Russian scientists have created crown ether compounds for detecting heavy metals.

Researchers at RTU MIREA have synthesized and studied two new macrocyclic compounds containing a crown ether fragment. A crown ether is a cyclic simple ether linked through oxygen atoms. The composition and properties of the obtained compounds were thoroughly investigated using modern physicochemical analysis methods, such as NMR, UV spectroscopy, and fluorescence spectroscopy.

The developed compounds—crown ethers—serve as selective receptors (ionophores) for barium, lead, and ammonium ions. They were utilized to create ion-selective polymer membranes used in electrochemical sensors (amperometric and ion-selective electrodes). The crown ethers were able to stabilize complexes with these ions, resulting in effective ion transfer from water to the membrane. This enabled the sensors to accurately determine ion concentrations in water and plants.

These compounds form stable complexes with barium and ammonium cations, and their behavior in the polymer membrane varies, explained Leonid Martynov, an associate professor at the Department of Analytical Chemistry at the M.V. Lomonosov Institute of Fine Chemical Technologies at RTU MIREA. The researcher notes that one of the compounds diffuses more slowly than the other, which is linked to the presence of additional structural barriers in one of them.

Such differences could be leveraged to develop new sensor systems for environmental monitoring of natural waters and assessing their contamination with heavy metal ions, as well as determining inorganic cations.

The results of the joint research conducted by the M.V. Lomonosov Institute of Fine Chemical Technologies at RTU MIREA and the A.N. Nesmeyanov Institute of Element-Organic Compounds of the Russian Academy of Sciences have been published in the journal New Journal of Chemistry.