Binding studies and anion-selective electrodes with neutral isophthalamide-based receptors

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Acyclic isophthalamide hosts are investigated for anion recognition.
• Hydrogen bonding interactions are crucial for molecular recognition processes.
• Developing selective anion sensors is important for environmental and clinical monitoring.

Purpose of the Study:

• To synthesize and characterize novel acyclic isophthalamide-based hosts.
• To evaluate the anion binding properties and selectivity of the synthesized receptors.
• To assess the performance of these receptors as ionophores in anion-selective electrodes.

Main Methods:

• Synthesis of two acyclic isophthalamide-based host molecules.
• Anion binding studies using proton nuclear magnetic resonance ((1)H-NMR) titrations.
• Fabrication and electrochemical evaluation of plasticised polymeric membrane-based anion-selective electrodes.

Main Results:

• The synthesized receptors exhibited distinct binding modes for various anions.
• Incorporation of aminomethylpyrrole groups enhanced receptor selectivity.
• Potentiometric studies confirmed NMR findings, showing good sensing abilities.
• Receptors demonstrated notable selectivity for hydrophilic anions like fluoride and sulfate.
• A low detection limit of 9 × 10(-7) M was achieved for fluoride anion detection.

Conclusions:

• The structurally simple isophthalamide-based receptors effectively bind anions through hydrogen bonding.
• The developed receptors show promising selectivity and sensitivity, particularly for fluoride and sulfate.
• These findings highlight the potential of these receptors for constructing advanced anion-selective sensors.