Physicochemical characterization of silicon-containing glycolipids by DSC, FT-Raman spectroscopy and X-ray diffraction

2003 ◽  
Vol 124 (1) ◽  
pp. 1-13 ◽  
Author(s):  
M Uhr ◽  
S Wartewig ◽  
T Unruh ◽  
H Richter
Keyword(s):  
Raman Spectroscopy ◽  
Physicochemical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

scholarly journals The preparation and characterization of SeCl3SbF6, improved syntheses of MCl3(As/Sb)F6 (M = S, Se), and the X-ray crystal structure determination of SeCl3AsF6 and a new phase of SBr3SbF6

1996 ◽  
Vol 74 (9) ◽  
pp. 1671-1681 ◽  
Author(s):  
Jack Passmore ◽  
Paul D. Boyle ◽  
Gabriele Schatte ◽  
Todd Way ◽  
T. Stanley Cameron
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Ft Raman Spectroscopy ◽  
New Phase ◽  
Ft Raman

Alternative and, in some cases, improved syntheses of the salts MX3(As/Sb)F6 (M = S, Se) and SCl3(SbCl6/AlCl4) are described. In addition, the synthesis of SeCl3SbF6 is reported. The compounds were characterized by FT–Raman spectroscopy and the X-ray crystal structures of SeCl3AsF6 (also 77Se NMR) and a new phase of SBr3SbF6 were determined. Crystals of SeCl3AsF6 and SBr3SbF6 are monoclinic, space group P21/c with [values for SBr3SbF6 in brackets] a = 7.678(1) [8.137(1)] Å, b = 9.380(3) [9.583(2)] Å, c = 11.920(3) [12.447(2)] Å, β = 98.19(2)° [97.36(1)]°, V = 849.72(3) [962.6(3)] Å3,z = 4, Dx = 2.925 [3.502] Mg m−3, R = 0.0525 [0.055], and Rw = 0.0554 [0.060] for 1151 [1472] observed reflections. Key words: MX3+ salts, FT–Raman spectroscopy, X-ray crystal structures of SeCl3AsF6, SBr3SbF6, and preparation of SeCl3SbF6.

scholarly journals Fabrication, Characterization, and Antimicrobial Activity, Evaluation of Low Silver Concentrations in Silver-Doped Hydroxyapatite Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
A. Costescu ◽  
C. S. Ciobanu ◽  
S. L. Iconaru ◽  
R. V. Ghita ◽  
C. M. Chifiriuc ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Raman Spectroscopy ◽  
Hydroxyl Groups ◽  
Major Public Health Problem ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Raman Spectroscopy ◽  
Ft Ir ◽  
Ft Raman

The aim of this study was the evaluation of(Ca10-xAgx)(PO4)6(OH)2nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years as a major public health problem worldwide. In this paper, we report a comparison of the antimicrobial activity of low concentrations silver-doped hydroxyapatite nanoparticles. The silver-doped nanocrystalline hydroxyapatite powder was synthesized at 100°C in deionised water. The as-prepared Ag:Hap nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, and FT-Raman spectroscopy. X-ray diffraction (XRD) studies demonstrate that powders obtained by coprecipitation at 100°C exhibit the apatite characteristics with good crystal structure, without any new phase or impurities found. FT-IR and FT-Raman spectroscopy revealed the presence of the various vibrational modes corresponding to phosphates and hydroxyl groups and the absence of any band characteristic to silver. The specific microbiological assays demonstrated that Ag:HAp-NPs exhibited antimicrobial features, but interacted differently with the Gram-positive, Gram-negative bacterial and fungal tested strains.

The preparation, X-ray crystal structure, and spectroscopic characterization of pentafluorophenyl-bis(pentafluorophenylthio)sulfonium hexafluoroarsenate, [(C6F5S)2SC6F5][AsF6]

