Ln2(OH)5NO3•xH2O (Ln = Y, Gd-Lu):: A novel family of anion exchange intercalation hosts

A class of anion exchangeable layered hydroxides incorporating the smaller lanthanides within the layers has been synthesized via a hydrothermal route. These materials have the composition Ln(2)(OH)(5)NO3 center dot xH(2)O (Ln = Y, Gd-Lu; x approximate to 1.5) and the potential to combine the properties of the lanthanides with the flexibility of intercalation hosts. Powder XRD data suggest that the crystallinity of the Gd phase is lower than that of the other materials, and reactions with the larger lanthanides lead to the formation of other phases, indicating a limiting cationic radius for these materials. The anion exchange capacity of these materials has been shown by facile reactions with a range of organic carboxylate and sulfonate anions, leading to the complete replacement of the nitrate anion.