Liquid membrane transport and silver selective electrode based on novel bis(3-pyridinecarboxylate) calix[4]arene as ionophore

A novel calix[4]arene derivative (5,11,17,23-tetra-tert-butyl-25,27-bis(3-p yridinecarboxylate)-26,28-dihydroxy-calix[4]arene) (1), bearing two nicotin ic moieties, has been synthesized by a convenient method in 40% yield. The liquid membrane transport and the silver selective electrode based on calix [4]arene derivative (1) show excellent cation selectivities for Ag+ and Hg2 + over other alkali and alkaline earth, transition metal ions, and ammonium ion. The higher cation selectivity is mainly attributed to that the host-g uest interaction which occurs between the cations and the derivative calix[ 4]arene (1) is determined by the functional groups which act as binding sit es. (C) 2000 Elsevier Science B.V. All rights reserved.