The lnteractions between Anthraquinone Dyes and Ethyl Benzoate in Carbon Tetrachloride

Abstract

The complex formation between anthraquinone dyes and ethyl benzoate (EB) in carbon tetrachloride was investigated by paper chromatography. The equilibrium constants of the complex formation were calc. ulated from the following relation, iog (itEllllii51kkif. fR iSllii2i Z Ki cA z K2.. cA2 El Ks. cAswhere Rt and Rfo are the Rf values of dyes in the eluent of CCI in the presence of EB and in lts absence, respectively. And are the sumsof equilibrium constants in each complex fermation of 1 1, 1 2, (dye EB), respectively. cA is the initial concentration of EB in the eluent.Only a 1 1 complex was observed for the most dyes, and the dipole-dipole interaction between CO of dye and COO of EB was suggested by spectral investigation. A 1 1 and a 1: 2 complex were observed for the dye having phenolic OH, and this dye had much larger 2) Ki than the other dyes, due to the hydrogen bonding between the dye and EB.