1998 ◽  
Vol 76 (7) ◽  
pp. 1050-1059 ◽  
Author(s):  
Scott Brownridge ◽  
T Stanley Cameron ◽  
Jack Passmore ◽  
Gabriele Schatte ◽  
George W Sutherland
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Room Temperature ◽  
Spectroscopic Characterization ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Pentafluorophenyl-bis(pentafluorophenylthio)sulfonium hexafluoroarsenate, [(C6F5S)2SC6F5][AsF6], was prepared by the reaction of (C6F5)2S2 and AsF5 in liquid SO2 at room temperature. The compound has been characterized by single-crystal X-ray and powder diffraction, and IR and FT-Raman spectroscopy. Crystals of [(C6F5S)2SC6F5][AsF6] are orthorhombic, space group P212121 (cell dimensions measured at room temperature in brackets): a = 13.132(3) [13.157(2)] Å, b = 21.477(4) [21.575(3)] Å, c = 8.770(2) [8.775(1)] Å, α = ß = γ = 90.00°; V = 2473.3(9) Å3, Z = 4, temperature = 181 ± 1 K. The structure consists of [AsF6]- anions and [(C6F5S)2SC6F5]+ cations that have a different structure than the related [X2MMMX]+ cations (M = S, Se; X = Cl, Br), which contain a trichalcogen chain with a pronounced chalcogen-chalcogen bond alternation. Ab initio calculations suggest the observed [(C6F5S)2SC6F5]+ geometry is due to steric and solid state effects. Comparison of the Raman spectra of [(C6F5)S2SC6F5][AsF6], [Cl2SSSCl][AsF6], and [(CH3)2ClS3]+ implies that [(CH3)2ClS3]+ has a structure with equal sulfur-sulfur distances, and therefore the structure is likely [(CH3S)2SCl]+ and probably not the previously reported [(CH3)2SSSCl]+.Key words: [R3X3]+ cations, X-ray crystal structure, FT-Raman spectroscopy, [(C6F5S)2SC6F5]+, pentafluorophenyl-bis(pentafluorophenylthio)sulfonium cation, hexafluoroarsenate.

scholarly journals Physicochemical characterization of Lavandula spp. honey with FT-Raman spectroscopy

Talanta ◽  
2018 ◽  
Vol 178 ◽  
pp. 43-48 ◽  
Author(s):  
Ofélia Anjos ◽  
António J.A. Santos ◽  
Vasco Paixão ◽  
Letícia M. Estevinho
Keyword(s):  
Raman Spectroscopy ◽  
Physicochemical Characterization ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Deposition of TRISO Particles With Superhard SiC Coatings and the Characterization of Anisotropy by Raman Spectroscopy

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
E. López-Honorato ◽  
P. J. Meadows ◽  
J. Tan ◽  
Y. Xiang ◽  
P. Xiao
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Pyrolytic Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Substrate ◽  
High Concentrations ◽  
Triso Particles ◽  
Sic Coatings

In this work we have deposited silicon carbide (SiC) at 1300°C with the addition of small amounts of propylene. The use of propylene and high concentrations of methyltrichlorosilane (9 vol %) allowed the deposition of superhard SiC coatings (42 GPa). The superhard SiC could result from the presence of a SiC–C solid solution, undetectable by X-ray diffraction but visible by Raman spectroscopy. Another sample obtained by the use of 50 vol % Argon, also showed the formation of SiC with good properties. The use of a flat substrate together with the particles showed the importance of carrying out the analysis on actual particles rather than in flat substrates. We show that it is possible to characterize the anisotropy of pyrolytic carbon by Raman spectroscopy.

The use of NIR-FT-Raman spectroscopy for the characterization of polymer-supported reagents and catalysts

Tetrahedron ◽  
2001 ◽  
Vol 57 (41) ◽  
pp. 8675-8683 ◽  
Author(s):  
B Altava ◽  
M.I Burguete ◽  
E Garcı́a-Verdugo ◽  
S.V Luis ◽  
M.J Vicent
Keyword(s):  
Raman Spectroscopy ◽  
Ft Raman Spectroscopy ◽  
Polymer Supported ◽  
Ft Raman

scholarly journals Assay and physicochemical characterization of the antiparasitic albendazole

2012 ◽  
Vol 48 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Noely Camila Tavares Cavalcanti ◽  
Giovana Damasceno Sousa ◽  
Maria Alice Maciel Tabosa ◽  
José Lamartine Soares Sobrinho ◽  
Leila Bastos Leal ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
Analytical Techniques ◽  
Assay Method ◽  
Active Pharmaceutical Ingredients ◽  
X Ray Diffraction ◽  
Melting Points ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Complementary Techniques

The aim of this study was to characterize three batches of albendazole by pharmacopeial and complementary analytical techniques in order to establish more detailed specifications for the development of pharmaceutical forms. The ABZ01, ABZ02, and ABZ03 batches had melting points of 208 ºC, 208 ºC, and 209 ºC, respectively. X-ray diffraction revealed that all three batches showed crystalline behavior and the absence of polymorphism. Scanning electron microscopy showed that all the samples were crystals of different sizes with a strong tendency to aggregate. The samples were insoluble in water (5.07, 4.27, and 4.52 mg mL-1, respectively) and very slightly soluble in 0.1 M HCl (55.10, 56.90, and 61.70 mg mL-1, respectively) and additionally showed purities within the range specified by the Brazilian Pharmacopoeia 5th edition (F. Bras. V; 98% to 102%). The pharmacopeial assay method was not reproducible and some changes were necessary. The method was validated and showed to be selective, specific, linear, robust, precise, and accurate. From this characterization, we concluded that pharmacopeial techniques alone are not able to detect subtle differences in active pharmaceutical ingredients; therefore, the use of other complementary techniques is required to ensure strict quality control in the pharmaceutical industry.

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