X-Ray Diffraction Patterns of 2,4,7-Trinitrofluorenone Derivatives of Aromatic Hydrocarbons

1952 ◽  
Vol 24 (5) ◽  
pp. 822-826 ◽  
Author(s):  
L. J. E. Hofer ◽  
W. C. Peebles
Keyword(s):  
Aromatic Hydrocarbons ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Derivatives Of

X-Ray Diffraction Patterns of Solid Aromatic Hydrocarbons

1951 ◽  
Vol 23 (5) ◽  
pp. 690-695 ◽  
Author(s):  
L. J. E. Hofer ◽  
W. C. Peebles
Keyword(s):  
Aromatic Hydrocarbons ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Identification of Crystalline Derivatives of Butyrophenones by X-Ray Diffraction: Examination of Pure Compounds and Active Substances in Pharmaceutical Formulations

1971 ◽  
Vol 54 (6) ◽  
pp. 1406-1419
Author(s):  
E Okkerse ◽  
A De Leenheer ◽  
A Heyndrickx
Keyword(s):  
Diffraction Data ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
X Ray Diffraction ◽  
Photographic Recording ◽  
X Ray ◽  
Pure Compounds ◽  
Diffraction Patterns ◽  
Derivatives Of ◽  
Active Substances

Abstract Isolation and crystallization procedures have been developed for butyrophenones as free substances and from pharmaceutical formulations, namely ampoules, coated tablets, drops, and tablets. Crystallization as free bases, picrates, picrolonates, chlorhydrates, bromates, sulfates, and phosphates was attempted for all compounds. For the crystalline derivatives, the X-ray diffraction data were obtained by the Debye-Scherrer powder technique with photographic recording. The products have been classified according to their X-ray data, using “Hanawalt’s three strongest lines index” and the “innermost line index” systems. The butyrophenones could be identified with certainty by direct comparison of the X-ray diffraction patterns of compounds isolated from dosage forms with reference patterns.

Characterization of Carboxylic Acids: Identification of Their Anilide Derivatives by X-ray Diffractometry

1976 ◽  
Vol 30 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Kenneth J. Garska
Keyword(s):  
Mass Spectrometry ◽  
Carboxylic Acid ◽  
Qualitative Analysis ◽  
Carboxylic Acids ◽  
Isomeric Form ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Derivatives Of

In order to extend the data available for the characterization of carboxylic acids, an x-ray diffraction technique has been used for the identification of their anilide derivatives. This technique often makes possible the identification of carboxylic acids that cannot be examined readily by other techniques such as gas chromotography and mass spectrometry. Reference x-ray diffraction patterns have been obtained for the anilide derivatives of 32 carboxylic acids containing up to 18 carbon atoms. Detailed descriptions are given for obtaining and qualitatively using the x-ray diffraction patterns of these anilides. The x-ray diffraction patterns of these anilides are unique; even closely related acids which differ only in isomeric form produce anilide derivatives which exhibit different and characteristic x-ray diffraction patterns. In the qualitative analysis of single or multicomponent carboxylic acid-containing mixtures, this x-ray diffraction technique is used either alone or with infrared spectrometric techniques.

X-RAY DIFFRACTION PATTERNS OF DINITROPHENYL DERIVATIVES OF AMINO COMPOUNDS

1952 ◽  
Vol 30 (8) ◽  
pp. 575-580 ◽  
Author(s):  
H. M. Rice ◽  
F. J. Sowden
Keyword(s):  
Powder Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amino Compounds ◽  
Diffraction Patterns ◽  
First Time ◽  
Derivatives Of

The 2,4-dinitrophenyl derivatives of a number of amino compounds have been prepared and their X-ray powder diffraction measurements made. This appears to be the first time this information has been obtained and it is submitted as a method of identification.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Infrared spectroscopic study of the YPO4-YCrO4 system

1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek
Keyword(s):  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Point Of View ◽  
Mixed Crystals ◽  
Crystal Symmetry ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectroscopic ◽  
Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

scholarly journals Deep learning for visualization and novelty detection in large X-ray diffraction datasets

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lars Banko ◽  
Phillip M. Maffettone ◽  
Dennis Naujoks ◽  
Daniel Olds ◽  
Alfred Ludwig
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Artificial Intelligence ◽  
Deep Learning ◽  
Novelty Detection ◽  
Structural Similarity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Post Hoc

AbstractWe apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the structural similarity of textured diffraction patterns. While other artificial intelligence (AI) agents are effective at classifying XRD data into known phases, a similarly conditioned VAE is uniquely effective at knowing what it doesn’t know: it can rapidly identify data outside the distribution it was trained on, such as novel phases and mixtures. These capabilities demonstrate that a VAE is a valuable AI agent for aiding materials discovery and understanding XRD measurements both ‘on-the-fly’ and during post hoc analysis.

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