scholarly journals The hydrocarbon-bearing clathrasil chibaite and its host–guest structure at low temperature

IUCrJ ◽  
2018 ◽  
Vol 5 (5) ◽  
pp. 595-607 ◽  
Author(s):  
K. S. Scheidl ◽  
H. S. Effenberger ◽  
T. Yagi ◽  
K. Momma ◽  
Ronald Miletich

The natural sII-type clathrasil chibaite [chemical formula SiO2·(M 12,M 16), where M x denotes a guest molecule] was investigated using single-crystal X-ray diffraction and Raman spectroscopy in the temperature range from 273 to 83 K. The O atoms of the structure at room temperature, which globally conforms to space group Fd{\overline 3}m [V = 7348.9 (17) Å3, a = 19.4420 (15) Å], have anomalous anisotropic displacement parameters indicating a static or dynamic disorder. With decreasing temperature, the crystal structure shows a continuous symmetry-lowering transformation accompanied by twinning. The intensities of weak superstructure reflections increase as temperature decreases. A monoclinic twinned superstructure was derived at 100 K [A2/n, V = 7251.0 (17) Å3, a′ = 23.7054 (2), b′ = 13.6861 (11), c′ = 23.7051 (2) Å, β′ = 109.47°]. The transformation matrix from the cubic to the monoclinic system is ai ′ = (½ 1 ½ / ½ 0 −½ / ½ −1 ½). The A2/n host framework has Si—O bond lengths and Si—O—Si angles that are much closer to known values for stable silicate-framework structures compared with the averaged Fd{\overline 3}m model. As suggested from band splitting observed in the Raman spectra, the [512]-type cages (one crystallographically unique in Fd{\overline 3}m, four different in A2/n) entrap the hydrocarbon species (CH4, C2H6, C3H8, i-C4H10). The [51264]-type cage was found to be unique in both structure types. It contains the larger hydrocarbon molecules C2H6, C3H8 and i-C4H10.

2021 ◽  
Author(s):  
Xinru Hu ◽  
Jilin Wang ◽  
Jian He ◽  
Guoyuan Zheng ◽  
Disheng Yao ◽  
...  

Abstract Two kinds of novel organic-inorganic bismuth-halide hybrid monocrystalline compounds (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were synthesized and characterized. The crystal structure, intermolecular interaction, morphology, chemical groups and bonds, optical and thermal stability of the samples were systematically investigated through single crystal X-ray diffraction, Hirshfeld surface analysis, SEM, FTIR, TG and UV-vis diffuse reflectance spectra. The results indicated that (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 crystals displayed a monoclinic system with the space group P21/c and P21/n at room temperature, respectively. These materials showed strong absorption in the ultraviolet and visible light regions, resulting in very low Eg, which could be continuously adjustable from 1.67 eV to 3.21 eV by changing the halogen ratio. In addition, these hybrid materials also exhibited good thermal stability. The decomposition temperature of (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were 260℃ and 300℃ respectively. Therefore, these organic-inorganic bismuth-halide hybrid compounds have excellent development potential in the field of solar cell research.


2016 ◽  
Vol 31 (3) ◽  
pp. 233-239
Author(s):  
Jose H. Quintana Mendoza ◽  
J. A. Henao ◽  
Carlos E. Rondón Flórez ◽  
Carlos E. Puerto Galvis ◽  
Vladimir V. Kouznetsov

The title compound, the 4-phenyl-6-(trifluoromethyl)-3,4-dihydroquinolin-2(1H)-one (4) with chemical formula: (C16H12F3NO), was synthesized from N-[4-(trifluoromethyl)phenyl]cinnamamide (3), chemical formula: (C16H12F3NO), through an intramolecular cyclization mediated by triflic acid. Preliminary molecular characterization of both compounds was performed by Fourier transform infrared spectroscopy, gas chromatography mass spectrometry, and nuclear magnetic resonance spectroscopy (1H, 13C); crystallographic characterization was completed by X-ray diffraction of polycrystalline samples. The title compound 4 crystallized in a monoclinic system and unit-cell parameters are reported [a = 16.002 (3), b = 5.170 (1), c = 17.733 (3) Å, β = 111.11 (2)°, unit-cell volume V = 1368.5 (3) Å3, Z = 4] P21/c (No. 14) space group; the title compound 3 crystallized in a monoclinic system and unit-cell parameters are reported [a = 12.902 (2), b = 5.144 (1), c = 20.513 (5) Å, β = 91.67 (2)°, unit-cell volume V = 1360.7 (4) Å3, Z = 4] P21/c (No. 14) space group.


