S. Motomizu
Oct 1, 1971
Citations
0
Influential Citations
11
Citations
Journal
Analytica Chimica Acta
Abstract
Abstract 6-Nitroso-3-dimethylaminophenol (nitroso-DiMAP) and its cobalt complex have been studied in detail. The reagent is stable in 0.01 M hydrochloric acid solution for at least a month. Its acid dissociation constants, pKa1 and pKa2, were determined to be 2.69 ± 0.03 and 8.40 ± 0.05, respectively. A 1:3 complex is formed with cobalt, the formation constant, log KMR3, being 26.77 ± 0.12. The reagent is extracted into 1,2-dichloroethane in the form HR, the partition coefficient, log DHR, being 1.42 ± 0.02. The partition coefficient of the complex, log DMR3, is 3.11. The extracted cobalt complex is stable to back-extraction with (1+2) hydrochloric acid, whereas excess of reagent is removed to the aqueous phase. The molar absorptivity of the complex in the organic phase is 6.0·104 at 456 nm.