Mechanochemical Solid Form Screening of Zeolitic Imidazolate Frameworks Using Structure-Directing Liquid Additives.

Area of Science:

• Materials Science
• Chemistry
• Crystallography

Background:

• Zinc imidazolate (ZnIm2) is the simplest zeolitic imidazolate framework (ZIF) material.
• Discovering new forms of ZnIm2 is crucial for understanding metal-organic frameworks (MOFs).
• Existing synthesis methods have limitations in exploring diverse MOF structures.

Purpose of the Study:

• To systematically apply liquid-assisted grinding (LAG) for screening ZnIm2 forms.
• To explore the effect of different liquid additives on ZnIm2 synthesis.
• To discover novel topological and crystallographically distinct forms of ZnIm2.

Main Methods:

• Systematic screening of 45 liquid additives using mechanochemical liquid-assisted grinding (LAG).
• Computational exploration using dispersion-corrected periodic density functional theory (DFT) calculations.
• Characterization of synthesized ZnIm2 forms, including crystallographic analysis.

Main Results:

• Identified eight different ZnIm2 topological forms, including two new forms of the crb (BCT) topology.
• Synthesized 13 crystallographically distinct solid forms, amorphous phases, and an interrupted moc-Zn4Im8HIm.
• LAG accelerated synthesis and directed the formation of topologically different MOFs.

Conclusions:

• LAG is a powerful mechanochemical tool for discovering novel metal-organic materials.
• Liquid additives can significantly influence and direct MOF synthesis.
• This study demonstrates the potential of LAG for predicting additive-directed MOF synthesis.