Association constants and heats of formation of heteroassociates of anions of sulphophthaleine dyes
作者:S. A. Shapovalov
DOI:10.1134/s0036024410110178
日期:2010.1
The tendency of anions of sulphophthaleine dyes to heteroassociation was studied in aqueous solutions of phenol red, bromophenol blue, bromocresol green, bromocresol purple, and bromothymol blue. It was spectrophotometrically determined that single-(Han(-)) and double-charged anions (An(2-)) of sul-phophthaleines can form stable heteroassociates of composition Ct(+) center dot HAn(-) and (Ct(+))(2) center dot An(2-) with cations (Ct(+)) of polymethine dyes, pinacyanol, and quinaldine red. The values of enthalpy formation of ions of dyes and heteroassociates were calculated using semi-empirical methods, then correlated with experimentally determined values of equilibrium association constants.