Characteristic of the Ag(II)/Ag(I) system in the presence of 2-pyridinecarboxylic acid in acetonitrile

摘要

Formation constants of the complexes of Ag(I) with 2-pyridine-carboxylic acid (Hpic) were determined by the potentiometric method: β01=36, β02=537. It was shown by IR spectroscopy that the complexation of Ag(I) ions in acetonitrile proceeds without the formation of Ag-O bond and the complexes have the following forms: AgHpic+and Ag(Hpic)2+. Oxidation of Ag(Hpic)2+at the potential ϕ=1850 mV vs. NHE resulted in the complex Ag(Hpic)22+. The formal potentialEf0=1.772 V vs. NHE of the system Ag(Hpic)22++e⇌Ag(Hpic)++Hpicwas determined by chronovoltamperometry, while the formal potentialEf0=1.841 V vs. NHE of the system Ag(Hpic)22++e⇌Ag(Hpic)2+was calculated. Properties of the system in water and acetonitrile were co