ChemInform Abstract: LIGAND STRUCTURE AND COMPLEXATION, XXII. 2,6-BIS(AMINOMETHYL)PYRIDINE AS A COMPLEX LIGAND AND NEW BUILDING BLOCK FOR CROWN ETHER SYNTHESIS

1978 ◽  
Vol 9 (38) ◽  
Author(s):  
E. BUHLEIER ◽  
W. WEHNER ◽  
F. VOEGTLE
Keyword(s):  
Crown Ether ◽  
Building Block ◽  
Ligand Structure ◽  
Ether Synthesis ◽  
Complex Ligand

Polycarboxylate crown ethers from meso-tartaric acid

1991 ◽  
Vol 69 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Frank R. Fronczek ◽  
Richard D. Gandour ◽  
Thomas M. Fyles ◽  
Philippa J. Hocking ◽  
Susan J. McDermid ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crown Ether ◽  
Tartaric Acid ◽  
Crown Ethers ◽  
Nmr Spectra ◽  
Product Distribution ◽  
Complexing Agents ◽  
Triclinic Space Group ◽  
The Stability ◽  
Ether Synthesis

The synthesis of crown ethers derived from meso-tartaric acid was investigated. The sodium salt of the bis(dimethylamide) of meso-tartaric acid reacted with diethylene glycol ditosylate to give a mixture of 18-crown-6 tetraamide and 27-crown-9 hexaamide crown ethers. The 2R,3S,11S,12R 18-crown-6 isomer crystallized in triclinic space group [Formula: see text] (a = 7.557(2), b = 8.866(2), c = 10.4133(13) Å, α = 94.13(2), β = 95.86(2), γ = 99.26(2)°, R = 0.040 for 2090 observed of 3129 unique reflections). The structures of the remaining products were then assigned from the NMR spectra. The solution conformations of the amide crown ethers were examined by NMR, and provide a rationale for the product distribution obtained. One of the 18-crown-6 isomers and a mixture of the two 27-crown-9 isomers were hydrolyzed to the respective crown ether carboxylic acids, and the stability constants for complexation of cations were determined by potentiometric titration. The meso tetra- and hexacarboxylates are remarkably nonselective and inefficient cation complexing agents, compared to related crown ethers from R,R-(+)-tartaric acid, due to the unfavorable conformational control exerted by the tartaro units. Key words: crown ether synthesis, complexation, crown ether conformation, meso-tartaric acid, crystal structure.

ChemInform Abstract: LIGAND STRUCTURE AND COMPLEXATION, VII. SIMPLE SYNTHESES OF NEW CROWN ETHER AMINES

1976 ◽  
Vol 7 (36) ◽  
pp. no-no
Author(s):  
WERNER RASSHOFER ◽  
WINFRIED WEHNER ◽  
FRITZ VOEGTLE
Keyword(s):  
Crown Ether ◽  
Ligand Structure

scholarly journals Self-Organization of -Crown Ether Derivatives into Double-Columnar Arrays Controlled by Supramolecular Isomers of Hydrogen-Bonded Anionic Biimidazolate Ni Complexes

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Makoto Tadokoro ◽  
Kyosuke Isoda ◽  
Yasuko Tanaka ◽  
Yuko Kaneko ◽  
Syoko Yamamoto ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Crown Ether ◽  
Building Block ◽  
The Other ◽  
Optical Isomer ◽  
Self Organization ◽  
Optical Isomers ◽  
One Dimensional ◽  
Molecular Building Block ◽  
Hydrogen Bonded

Anionic tris (biimidazolate) nickelate (II) ([Ni(Hbim)3]−), which is a hydrogen-bonding (H-bonding) molecular building block, undergoes self-organization into honeycomb-sheet superstructures connected by complementary intermolecular H-bonds. The crystal obtained from the stacking of these sheets is assembled into channel frameworks, approximately 2 nm wide, that clathrate two cationic K+-crown ether derivatives organised into one-dimensional (1D) double-columnar arrays. In this study, we have shown that all five cationic guest-included crystals form nanochannel structures that clathrate the 1-D double-columnar arrays of one of the four types of K+-crown ether derivatives, one of which induces a polymorph. This is accomplished by adaptably fitting two types of anionic [Ni(Hbim)3]−host arrays. One is a network with H-bonded linkages alternating between the two different optical isomers of the and types with flexible H-bonded [Ni(Hbim)3]−. The other is a network of a racemate with 1-D H-bonded arrays of the same optical isomer for each type. Thus, [Ni(Hbim)3]−can assemble large cations such as K+crown-ether derivatives into double-columnar arrays by highly recognizing flexible H-bonding arrangements with two host networks of and .

Studies on a selena-aza-crown ether: Synthesis and catalytic behavior in hydrosilylation

1997 ◽  
Vol 2 (4) ◽  
pp. 464-466 ◽  
Author(s):  
Xu Wei ◽  
Liu Xiufang ◽  
Lu Xueran ◽  
Xu Hansheng
Keyword(s):  
Crown Ether ◽  
Catalytic Behavior ◽  
Ether Synthesis ◽  
Aza Crown Ether

POTASSIUM FLUORIDE ON ALUMINA AS BASE FOR CROWN ETHER SYNTHESIS

1980 ◽  
Vol 9 (5) ◽  
pp. 533-536 ◽  
Author(s):  
Junko Yamawaki ◽  
Takashi Ando
Keyword(s):  
Crown Ether ◽  
Potassium Fluoride ◽  
Ether Synthesis

scholarly journals A novel profluorescent paramagnetic diaza-crown ether: synthesis, characterization and alkaline metal-ion complexation

RSC Advances ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 6078-6083 ◽  
Author(s):  
Anca G. Coman ◽  
Cristina Stavarache ◽  
Anca Paun ◽  
Codruţa C. Popescu ◽  
Niculina D. Hădade ◽  
...  
Keyword(s):  
Free Radical ◽  
Crown Ether ◽  
Metal Ion ◽  
The Other ◽  
Alkaline Metal ◽  
Metal Ion Complexation ◽  
Stable Free Radical ◽  
Ion Complexation ◽  
Fluorescent Moiety ◽  
Ether Synthesis

Starting from Kryptofix 22 two different branches were covalently attached through the nitrogen atoms, one containing a fluorescent moiety and the other the stable free radical TEMPO.

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