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Updated: Jun 24, 2025
06:44
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
69.0K
Optical Property Control by the Interligand Charge Transfer Excited State in Brominated Homoleptic and Heteroleptic
Yuto Konishi1, Takumi Ehara2, Luxia Cui1
1Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Inorganic Chemistry
|June 11, 2024
Summary
Researchers developed novel aluminum complexes with tunable photofunctionality. Bromination degree controlled emission color, enabling new applications for advanced functional materials.
Area of Science:
- Materials Science
- Coordination Chemistry
- Photochemistry
Background:
- Aluminum complexes offer potential for novel functional materials due to abundance and low cost.
- Controlling photofunctionality in aluminum-based complexes remains an underexplored area.
- Previous work established dinuclear triple-stranded helicates incorporating two aluminum ions (ALPHY).
Purpose of the Study:
- To synthesize and characterize novel homoleptic and heteroleptic aluminum complexes.
- To investigate the impact of bromination on the photophysical properties of these complexes.
- To elucidate the mechanisms governing their optical behavior.
Main Methods:
- Synthesis of homoleptic and heteroleptic complexes using brominated Schiff base ligands and AlCl3.
- Single-crystal X-ray structural analysis to determine complex structures.
- Optical spectroscopy (emission, circular dichroism) and ultrafast spectroscopy.
Main Results:
- Novel homoleptic and heteroleptic aluminum complexes were successfully synthesized and structurally characterized.
- Increasing bromination degree tuned emission color from yellow (550 nm) to orange (566 nm).
- Optical resolution revealed mirror-image circular dichroism and circularly polarized luminescence.
- Ultrafast spectroscopy identified interligand charge transfer (ILCT) as the key mechanism for optical properties.
Conclusions:
- The degree of bromination offers a viable strategy for tuning the photofunctionality of aluminum complexes.
- Heteroleptic complexes facilitate ILCT in nonpolar environments, influencing decay pathways.
- These findings represent significant progress in developing advanced photofunctional multinuclear aluminum-based materials.
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