Multiple Stimuli-Responsive Supramolecular Gel Formed from Modified Adenosine

Area of Science:

• Supramolecular Chemistry
• Materials Science

Background:

• Low-molecular-weight gelators are crucial for developing novel materials with tunable properties.
• Adenosine-based urea derivatives offer a promising scaffold for designing sophisticated gelators.

Purpose of the Study:

• To synthesize and characterize novel urea derivatives as low-molecular-weight gelators.
• To investigate the gelation behavior and stimuli-responsive properties of these compounds in various solvents.

Main Methods:

• Synthesis of adenosine-based urea derivatives with modified ribose moieties.
• Solubility and gelation studies in halogenated solvents.
• Rheological analysis to determine viscoelastic properties.
• Investigation of phase transitions induced by thermal, mechanical, and chemical stimuli.

Main Results:

• Compound 2 selectively formed thermally stable supramolecular gels in halogenated solvents.
• The supramolecular gel exhibited reversible gel-sol transitions upon heating-cooling cycles.
• Multiple mechano-responsive gel-sol transitions were observed.
• Anion addition (e.g., fluoride) and solvent changes (e.g., methanol) induced gel-to-sol transitions, with subsequent regelation possible.

Conclusions:

• Adenosine-based urea derivatives can function as effective low-molecular-weight gelators.
• The designed gelators demonstrate significant thermal and mechanical stability.
• The supramolecular gels display versatile stimuli-responsive behaviors, opening avenues for smart material development.