Construction and function of a highly efficient supramolecular luminescent system.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Photophysics

Background:

• Aggregation-induced emission (AIE) is a key phenomenon for developing efficient luminescent materials.
• Supramolecular co-crystals offer tunable properties through controlled molecular assembly.

Purpose of the Study:

• To investigate the self-assembly, crystal structure, and photophysical properties of two polymorphs (C1 and C2) of a supramolecular co-crystal.
• To correlate crystal packing and intermolecular interactions with luminescence and mechanochromic behavior.

Main Methods:

• Single-crystal X-ray diffraction to determine molecular stacking and crystal structures.
• Photophysical measurements (emission spectra, quantum yield) to characterize luminescence.
• Mechanical stimuli application to assess mechanochromic response.

Main Results:

• Two polymorphs, C1 (block-like) and C2 (needle-like), were identified.
• Crystal C1, with strong π-π interactions, showed weak green emission (2% efficiency).
• Crystal C2 exhibited bright yellow emission, and C1 demonstrated mechanochromic behavior.

Conclusions:

• The crystal packing and intermolecular interactions significantly influence the photophysical properties of AIE materials.
• Polymorphism in supramolecular co-crystals can lead to distinct luminescence characteristics and functional properties like mechanochromism.