pH-metric investigation of the system containing palladium(II) ion and obidoxime chloride

Abstract

The formation of a complex between palladium (II) chloride obidoxime chloride has been studied by means of pH-metric measurements. Thee mean value of the real stability constant of the complex in aqueous medium of ionic strengths 0.55 M and 1.0 M (KCl) at 298 K was log K-S = 6.72. This value was close to that (log K-S = 6.63) obtained previously by spectrophotometric methods but after appropriate correction with respect to the corresponding value of the first acidic constant of obidoxime chloride which was also determined under the same experimental conditions. The participation of only one oxime group in obidoxime-Pd(II) complex formation has been established, whose acidity significantly increases with coordination to palladium (II) ion. The pH-metric studies confirmed previously defined components ratio (1:1) in the complex by spectrophotometric methods.