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Novel Cesium‐Selective Electrodes Based on Lipophilic 1,3‐Bisbridged Cofacial‐calix[6]crowns
Author(s) -
Jeon Seungwon,
Yeo Heekyoung,
Lee Hyo Kyoung,
Ko Seung Whan,
Nam Kye Chun
Publication year - 2004
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200402847
Subject(s) - ionophore , caesium , crown ether , selectivity , chemistry , membrane , ether , calixarene , ion , electrode , nuclear chemistry , inorganic chemistry , analytical chemistry (journal) , crystallography , chromatography , molecule , organic chemistry , catalysis , biochemistry
Five bisbridged calix[6]crowns have been investigated as Cs + ionophore in PVC membrane electrodes. As ionophores, three 1,3‐bisbridged calix[6]crown‐4‐ethers( I–III ), 1,3‐bisbridged calix[6]crown‐5‐ether( IV ), and 1,3‐bisbridged calix[6]crown‐6‐ether( V ) have been evaluated. The membranes all give good Nernstian response in the concentration range from 1×10 −7 to 1×10 −1 M of cesium ion. The best detection limits (−log a Cs +=7.08–7.36) are obtained for electrode membranes containing 1,3‐bisbridged cofacial‐calix[6]crown‐4‐ethers( I‐III ), and the values are the lowest compared with those reported previously. The highest selectivity coefficients [ $\rm{ {\rm p}K_{{\rm Cs}^ + ,{\rm j}}^{{\rm pot}} = 5.53({\rm Cs/Na}),}$ 3.74(Cs/K), 2.63(Cs/Rb)] are obtained for the membrane of 1,3‐bisbridged calix[6]crown‐4‐ether( II ), and these values are also the highest compared with previous reports for Cs + ‐ISEs. The highest selectivity towards cesium ion is attributed to the geometrically cofacial positions of two crown‐ethers in calix[6]crowns in order to provide the complex of cesium ion and eight oxygens of cofacial crowns.