Tunable Fluorescence in Two-Component Hydrogen-Bonded Organic Frameworks Based on Energy Transfer

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Fluorescent Materials

Background:

• Hydrogen-bonded organic frameworks (HOFs) are crystalline materials formed through non-covalent interactions.
• Developing functional HOFs with tunable properties is crucial for advanced applications.
• Energy transfer mechanisms in porous organic materials are of significant interest.

Purpose of the Study:

• To construct two-component HOFs (TC-HOFs) using molecules with identical molecular skeletons.
• To investigate the energy transfer processes within these TC-HOFs.
• To demonstrate the ability to continuously modulate the fluorescence properties of TC-HOFs.

Main Methods:

• Synthesis of a dumbbell-shaped HOF-forming molecule (TPAD) with cyan fluorescence.
• Incorporation of an energy acceptor molecule (BTAD) with a similar skeleton into the TPAD framework.
• Characterization of the resulting TC-HOFs and analysis of their photophysical properties.

Main Results:

• Formation of stable TC-HOFs with homogeneous distribution of the acceptor within the donor framework.
• Observation of efficient nonradiative energy transfer from TPAD (donor) to BTAD (acceptor).
• Continuous modulation of fluorescence color from cyan to orange by varying the BTAD content.

Conclusions:

• TC-HOFs with continuously adjustable composition can be successfully constructed from molecules sharing the same molecular skeleton.
• Efficient nonradiative energy transfer occurs within these porous TC-HOFs.
• This work presents the first example of TC-HOFs exhibiting energy transfer, opening new avenues for designing responsive porous materials.