Metallo-supramolecular gels based on a multitopic cyclam bis-terpyridine platform

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Polymer Chemistry

Background:

• Soluble metallopolymers, formed by self-assembling metal ions and ligands, offer potential for advanced materials.
• These materials exhibit diverse properties including magnetic, redox, optical, and mechanical characteristics.
• A new generation of
• intelligent
• molecular gels is emerging.

Purpose of the Study:

• To prepare and characterize metallo-supramolecular gels using a multitopic cyclam bis-terpyridine (CHTT) platform.
• To investigate the "intelligent" properties of these novel molecular gels.
• To analyze the structural and rheological behavior of the metallo-supramolecular systems.

Main Methods:

• UV-visible spectroscopy
• Cyclic voltammetry
• Viscosimetry and rheology
• Small-angle neutron scattering (SANS)

Main Results:

• SANS data confirmed the formation of rod-like species with extractable radius and aspect ratio.
• Rheological analysis indicated weak gel behavior, distinct from typical organogels.
• The metallo-supramolecular gels demonstrated chemosensitivity to metal type, stoichiometry, solvent, and counterion.

Conclusions:

• The CHTT platform enables the creation of metallo-supramolecular gels with tunable "intelligent" properties.
• The Co(II)/CHTT system exhibits reversible electro-sensitivity, switching between gel and liquid states.
• These materials display mechanical sensitivity, transitioning between viscous states under shear stress.