Abstract

EFFECT OF ETHANOL-WATER SOLVENTS ON THE STABILITY CONSTANTS OF AZO DYES DERIVED FROM SUBSTITUTED 2, 4-DIHYDROXYACETOPHENONE

Dunia Butrus Toma Al-Bakzo* and Mohammad Mahmoud Hussein Al-Niemi

ABSTRACT

This research included the preparation of (16) azo dyes derived from the reaction of substituents 2,4-dihydroxyacetophenone with the sulfanilic acid sodium salt reagent under the optimal conditions for their formation. The values of the stability constants of all the resulting azo dyes were found, and then the values of the dielectric constants (D) were set for the (ethanol-water) mixture at different percentage weights (0%, 20%, 40%, 60% and 80%) and at a temperature (20oC) and at base and neutral acidic functions. From the obtained practical results, it was found that changing the percentage of ethyl alcohol in the mixture (ethanol-water) in the final mixture of the dye formation reaction clearly affects the values of the dielectric constants (D) for the solvent, noting that the values of the stability constants were within five different alcohol ratios, this means that the absence of any value from the aforementioned ratios indicates that the azo dyes produced at that ratio is unstable.

Keywords: Ethanol-water solvents, stability, azo dyes, 2, 4-dihydroxyacetophenone.