This invention concerns ionic perfluorovinyl compounds, the polymers obtained from these compounds and their applications. The compounds comprise at least one perfluorovinyl group and at least one group chosen from -O or one of the groups -NC=N, -C(C=N)2, -NSO2R or -C[SO2R]2 or a pentacyclic group comprising at least one N, C-C=N, CR, CCOR or CSO2R group. The compounds and/or their polymers are of use in the preparation of ionically conducting materials, electrolytes and selective membranes.