scholarly journals Growth, Nucleation Kinetics and Structural Studies on L-Valine Piperazinium Single Crystals

2019 ◽  
Vol 31 (9) ◽  
pp. 1966-1970 ◽  
Author(s):  
R. Arunkumar ◽  
D. Benny Anburaj
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Slow Growth ◽  
Growth Parameters ◽  
Solubility Curve ◽  
Structural Studies ◽  
Nucleation Kinetics ◽  
Growth Technique ◽  
Time Period ◽  
Temperature Induction

A single crystal of L-valine piperazinium was grown by slow growth technique. Structural studies confirm the monoclinic structure with space group P21. The solubility curve showing high soluble in water and peak shows positive solubility nature. A tiny nucleation formed at 10 ºC for room temperature process and it gradually increasing with respect process temperature. Induction period revels that time period for nucleation at constant temperature and it absorbed that in (10 ºC) 500 s for room temperature. The calculated interfacial tension values are greater than one order other amino acid based piperazinium. By using growth parameters bulk L-valine piperazinium crystal were harvested and single crystal XRD confirms that formation of L-valine piperazinium crystals.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

scholarly journals Nucleation Kinetics, Growth and Characterization Studies of a Diamagnetic Crystal-Zinc Sulphate Heptahydrate (ZSHH)

2009 ◽  
Vol 6 (3) ◽  
pp. 871-879 ◽  
Author(s):  
R. Kanagadurai ◽  
R. Durairajan ◽  
R. Sankar ◽  
G. Sivanesan ◽  
S. P. Elangovan ◽  
...  
Keyword(s):  
Induction Period ◽  
Zinc Sulphate ◽  
Critical Nucleus ◽  
Growth Parameters ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
Nucleation Kinetics ◽  
Growth Technique ◽  
Free Energy Of Formation ◽  
Ft Ir

Solubility, metastable zone width and induction period measurements have been performed on zinc sulphate heptahydrate (ZSHH). Interfacial tension values determined from induction period measurements have been used for the evaluation of the nucleation parameters such as radius of critical nucleus and the free energy of formation of critical nucleus. ZSHH crystallizes in the orthorhombic structure. Crystals of diamagnetic zinc sulphate heptahydrate have been grown by temperature lowering solution growth technique with the optimized growth parameters. The as-grown ZSHH crystals were characterized by the powder X-ray diffraction, UV-VIS absorption and transmittance, FT-IR absorption, TG-DTA, microhardness and etching studies.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2019 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.51 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

scholarly journals Analysis of LiKSO4 crystals in the temperature range from 573 to 943 K

2000 ◽  
Vol 56 (4) ◽  
pp. 607-617 ◽  
Author(s):  
Carlos Basílio Pinheiro ◽  
Marcos Assunção Pimenta ◽  
Gervais Chapuis ◽  
Nivaldo Lúcio Speziali
Keyword(s):  
Single Crystal ◽  
Phase Ii ◽  
Room Temperature ◽  
Structure Model ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Displacements ◽  
Disordered Models ◽  
Different Temperatures

The structural phases observed in LiKSO_4 crystals due to thermotropic transitions have been studied for more than a century. Nowadays many different phases are referenced, but some of the results are still controversial. Structural studies by single-crystal X-ray diffraction from room temperature to 803 K are presented here. Phase II (708 \lt T \lt 943 K) is extensively discussed on the basis of ordered and disordered models, using harmonic and anharmonic atomic displacements, and considering a twinned crystal composed of three orthorhombic domains. Analyses of the same phase at different temperatures determine the best structure model.

Lewis-Base Adducts of Lead(II) Compounds. XVI. Synthetic and Structural Studies of Some Adducts of 2-Aminomethylpyridine With Lead(II) Compounds

1996 ◽  
Vol 49 (10) ◽  
pp. 1127 ◽  
Author(s):  
JM Harrowfield ◽  
H Miyamae ◽  
BW Skelton ◽  
AA Soudi ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Lewis Base ◽  
Structural Studies ◽  
Problem Structure ◽  
Coordination Environment ◽  
X Ray ◽  
The Third ◽  
Structure Determinations ◽  
Centrosymmetric Dimers

