Enhanced Long Persistent Luminescence by Multifold Interpenetration in Metal-Organic Frameworks

Area of Science:

• Materials Science
• Chemistry
• Solid-State Physics

Background:

• Metal-organic frameworks (MOFs) are investigated for long persistent luminescence (LPL) applications.
• Large pore sizes in conventional MOFs limit efficient intermolecular interactions crucial for LPL.
• Developing MOFs with enhanced LPL properties is an active research area.

Purpose of the Study:

• To explore a novel strategy for achieving LPL in MOFs using multifold interpenetration.
• To investigate the correlation between framework interpenetration multiplicity and LPL performance.
• To understand the influence of structural density on luminescence properties.

Main Methods:

• Synthesis of MOFs with varying degrees of framework interpenetration (twofold and threefold).
• Characterization of the synthesized MOFs' crystal structures and porosity.
• Measurement and comparison of the long persistent luminescence properties of different MOF structures.

Main Results:

• Multifold interpenetration, particularly threefold interpenetration, leads to denser MOF frameworks.
• Increased framework density enhances both inter- and intramolecular interactions.
• MOFs with threefold interpenetration exhibit significantly enhanced LPL compared to twofold interpenetration.
• Metal-cluster and heavy-halogen effects were observed to modulate LPL duration and color.

Conclusions:

• Multifold interpenetration is an effective strategy to boost LPL in MOFs.
• Higher interpenetration multiplicity results in improved LPL due to enhanced interactions.
• Structural control in MOFs offers a pathway to tune luminescence for advanced applications.