Two new cyclic pentacoordinative organotin(IV) complexes, 2,4-dihydroxyacetophenone tribenzyltin(HAPTBT) and 2,4-dihydroxyacetophenone triphenyltin(HAPTPT) were synthesized and used as anion ionophore for PVC membrane electrode. The new electrodes exhibit specificity selectivity for salicylate. The electrode based on HAPTBT as a neutral carrier displays a highly potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal- > SCN- > I- > NO2- > Br- > Cl- > ClO4- > NO3- > SO42-. The electrode has the advantages of fast response, stability and reproducibility, simplicity. The response mechanism is discussed in view of UV spectroscopy technique. The results show that there are close relationship between the potentiometric response characteristics and structure of organotin(IV) complexes. The electrode was applied to medicine analysis with satisfactory results.
A novel heterocyclic haxacoordinated organotin(Ⅳ) complex, bis (?-vanillin)-semi-ethylenediamine dibenzyltin (VEDBT) was synthesized and used as anion ionophore for PVC membrane electrode; the novel electrode exhibits a linear response towards salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions, the selective pattern is: Sal-> SCN-> ClO4-> I-> NO2-> NO3-> Cl-≈ Br-> SO42-. The behaviour of the electrode is influenced by the experimental conditions. The response mechanism was also investigated by UV spectroscopy. The electrode was applied to the determination of salicylate in pharmaceutical samples with satisfactory results.