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 2:1 adducts of 2-aminomethylpyridine ('amp') with lead(II) nitrate and thiocyanate . [(amp)2Pb(NO3)2]2 is triclinic, Pī, a 11.616(4), b 11.145(6), c 7.341(3) Ǻ, α 83.87(4), β 89.17(3), γ 64.12(3)°, Z = 1 dimer ; R was 0.043 for No 3529 independent 'observed' (I > 3σ(I)) reflections. [(amp)2Pb(SCN)2]2 is also triclinic, Pī , a 12.121(9), b 9.301(14), c 8.615(8) Ǻ, α 70.11(10), β 84.00(7), γ 79.38(10)°, Z = 1 dimer (R 0.033 for No 3467). Both complexes are centrosymmetric dimers ; the coordination environment is made up in each case of a pair of N,N°-bidentate bases, one terminally bound anion (O,O°-chelating nitrate or S-bonded thiocyanate ) and bridging anions. In the case of the thiocyanates, these bridge end-on, so that the lead(II) environment is seven-coordinate PbN5S2; in the nitrate, the anion chelates through two of its oxygen atoms, bridging via the third, so that the lead(II) environment is nine-coordinate PbN4O5. A 'problem structure', [(amp)2Pb(ClO4)2], monoclinic, C2/c (?), a 14.528(3), b 8.203(3), c 15.495(6) Ǻ, β 91.14(3)°, Z = 4 f.u ., R 0.044 for No 1775, is also recorded, the crystal seemingly a disordered aggregate of [(N, N′-amp)2Pb(OClO3)2] moieties.

scholarly journals Preparation of Samarium Doped Calcium Hydrogen Phosphate and Study of Its Density and Thermal and Dielectric Characteristics

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
K. K. Bamzai ◽  
Goldy Slathia ◽  
Bindu Raina ◽  
Rashmi Gupta ◽  
Seema Verma ◽  
...  
Keyword(s):  
Single Crystal ◽  
Growth Parameters ◽  
X Ray Diffraction ◽  
Hydrogen Phosphate ◽  
Monoclinic System ◽  
Dielectric Characteristics ◽  
Growth Technique ◽  
Temperature Solution ◽  
Flotation Method ◽  
Kinetics Of

Samarium doped calcium hydrogen phosphate was synthesized as single crystal by room temperature solution growth technique, namely, silica gel technique. The kinetics of the growth parameters was studied with regard to variation of pH, dopant concentration, gel ageing, and upper reactant concentration. The optimum conditions for the growth of good quality single crystal were worked out. Single crystal X-ray diffraction analysis establishes that the crystal belongs to monoclinic system. The density observed by the flotation method is greater than the density of the reported pure calcium hydrogen phosphate thereby suggesting the incorporation of the dopant (Sm) ion into the lattice of host (CHP). Thermal analysis gave two sharp endothermic peaks which are due to partial dehydration and phase transition, respectively. Dielectric studies establish a shift in the Curie temperature from 355 to 370°C only at higher frequencies thereby suggesting the relaxational behavior of the material.

Lewis-Base Adducts of Lead(II) Compounds. XVIII. Synthetic and Structural Studies of Some 1:1 and 2:1 Adducts of 2,4,6-Tris (2-pyridyl)-1,3,5-triazine With Lead(II) Nitrate

1996 ◽  
Vol 49 (10) ◽  
pp. 1147 ◽  
Author(s):  
JM Harrowfield ◽  
DL Kepert ◽  
H Miyamae ◽  
BW Skelton ◽  
AA Soudi ◽  
...  
Keyword(s):  
Single Crystal ◽  
Polymer Chain ◽  
Room Temperature ◽  
Lewis Base ◽  
Lead Atom ◽  
Structural Studies ◽  
Complex Species ◽  
X Ray ◽  
The Third ◽  
Metal Ligand

