Multi-Emission from Single Metal-Organic Frameworks under Single Excitation

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Multi-emission materials are gaining prominence for applications beyond single-emission counterparts.
• Robust design strategies for single-matrix, multi-emission systems under single excitation are critically needed.
• Metal-organic frameworks (MOFs) present a promising platform due to their tunable structures and porosity.

Purpose of the Study:

• To review and classify multi-emission MOFs based on excitation sites.
• To discuss emission mechanisms, including antenna effect, excited-state intramolecular proton transfer (ESIPT), and tautomerism.
• To explore factors influencing emissions, such as ligand-metal energy transfer and host-guest interactions.

Main Methods:

• Summarization and classification of existing literature on multi-emission MOFs.
• Analysis of emission mechanisms and influencing factors.
• Review of design strategies and applications.

Main Results:

• Multi-emission MOFs can be rationally designed and prepared by controlling emissive factors and mechanisms.
• Guest species within MOF pores contribute to multi-emission properties.
• Key emission mechanisms include antenna effect, ESIPT, and tautomerism.

Conclusions:

• Predictable design and preparation of multi-emission MOFs are achievable through rational control of emissive factors and mechanisms.
• Multi-emission MOFs enable advanced applications like ratiometric sensing, bioimaging, white LEDs, and anti-counterfeiting.
• This review provides insights for developing other multi-emission systems with structure-derived functionalities.