The syntheses and Ag+-selective electrode properties of benzothiazolylthiaalkoxy functionalized calix[4]arenes: an investigation of the structure–selectivity relationship in the ionophore-based ISEs

A series of benzothiazolylthiaalkoxy functionalized calix[4]arenes with different tether length between the benzothiazolyl and calix[4]aryl groups have been synthesized and characterized for comparison between the coordinate adjustment behaviors of the two benzothiazolyl groups in the generation of ion-selective electrodes (ISEs). ISEs based on these calix[4]arenes showed excellent Ag+ selectivities, log KAg,Mpot≤−4.0, against most of the interfering cations examined, except for Hg2+ having a very weak interference (log KAg,Mpot≤−2.5). Their plausible recognition mechanism as well as their structure–selectivity relationships are also discussed.