A new family of rare-earth polymeric framework RPF-4 has been obtained and its structure solved from an intrinsically triple twinned crystal. The framework formed by a H-O bond free rare-earth matrix, with the Ln atoms separated in two directions, makes them very promising materials for light-emitting diodes. The properties of the materials as heterogeneous catalysts are reported, too. IR spectroscopy suggests the presence of a peroxo complex that acts as active species in the oxidation reaction.