Synthesis and Structural Characterization of Rigid Rod-Like Unsubstituted Quinoline Oligomers

1988 ◽  
Vol 134 ◽  
Author(s):  
Long Y. Chiang ◽  
Rodney V. Kastrup ◽  
Chang S. Hsu ◽  
John W. Swirczewski
Keyword(s):  
Molecular Weight ◽  
Reaction Mechanism ◽  
Structural Characterization ◽  
Spectroscopic Data ◽  
Bulk Material ◽  
Condensation Reaction ◽  
X Ray ◽  
Rigid Rod ◽  
Crystal Structural

ABSTRACTThe structure of quinoline oligomers synthesized by the catalytic dehydrogenative condensation reaction of 1,2,3,4-tetrahydroquinoline was elucidated on the basis of various spectroscopic data including the 2D COSY 1H NMR. The x-ray crystal structural study of two quinoline dimers successfully isolated from the bulk material resolved the puzzle of ring conjunction positions between quinoline units of the oligomer product. A reaction mechanism is proposed. From this mechanism a delicate balance between dehydrogenation and polymerization activity of the catalyst is required to optimize the yield and the molecular weight of the product.

Structural Characterization of a Cage Ligand Fragmentation Reaction

1994 ◽  
Vol 47 (1) ◽  
pp. 181 ◽  
Author(s):  
JM Harrowfield ◽  
AM Sargeson ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Room Temperature ◽  
Fragmentation Reaction ◽  
X Ray ◽  
Nitrogen Donor ◽  
Crystal Structural

The room temperature X-ray single-crystal structural characterization of a protonated copper(II) complex of a ligand artefact, L′, of L = N-Me6sar (described in an accompanying paper) is recorded, the new ligand L′ being generated formally by elimination of a CH2CH2 bridge between a pair of nitrogen donor atoms of L. The complex, [ ClCu (H2L′) (ClO4)3.2H2O, is orthorhombic, Pccn , a 22.528(7), b 10.544(3), c 13.748(6) Ǻ, Z = 4 formula units, R being 0.053 for 1133 independent 'observed' [I > 3σ(I)] reflections. The cation, containing five-coordinate square-pyramidal ClCuN4 copper, is disposed with the Cu- Cl bond [2.458(3)Ǻ] lying on a crystallographic 2 axis; Cu-N distances are 2.094(8) and 2.093(8)Ǻ.

Synthesis and structural characterization of m-terphenyl Schiff base ligands and their aluminum complexes

2004 ◽  
Vol 82 (9) ◽  
pp. 1346-1352 ◽  
Author(s):  
Diane A Dickie ◽  
Hanifa Jalali ◽  
Rahul G Samant ◽  
Michael C Jennings ◽  
Jason AC Clyburne
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Structural Characterization ◽  
Condensation Reaction ◽  
Schiff Base Ligands ◽  
X Ray ◽  
X Ray Crystallography ◽  
Aluminum Complexes

2,4,6-Triphenylbenzaldehyde 1 undergoes a condensation reaction with 2-aminophenol to give N-(2′,4′,6′-triphenylbenzylidene)-2-iminophenol (TPIP) 2. The imine 2 can be reduced with NaBH4 in ethanol to form N-(2′,4′,6′-triphenylbenzyl)-2-aminophenol (TPAP) 3. Addition of trimethylaluminum to 2 or 3 results in the formation of the complexes TPIP-AlMe2·AlMe3 (4) or TPAP-AlMe2 (5). Compounds 2, 3, and 4 have been crystallographically characterized.Key words: N,O ligands, aluminum, m-terphenyl, Schiff bases, X-ray crystallography.

scholarly journals Structural Characterization of Iron Oxide Grown On 18% Ni-Co-Mo-Ti Ferrous Base Alloy Aged Under Superheated Steam Atmosphere

2021 ◽  
Author(s):  
Andréia de Souza Martins Cardoso ◽  
Hugo Ribeiro da Igreja ◽  
Pedro Soucasaux Pires Garcia ◽  
Rodrigo Chales ◽  
Juan Manuel Pardal ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Oxide Layer ◽  
Structural Characterization ◽  
Base Alloy ◽  
Bulk Material ◽  
Wear Testing ◽  
Material Surface ◽  
Isotopic Enrichment ◽  
X Ray

Abstract 18% Ni-Co-Mo-Ti Ferrous base alloys are special materials, widely used in the industry of ​​isotopic enrichment after specific annealing and aging thermal treatment. The desirable high mechanical properties can then be attained by adequate aging heat treatment, answering the structural materials specifications required by defense applications in aerospace and nuclear engineering. For instance, the isotopic enrichment, in rocket engine envelope application, when associated with high temperature and chemical residues like acidic solutions, can induce corrosion and hydrogen embrittlement in martensite structures. To limit these corrosion and hydrogen embrittlement phenomena, an adherent and protective layer of iron oxides can be grown on the material surface by using adequate atmosphere during the aging treatment. Due to its application in strategic areas, the characterization of these oxide layers in maraging steels is of importance as well as the understanding of their growth kinetics. For this purpose, several techniques, such as Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), Microabrasive wear testing, Hardness, Grazing Incidence X-ray Diffraction (GIXRD) and X-ray Photoelectron Spectroscopy (XPS), have been performed for chemical and structural characterization of the oxide films formed after vapor exposed thermal aging at 510°C . The oxide layer consists mostly in two sub-layers composed by magnetite (Fe3O4) and an external layer of hematite (Fe2O3). A thick interface between the oxide layer and the bulk is enriched in Ti and Mo, whereas the analyses of deep bulk material show an enriched area with Ni and Co.

X-ray single-crystal structural characterization of Na2MgSiO4 with cristobalite-type structure synthesised at 22 GPa and 1800 °C

2018 ◽  
Vol 30 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Ekaterina A. Sirotkina ◽  
Luca Bindi ◽  
Andrey V. Bobrov ◽  
Anastasia Tamarova ◽  
Dmitry Yu. Pushcharovsky ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Type Structure ◽  
X Ray ◽  
Crystal Structural

The X-ray crystal structural characterization of dipotassium bisoxalato copper(II) tetrahydrate, [K2Cu(ox)2·4H2O] (ox=oxalate dianion)

2001 ◽  
Vol 319 (1-2) ◽  
pp. 240-246 ◽  
Author(s):  
Jian Fan ◽  
Wei-Yin Sun ◽  
Taka-aki Okamura ◽  
Kai-Bei Yu ◽  
Norikazu Ueyama
Keyword(s):  
Structural Characterization ◽  
X Ray ◽  
Crystal Structural

New horizons for the structural characterization of stainless steel slags by X-ray powder diffraction

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 61-66 ◽  
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
G. Kley ◽  
K. Adam ◽  
F. Emmerling ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Powder Diffraction ◽  
Structural Characterization ◽  
X Ray ◽  
New Horizons

scholarly journals Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4443
Author(s):  
Jiangyan Huo ◽  
Min Lei ◽  
Feifei Li ◽  
Jinjun Hou ◽  
Zijia Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Gut Microbiota ◽  
Structural Characterization ◽  
Hot Water ◽  
Nmr Analysis ◽  
Gastrodia Elata ◽  
Hot Water Extraction ◽  
Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

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