Oxovanadium(IV) heteromacrocyclic complexes as ionophores for iodide-selective electrodes

Highly selective poly(vinyl chloride) (PVC) membrane electrodes, based on oxovanadium(IV) complexes of heteromacrocyclic compounds as new iodide-selective ionophores for ion-selective electrodes (ISEs), were fabricated with a composition of PVC (28.1 wt%), plasticizers (69.3 wt%), ionophores (2.6 wt%), and cation excluders (15 mol% relative to the ionophore). The electrode prepared from oxovanadium(IV) tetraphenyl porphyrin with 2-nitrophenyl octyl ether (o-NPOE) as the membrane solvent and tetradodecylammonium chloride (TDDACl) as the cation excluder was found to exhibit the best sensitivity over a wide concentration range from 5.0 x 10-7 to 2.1 x 10-2 M with a Nernstian response of -59.02 mV per decade and the highest ion-selectivity toward I- ions over perchlorate ions (I-/ClO4- = 91). Graphical Abstract Heteromacrocyclic complexes of vanadium(IV) oxide were developed as ionophores for ionselective electrodes (ISEs). The ISE based on oxovanadium(IV) tetraphenyl porphyrin using o-NPOE as the membrane solvent and TDDACl as the cation excluders was found to exhibit the best sensitivity toward the I- ions over a wide concentration range with a Nernstian response and the highest ion-selectivity toward the I- ions over perchlorate ions.