ACTIVITIES OF SODIUM SALTS OF 1-AMINO-4-ALKYLAMINOANTHRAQUINONE-2-SULFONIC ACID IN AQUEOUS SOLUTIONS.

Article abstract of DOI:10.1246/bcsj.54.654

The mean activity coefficients of sodium salts of 1-amino-4-alkylaminoanthraquinone-2-sulfonic acid (alk equals Me(MAS), Et, n-Pr, or n-Bu (n-BAS) in aqueous solutions ranging in concentration from 10** minus **3 to 10** minus **2 mol kg** minus **1 have been determined by means of isopiestic measurements at 50 and 60 degree C respectively. It is found that the mean activity coefficients of these dyes are much smaller than unity, the coefficients of MAS being the largest, and those of n-BAS, the smallest. The coefficients are found to decrease with an increase in the dye concentration. An examination of the results obtained by Miliceivic treatment suggests that the MAS exists as dimer or trimers, and the other dyes, as tetramers, at 60 degree C.