Molecular Design of Calixarene-Based Sodium-Selective Electrodes Which Show Remarkably High 105.0 - 105.3 Sodium/Potassium Selectivity

Article abstract of DOI:10.1246/cl.1994.1115

Several ionophores for the Na⁺-selective electrode were developed from calix<4>arene crown ethers with a short -(CH2CH2O)2CH2CH2- crown loop on the lower rim.The ionophoric cavities generated in these ionophores are much smaller and more rigid than those derived from calix<4>arene crown ethers with a long -(CH2CH2O)3CH2CH2- crown loop.It was shown that two electrodes possess Na⁺ selectivity (with respect to K⁺) exceeding a factor of 10⁵ which is higher by more than two orders of magnitude than that of the former calix<4>arene-based Na⁺-selective electrodes!