Concomitant polymorphs of methoxyflavone (5-methyl-7-methoxyflavone)

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 38709-38715 ◽  
Author(s):  
Ningbo Gong ◽  
Kun Hu ◽  
Guimin Jin ◽  
Guanhua Du ◽  
Yang Lu
Keyword(s):  
Crystal Structure ◽  
Amorphous Phase ◽  
Bioactive Compound ◽  
X Ray ◽  
First Report

A novel metastable polymorph and an unstable amorphous phase of methoxyflavone were discovered after a decade since the first report of the X-ray crystal structure of this bioactive compound.

Crystal Structure of a Novel Furo-Furan Lactone from Heliotropium eichwaldi

2012 ◽  
Vol 67 (3) ◽  
pp. 269-271
Author(s):  
Sadiqa Firdous ◽  
Nida Hassan Ansari ◽  
Seik Weng Ngb ◽  
Sammer Yousuf ◽  
Abdul Malik
Keyword(s):  
Crystal Structure ◽  
Ethyl Acetate ◽  
Soluble Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report ◽  
First Time

A novel furo-furan lactone 1 has been isolated as fine needles from the ethyl acetate-soluble fraction of Heliotropium eichwaldi. This is the first report of any furo-furan from the genus Heliotropium. β -Sitosterol 3-O-β -D-glucoside 2 has also been obtained for the first time from this source. The structure of 1 was elucidated by X-ray diffraction studies.

The Great Barrier Reef Expedition 1928–29: The crystal structure and occurrence of weddellite, ideally CaC2O4·2.5H2O, from the Low Isles, Queensland

2016 ◽  
Vol 80 (2) ◽  
pp. 399-406 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy
Keyword(s):  
Crystal Structure ◽  
Coral Reef ◽  
Low Temperature ◽  
Great Barrier Reef ◽  
Single Crystal ◽  
Structure Study ◽  
Barrier Reef ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Report

Abstract“Envelope crystals” collected during The Great Barrier Reef Expedition in May 1929 have been studied using low-temperature synchrotron single-crystal X-ray diffraction. The crystals are shown to be weddellite, with the largest content of zeolitic water reported to date. A new H2O site has been located within the crystal structure. Study of the crystals show that the end-member formula for weddellite should be reported as CaC2O4·(2.5 – x)H2O, where 0≤x≤ 0.25, instead of CaC2O4·(2H2O or CaC2O4·(2 + x )H2O. This is also the first report of weddellite occurring in a coral reef.

scholarly journals X-ray crystal structure of [L 2Ag3]+[OTf]−·5C6D6: a monoanionic bisphosphinimine ligand supported trisilver complex

2021 ◽  
Vol 77 (10) ◽  
pp. 1025-1028
Author(s):  
Sam L. Drescher ◽  
Christopher P. Forfar ◽  
René T. Boeré ◽  
Paul G. Hayes
Keyword(s):  
Crystal Structure ◽  
Asymmetric Unit ◽  
High Quality ◽  
Metal Centers ◽  
X Ray ◽  
First Report ◽  
Bond Lengths ◽  
Solvent Molecules ◽  
Deuterated Benzene ◽  
Silver Atoms

The compound bis{μ3-2,5-bis[N-(4-isopropylphenyl)-P,P-diphenylphosphorimidoyl]pyrrol-1-ido-κ3 N:N′:N′′}trisilver(I) trifluoromethanesulfonate deuterated benzene pentasolvate, [Ag3(C46H44N3P2)2](CF3O3S)·5C6D6, (I), was synthesized from two equivalents of NaL [L = 2,5-(4- i PrC6H4N=PPh2)C4H2N] and three equivalents of AgOTf (OTf = OSO2CF3). High-quality crystals of (I) formed with five deuterated benzene solvent molecules in the asymmetric unit. Notably, the bond lengths and angles between the three silver atoms are markedly different, unlike in most other reported trisilver complexes that tend to form three equivalent metal centers. Additionally, to the best of our knowledge, this is the first report of a trisilver complex with six nitrogen donors from two bisphosphinimine ligands.

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