Post-synthetic ion-exchange process in nanoporous metal-organic frameworks; an effective way for modulating their structures and properties

In recent years, MOFs have amused fundamental attention because of their unique properties and their applications in gas sorption, catalysis, separation, drug delivery and synthesis of nano materials. Up to now, two bunches of exchange that occurred in metal nodes and secondary building units (SBUs) of MOFs have been studied. In the first group, M. Lalonde and co-workers, have reported metal exchange involving metal nodes in MOFs have been reported.1 Their discussion focused on the system where metal cations were exchanged directly in the node. C. K. Brozek and co-workers, in the other group, has checked the cation exchange at MOF’s SBUs.2 They also ambient their discussion to substitution that just occurs at SBUs and not in the pores. In addition, both of them studied the cation exchange, whiles the ion exchange that occurs at MOFs doesn’t confine to cation exchange. Ion-exchange is one of the interesting properties of anionic or cationic MOFs which do not have neutral frameworks. We want to outline the available observations of all types of ion exchange at MOFs pores. When the factors that make ions in the pores exchangeable are explaining, particular materials could be selected for ion-exchange including cation exchange anion exchange, and their exact compounds could be designed. In this section, we classified two branches of ion-exchange on their examples and reported cases and their applications. Anion-exchange For MOFs that have cationic coordination frameworks, the anions are generally included for charge balance and/or serving as templates in the available empty spaces. As a result, anion-exchange properties for such MOFs materials have been extensively foraged. Cation-exchange Sometimes the exchange of metal ions or organic cations within anionic MOFs can modulate the chemical properties of a MOF and this could be achieved simply by merging the sample into a solution containing certain metal salt or organic cations to generate a turned anionic MOF. Ion exchange has already yielded some amazing results and new materials that have not been accessible otherwise, but the limit of its usage for architecting new MOFs in a systematic predictive manner depends on understanding its mechanism. We contemplated to provide a blueprint towards this goal.