75507-20-9Relevant academic research and scientific papers
Liquid-Liquid-Extraction of Metal Ions with Lariat Ethers
Gloe, K.,Muehl, P.,Beger, J.,Poeschmann, C.,Petrich, M.,Beyer, L.
, p. 413 - 421 (2007/10/02)
Lariat ethers of various ring size and substitution are synthesized and characterized by physical data and chemical analysis.The extraction behaviour of the crown compounds towards Na+, K+, Cs+ and Ag+ in a picric acid solution has been investigated.The extraction constants for 1:1 and 1:2 complexes are determined using the equilibrium distribution data.The results show that the flexible side chain in the investigated compounds has in no case a positive effect on the metal picrate extraction.
Synthesis and Alkali-cation Complexing Properties of 12-Crown-4 Derivatives
Miyazaki, Takeshi,Yanagida, Shozo,Itoh, Akira,Okahara, Mitsuo
, p. 2005 - 2009 (2007/10/02)
Benzyloxymethyl-12-crown-4, a precursor of hydroxymethyl-12-crown-4, is prepared in an excellent yield by the reaction of 3-benzyloxy-1,2-propanediol with 1,8-dichloro-3,6-dioxaoctane in the heterogeneous t-BuOLi/t-BuOH/LiBr*2H2O reaction system.The hydrogenolysis in the presence of p-toluenesulfonic acid leads to a good yield of hydroxymethyl-12-crown-4.The sandwich-type 2:1 complexation with Na+ of 12-crown-4 and hydroxymethyl-12-crown-4 derivatives was discussed on the basis of the stability constants and the solvent extraction in the CH2Cl2-water system.
Synthesis of Substituted Crown Ethers from Oligoethylene Glycols
Ikeda, Isao,Yamamura, Shingo,Nakatsuji, Yohji,Okahara, Mitsuo
, p. 5355 - 5358 (2007/10/02)
A convenient synthetic method for preparing 12-crown-4, 15-crown-5, 18-crown-6, and 21-crown-7 bearing various substituents by intramolecular cyclization of the corresponding substituted oligoethylene glycols in high yields is described.Substituents include modifiable pendent groups such as phenyl and hydroxymethyl, as well as various alkyl groups.Stability constants for the new substituted crown ethers with sodium and potassium ions in methanol were determined by potentiometric titration.The absolute effect of pendent groups on stability constants was insignificant.
