VOLTAMMETRIC BEHAVIOR OF SILVER(I) AT CARBON COMPOSITE ELECTRODES CONTAINING CHEMICALLY IMMOBILIZED THIACROWN COMPOUNDS

The electrochemical behavior of silver(I) at carbon composite electrod es containing various thiacrown ethers and 1,4-dithiacyclanes covalent ly bonded to a silicone support was studied by cyclic voltammetry. It was found that the activity of immobilized compounds to silver ions in creases in the order [6]aneS(2) < [7]aneS(2) < [12]S(2)C4 < [16]aneS(4 ) < [18]S(4)C6. The ligand effect on the electroreduction of silver(I) and other metal ions was found to be determined to a large extent by the adsorption properties of the modifier toward these metals. The par ameters of the electrode process at a carbon composite electrode signi ficantly depend on the size of the cavity and the number of sulfur don or atoms in the molecules of thia compounds covalently bonded to the h ydrophobic silicone support entering into the carbon composition. It i s demonstrated that the use of immobilized [16]aneS(4) and [18]S(4)C6 crown tetrathioethers as modifiers considerably improves the voltammet ric characteristics of silver as compared with those obtained with fre e ligands as modifiers.