Polarographic behaviors of tetraphenylstibonium chloride towards several kinds of metal ions

Studies on analytical application of onium compounds. XIV

Abstract

Tetraphenylstibonium chloride, (C₆H₅)₄SbCl, was synthesized and its polarographic behaviors have been investigated. The polarogram showed a two-step wave with the use of 0.1 N potassium chloride as a supporting electrolyte and a saturated calomel electrode. Its half-wave potentials were -0.72 V and -1.11 V, respectively. The half-wave potential of the first wave was not changed by a change in pH, but that of the second wave was. The electrode reaction of the first wave was found to be controlled by the rate of the diffusion, and there was a proportional relationship between the concentration and wave height when the concentration range was 5.76×10^-55.76×10^-3 M/l. The relationship between concentration and wave-height of the second wave was similar to that of an isothermal adsorption curve, and showed good agreement with Langmuirs adsorption equation. In the investigation of the reaction of (C₆H₅)₄SbCl and various metal complex ions, those of bismuth, mercury, stibium, and cadmium were tested by amperometric titration. The first two were able to be titrated within an error of ±2% and ±3%, respectively.