The synthesis of a novel kind of bipolar ion exchangers with a well-defined structure based on functional acidic 5-thio-2H-tetrazolium groups is described. A macroporous resin with ortho-carboxylic acid groups (m-T1), a gel-type resin with ortho-sulfonic acid substituted tetrazolium groups (g-T4) and surface modified fibres with ortho-, meta- para-carboxyl-substituted tetrazolium cations (f-T1, f-T2 and f-T3) were prepared. Immobilisation of appropriate acidic dithizone derivatives onto the different chloromethylated polymeric supports and subsequent oxidation yielded the heterocyclic functionalities. The proposed structure was confirmed by synthesis of free model compounds and comparative IR-spectroscopic investigations. Theoretical calculations of conformation ant charge distribution were carried out by molecular modeling. The theoretical capacities of the resins calculated from acid-base titrations are distinctly lower than the data obtained from elementary analysis. The results of sorption experiments with electrolytes and conductivity measurements do not confirm the expectation of a simultaneous sorption of cations and anions similar to snake-cage polymers. These facts can be explained by the formation of an inner salt structure of the functional groups comparable with free betaines in aqueous solution. As a consequence, weak adsorptive dipole-induced-dipole interactions result in a specific uptake of Au(III) species from dilute hydrochloric acid media.