Solvent Templating and Structural Dynamics of Fluorinated 2D Cu-Carboxylate MOFs Derived from the...

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Layered 2D metal-organic frameworks (MOFs) offer enhanced flexibility and tunability compared to traditional 3D MOFs.
• Developing responsive functional materials requires precise control over MOF self-assembly and layer stacking.
• Significant synthetic challenges exist in simultaneously controlling molecular building block assembly and ordered MOF layer stacking.

Purpose of the Study:

• To achieve controlled formation of 2D MOFs with tunable stacking modes and distances.
• To investigate the structural dynamics and solvent-exchange-triggered transformations of these 2D MOFs.
• To explore the gas adsorption properties, specifically N2 adsorption, and the influence of crystal size.

Main Methods:

• Solvent-templated growth of 2D Cu(II)-carboxylate MOFs using a diffusion-controlled deposition approach.
• Utilizing various solvent mixtures to influence MOF formation and layer stacking.
• Employing solvent exchange to trigger structural dynamics and postsynthetic transformations.
• Investigating gas adsorption properties, including N2 adsorption capacity, on model 2D MOF systems.

Main Results:

• Successfully synthesized a series of 2D Cu(II)-carboxylate MOFs with controlled stacking modes and distances.
• Demonstrated in-plane and out-of-plane structural dynamics in the 2D MOFs upon solvent exchange.
• Achieved selective postsynthetic transformations between different 2D MOF structures.
• Observed a significant crystal size effect on the N2 adsorption capacity in a model 2D MOF system.

Conclusions:

• Controlled synthesis of 2D MOFs with tunable structural features is achievable through diffusion-controlled deposition.
• The dynamic structural behavior of these 2D MOFs enables selective postsynthetic modifications.
• Crystal size plays a crucial role in determining the gas adsorption performance of 2D MOFs.