Synthesis of Lipophilic Acyclic Diionizable Polyethers and Selective Transport of Alkaline-Earth Cations in Bulk Liquid Membrane System

✍ Scribed by Jong Seung Kim; Moon Hwan Cho; Sang Chul Lee; Yong-Ill Lee; Wonbo Sim; Nam Sook Cho

• Book ID: 102617324
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 93 KB
• Volume: 55
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1996.1338

✦ Synopsis

Selective transport of alkaline-earth cations in a bulk liquid membrane system by lipophilic acyclic polyether dicarboxylic acids is reported. Introduction of proton-ionizable groups into such polyethers shows a distinct advantage over neutral macrocycles in that transfer of a metal ion into an organic medium does not require concomitant transport of an aqueous phase anion. A new organic ligand 1,5-bis[2-(2-carboxypentadecyloxy)phenoxy]-3-oxapentane (8) which bears a tetradecyl group as an alkyl chain at the a-position of the carboxylic acid side-arm unit is sufficiently lipophilic to avoid loss of the complexing agent into the aqueous phase during solvent extraction and exhibited a calcium selectivity over other alkaline-earth cations.