Ammonium Ion Binding Property of Naphtho-Crown Ethers Containing Thiazole as Sub-Cyclic Unit

摘要

A short and efficient synthesis,solvent extraction and potentiometric measurements of new thiazole-containing naphtho-crown ethers are reported.The naphthalene moiety enhances the ammonium ion selectivity over potassium ion.The selectivity of NH_4~+/K~+ follows the trend 3 approx=2 > 1,indicating that the differences in conformational changes of 2 and 3 in forming ammonium complexes affect little on the resulting ammonium/ potassium extraction selectivity ratio.The ammonium ion-selective electrodes were prepared with n-octylphenyl ether plasticized poly(vinyl chloride)membranes containing 1-4;the effect of one naphthalene unit introduced on either right(2)or left(3)side of thiazolo-crown ether on their potentiometric properties(e.g.,ammonium ion selectivity over other cations,response slopes,and detection limits)were not apparent.However,the ammonium ion selectivity of 1,2 and 3 over other alkali metal and alkaline earth metal cations is 10-100 times higher than that of nonactin.