Structural elucidation of microcrystalline MOFs from powder X-ray diffraction.

Area of Science:

• Materials Science
• Crystallography
• Chemistry

Background:

• Metal-organic frameworks (MOFs) are advanced materials with rapidly growing applications.
• Understanding MOF structure-function relationships is vital for technological potential.
• Single crystal X-ray diffraction (XRD) is the gold standard for MOF structure determination but often not feasible.

Purpose of the Study:

• To provide an overview of ab initio powder XRD for MOF structure solution.
• To highlight the application of direct-space strategies in challenging MOF structure elucidations.
• To demonstrate the power of powder XRD for understanding MOF chemistry.

Main Methods:

• Overview of ab initio powder X-ray diffraction (XRD) techniques.
• Application of direct-space strategies for structure solution from powder data.
• Analysis of challenging MOF structures obtained from various synthesis methods.

Main Results:

• Ab initio powder XRD is a powerful technique for MOF structure elucidation when single crystals are unobtainable.
• Direct-space strategies are effective for solving complex MOF structures from powder data.
• Successful structure solutions were achieved for MOFs synthesized via solvothermal, instant, and mechanochemical methods.

Conclusions:

• Powder XRD analysis is essential for advancing MOF chemistry, especially for microcrystalline or poorly crystalline materials.
• The direct-space strategy offers a robust approach to MOF structure solution from powder data.
• This work encourages wider adoption of powder XRD for MOF research to overcome limitations of single crystal analysis.