Reaction of cobalt with 2-Nitroso-5-Diethylaminophenol and the solvent extraction of its cobalt complex.
2-Nitroso-5-diethylaminophenol (nitroso-DEAP) is a useful reagent for cobalt, with which it forms a 1:3 complex. Its pK(a1) and pK(a2) values are 2.83 and 8.38, and the formation constant, log K(MR(3)), is 24.73. The reagent and complex may be extracted into 1,2-dichloroethane from water, the log of the respective partition coefficients being 2.35 and 7.3. The extracted cobalt complex is not stripped by 6M hydrochloric acid, whereas excess of the reagent is. The molar absorptivity of the complex in 1,2-dichloroethane is 6.2 x 10(4) 1.mole(-1) cm(-1) at 462 nm, which is larger than that of other nitroso derivatives.
Motomizu
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Department of Chemistry Faculty of Science, Okayama University Tsushima, Okayama-shi, Japan.