Novel bis(phenylselenoalkoxy)calix[4]arene molecular tweezer receptors as sensors for ion-selective electrodes

Abstract

Four tweezer-like 25,27-dihydroxy-26,28-bis(phenylselenoalkoxy)-5,11,17,23-tetra-tert-butylcalix[4]arenes 5–8 were synthesized for the evaluation of their ion-selectivity in ion-selective electrodes (ISEs). For investigation of the influences of the coordinate atoms on the ion-selectivity, 25,27-dihydroxy-26,28-bis(alkylthiaalkoxy)-5,11,17,23-tetra-tert-butylcalix[4]arenes 9–11 were also prepared and characterized. On the other hand, 1,3-bis(phenylseleno)propane 12 was synthesized for comparison of the influences of coordinate patterns of different ionophores on the ion-selectivity of ISEs. ISEs based on 5–12 as neutral ionophores were prepared, and their selectivity coefficients for Ag⁺ (log K^pot_Ag,M) were investigated against alkali metal, alkaline-earth metal, lead, and ammonium ions and some transition metal ions using the fixed interference method (FIM). These ISEs showed excellent Ag⁺ selectivity over most of the interfering cations examined, except for Hg²⁺, which had relatively smaller interference (log K^pot_Ag,Hg ≤ −1.6).