2004 ◽  
Vol 19 (4) ◽  
pp. 378-384
Author(s):  
A. Rafalska-Lasocha ◽  
M. Grzywa ◽  
B. Włodarczyk-Gajda ◽  
W. Lasocha

The X-ray diffraction patterns of two organic acids 1-naphthalenesulfonic acid dihydrate and 2-naphthalenesulfonic acid hydrate were measured at room temperature. Complexes of these acids with 1,8-bis(dimethylamino)naphthalene (DMAN) were synthesized, purified and investigated by means of X-ray powder diffraction. 1-Naphthalenesulfonic acid dihydrate as well as its complex with 1,8-bis(dimethylamino)naphthalene crystallize in the monoclinic system with unit cell parameters refined to a=0.91531(8) nm, b=0.7919(1) nm, c=0.8184(1) nm, β=101.618(9)° space group P21/m (11) and a=1.7781(4) nm, b=2.0122(4) nm, c=1.2337(2) nm, β=96.54(3)°, space group C2/m (12), respectively. 2-Naphthalenesulfonic acid hydrate crystallizes in the orthorhombic system with a=2.2749(3) nm, b=0.7745(1) nm, c=0.591 36(9) nm, space group Pnma, whereas its complex with 1,8-bis(dimethylamino)naphthalene crystallizes in the triclinic system a=1.3969(6) nm, b=1.4292(5) nm, c=1.1741(6) nm, α=90.93(3)°, β=98.14(3)°, γ=113.93(3)°, space group P-1 (2).


2011 ◽  
Vol 35 (1) ◽  
pp. 51-59 ◽  
Author(s):  
AA Shaikh ◽  
Susumi Akter ◽  
MS Rahman ◽  
Pradip K Bakshi

The reaction of thiamine.HCl (ThHCl) with K2Cr2O7 has been studied in aqueous solution at room temperature. The compound obtained is ionic 1 : 1 in which thiamine is present as a cation and Cr2O7 2- as an anion. The chemical formula of the salt, (C12H18N4OS) (Cr2O7) (symbolically ThHCr2O7), has been established by elemental analysis, IR and UV/Vis spectra, magnetic measurement, thermal analysis, conductivity measurement, cyclic voltammetric study and X-ray diffraction analysis.DOI: http://dx.doi.org/10.3329/jbas.v35i1.7970Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 51-59, 2011


2011 ◽  
Vol 26 (4) ◽  
pp. 346-349 ◽  
Author(s):  
M. A. Macías ◽  
J. A. Henao ◽  
Lina María Acosta ◽  
Alirio Palma

The 6,8-dimethyl-cis-2-vinyl-2,3,4,5-tetrahydro-1H-benzo[b]azepin-4-ol (2a) (Chemical formula C14H19NO) and 8-chloro-9-methyl-cis-2-(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H-benzo[b]azepin-4-ol (2b) (Chemical formula C14H18ClNO) were prepared via the reductive cleavage of the bridged N-O bond of the corresponding 1,4-epoxytetrahydro-1-benzazepines. The X-ray powder diffraction patterns for the new compounds were obtained. The compound 2a was found to crystallize in an orthorhombic system with space group Pmn21 (No. 31), refined unit-cell parameters a = 19.422(6) Å, b = 6.512(3) Å, c = 9.757(4) Å and V = 1234.0(5) Å3. The compound 2b was found to crystallize in a monoclinic system with space group P21/m (No. 11), refined unit-cell parameters a = 17.570(4) Å, b = 8.952(3) Å, c = 14.985(4) Å, β = 101.66(2)°, and V = 2308.3(9) Å3.


