Zhukova Y. Spectrophotometric, protolytic, solvatochromic properties of 4-hydroxystyryl dyes and their analytical application

The dissertation is devoted to the thorough research of 4-hydroxystyryl dyes (GSD), in particular, to study their spectrophotometric, protolytic, solvatochromic properties and their application in analytical chemistry. In this paper we present the results of a series of 4-hydroxystyryl dyes – derivatives of 1,3,3-trimethyl-3H-indolium, benzthiazolium, 4-pyridinium, 2- and 4-quinolinium. Protolytic transformations of dyes and their acidity constants are determined by spectrophotometric method. Simple and accessible titrimetric methods have been developed using GSD dyes as indicators, namely, in determining acid numbers in food products - vegetable oils, animal fats and biodiesel containing fuels. The solvatochromic properties of GSD were investigated. Spectrophotometric and colorimetric methods for determining the composition of aqueous-organic mixtures based on aprotic solvents using the solvatochromic shifts of the merocyanine forms of GSD as an analytical signal were developed.