Anion Exchange of the Cationic Layered Material [Pb₂F₂]²⁺

We demonstrate the complete exchange of the interlamellar anions of a 2-D cationic inorganic material. The α,ω-alkanedisulfonates were exchanged for α,ω-alkanedicarboxylates, leading to two new cationic materials with the same [Pb₂F₂]²⁺ layered architecture. Both were solved by single crystal X-ray diffraction and the transformation also followed by in situ optical microscopy and ex situ powder X-ray diffraction. This report represents a rare example of metal–organic framework displaying highly efficient and complete replacement of its anionic organic linker while retaining the original extended inorganic layer. It also opens up further possibilities for introducing other anions or abatement of problematic anions such as pharmaceuticals and their metabolites.