Novel Luminescent Ionic Adducts Based on Pyrene-1-sulfonate

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Physical Chemistry

Background:

• Ionic liquids (ILs) are versatile materials with tunable properties.
• Pyrene-1-sulfonate is a fluorescent anion with potential applications.
• Developing novel ILs with specific functionalities is an ongoing research area.

Purpose of the Study:

• To synthesize and characterize novel ionic compounds using pyrene-1-sulfonate as the emitting anion.
• To investigate the thermal properties and potential ionic liquid behavior of these compounds.
• To explore the supramolecular behavior and potential applications of pyrene-1-sulfonate based salts.

Main Methods:

• Synthesis of pyrene-1-sulfonate salts via metathesis reactions.
• Thermal analysis using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).
• Spectroscopic characterization (emission lifetime) and light scattering measurements.
• Evaluation of graphite flake functionalization/exfoliation potential.

Main Results:

• One trimethylpropylammonium hepta(isooctyl)octasilsesquioxane pyrenesulfonate adduct exhibited ionic liquid behavior with a glass transition at -4.2 °C.
• Pyrene-1-sulfonate imidazolium-based salts were crystalline solids with melting points above 100 °C and showed complex, rate-dependent thermograms.
• Spectroscopic and light scattering data indicated the formation of supramolecular structures and aggregates in solution.
• The pyrene-1-sulfonate anion promotes supramolecular assembly through cation interactions.

Conclusions:

• Pyrene-1-sulfonate can function as an emitting anion for ionic liquids, but its utility is cation-dependent.
• The polycyclic nature of pyrene-1-sulfonate influences the thermal behavior and promotes supramolecular organization.
• These novel pyrene-1-sulfonate salts show potential for applications in materials science, including graphite functionalization.