Guest-Responsive Reversible Electron Transfer in a Crystalline Porous Framework Supported by a Dynamic Building Node.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Crystallography

Background:

• Donor-acceptor (D-A) assemblies are crucial for electronic applications.
• Controlling electron transfer (ET) in solid-state materials remains a significant challenge.
• Metal-organic frameworks (MOFs) offer tunable porous structures for advanced functionalities.

Purpose of the Study:

• To demonstrate a reversible, switchable electron transfer process in a crystalline D-A assembly.
• To investigate the role of guest-responsive structural transformations in controlling electronic properties.
• To engineer a porous MOF with switchable redox activity.

Main Methods:

• Synthesis of a porous metal-organic framework (MOF) with anthracene (donor) and naphthalenediimide (acceptor) struts.
• Solvent-assisted linker exchange (SALE) to create a control MOF with a neutral strut.
• X-ray diffraction, spectroscopy, and theoretical analyses to characterize structural and electronic properties.

Main Results:

• A redox-active D-A MOF exhibiting reversible electron transfer (ET) was successfully synthesized.
• Guest-responsive structural transformation at room temperature was shown to reversibly switch the ET process.
• A control MOF confirmed the necessity of the D-A configuration for switchable electronic states.
• Dynamic metal paddle-wheel nodes were identified as key to structural flexibility and ET control.

Conclusions:

• Demonstrated a novel MOF-based system for switchable electron transfer.
• Highlighted the potential of dynamic MOF nodes for controlling guest-responsive electronic functions.
• Opened new avenues for designing smart materials with tunable electronic properties.