Synthesis and characterization of isostructural cadmium zeolitic imidazolate frameworks via solvent-assisted linker exchange

Abstract

Herein, we present the first examples of solvent-assisted linker exchange (SALE) in zeolitic imidazolate frameworks (ZIFs). By exposing the ZIF CdIF-4 to excess solutions of 2-nitroimidazole and 2-methylimidazole under solvothermal conditions, we were able to obtain a previously reported ZIF CdIF-9 in high yield, as well as synthesize a new ZIF, Solvent-Assisted Linker-Exchanged Material-1 (SALEM-1). The parent and daughter ZIFs are isostructural (RHO zeolitic topology) and highly porous. Despite the high thermal and chemical stability of ZIFs, single crystal-to-single crystal linker exchange appears to be a suitable tool for the modification and functionalization of these materials. We anticipate that the addition of SALE to the arsenal of known synthetic techniques for ZIFs will significantly facilitate the quest to obtain interesting and useful ZIF compounds, including compounds that cannot be synthesized directly.