Cesium-ion selective electrodes based on calix[4]arene dibenzocrown ethers

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Electrochemistry

Background:

• Calix[4]arene dibenzocrown ethers are complex macrocyclic compounds with potential applications in ion sensing.
• Developing selective ion-selective electrodes (ISEs) is crucial for accurate chemical analysis.
• Cesium ion (Cs(+)) detection is important in various environmental and industrial monitoring applications.

Purpose of the Study:

• To synthesize and evaluate novel calix[4]arene dibenzocrown ether compounds as Cs(+)-selective ligands.
• To investigate the performance of these ligands in solvent polymeric membrane electrodes.
• To determine the potentiometric selectivity of the developed electrodes for Cs(+) over other cations.

Main Methods:

• Synthesis of four calix[4]arene dibenzocrown ether derivatives (compounds 1-4).
• Fabrication of solvent polymeric membrane electrodes incorporating the synthesized ionophores.
• Potentiometric measurements to assess the linear response concentration range and selectivity coefficients of the electrodes.

Main Results:

• Compound 1 (25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-6) exhibited a linear response range of 1x10(-1) to 1x10(-6) M for Cs(+).
• The ISE based on compound 1 demonstrated a high Cs(+)/Na(+) selectivity (selectivity coefficient K(Cs,Na)(Pot) ≈ 10(-5)).
• Increasing the crown ether ring size from 6 to 7 and 8 (compounds 2-4) successively reduced Cs(+) selectivity over other alkali metal cations.

Conclusions:

• Calix[4]arene dibenzocrown ethers are effective Cs(+)-selective ligands for ion-selective electrodes.
• Compound 1 shows promising selectivity for Cs(+) detection, particularly over Na(+).
• The size of the dibenzocrown ether ring significantly influences the Cs(+) selectivity of the developed electrodes.