A saponification-triggered gelation of ester-based Zn(II) complex through conformational transformations

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Bis-salen Zinc(II) complexes are known for their diverse applications.
• Controlling self-assembly and material properties of metal complexes is crucial for developing advanced materials.
• Saponification is a chemical process typically used for ester hydrolysis.

Purpose of the Study:

• To describe a novel saponification-triggered gelation process.
• To investigate the structural modifications and self-assembly mechanism of an ester-based bis-salen Zn(II) complex upon treatment with NaOH.
• To characterize the resulting inorganic gel material (IGM).

Main Methods:

• Synthesis and structural modification of an ester-based bis-salen Zn(II) complex.
• Induction of gelation using sodium hydroxide (NaOH).
• Characterization using photophysical studies, Density Functional Theory (DFT) calculations, and rheological measurements.

Main Results:

• A novel gelation process was triggered by saponification of the ester groups in the bis-salen Zn(II) complex.
• NaOH-induced structural modifications tuned dipolar and π-interactions, leading to J-aggregation.
• The formation of an inorganic gel material (IGM) was confirmed through comprehensive characterization.

Conclusions:

• Saponification can be a viable strategy to induce gelation in specific ester-containing metal complexes.
• The study demonstrates the formation of a novel inorganic gel material (IGM) from a bis-salen Zn(II) complex.
• The findings highlight the potential for designing functional supramolecular materials through controlled chemical transformations.