Adducts of lead(II) nitrate with 2,4,6-tris(2-pyridyl)-1,3,5-triazine (' trz ') have been synthesized and structurally characterized by room-temperature single-crystal X-ray studies, for 1:1 and 1:2 stoichiometry. Crystals of [( trz ) Pb (NO3)2](∞|∞) are monoclinic, P 21/c, a 10.531 (1), b 12.856(2), c 16.874(3) Ǻ, β 102.83(1)°, Z = 4 f.u .; R was 0.027 for No = 2773 'observed' (I > 3σ(I)) reflections. The complex is an infinite polymer; the plane of the tridentate trz ligand lies normal to the polymer axis ( Pb -N(central; distal) 2.523(5); 2.594(5), 2.568(5) Ǻ) with unsymmetrically bidentate nitrate groups to either side ( Pb -O 2.598(6), 2.928(7); 2.556(6), 2.911(7) Ǻ). The third oxygen of each nitrate group bridges to the next lead atom in the polymer chain ( Pb -O 3.008(5), 3.083(6)Ǻ). [( trz )2Pb(NO3)2] is monoclinic, C 2/c, a 15.723(5), b 10.034(2), c 24.379(15) Ǻ, β 106.84(4)°, Z = 4 f.u .; R was 0.038 for No 3030. The compound is a methanol monosolvate. The complex species is mononuclear, with the lead atom located on a crystallographic 2 axis and 10-coordinated by pairs of symmetry-related tridentate trz ( Pb -N(central; distal) 2.779(4); 2.800(5), 2.818(5) Ǻ) and bidentate nitrate ligands ( Pb -O 2.796(6), 2.689(5)Ǻ). A hexahydrate has also been obtained (triclinic, Pī a 23.580(9), b 10.147(4), c 9.762(4)Ǻ, α 113.14(3), β 92.11(3), γ 101.60(3)°, Z = 2 f.u ; R 0.041 for No 5633); although metal-ligand distances are similar to those found in the methanol solvate, and quasi-2 symmetry is retained, a very different stereochemistry is evident in respect of the relative dispositions of the ligands about the (quasi)-2 axis, involving a substantial twist of the two nitrate ligands relative to the triazines, and a flattening of the latter. The coordination polyhedron is different in the two 1:2 adducts. In the methanol solvate the stereochemistry is pentagonal antiprismatic whereas in the hexahydrate it is bicapped square antiprismatic.

Lewis-Base Adducts of Lead(II) Compounds. XIX. Synthetic and Structural Studies of Some 1:1 Adducts of 2,4,6-Tris (2-pyridyl)-1,3,5-triazine With Lead(II) (Pseudo-)Halides

1996 ◽  
Vol 49 (10) ◽  
pp. 1157 ◽  
Author(s):  
JM Harrowfield ◽  
H Miyamae ◽  
BW Skelton ◽  
AA Soudi ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Lewis Base ◽  
Structural Studies ◽  
Adjacent Pair ◽  
X Ray ◽  
Structure Determinations ◽  
Pseudo Halides

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1:1 adducts of 2,4,6-tris(2-pyridyl) 1,3,5-triazine (' trz ') with lead(II) chloride, bromide, iodide and thiocyanate, the chloride and bromide being methanol monosolvates. [( trz )PbCl2](∞|∞). MeOH is monoclinic, P 2/c, a 9.178(2), b 14.833(3), c 7.347(8) Ǻ, β 93.89(2)°, Z = 2 f.u .; R was 0.042 for No = 1451 'observed' (I > 3σ(I)) reflections; the bromide is related, having a derivative triclinic cell, Pī, a 9.259(3), b 15.153(6), c 7.428(2) Ǻ, α 90.28(3), β 94.62(2), γ 91.15(3)°, Z = 2 f.u .; R was 0.047 for No 2729. [( trz )PbI2](∞|∞), also solvated, is triclinic, Pī , a 15.266(9), b 8.9448(8), c 8.148(11) Ǻ, α 80.60(6), β 77.05(7), γ 83.45(3)°, Z = 2; R was 0.032 for No 3222. In all three compounds an infinite PbX2PbX2Pb polymer is found with the plane of the tridentate trz lying quasi normal to the polymer axis. Pb -N distances lie between 2.63(1) and 2.803(8) Ǻ; Pb-Cl are 2.848(3) and 3.074(3), Pb -Br 2.963(2)-3.257(2) and Pb-I 3.192(3)-3.466(2) Ǻ. The thiocyanate, monoclinic, C 2/c, a 16.974(6), b 6.410(2), c 39.49(2) Ǻ, β 96.33(4)°, Z = 8, R 0.13 for No 2465, is a column of dimeric units stacked up b, successive lead atoms being bridged by thiocyanate sulfur atoms packed in between them, and quasi-parallel to a, and by thiocyanates parallel to b which link pairs of lead atoms in each dimer with the same b coordinate by pairs of bridging nitrogens and bridging sulfurs from the adjacent pair.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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