Study of kinetics of complexation reaction of Co2+ with 2-benzoylpyridine-4-phenyl-3-thiosemicarbazone and kinetic-spectrophotometric determination of cobalt

Kinetics of the complexation reaction of Co2+ with 2-benzoylpyridine-4-phenyl-3-thiosemicarbazone (BPPT) was spectrophotometrically examined at 421 nm. The ligand that was developed for a simple kinetic-spectrophotometric determination of Co2+ was based on 1:2 complex formation between Co2+ and BPPT. The complexation reaction was carried out in ethanol-water medium at 25 °C. Kinetic and activation parameters of the complexation reaction were calculated, and the rate equation and the reaction mechanism were proposed. The calibration graph is linear in the concentration range of 0.10−2.91 mg·L−1 for the tangent method. The species that caused interference were investigated.