Synthesis and structure of a stegane from dimethylmatairesinol

1984 ◽  
Vol 37 (8) ◽  
pp. 1775 ◽  
Author(s):  
RC Cambie ◽  
GR Clark ◽  
PA Craw ◽  
PS Rutledge ◽  
PD Woodgate
Keyword(s):  
Trifluoroacetic Acid ◽  
Oxidative Coupling ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray

Oxidative coupling of dimethylmatairesinol with thallium tristrifluoroacetate (prepared in situ from thallium(III) oxide and trifluoroacetic acid) and boron trifluoride etherate gives a high yield of an isostegane which has been isomerized thermally to a stegane. Stereochemical assignments have been confirmed by X-ray diffraction studies.

scholarly journals In situ X-ray diffraction computed tomography studies examining the thermal and chemical stabilities of working Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes during oxidative coupling of methane

2020 ◽  
Vol 22 (34) ◽  
pp. 18964-18975
Author(s):  
Dorota Matras ◽  
Antonis Vamvakeros ◽  
Simon D. M. Jacques ◽  
Vesna Middelkoop ◽  
Gavin Vaughan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Solid State ◽  
Oxidative Coupling ◽  
Structural Changes ◽  
Oxidative Coupling Of Methane ◽  
Membrane Reactors ◽  
Solid State Chemistry ◽  
X Ray Diffraction ◽  
X Ray

In situ XRD-CT and post-reaction SEM/EDX were used to study the solid-state chemistry and structural changes of Ba0.5Sr0.5Co0.8Fe0.2O3−δ membrane reactors during the oxidative coupling of methane reaction.

scholarly journals La-Faujasite zeolite activated with boron trifluoride: synthesis and application as solid acid catalyst for isobutane–isobutene alkylation

2021 ◽  
Author(s):  
David Bolonio ◽  
Yolanda Sánchez-Palencia ◽  
María-Jesús García-Martínez ◽  
Marcelo F. Ortega ◽  
José Eugenio Ortiz ◽  
...  
Keyword(s):  
Boron Trifluoride ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Boron Trifluoride Etherate ◽  
Acid Sites ◽  
Alkylation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fau Zeolite ◽  
Sodium Form

AbstractThe sodium form of Faujasite Y (Na-FAU) zeolite has been synthesized by the hydrothermal method, and it has been exchanged with ammonium sulphate and later with lanthanum (III) chloride solutions to obtain the La-FAU catalyst. The three zeolites Na-FAU, NH4+-FAU and La-FAU have been characterized by microcrystalline X-ray diffraction, X-ray fluorescence, surface area, pore volume and Brönsted acid sites. The La-FAU catalyst has been successfully activated with boron trifluoride etherate, and it has been tested in the alkylation reaction of isobutane with isobutene up to 112 h of time on stream, since the raw La-FAU catalyst showed a rapid deactivation.

Oxidative Coupling of Lignans. II. Non-Phenolic Coupling of Diarylbutane Lignans Related to Matairesinol Dimethyl Ether

1988 ◽  
Vol 41 (3) ◽  
pp. 305 ◽  
Author(s):  
JS Buckleton ◽  
RC Cambie ◽  
GR Clark ◽  
PA Craw ◽  
CEF Rickard ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Trifluoroacetic Acid ◽  
Oxidative Coupling ◽  
X Ray ◽  
X Ray Crystallography

The non- phenolic oxidative coupling of some diarylbutane lignans related to matairesinol dimethyl ether (1) has been investigated. Coupling with a thallium(III) oxidant, prepared in situ from thallium(III) oxide and trifluoroacetic acid, converts these lignans efficiently into either dibenzocyclooctadiene or aryltetralin lignans. The dibenzocyclooctadiene lignan (5) prepared from oxidative coupling of matairesinol dimethyl ether has been converted into compound (26) which has significant in vitro antileukaemic activity. The structure of the isostegane (27) formed by oxidative coupling of dimethylbutane (14) has been confirmed by X-ray crystallography.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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