Synthesis of ZIF‐8 and ZIF‐67 by Steam‐Assisted Conversion and an Investigation of Their Tribological Behaviors

Water difference: Using H2O as the reaction medium in a conventional hydrothermal synthesis gives two nonporous materials with dense dia frameworks, dia(Zn) and dia(Co), from 2-methylimidazole and M(OAc)2 (M=Zn, Co; see structures, left). However, separation of the H2O and a solid mixture of the same starting materials in a steam-assisted conversion gives open-framework porous materials, ZIF-8 and ZIF-67 (right).