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Документ Solvatochromism of some food azo dyes(Одеський національний університет імені І. І. Мечникова, 2020) Bevziuk, Kateryna V.; Bazel, Ya. R.; Chebotaryov, Aleksandr N.; Чеботарьов, Олександр Миколайович; Чеботарёв, Александр Николаевич; Snigur, Denys V.; Снигур, Денис Васильевич; Снігур, Денис Васильович; Бевзюк, Екатерина Викторовна; Бевзюк, Катерина ВикторівнаIn the current study the solvatochromic properties of such food azo dyes as tartrazine, sunset yellow FCF and carmoisine were described. It was shown that with an increase in the dielectric permittivity of the solvent, a bathochromic shift of the absorption band maxima of azo dyes is observed, which corresponds to the π → π* electronic transition. It has been established that the values of the molar absorptivities of the dominant acid-base form of azo dyes in organic solvents almost linearly (R≈0.90-0.92) increase with an increase in their dielectric permittivity. It is noted that there is a weak correlation (R = 0.70-0.80) between the position of the absorption maximum of the dye and the value of the Hansen parameter.Документ Tristimulus Colorimetric and Spectrophotometric Study of the State of 4-Hydroxystyryl Dyes in Aqueous Solutions(2017) Chebotaryov, Aleksandr N.; Snigur, Denys V.; Zhukova, Yu. P.; Bevziuk, Kateryna V.; Studenyak, Ya. I.; Bazel, Ya. R.; Снігур, Денис Васильович; Снигур, Денис Васильевич; Чеботарёв, Александр Николаевич; Чеботарьов, Олександр МиколайовичAcid-base properties of 4-hydroxystyryl dyes in aqueous solution have been studied by means of chemical tristimulus colorimetry and spectrophotometry. Ionization and hydroxylation constants of the dyes have been determined using chromaticity functions of specific and CIE color difference. It has been shown that aggregation processes in the solution of 4-hydroxystyryl dyes can be observed by means of tristimulus colorimetry. A scheme of acid-base transformations of the studied dyes in the solution has been suggested, and selected spectrophotometric parameters of the equilibrium ionic and molecular forms have been determined.