Absorption Spectra of Dyes. III. On the Composition of Complexes Formed in Mixtures of Chlorazol Sky Blue FF and p-Nitroaniline→γ Acid in Aqueous Solution

Abstract 1. The change in spectrum at 620 mμ of the mixture of Chlorazol Sky Blue FF and p-nitroaniline→γ acid in aqueous solution was measured in detail at room temperature, by varying the concentration of the component dyes. 2. On the assumption that the spectral change is due to the complex formation, the composition of complexes was discussed by comparing the observed and the calculated difference in optical density. 3. It may be supposed that a 1:1 complex occurs to a great extent over a range of low concentration of p-nitroaniline→γ acid as compared with that of Chlorazol Sky Blue FF, and that higher complexes are formed in the presence of an excess of the acid dye.