Switchable fluorescent organogels and mesomorphic superstructure based on naphthalene derivatives.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Organogelators are crucial for developing responsive materials.
• Hydrogen bonding and pi-pi stacking are key interactions in self-assembly.
• Fluorescent organogels offer potential in sensing and imaging applications.

Purpose of the Study:

• To design and synthesize novel bisurea-functionalized naphthalene organogelators.
• To investigate their gelling capabilities and switchable fluorescence properties.
• To explore their response to thermal and chemical stimuli.

Main Methods:

• Synthesis of bisurea-functionalized naphthalene derivatives.
• Gelling ability assessment in various solvents.
• Fluorescence spectroscopy to study emission properties.
• Temperature and chemical stimuli (fluoride anions, protons) for gel-sol transition control.
• Polarizing optical microscopy and small-angle X-ray scattering for structural analysis.

Main Results:

• The synthesized organogelators demonstrated excellent gelling ability.
• Switchable fluorescence was observed in the gel state, sensitive to temperature and chemical stimuli.
• A stronger, red-shifted emission was noted in the gel state compared to solutions.
• Reversible gel-sol transitions were achieved by temperature changes or addition of fluoride anions and trifluoroacetic acid.
• The gelators exhibited liquid crystalline properties, forming a columnar phase.

Conclusions:

• Bisurea-functionalized naphthalene organogelators are effective in forming gels with switchable fluorescence.
• The materials display liquid crystalline behavior.
• Their responsive nature to temperature and chemical stimuli opens avenues for smart material applications.