Synthesizing New Hybrid Zeolitic Imidazolate Frameworks by Controlled Demolition and Reconstruction

Abstract

A synthesis method to obtain new zeolite imidazolate framework (ZIF) materials that are otherwise difficult to synthesize by known techniques such as direct crystallization or solvent-assisted linker exchange, is demonstrated. Treatment of an easily synthesized “template” ZIF (such as ZIF-8) with an acid gas (humid SO2) allows controlled demolition of metal-linker coordination bonds, while preserving overall crystal topology. The partially demolished crystals are then reconstructed into highly crystalline mixed-linker ZIFs with unique characteristics by insertion of different linkers that displace the damaged linkers. One illustration shows the synthesis of a series of mixed-linker ZIFs containing benzimidazole linkers that show entirely different gate-opening and diffusion characteristics from ZIFs of the same composition prepared by direct crystallization. Also shown is the synthesis of new mixed-linker SOD-topology ZIFs containing bulky halobenzimidazole and alkylbenzimidazole linkers, which are very d...