Measuring and Modulating Substrate Confinement during Nitrogen-Atom Transfer in a Ru₂-Based Metal-Organic Framework.

Area of Science:

• Materials Science
• Catalysis
• Physical Chemistry

Background:

• Metal-organic frameworks (MOFs) offer tunable porosity for heterogeneous catalysis.
• Understanding substrate mobility within MOFs is crucial for designing efficient catalysts.
• Experimental data on substrate confinement in MOFs are scarce.

Purpose of the Study:

• To investigate substrate mobility and confinement in MOFs using kinetic isotope effect (KIE) analysis.
• To explore the role of mesoporosity in substrate confinement within MOFs.
• To provide evidence for quantum tunneling in MOF-mediated reactions.

Main Methods:

• Utilized kinetic isotope effect (KIE) analysis to probe substrate mobility.
• Synthesized and characterized a microporous Ru2-based MOF.
• Investigated C-H amination reactions within the MOF structure.

Main Results:

• Demonstrated that KIE analysis can quantify substrate confinement based on MOF mesoporosity.
• Provided evidence suggesting quantum tunneling occurs during interstitial C-H amination within a Ru2-based MOF.
• Established a link between MOF structure, substrate mobility, and reaction mechanisms.

Conclusions:

• KIE analysis is a powerful tool for evaluating substrate confinement in porous materials.
• Substrate confinement in MOFs can lead to quantum tunneling effects in catalytic processes.
• This study presents a novel experimental approach to study substrate dynamics in heterogeneous catalysts.