Studies of the phosphorodiamidates of alkali metals

1969 ◽  
Vol 47 (14) ◽  
pp. 2613-2617 ◽  
Author(s):  
Y. N. Sadana
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Alkali Metals ◽  
Potassium Salts ◽  
X Ray ◽  
Diffraction Patterns ◽  
Sodium And Potassium

Phosphorodiamidates of lithium, rubidium, and cesium have been prepared and characterized. The infrared spectra and the X-ray powder diffraction patterns of these and the previously known sodium and potassium salts have been recorded and discussed.

Solid State Transitions in Alkali Alkanoates: Diffractometric and Conductometric Measurements on Rubidium and Cesium Propanoates

1979 ◽  
Vol 34 (10) ◽  
pp. 1212-1215 ◽  
Author(s):  
G. Spinolo ◽  
A. Cingolani ◽  
M. Sanesi
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
State Transitions ◽  
Potassium Salts ◽  
X Ray ◽  
Rubidium Salt ◽  
Suitable Temperature ◽  
Temperature Ranges ◽  
Sodium And Potassium

Abstract Conductometric measurements on solid rubidium and cesium propanoates and X-ray powder diffraction measurements on the rubidium salt have been carried out over suitable temperature ranges. The results obtained, along with the previous ones concerning the lithium, sodium and potassium salts, have been discussed in relation to possible melting mechanisms (involving various kinds of disorder, e.g., positional, orientational, conformational) active in the alkali alkanoates family.

scholarly journals Solid State Transitions in Alkali Alkanoates: Diffractometric and Conductometric Measurements on Lithium, Sodium and Potassium Propanoates

1979 ◽  
Vol 34 (5) ◽  
pp. 575-578 ◽  
Author(s):  
A. Cingolani ◽  
G. Spinolo ◽  
M. Sanesi
Keyword(s):  
Phase Transitions ◽  
Solid State ◽  
Temperature Dependence ◽  
Powder Diffraction ◽  
State Transitions ◽  
Potassium Salts ◽  
Crystalline Phases ◽  
X Ray ◽  
Temperature Ranges ◽  
Sodium And Potassium

Abstract Conductometric measurements on solid lithium, sodium and potassium propanoates and X-ray powder diffraction measurements on the sodium and potassium salts have been performed over temperature ranges including solid state transitions. The temperature dependence of the transport and lattice parameters of the different crystalline phases and the changes of the same parameters in correspondence with phase transitions have been put into evidence.

The thermal behaviour of an Fe-rich illite

Clay Minerals ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 45-52 ◽  
Author(s):  
E. Murad ◽  
U. Wagner
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Phase Changes ◽  
X Ray ◽  
Structural Breakdown ◽  
Characteristic Features ◽  
Diffraction Patterns ◽  
Good Agreement ◽  
Subsequent Disappearance

AbstractThe phase changes that took place upon heating an Fe-rich illite (OECD #5) to 1300°C in an oxidizing atmosphere were studied by a variety of mineralogical techniques. Infrared spectra, showing the stepwise dehydroxylation of the illite, showed good agreement with variations in sample colour and Mössbauer spectra. Dehydroxylation did not lead to noticeable variations in X-ray powder diffraction patterns until the structural breakdown of illite and formation of new phases at about 900°C Mössbauer spectroscopy proved to be very sensitive to all changes induced by heating, showing the disappearance of Fe2+ at 250°C, the gradual dehydroxylation between about 350 and 900°C, and characteristic features of the products formed at higher temperatures, e.g. the formation of hematite as the illite structure breaks down and the subsequent disappearance of hematite due to the incorporation of Fe in glass above 1200°C. The formation of hematite in clusters large enough to order magnetically at room temperature was first observed in the sample heated to 900°C, whereas at 4.2 K, significant proportions of a magnetically ordered phase could already be identified in the sample heated to 650°C.

Physico-Chemical Characterization of Some 5,5-Disubstituted-1,3-Dixanthyl Barbituric Acids

1967 ◽  
Vol 21 (4) ◽  
pp. 225-231 ◽  
Author(s):  
B. C. Flann ◽  
J. A. R. Cloutier
Keyword(s):  
Experimental Data ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Chemical Characterization ◽  
Melting Points ◽  
X Ray ◽  
Physico Chemical ◽  
Diffraction Patterns ◽  
Derivatives Of

The dixanthyl derivatives of 21 clinically important barbituric acids have been prepared. Melting points, infrared spectra, and x-ray powder-diffraction patterns of the purified compounds are presented. Infrared evidence is used to discuss the position of the linkage between the xanthyl and barbiturate portions of the derivatives. The experimental data should prove of particular value for the microchemical identification of barbiturates.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Synthesis of Sulfoquinovose and Sulfoquinovosyl Diacylglycerides, and a Fluorogenic Substrate for Sulfoquinovosidases

2019 ◽  
Author(s):  
Yunyang Zhang ◽  
Janice Mui ◽  
Thimali Arumaperuma ◽  
James P. Lingford ◽  
ETHAN GODDARD-BORGER ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Fluorogenic Substrate ◽  
Potassium Salts ◽  
X Ray ◽  
Sulfoquinovosyl Diacylglycerol ◽  
Sodium And Potassium

<p>The sulfolipid sulfoquinovosyl diacylglycerol (SQDG) and its headgroup, the sulfosugar sulfoquinovose (SQ), are estimated to harbour up to half of all organosulfur in the biosphere. SQ is liberated from SQDG and related glycosides by the action of sulfoquinovosidases (SQases). We report a 10-step synthesis of SQDG that we apply to the preparation of saturated and unsaturated lipoforms. We also report an expeditious synthesis of SQ and (<sup>13</sup>C<sub>6</sub>)SQ, and X-ray crystal structures of sodium and potassium salts of SQ. Finally, we report the synthesis of a fluorogenic SQase substrate, methylumbelliferyl a-D-sulfoquinovoside, and examination of its cleavage kinetics by two recombinant SQases.</p>

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.

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