The solvent extraction of alkali metal picrates with 4,13-N,N?-dibenzyl-4,13-diaza-18-crown-6
[ X ]
Tarih
1998
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Extraction of alkali metal picrates with N,N'-dibenzyl-18-crown-6 was carried out, with dichloromethane as water-immiscible solvent, as a function [ligand]/[metal cation]. The extractability of metal picrates (Li+, Na+, K+ Rb+, Cs+) was evaluated as a function of [L]/[M+]. The extractability of complex cation-picrate ion pairs decreases in this sequence: Li+ > Rb+ > Cs+ > K+ > Na+. The overall extraction equilibrium constants (K-ex) for complexes of N,N'-dibenzyl-18-crown-6 with alkali metal picrates between dichloromethane and water have been determined at 25 degrees C. The values of the extraction constants (log K-ex) were determined to be 10.05, 6.83, 7.12, 7.83, 6.73 for Li+ Na+, K+, Rb+ and Cs+ compounds, respectively. DB186 shows almost 2-fold extractability against Li+ compared to the other metal picrates, whereas it shows no obvious extractability difference amongst the other metal cations when [L]/[M+] is 0.2-1. However, an increasing extractability is observed for Cs+ when [L]/[M+] [1]. (C) 1998 Elsevier Science B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Diaza-Crown Ether, Solvent Extraction, Alkali Metal Picrate
Kaynak
Talanta
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
47
Sayı
1
