Removal of Toxic Anions from Environmental Water by using Cage Compounds

• Published in: Green Science and Technology pp. 194 - 214
• Main Author: Kondo, Mitsuru
• Format: Book Chapter
• Language: English
• Published: CRC Press 2020
• Edition: 1
• Subjects: MSD Animal Health; Organic Bridging Ligands; Anion Hosts; Ii Ion; Removal Activity; Anion Exchange Reactions; Aqueous Solutions; MeCN Solution; Single Crystal XRD Analysis; Single Crystal XRD; Large DNA Fragment; Cage Framework; Weak Crystal Field; Cage Structure; Compound 6b; Cage Compounds; Counter Anions; Elongated Octahedral Geometry; Renin Receptor; Anion Exchange Resins; Ethanol Fermentation; Anion Removal; ESI TOF Mass Spectrum
• ISBN: 9780367415136; 0367415135
• DOI: 10.1201/9780367814953-14

Anion exchange and biological reduction of ClO4− have been considered to be available technologies for ClO4− removal from aqueous solutions. The host materials that exhibit selective recognition and encapsulation of the target anions are known as “anion hosts,” often also called “anion receptors.” The recognition and removal of the anion function even in aqueous solutions, and the removal proceeds unaffected by the disturbing coexisting anions. The ClO4− removal by anion exchange reactions by water-insoluble M2L4 cage compounds was studied in continuing works. The changes of the concentrations of anions of each solution were monitored by ion chromatography. The chapter describes new coordination compounds that show ClO4− removal activities from aqueous solutions. Regeneration of the resins after ClO4− adsorption is an important subject for anion-exchange resins in practical use. The structures of the compounds obtained from Flexible bis-imidazole- and bis-benzimidazole-type ligands are largely dependent on the type of metal ions, counter anions, and reaction solvents used in the synthesis.