Abstract

Analytical equations were derived for the extraction of univalent metal salts (MA) by crown ethers (L) into polar
diluents. Then, NaMnO4 was extracted at 25 ?C by benzo-15-crown-5 and -18-crown-6 ethers (B15C5 and B18C6)
from a water (w)-phase into a 1,2-dichloroethane (DCE)-one. So, the extraction constants of Kex1 and Kex2 were
determined, where Kex1 = [NaLMnO4]DCE/[Na+][L]DCE[MnO4
?] and Kex2 = [NaL+]DCE[MnO4
?]DCE/[Na+][L]DCE[MnO4
?]
(= Kex1/KNaLMnO4
DCE). From the calculation processes of these Kex values, KD,MnO4 and KMLA
DCE values with MLA =
NaLMnO4 were obtained and also KNaL
DCE values were estimated from the thermodynamic cycle of KML
DCE =
Kex2/KD,MKD,A. Here, the KMLA
DCE, KD,A or KD,M, and KML
DCE values denote an ion-pair formation constant of MLA in
the DCE-phase, a distribution constant of A? or M+ between the w- and DCE-phases, and a complex formation one
of a complex ion ML+ in the DCE-phase, respectively. The same values were obtained for the w/nitrobenzene (NB)
extraction systems. By comparing the KNaL
org and KD,NaL (= [NaL+]NB/[NaL+]: distribution constant into NB) values
with those previously-reported by other methods, the validity of the equations was confirmed. Additionally,
extraction-abilities of the extraction systems with DCE and NB were examined, using component equilibrium
constants reported before.

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