Insights into Functionalization of Metal-Organic Frameworks Using In Situ NMR Spectroscopy.

Area of Science:

• Materials Science
• Chemistry
• Spectroscopy

Background:

• Postsynthetic reactions are crucial for creating functional metal-organic frameworks (MOFs).
• Current evaluation methods for MOF reactions are often destructive and time-consuming.
• Developing non-destructive techniques is essential for efficient MOF functionalization.

Purpose of the Study:

• To introduce and validate in situ NMR spectroscopy for monitoring MOF postsynthetic reactions.
• To demonstrate a simplified and non-destructive approach for reaction screening in MOF chemistry.
• To gain mechanistic insights into solvent-assisted ligand exchange (SALE) and postsynthetic modification (PSM) reactions.

Main Methods:

• Utilizing in situ NMR spectroscopy to observe liquid-state species during MOF reactions.
• Applying the technique to study SALE and postsynthetic modification (PSM) of zirconium MOF UiO-67.
• Examining SALE reactions with aluminum MOF DUT-5 using the developed in situ method.

Main Results:

• The in situ NMR method successfully monitored SALE and PSM reactions in real-time without sample decomposition.
• Both the incoming and outgoing ligands in SALE reactions were observable.
• The technique provided valuable insights into the reaction dynamics of MOF functionalization.

Conclusions:

• In situ NMR spectroscopy is a powerful, non-destructive tool for studying MOF postsynthetic reactions.
• This method simplifies reaction screening and offers mechanistic understanding.
• The approach is expected to be broadly applicable to various MOF-solute interactions.