143093-93-0Relevant articles and documents
Macrocyclic Polyether Tetralactams II : A Study of their Binding Properties with Alkaline - Earth Cations
Pigot, Thierry,Duriez, Marie-Christine,Picard, Claude,Cazaux, Louis,Tisnes, Pierre
, p. 4359 - 4368 (1992)
Solvent extractions of alkali and alkaline-earth picrates were carried out in a water-chloroform system using newly synthesized tetralactams containing dimethyleneoxy moieties.These ligands display excellent extracting properties for Ca2+, Ba2+ and Sr2+ cations.Some of the less lipophilic derivatives have greater preference for Ba2+ vs.Na+ and Zn2+ and, to a lesser extent, K+, Mg2+ and Ca2+.In addition, the stability constants were determined for the 1:1 and the 1:2 M2+:tetralactam complex by UV spectrophotometry in THF solution.In each series of tetralactams log KS values as high as 6 were observed for Ca2+, Sr2+ and Ba2+ ions.The 18-, 21- and 24-membered tetralactams complex preferentially Sr2+, Ca2+ and Ba2+ cations respectively.Keywords: Tetralactam; Complexation; Stability Constants; Liquid-Liquid-Extraction; Alkaline-Earth Cations