using thermo gravimetric (TG) and differential thermal analysis (DTA).     

Crystal growth,structure and characterization of p-Toluidinium picrate

p-Toluidinium picrate (PTP), is a proton transfer complex of 2,4,6-trinitrophenol as an electron acceptor with p-toluidine as electron donor, crystallizing in the monoclinic system with four molecules in the unit cell (space group P2₁/c). The vibrational patterns of the organic crystal PTP in comparison with that of the parent compound clearly evidences the complex formation. Loss of hydroxyl proton at O1 leading to specific electron delocalization around C1 is observed. Crystallographic data are reported as a=12.9304(6)  Å, b=15.7176(7)  Å, c=7.5403(4)  Å, β=101.837(5)°. The crystalline cohesion is achieved by N–H…O and C–H…O hydrogen bonds and the ions are linked into three dimensional network. Intermolecular hydrogen bonding between nitrogen of p-toluidine and phenolate ion of picric acid results in charge transfer. A sharp endotherm in the DSC curve, no decomposition up to the melting point and poor absorbance in the visible region indicate the suitability of the material for potential applications.     

Growth and characterization of a new potential second harmonic generation material from the amino acid family: L‐Valinium picrate

L‐Valinium picrate (C₅H₁₂NO₂)⁺. (C₆H₂N₃O₇)^–, a non‐linear optical material from the amino acid family which has large second harmonic generation (SHG) efficiency, was grown by slow evaporation method. Characterization of the crystals was made using single crystal X‐ray diffraction. The functional groups and the modes of vibrations were found by using the Fourier transform infrared (FTIR) spectroscopy. The second harmonic generation (SHG) conversion efficiency was investigated using the Kurtz and Perry method. The SHG conversion efficiency is 60 times higher than that of the standard KDP and 8 times higher than that of the standard Urea and the optical transparency was analyzed using UV‐visible‐NIR absorption spectrum. The structural features of the material leading to the large SHG efficiency are discussed. Microhardness and dielectric studies were also carried out. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Cobalt phthalocyanine nanowires: Growth,crystal structure,and optical properties

Cobalt phthalocyanine nanowires with new crystal structure and broad optical absorption spectra were fabricated by using organic vapor phase deposition method. The morphology, crystal structure and optical properties of CoPc nanowires were characterized by SEM, X‐ray diffraction, Fourier transform infrared and UV‐visible spectroscopies. Analyses of X‐ray diffraction patterns and Fourier transform infrared spectra indicate that the crystal structure of CoPc nanowires represents a new polymorph, which is designated J‐CoPc. These J‐CoPc nanowires with high directionality (average diameter ∼50 nm) surprisingly possess much broader optical absorption spectra in the visible spectral region than those of the α‐ and β‐phase CoPc, enabling high potential for practical applications in novel molecular electronic/optical devices.     

A novel metal‐organic coordination complex crystal: tri‐allylthiourea zinc chloride (ATZC)

A new metal‐organic coordination nonlinear optical crystal, tri‐allylthiourea zinc chloride (ZnCl₂(AT)₃, where AT is CH₂=CHCH₂NHCSNH₂, abbreviated as ATZC), is reported. It was synthesized in water and recrystallized in ethanol. For the crystal structure, optical and thermal characterization were determined by elemental analyses, X‐ray diffraction, infrared spectroscopy, differential scanning calorimeter, thermogravimetric analysis, and powder SHG efficiency meansurement. It belongs to the trigonal system, space group R3, with a = 11.0498(4) Å, c = 16.0416(11) Å, z = 3 and V = 1696.24(15) ų. It exhibits powder SHG efficiency the same order as Urea crystal. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth,crystal structure and spectrum of a novel rare‐earth orthophosphate crystal: Yb:LuPO4

Yb: LuPO₄ crystals with the size up to 6×2×0.5mm³ were grown by the flux growth process using lead pyrophosphate Pb₂P₂O₇ as the high‐temperature solvent. The crystal structure of Yb: LuPO₄ crystals at room temperature was refined by using single crystal X‐ray diffraction data. Crystal structure analysis showed that Yb: LuPO₄ crystals possessed the tetragonal xenotime structure. The polarized absorption spectra of Yb: LuPO₄ were tested at room temperature. The results showed that the absorption spectral region of Yb: LuPO₄ crystal was well matched for pumping with readily available diode lasers.     

Crystal structure characterization of the quaternary compounds CuFeAlSe3 and CuFeGaSe3

The crystal structure of the chalcogenide compounds CuFeAlSe₃ and CuFeGaSe₃, belonging to the system I‐II‐III‐III₃, were characterized using X‐ray powder diffraction data. Both compounds crystallize in the tetragonal space group P42c (N° 112), Z = 1, with unit cell parameters a = 5.609(1) Å, c = 10.963(2) Å for CuFeAlSe₃ and a = 5.6165(3) Å, c = 11.075(1) Å for CuFeGaSe₃. These compounds are isostructural with CuFeInSe₃, and have a normal adamantane structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)