Exploring the Scope of Macrocyclic “Shoe-last” Templates in the Mechanochemical Synthesis of RHO Topology Zeolitic Imidazolate Frameworks (ZIFs)

The macrocyclic cavitand MeMeCH(2) is used as a template for the mechanochemical synthesis of 0.2MeMeCH(2)@RHO-Zn(16)(Cl(2)Im)(32) (0.2MeMeCH(2)@ZIF-71) and RHO-ZnBIm(2) (ZIF-11) zeolitic imidazolate frameworks (ZIFs). It is shown that MeMeCH(2) significantly accelerates the mechanochemical synthesis, providing high porosity products (BET surface areas of 1140 m(2)/g and 869 m(2)/g, respectively). Templation of RHO-topology ZIF frameworks constructed of linkers larger than benzimidazole (HBIm) was unsuccessful. It is also shown that cavitands other than MeMeCH(2)—namely MeHCH(2), MeiBuCH(2), HPhCH(2), MePhCH(2), BrPhCH(2), BrC5CH(2)—can serve as effective templates for the synthesis of x(cavitand)@RHO-ZnIm(2) products. The limitations on cavitand size and shape are explored in terms of their effectiveness as templates.