Electrooxidation of low-permittivity solvents in acetonitrile and solubility of trihexylamine in acetonitrile

In the first part of the work, anodic oxidation of some selected low-permittivity liquids (1,4-dioxane, diethyl ether, diisopropyl ether, dichloromethane, trichloromethane, tetrahydrofuran, carbon disulfide, triethylamine, trihexylamine, ethyl acetate, 1-pentyl acetate) was investigated on platinum electrode in acetonitrile which provided a higher-permittivity medium to enable the electrode processes. The pure solvents containing supporting electrolyte were also studied, and in several solvents, very low currents flowed when their cyclic voltammograms were recorded between 0 and 4 V. Contrarily, dissolving them in acetonitrile, high currents could be recorded and their anodic peaks appeared. The most remarkable difference between the pure liquid and acetonitrile solution was produced by the amines. Trihexylamine was immiscible with acetonitrile, so its solubility was determined by using the cosolvent calibration method (mixture of acetonitrile and 1-propanol) for the voltammetric determination, and the saturated concentration of the amine was 44.253 ± 0.564 mM.