Polarographic Study of Stability Constants of Cadmium(II) Complexes with β-picoline and Some Hydroxy Acids

Abstract

The mixed ligand complexes of b-picoline (b-pico), malate (mal^2–) and tartrate (tart^2–) with Cd(II) have been studied polarographically at constant ionic strength (μ = 1.5 M, NaNO₃) and pH 5.95 at 25 ± 0.1°C. The reduction of the complexes at d.m.e. is reversible and diffusion-controlled. Three mixed complexes [Cd(mal)(b-pico)], [Cd(mal)(b-pico)₂] and [Cd(mal)₂(b-pico)]^2– are formed in Cd(II) b-picoline-malate system with the stability constants log b₁₁ = 2.7224, b₁₂ = 4.2805 and b₂₁ = 3.9661. Two mixed complexes [Cd(b-pico)(tart)] and [Cd(b-pico)₂(tart)] are formed in Cd-b-picolinetartrate system are their stability constants are found to be log b₁₁ = 2.1368 and log b₁₂ = 4.1065, respectively.