Extraction of iridium(IV) from hydrochloric acid media with crown ether in chloroform, and its determination by ICP-AES

Abstract

A new method for the quantitative extraction and determination of trace amounts of iridium from hydrochloric acid media has been established based on the formation of an ion-association complex of iridium hexachloro anion IrCl6(2-) with dicyclohexyl-18-crown-6 (DC18C6) oxonium cation in chloroform, then determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The effect of various factors (solvent, acid concentration, crown ether, reagent concentration, shaking time, composition of the extracted species, foreign ions, etc.) on the extraction and back-extraction of iridium has been investigated. The procedure was used to determine traces of iridium in palladium chloride and rhodium chloride.

Extraction of short-lived zirconium and hafnium isotopes using crown ethers: A model system for the study of rutherfordium

“…These species cannot interact directly with the oxygen atoms of the ligand. The donor atoms of the crown ether usually coordinate to positively charged species, but crown ethers can be used to extract anionic complexes by forming ion-association complexes [16]. Crown ethers such as DB18C6 are known to form positively charged hydronium complexes by coordinating with a H 3 O + molecule [17,18].…”

Use of dicyclohexano-18-crown-6 to separate traces of silver(I) from potassium thiocyanate in hydrochloric acid media, and determination of the silver by atomic absorption spectrometry

“…Previously reported similar extraction techniques for other noble metals [17,19,20,22] were conducted in chloride media. To avoid matrix conversion, and to highly simplify the separation procedure, the use of 1.0 mol L -1 hydrochloric acid in the silver-containing sample solution was therefore taken as optimum.…”

“…silver was extracted more efficiently as its anionic thiocyanate complex, [Ag(SCN) 2 ] -, by ion-association with the cationic potassium crown ether [DC18C6·K] + in 1,2-dichloroethane. The same ion-association mechanism with DC18C6 has also been used for the successful separation of platinum [19], palladium [20], rhodium [21], and iridium [22] from their mixtures.…”

Studies of Flerovium and Element 115 Homologs with Macrocyclic Extractants

“…In cases where the cation is much smaller than the crown ether cavity, 1:2 complexes can form where oxygen atoms are located as close to the cation as possible [164]. Other well-known 2:1 sandwich complexes have been known to form with crown ethers extracting anionic complexes by formation of ion-association complexes [166]. Crown ethers, specifically 18-crown-6 (18C6)…”