Highly luminescent olefin-linked covalent organic frameworks

Area of Science:

• Materials Science
• Organic Chemistry
• Supramolecular Chemistry

Background:

• Covalent organic frameworks (COFs) are crystalline porous polymers with tunable properties.
• Enhancing the photoluminescence quantum yield (PLQY) of COFs is crucial for optical applications.
• Developing novel COF structures with efficient light-emission characteristics remains an active research area.

Purpose of the Study:

• To synthesize a new olefin-linked covalent organic framework (COF) with high fluorescence quantum yield.
• To investigate the relationship between structural ordering, conjugation, and optical properties in the developed COF.
• To establish a new benchmark for fluorescence quantum yield in COF materials.

Main Methods:

• Synthesis of an olefin-linked COF using 1,3,5-triformylbenzene (TFB) and tetraethyl p-xylylenediphosphonate (TEXDP).
• Utilized the Horner-Wadsworth-Emmons reaction for framework construction.
• Characterization of the COF's structure, aromatic ordering, and conjugation.

Main Results:

• Successfully synthesized the TFB-TEXDP-COF material.
• The resulting COF exhibited significant aromatic columnar ordering and high conjugation.
• Achieved a record fluorescence quantum yield of up to 41% among COFs.

Conclusions:

• The developed olefin-linked COF demonstrates exceptional fluorescence properties.
• The combination of aromatic ordering and high conjugation is key to achieving high quantum yields.
• This work sets a new standard for luminescent COFs and opens avenues for advanced optical materials.