2010 ◽  
Vol 96 ◽  
pp. 87-92 ◽  
Author(s):  
Lin Rui Hou ◽  
Chang Zhou Yuan

We report the synthesis of the taper-like BiVO4 nanorods by employing a solid-state grinding synthetic strategy. The X-ray diffraction (XRD) indicates that the as-prepared BiVO4 nanorods were crystallized in a monoclinic system. The diameter and length of taper-like nanorods are confirmed by the scanning electron microscopy (SEM) technology. The diameter and length of the taper-like nanorods are 100 nm and 1 μm, respectively. And the photocatalytic activity of the taper-like BiVO4 nanorods was evaluated by measuring the degradation of methylene blue (MB) in water under sunlight irradiation. MB was degraded nearly to nothing under sunlight irradiation for 120 min at room temperature in air. These results indicate the as-prepared product is a good sun-driven photocatalyst. In addition, the degradation mechanism of methylene blue over BiVO4 nanorods was tentatively investigated.


2005 ◽  
Vol 20 (1) ◽  
pp. 67-70
Author(s):  
B. Lasocha ◽  
M. Grzywa ◽  
W. Lasocha

X-ray diffraction investigations of two phenol derivatives - 2,2′-Thiobis(4-methyl-6-tert-butylphenol) and 2,2′-Methylenebis(4-methyl-6-tert-butylphenol) were carried out. Both compounds at room temperature have similar cell volume and the same number of molecules in an unit cell. However, 2,2′-Thiobis(4-methyl-6-tert-butylphenol) crystallizes in the monoclinic system with unit cell parameters refined to a=0.8278(2) nm, b=1.2968(4) nm, c=1.9493(7) nm, β=90.93(2)°, space group P21∕n(14), whereas 2,2′-Methylenebis(4-methyl-6-tert-butylphenol) crystallizes in the orthorhombic system with unit cell parameters refined to a=1.6203(5) nm, b=1.2827(5) nm, c=1.0197(3) nm, space group Pna21(33). The investigated C22H30O2S turned out to be a new polymorph of 2,2′-Thiobis(4-methyl-6-tert-butylphenol).


2011 ◽  
Vol 26 (1) ◽  
pp. 74-77 ◽  
Author(s):  
H. A. Camargo ◽  
N. M. Habran ◽  
J. A. Henao ◽  
D. F. Amado ◽  
V. V. Kouznetsov

The 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene (chemical formula C20H21N) was prepared by means of a condensation between alpha-naphthylaldehyde and 3,5-dimethylaniline in anhydrous ethanol to obtain the aldimine (1) which was reduced with NaBH4 to afford the 1-[N-(3,5-dimethylphenylamino)]methylnaphtalene (2), and finally, the compound (3) was obtained by N-alkylation reaction of (2) with methyl iodine (CH3I) and potassium carbonate (K2CO3) in acetone. Final compound (3) was purified by chromatographic column. The XRPD pattern for the new compound, 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene, was obtained. This compound crystallizes in monoclinic system with space group P21/a (No. 14) and refined unit-cell parameters a=13.260(4) Å, b=15.495(5) Å, c=7.719(5) Å, β=90.19(6), and V=1586(1) Å3.


2011 ◽  
Vol 26 (S1) ◽  
pp. S55-S57
Author(s):  
M. A. Macías ◽  
J. A. Henao ◽  
Carlos Mario Sanabria ◽  
Alirio Palma

The 7-methyl-cis-2-(1’-naphthyl)-2,3,4,5-tetrahydro-1H-benzo[b]azepin-4-ol (chemical formula C21H21NO) was prepared via the reductive cleavage of the bridged N-O bond of the corresponding 7-methyl-2-exo-(1′-naphthyl)-1,4-epoxytetrahydro-1-benzazepine. The X-ray powder diffraction pattern for the new compound was analyzed and found that the title compound crystallizes in a monoclinic system with space group P2/c (No. 13) and refined unit-cell parameters a = 11.012(2), b = 18.613(5), c = 7.316(4) Å, β = 102.88(3) ° and V = 1461.8(7) Å3.


Author(s):  
C. Wolpers ◽  
R. Blaschke

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.


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