Four thiacalix[4]biscrown ethers with 1,3-alternate conformation were examined for the potentiometric responses in poly(vinyl chloride) membrane electrodes. Their potentiometric selectivities toward potassium and cesium ions over other alkali, alkaline earth, and transition metal ions were measured by the fixed interference method (FIM). Among the ionophores, 1,3-alternate thiacalix[4]biscrown-6,6 showed a high selectivity for cesium over potassium ion and so was optimized as a Cs(+)-selective electrode. The electrode exhibited a linear response with a near Nernstian slope of 57.6mV per decade in the concentration range of 1.0x10(-6) to 3.2x10(-2)M. It was suitable for use in aqueous solution in a wide range of pH 2.5-12.5 and had a fast response time of ca. 5s. On the basis of 1,3-alternate thiacalix[4]biscrown-6,6, the electrode has a wide linear range and selectivity for cesium ion over potassium ion ( log K (Cs (+ ),K (+))=- 3.7 ) better than those previously reported with other ionophores.
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http://dx.doi.org/10.1016/j.talanta.2004.04.015 | DOI Listing |
Int J Mol Sci
November 2024
A.M. Butlerov Chemistry Institute, Kazan Federal University, 18 Kremlyovskaya Str., 420008 Kazan, Russia.
Cancer is one of the most common diseases in developed countries. Recently, gene therapy has emerged as a promising approach to cancer treatment and has already entered clinical practice worldwide. RNA interference-based therapy is a promising method for cancer treatment.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
A.M. Butlerov Chemical Institute, Kazan Federal University, Kremlevskaya, 18, Kazan 420008, Russian Federation. Electronic address:
Phys Chem Chem Phys
December 2024
Kazan Federal University, Kremlevskaya 18 str, Kazan 420008, Russian Federation.
The rational design of organic ligands with the aim to control their binding abilities towards different metal ions can be considered as one of the key concepts in supramolecular coordination chemistry. Regarding the macrocyclic compounds of thiacalix[4]arene family, this can be achieved the targeted modulation of macrocyclic platform rigidity as well as the proper choice of appended binding sites. Four macrocyclic salen-type ligands based on lower rim disubstituted thiacalix[4]arene derivatives, adopted in a cone conformation, bearing highly coordinating iminophenolic or catecholic groups and two -CH- moieties as spacers but presenting different abilities to form H-bonds, were chosen to elucidate the interplay between the conformational flexibility of the macrocyclic ligands, propensity to participate in the intermolecular H-bonding and the extraction ability of 3d-metal cations.
View Article and Find Full Text PDFDalton Trans
November 2024
Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Max-Eyth-Straße 2, 24118 Kiel, Germany.
J Am Chem Soc
October 2024
College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, PR China.
The pursuit of precision in the engineering of metal nanoparticle assemblies has long fascinated scientists, but achieving atomic-level accuracy continues to pose a significant challenge. This research sheds light on the hierarchical assembly processes of two high-nuclearity Cu(I) nanoclusters (NCs). By employing a multiligand cooperative stabilization strategy, we have isolated a series of thiacalix[4]arene (TC4A)/alkynyl coprotected Cu(I) NCs (, where = , , , ).
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