Halogen Bonding Heteroditopic Materials for Cooperative Sodium Iodide Binding and Extraction

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Analytical Chemistry

Background:

• Halogen bonding (XB) is an important non-covalent interaction utilized in molecular recognition.
• Silica-based materials offer versatile platforms for developing functionalized adsorbents.
• Efficient extraction of ion pairs from aqueous solutions is crucial for various chemical processes.

Purpose of the Study:

• To design and synthesize novel silica-based materials functionalized with heteroditopic halogen bonding receptors.
• To investigate the cooperative binding and extraction capabilities of these XB materials for sodium halide ion pairs.
• To evaluate the efficiency of XB-mediated binding in enhancing sodium iodide extraction from aqueous media.

Main Methods:

• Synthesis of silica-based materials incorporating mono- and bis-iodotriazole benzo-15-crown-5 groups.
• Characterization using CHN elemental analysis, 13C CP/MAS NMR, and ATR-FTIR spectroscopy.
• Solid-liquid extraction studies using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

Main Results:

• Successful incorporation of ion-pair receptor frameworks onto the silica material was confirmed.
• The bidentate XB functionalized material demonstrated efficient extraction of sodium iodide (NaI) from water.
• Cooperative XB-mediated binding resulted in a two-fold enhancement in NaI extraction efficiency compared to a hydrogen bonding analogue.

Conclusions:

• Heteroditopic halogen bonding receptors on silica are effective for ion pair extraction.
• Cooperative binding is a key factor in enhancing the extraction performance of XB materials.
• These XB materials show significant potential for selective ion pair separation from aqueous solutions.