Arsenazo III and its analogues-IV The electronic structure of arsenzo III in media of different acidity.
By means of a single method, MOLCAO, the states of arsenazo III in strongly acidic, neutral and alkaline media has been studied. In the range from 1N sulphuric acid to pH 8, when the conjugated groups are not ionized the reagent is found in the azo form. Single stage ionization of the acidic (-OH, -NH-N) or basic (-N(2)-, CO) groups leads to a disruption of the symmetry of the system and to the appearance of the quinone-hydrazone form together with the azoide. The azoide and quinone hydrazone tautomers occur in the ratio 4:1 in concentrated sulphuric acid medium in and 22:3 alkaline medium.
Savvin
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Vernadsky Institute of Geochemistry and Analytical Chemistry, Academy of Sciences, Moscow, U.S.S.R.
Kuzin
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