Extraction of cesium by the nitrobenzene solution of hydrogen bis-1,2-dicarbollylcobaltate in the presence of 15-crown-5

Abstract

Extraction of microamounts of cesium by the nitrobenzene solution of H § bis-l,2-dicarbollylcobaltate (H+B -) in the presence of 15-crown-5 (15C5, L) has been investigated. The equilibrium data have been explained assuming the complexes HL § HL2 § CsL + and CsL2 + to be extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined.

Incorporating Size Selectivity into Synergistic Solvent Extraction: A Review of Crown Ether-Containing Systems

“…The cobalt(III) bis(nido-1,2-C 2 B 9 H 11 ) complex, commonly known as cobalt(III) bis(dicarbollide) or ambiguously as cobalt dicarbollide (Figure 1), has received the greatest attention. Cobalt(III) bis-(dicarbollide) has been combined primarily with 15C5, 18C6, or DB18C6 in nitrobenzene for the extraction of alkali or alkaline-earth cations, [163][164][165][166][167][168][169][170][171][172]178 lead(II), 173,174 and f elements. 118,175-177 A number of these papers are quite similar and report synergistic extraction constants, most of which are derived solely from crown ether extractant dependencies using computational methods.…”

“…A variety of inorganic anions ranging in size and complexity have been studied as alternatives to the use of carbon-based organophilic acids. Various organoantimonic acids, SbCl 6 - , , poly(oxometalates), − and cobalt(III) bis(dicarbollide) ,− have been combined with crown ethers in order to synergize cation extraction.…”

“…The cobalt(III) bis( nido -1,2-C 2 B 9 H 11 ) complex, commonly known as cobalt(III) bis(dicarbollide) or ambiguously as cobalt dicarbollide (Figure ), has received the greatest attention. Cobalt(III) bis(dicarbollide) has been combined primarily with 15C5, 18C6, or DB18C6 in nitrobenzene for the extraction of alkali or alkaline-earth cations, − , lead(II), , and f elements. ,− A number of these papers are quite similar and report synergistic extraction constants, most of which are derived solely from crown ether extractant dependencies using computational methods. These equilibrium constants should be closely examined prior to use, because the species used in their calculation are, in some cases, experimentally unfounded or their existence is chemically suspect.…”