Aldehyde-Tagged Zirconium Metal-Organic Frameworks: a Versatile Platform for Postsynthetic Modification

Area of Science:

• Materials Chemistry
• Organic Chemistry
• Catalysis

Background:

• Metal-organic frameworks (MOFs) offer tunable porous structures for diverse applications.
• UiO-67-type MOFs are a subclass with potential for post-synthetic functionalization.
• Aldehyde tags provide reactive sites for introducing new functionalities.

Purpose of the Study:

• To synthesize aldehyde-tagged UiO-67-type MOFs.
• To explore postsynthetic modification (PSM) strategies for functionalizing these MOFs.
• To evaluate the catalytic performance of a functionalized MOF in the Knoevenagel condensation.

Main Methods:

• Solvothermal synthesis and postsynthetic ligand exchange were used to create aldehyde-tagged UiO-67.
• C-N and C-C coupling reactions were employed for postsynthetic modification of the aldehyde tag.
• Tandem PSM was demonstrated to introduce multiple functionalities.
• The amino-functionalized MOF was tested as a heterogeneous catalyst for Knoevenagel condensation.

Main Results:

• Aldehyde-tagged UiO-67-type MOFs were successfully synthesized.
• Various functionalities were introduced via PSM, including tandem modifications.
• An amino-functionalized MOF catalyst demonstrated high efficiency, heterogeneity, and recyclability.
• The catalyst was effective for the Knoevenagel condensation reaction.

Conclusions:

• Postsynthetic modification of aldehyde-tagged UiO-67 MOFs is a viable strategy for introducing diverse functionalities.
• The amino-functionalized MOF serves as an efficient, recyclable heterogeneous catalyst for Knoevenagel condensation.
• This work expands the utility of MOFs through tailored functionalization for catalytic applications.