Li

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Development of novel fluorescent materials for advanced applications.
• Understanding the role of metal-ion coordination in self-assembly and optical properties.
• Exploration of stimuli-responsive gels for smart material design.

Purpose of the Study:

• To synthesize a novel fluorescent metallogel from non-fluorescent precursors.
• To investigate the influence of alkali metal ion size on gelation and morphology.
• To characterize the stimuli-responsive behavior and formation mechanism of the metallogel.

Main Methods:

• Synthesis of a low molecular weight aromatic ligand (H2SA) and its complexation with LiOH.
• Characterization using FTIR, UV-vis, fluorescence spectroscopy, lifetime measurements, SEM, and PXRD.
• Rheological experiments to confirm the gel phase and assess multi-stimuli responsiveness.

Main Results:

• Successful synthesis of a 1% w/v fluorescent metallogel exhibiting fibrous morphology.
• Lithium ion (Li+) induces fluorescence via chelation enhanced fluorescence (CHEF) and promotes gelation.
• Different alkali metal ions (Na+, K+, Cs+) lead to crystal formation, highlighting ion-size effects.
• The metallogel demonstrates multi-stimuli responsiveness to thermal and mechanical stress, with reswelling properties.
• Regioisomer H2PBA shows emission via intramolecular charge transfer (ICT) with LiOH.

Conclusions:

• The study demonstrates a facile method for creating fluorescent metallogels with tunable properties.
• Ion-size dependent self-assembly dictates the formation of either gels or crystals.
• The developed metallogel shows potential for applications requiring stimuli-responsive materials.