The structure and properties of oriented fibers of poly(pentamethylene terephthalate). II. Structural analysis of two different crystalline phases by x-ray crystallography

1978 ◽  
Vol 16 (12) ◽  
pp. 2189-2214 ◽  
Author(s):  
I. H. Hall ◽  
N. N. Rammo
Keyword(s):  
Structural Analysis ◽  
Structure And Properties ◽  
Crystalline Phases ◽  
X Ray ◽  
X Ray Crystallography

A new modification of [Ag4Br4(PPh3)4]: synthesis, structure and properties

2018 ◽  
Vol 73 (10) ◽  
pp. 733-738 ◽  
Author(s):  
Xintong Han ◽  
Shanshan Mao ◽  
Chuang Li ◽  
Kesheng Shen ◽  
Xinkui Shi ◽  
...  
Keyword(s):  
Solid State ◽  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Elemental Analysis ◽  
Supramolecular Structure ◽  
Chair Conformation ◽  
Cyclic Voltammograms ◽  
Structure And Properties ◽  
X Ray ◽  
X Ray Crystallography

AbstractA new modification of the homometallic silver(I) cluster [Ag4Br4(PPh3)4] has been prepared and characterized by elemental analysis, UV/Vis and IR spectroscopy, and X-ray crystallography. The tetramer shows a polycyclic structure with a chair conformation. The bromine atoms adopt μ2- and μ3-bridging modes. The shortest Ag–Ag distance in the cluster is 3.159(2) Å, which indicates significant Ag–Ag interactions. A supramolecular structure is arranged by hydrogen bonds (C–H···Br). Cyclic voltammograms of the cluster indicate a quasi-reversible Ag+/Ag couple. The fluorescence properties of the ligand and the Ag(I) cluster were studied in the solid state. The emission peaks of the Ag(I) cluster are attributed to ligand-centered luminescence.

Structural analysis of and selective CO2 adsorption in mixed-ligand hydroxamate-based metal–organic frameworks

2020 ◽  
Vol 49 (29) ◽  
pp. 9948-9952 ◽  
Author(s):  
Koh Sugamata ◽  
Chikaze Takagi ◽  
Keiko Awano ◽  
Teruyuki Iihama ◽  
Mao Minoura
Keyword(s):  
Structural Analysis ◽  
Single Crystal ◽  
Co2 Adsorption ◽  
Isonicotinic Acid ◽  
Metal Organic Frameworks ◽  
Mixed Ligand ◽  
Gas Sorption ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Organic

Two mixed-ligand metal–organic frameworks using benzene-1,4-dihydroxamic acid and isonicotinic acid were synthesized and fully characterized by single-crystal X-ray crystallography as well as N2, H2, and CO2 gas-sorption measurements.

N-methylated 25-oxasmaragdyrins: Synthesis, structure and properties

2016 ◽  
Vol 20 (05) ◽  
pp. 582-589
Author(s):  
Tejinder Kaur ◽  
Way-Zen Lee ◽  
Mangalampalli Ravikanth
Keyword(s):  
Pyrrole Ring ◽  
Electrochemical Techniques ◽  
Soret Band ◽  
2D Nmr ◽  
Structure And Properties ◽  
2D Nmr Spectroscopy ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Structural And Electronic Properties

The [Formula: see text]-methylated 25-oxasmaragdyrins were synthesized by reacting 25-oxasmaragdyrins with CH3I in presence of KOH in THF at reflux temperature. Although the reactions were carried out in presence of excess CH3I, we obtained only dimethyl-25-oxasma ragdyrins, where [Formula: see text]-methylations occurred at 24 and 26 “N”s of pyrrole rings of tripyrrane moiety of smaragdyrin core as confirmed by X-ray crystallography. The [Formula: see text]-methylated-25-oxasmaragdyrins were characterized in detail by 1D and 2D NMR spectroscopy, absorption, fluorescence and electrochemical techniques. The effect of distortion induced by methylation, clearly reflected in structural and electronic properties of the macrocycle. All the pyrrole and furan protons experienced upfield shifts in the 1H NMR and maximum upfield shifts were noted for the [Formula: see text]-methylated pyrrole ring protons. The absorption spectra showed broad Soret band and four ill-defined Q-bands with significant reduction in extinction coefficients. The [Formula: see text]-methylated 25-oxasmaragdyrins were comparatively less fluorescent. The redox studies indicated that they are difficult to oxidize and easier to reduce.

Synthesis, Crystal Structure and Properties of a Chiral 2D Zn(II) Coordination Polymer with Helical Chains

2013 ◽  
Vol 68 (4) ◽  
pp. 403-407 ◽  
Author(s):  
Ting-Ting Kang ◽  
Hao Tang ◽  
Yong-Li Wei ◽  
Shuang-Quan Zang
Keyword(s):  
Coordination Polymer ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Organic Layer ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
Structure And Properties ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Organic

A chiral two-dimensional (2D) coordination polymer {[Zn(cmmb)(1,4-bbi)]·H2O}n (1) has been synthesized by a hydrothermal reaction of Zn(NO3)2·6H2O with 4- (carboxymethoxy)-2-methylbenzoic acid (H2cmmb) and 1,1`-(1,4-butanediyl)bis(imidazole) (1,4-bbi). It has been characterized by elemental analysis, X-ray crystallography, IR spectroscopy and thermogravimetry, and also by its fluorescence properties. The metal-organic layer of the complex is held together with its neighbors via C-H···O hydrogen bonds to give rise to a chiral three-dimensional supramolecular network.

Stereostructure of slovanolides: X-ray crystallography of the 3-oxo-4αH,8α-benzoyloxy-10β,11α-diacetoxyslovanolide

1984 ◽  
Vol 49 (12) ◽  
pp. 2790-2800 ◽  
Author(s):  
Urszula Rychłewska ◽  
Miroslav Holub ◽  
Miloš Buděšínský ◽  
Zdenka Smítalová
Keyword(s):  
Structural Analysis ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Nmr Data

X-Ray structural analysis of 3-oxo-4αH,8α-benzoyloxy-10β,11α-diacetoxyslovanolide (XII) confirmed the correctness of the previously proposed structure of slovanolides. A comparison of the X-ray and 1H NMR data of lactone XII showed that the confirmation of this substance in crystals and in chloroform or benzene solutions is very similar. The structure of the lactone from Laserpitium marginatum has been corrected to formula XIa.

Influence of Heat Treatment on the Phase Composition and Microhardness of Coatings Based on Ti3SiC2/ TiC

2020 ◽  
Vol 839 ◽  
pp. 137-143 ◽  
Author(s):  
Dastan Buitkenov ◽  
Bauyrzhan K. Rakhadilov ◽  
Dosym Erbolatuly ◽  
Zhuldyz Sagdoldina
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Structural Analysis ◽  
Tool Steel ◽  
Uniform Structure ◽  
Structure And Properties ◽  
Powder Coatings ◽  
Detonation Spraying ◽  
X Ray

The paper discusses the results of studying the structure and properties of powder coatings based on Ti3SiC2/TiC, obtained by the method of detonation spraying on the surface of the tool steel N9. It is determined that the coating has a uniform structure, cracks and delaminations are not observed. The results of X-ray structural analysis of coatings showed that the coating before annealing consists of phases TiC and Ti3SiC2. After annealing, the formation of TiO2 phases and an increase in the intensity of the (103) and (108) reflections of the Ti3SiC2 phases are observed. It is established that an increase in the content of the phases of Ti3SiC2 in coatings leads to an increase in the microhardness of coatings.

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