B. Ziyadanogullari et al., Effect of structural modifications of diaza-18-crown-6 on the extractability and selectivity of univalent metal picrates, TALANTA, 53(5), 2001, pp. 1083-1087
The solvent extraction of univalent metal cations with N,N'-dibenzyl-1,4,10
,13-tetraoxa-7,16 diaza-2,3,11,12-dibenzocycloocta deca-2,11-diene (L-1), N
,N'-didodecyl-1,4,10,13-tetraoxa-7,16-diaza-2,3-benzocylooctadeca-2-ene (L-
2) and N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16-diaza-2,3,11,12-dibenzocyclo o
ctadeca-2,11-diene (L-3) with picrate anion into dichloromethane has been s
tudied at 25 degreesC by UV-visible spectroscopy. The extractability and se
lectivity of univalent metal picrates (Li+, Na+, Ag+, PhCH2NH3+, NH4+) was
evaluated as a function of [ligand]/[metal cation]. L-2 showed the highest
extractability and selectivity for Lit over the larger studied cations, and
also exhibited the highest [Li+]/[NH4+] selectivity as L/M = 1. (C) 2001 E
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