o-Quinone methides. Part 3. X-Ray crystal structure and reactivity of a stable o-quinone methide in the E-configuration

1986 ◽  
pp. 1391 ◽  
Author(s):  
Arturo Arduini ◽  
Andrea Pochini ◽  
Rocco Ungaro ◽  
Paolo Domiano
Keyword(s):  
Crystal Structure ◽  
Quinone Methide ◽  
Quinone Methides ◽  
X Ray

Quinones and quinone methides. IX. Oxidation of 2,4-Bis(1,1-dimethylethyl)-6-(4-methoxyphenylmethyl)phenol in alcoholic solvents: Monomeric products and the crystal structure of an unusual dimes, 2-[3,5-Bis(1,1-dimethylethyl)-2-{methoxy-(4-methoxyphenyl)methoxy} phenoxyl-1,5-bis(1,1-dimethylethyl)-3-[methoxy-(4-methoxyphenyl)methyl]benzene

1981 ◽  
Vol 34 (8) ◽  
pp. 1645 ◽  
Author(s):  
L Jurd ◽  
RY Wong
Keyword(s):  
Crystal Structure ◽  
Silver Oxide ◽  
Crystallographic Analysis ◽  
Quinone Methides ◽  
X Ray ◽  
High Yields ◽  
Methyl Benzene

Oxidation of the title benzylphenol (1) with silver oxide in alcoholic media forms benzylic ethers of type (5) in high yields; e.g. oxidation in methanol yields 2,4-bis(1,1-dimethylethyl)-6-[methoxy(4- methoxyphenyl)methyl]phenol(5a) together with an unusual dimer, the structure of which was shown by X-ray crystallographic analysis to be 2-[3,5-bis(1,1-dimethylethyl)-2-{methoxy(4-methoxyphenyl)- methoxy}phenoxy]-1,5-bis(1,1-dimethylethy)-3-[methoxy(4- methoxyphenyl)methyl]benzene (6). The benzylic ethers (5) are convenient intermediates for the syntheses of a variety of compounds related to (1).

Quinones and quinone methides. X. The crystal structure of a dimeric oxidation product from 2,4-Bis(1,1-dimethylethyl)-6-[(4-methoxyphenyl)methyl]phenol

1984 ◽  
Vol 37 (12) ◽  
pp. 2593
Author(s):  
RY Wong ◽  
L Jurd
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Oxidation Product ◽  
Crystallographic Analysis ◽  
Quinone Methides ◽  
X Ray ◽  
A Minor

The molecular structure of a minor oxidation product of the insect sterilant 2,4-bis(1,1-dimethylethyl) 6-[(4-methoxyphenyl)methyl]phenol has been established as (�)-cis-1,3,6,8-tetrakis(1,1-dimethyl-ethyl)-4b,9b-bis(4-methoxyphenyl)-4b,9b-dihydrobenzofuro[3,2-b]benzofuran by means of X-ray crystallographic analysis.

Triterpenoids from Hippocratea excelsa. The Crystal Structure of 29-Hydroxytaraxerol

2005 ◽  
Vol 60 (5) ◽  
pp. 577-584 ◽  
Author(s):  
Amilcar R. Aguilar-Gonzalez ◽  
Gonzalo J. Mena-Rejón ◽  
Nayely Padilla-Montaño ◽  
Alfredo Toscano ◽  
Leovigildo Quijano
Keyword(s):  
Crystal Structure ◽  
Spectral Analysis ◽  
Root Bark ◽  
Significant Activity ◽  
X Ray Diffraction ◽  
Quinone Methides ◽  
Heteronuclear Correlation ◽  
Antifungal Activities ◽  
X Ray ◽  
Antimicrobial And Antifungal Activities

The root bark of Hippocratea excelsa afforded a new derivative of β -amyrin, which was identified as its ferulate, together with components new in this species. They were identified as the rare 29-hydroxytaraxerol, 29-hydroxyglutinol, 29-hydroxyfriedelin and the sterol 6β -hydroxystigmast-4- en-3-one. The known triterpene quinone methides pristimerin and tingenone characteristics of this genus, β -sitosterol, trans-polyisoprene, squalene, β -amyrin, and the alditol galacticol characteristic of the Celastraceae were also isolated. The structures were established on the basis of spectral analysis, including homo- and heteronuclear correlation NMR experiments (COSY, DEPT, HMQC and HMBC) and by comparison with data reported in the literature. The structure of 29-hydroxytaraxerol was confirmed by X-ray diffraction. The antimicrobial and antifungal activities of the compounds were studied, but no significant activity was found.

A study on α-RuCl3 crystal structure by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 30-31
Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Scanning Tunneling Microscopy ◽  
Electron Density ◽  
Structure Determination ◽  
Electron Density Distribution ◽  
Scanning Tunneling ◽  
Monoclinic Space Group ◽  
Tunneling Microscopy ◽  
X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

X-ray Crystal Structure of ?9-THC-tosylate

Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
W Gul ◽  
P Carvalho ◽  
D Slade ◽  
M Avery ◽  
JR Duchek ◽  
...  
Keyword(s):  
Crystal Structure ◽  
X Ray

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Sign in / Sign up

Export Citation Format

Share Document